Investigation of

Performance Characteristics for

Sanitary Plumbing Fixtures

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UNITED STATES DEPARTMENT OF COMMERCE • Maurice H. Stans, Secretary

NATIONAL BUREAU OF STANDARDS • Lewis M. Branscomb, Director

Investigation of Performance Characteristics

for Sanitary Plumbing Fixtures

Building Research Division

Institute for Applied Technology

National Bureau of Standards

Washington, D.C.

As requested by

Building Research Advisory Board

National Academy of Sciences-National Research Council

Washington, D.C.

Building Science Series 22 /

Nat. Bur. Stand. (U.S.), Bldg. Sci. Ser. 22, 72 pages (January 1970) CODEN: BSSNB

Issued January 1970

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

(Order by SD Catalog No. C 13.29/2:22), Price 70 cents
FEB 2 7 1970

Hot ?ce> R*j

t usi

1110

Project Staff

The planning and execution of the various phases of this project were

carried out principally by the following persons, who were members of the

Building Research Division during the period of time over which the work

was done.

D. Watstein, T. Reichard, and L. F. Skoda of the Structures Section;

R. S. Wyly, R. W. Beausoliel, and C. J. Seay of the Environmental Engineering

Section; D. G. Moore, J. C. Richmond, J. W. Pitts, and W. C. Wolfe of the

Materials and Composites Section. P. R. Achenbach of the Division Office

served as project director and coordinator.

Library of Congress Catalog Card No. 71-600906
Foreword

Results are described from an investigation of performance characteristics

for sanitary plumbing fixtures conducted at the National Bureau of Standards

at the request of an ad hoc committee appointed by the National Academy of

Sciences-National Research Council. The committee identified significant per- formance characteristics, coordinated the investigation, and developed its conclusions in part on the basis of the results of the investigation at NBS.

The findings and recommendations given herein have been prepared by

NBS in a form suitable as supplemental information to appear as a chapter

within the publication proposed for issue by the NAS-NRC.
Contents

Page

\ Project staff ii Foreword iii 1. Introduction 1 1.1. Statement of the problem 1 1.2. Initiation of project 1 1.3. Authorization and funding 2

1.4. Work to be performed 2

1.5. Test specimens 2

1.6. Specimen identification 2

1.7. Field surveys 2

1.8. Discussion of performance tests and

performance requirements 3

1.9. Use of trade names for identifying instru- ments, materials, and equipment 4

1.10. Test titles 4

1.11. Applicability of findings to various types

of fixtures 4

1.12. Statistical limitations of findings 4

1.13. Units of measurement 4

2. Test procedures 5

2.1. Uniform loading (bathtub) (S101) 5

2.2. Concentrated load, static (bathtub)

(5102) 5

2.3. Rim load (bathtub) (S102A) 8

2.4. Concentrated dynamic load (bathtub)

(5103) 9

2.5. Concentrated load, sump sidewall (bathtub) (S104) 12

2.6. Drain-fitting load (bathtub) (S105) 14

2.7. Watertight-joint potential (bathtub)

(S106) 17

2.8. Surface inspection (M201) 17

2.9. Water absorption (M202) 19

2.10. Abrasion resistance (M203) 19

2.11. Cleanability and soilability (M203A)... 24

Page

2. Test procedures—Continued

2.12. Surface-impact resistance (bathtub)

(M204) 28

2.13. Dimensional stability (M205) 30

2.14. Bond maintenance (mechanical) (M206). 30

2.15. Surface slip resistance (bathtub or shower receptor) (M207) 30

2.16. Scratch resistance (M208) 32

2.17. Drainability (bathtub) (M209) 35

2.18. Hot-water resistance (bathtub) (T302). 38

2.19. Cigarette-burn resistance (T303) 43

2.20. Radiant-heater resistance (T303A) 46

2.21. Resistance to thermal shock (T304) 50

2.22. Resistance to household chemicals

(C501) 52

2.23. Stain resistance (C502) 54

2.24. Color stability (C503) 59

2.25. Surface texture aging (C504) 60

2.26. Odor (C505) 61

2.27. Noise control (bathtub) (N401) and

(N402) 61

2.28. Biological characteristics (B601) (B602)

(B603) 61

3. Tests requiring further development 61

3.1. Cleanability and soilability (M203A) 61

3.2. Surface slip resistance (M207) 61

3.3. Resistance to thermal shock (T304) 61

3.4. Other characteristics requiring test de- development 62

4. References ^_ 62 Appendix A: Inspection of FRPE manufacturing

processes, installed fixtures, and test facilities.. 64 Appendix B: Telephone survey of pressed-steel

bathtubs 67

IV
Investigation of Performance Characteristics

for Sanitary Plumbing Fixtures

Building Research Division

Institute for Applied Technology

National Bureau of Standards

This report gives findings and recommendations developed during an investigation

of performance characteristics for sanitary plumbing fixtures, conducted at the request

of the Building Research Advisory Board of the National Academy of Sciences-National

Research Council. The report describes the test methods that are recommended for the evaluation of 16 performance characteristics, and the nature of further work required to complete the development of four or five additional test procedures.

The suitability of various existing test methods for evaluating the functional and

performance characteristics of sanitary plumbing fixtures was investigated in the laboratory. In addition, new or modified tests for certain characteristics were developed. The laboratory

work was performed only on bathtubs and flat specimens provided by industry through

appropriate arrangements with the Building Research Advisory Board. Field inspection

trips were made to provide the NBS project staff with up-to-date information on certain manufacturing processes and on installation and use problems. The complexities involved

in the selection of valid performance levels are discussed, as well as the elements of judgment

involved. A format that might be used in specifying performance is suggested for each test procedure, and the rationale underlying each suggested format is given.

Key words : Performance characteristics ; sanitary plumbing fixtures ; test methods

performance level ; abrasion resistance ; scratch resistance ; stain resistance ; cigarette-burn resistance ; surface-impact resistance ; chemical

resistance ; concentrated static-load capacity ; cleanability and sodlability.

1. Introduction

1.1 Statement of the Problem

The recent introduction into the market of new

sanitary plumbing fixture materials, such as re- inforced plastics, has emphasized the need for

functional or performance criteria that would

be applicable to all materials. It is probable that

fixtures made of the new materials would have

^physical, chemical, and engineering properties different from those of the more conventional

porcelain-enameled or vitreous-china fixtures. Furthermore, the more conventional fixtures may

have higher levels of performance for some characteristics than are needed for satisfactory per- formance. Also, the tests in current use for

porcelain-enameled or vitreous-china fixtures may

not, in all cases, be suitable for use with a material such as a fiberglass-remforced plastic. Obviously if meaningful performance criteria are

to be developed for sanitary plumbing fixtures,

mot only is knowledge needed on the functional

and technical performance characteristics of such

fixtures, but it is also important to develop or

select suitable test procedures for evaluating these

characteristics. The investigation as herein described was concerned mostly with the testing

procedures.

1.2 Initiation of Project

Recognizing the need for establishing realistic performance requirements for plumbing fixtures,

the plumbing industry and agencies of the Federal Government requested the National Academy

of Sciences-National Research Council, through

its Building Research Advisory Board, to undertake the development of the essential performance

requirements and methods for their evaluation. An

ad hoc committee of the Building Research Advisory Board, consisting of persons from universities, government, and industry, was appointed

to plan and direct the study.

The National Bureau of Standards was re- quested by the Building Research Advisory Board

to carry out field and laboratory investigations,

and the development of test procedures for sanitary plumbing fixtures, with the principal emphasis on bathtubs. The ad hoc committee of the

1
Building Research Advisory Board and the subcommittees formed within it met with members of

the staff of the National Bureau of Standards at

selected intervals to review the progress of the

program and to advise on its broad phases. By

mutual agreement reached during the progress

of the work, the actual testing was limited to flat specimens and bathtubs.

1.3. Authorization and Funding

The investigation undertaken by the National

Bureau of Standards was authorized by the ad

hoc committee in June 1964, in accordance with

a proposal prepared by the Bureau. The work

wa9 financed jointly by multiple sponsors under

the auspices of the Building Research Advisory

Board and by the National Bureau of Standards.

1.4. Work to be Performed

By mutual, written agreement, the work to be

performed by the National Bureau of Standards was to include the following:

1. Inspect manufacturing facilities, testing laboratories, and typical installations of fixtures to familiarize project personnel with current operations, use conditions, and test procedures.

2. Review existing test proceduress of ASTM,

ASA, and other organizations, as well as commercial standards requirements, Federal specification

requirements, and selected regulatory requirements 1 for suitability, reproducibility of test results, and applicability to a wide range of construction materials.2

3. Identify, based on this review, existing test procedures that should be tried out on various

materials ; and develop new test procedures where

needed.

4. Carry out trials of existing and new test procedures on flat specimens and bathtubs.

5. Prepare a final report to the ad hoc committee and include in this report (a) a description of

the laboratory work that was performed on each

property of interest, (b) a description of each rec- ommended test procedure and apparatus, (c) the

rationale for the recommended test procedure, and

(d) a discussion of performance requirements that

might be pertinent to sanitary fixtures. Each of the properties of interest is discussed in

the succeeding sections, based on the above-mentioned report. However, because of both time and

budget limitations, it was not possible to recom- mend test procedures for all 28 properties that were judged important by the ad hoc committee.

Those tests requiring additional work are dis- cussed in the appropriate sections. It should be

pointed out in this connection that the original

1 This language was Intended to indicate plumbing code provisions. Several codes were reviewed.

2 This refers to the various materials that might be used in the manufacture of plumbing fixtures. Actual test development was

carried out only on bathtubs and flat specimens.

project agreement did not require that test proce

dures be recommended for all of the 28 properties

1.5. Test Specimens .-!»

Q-itO HU '3

ii

Two types of test specimens were utilized : flai squares, either 4-in X 4-in or 414-in X 4i^-in ii size, and whole bathtubs. The specimens wert furnished by various manufacturers in accordance

with arrangements made by the Building Researcl

Advisory Board and the ad hoc committee. Thi

plan adopted for specimen procurement called foi 100 squares from each of three or more manufac

turers of vitreous-china, enameled-steel, enamelec

cast-iron, fiberglass-reinforced polyester (FRPE)

and stainless-steel fixtures, respectively. Foui

whole bathtubs were to be furnished by each 0: three or more different manufacturers of enam

eled-steel and enameled cast-iron fixtures, respec

tively, and four whole bathtubs from each of foui or more manufacturers of fiberglass-reinforcec

polyester fixtures. This plan for specimen procurement was largeb

adhered to, except that (1) no stainless steel speci mens were obtained, (2) three brands of polyeste;

(FRPE) bathtubs rather than four were obtained I (3) only two manufacturers provided flat FRPI

specimens, and (4) two rather than three make

of enameled steel flat specimens were provided. Ii is not believed that these changes in the origina

plan for specimen procurement had any substan \ tial effect on the outcome of the investigation. Al

specimens were furnished with a white finish ex cept for one FRPE bathtub, which was green, an( one lot of flat cast-iron specimens which was fur

nished in five different colors. However, becausi

these cast-iron specimens were received late in thi investigation, it was not possible to include then

in the testing work.

1.6. Specimen Identification

Each lot of bathtubs and each lot of flat speci mens were assigned identification numbers on arj

rival in accordance with table 1.6-1. The reasoi: for including this table is to provide a more com'

plete identification of specimens referred to in th

tables and figures in later sections of the report

&

"

f

;i;

1.7. Field Surveys

Appendices A and B summarize the results 0

two limited surveys of bathtubs that had been ii service for varying periods of time. Appendix 1

relates to fiberglass-reinforced polyester bathtub

and Appendix B relates to porcelain-enameled

steel bathtubs.

These surveys were made to acquaint the proj

ect staff with typical manufacturing, installation

and use conditions, and to provide some guidano

in arriving at realistic test conditions. Refereno

to Appendices A and B at this point will be help

2
Table 1.6-1. Identification of specimens

Specimen Nos. Manufacturer Type of material Type of specimens

5A-1 to 101.

D B-lto4...

C-l to 4... ;i?D-l and 2. l|3A-lto4... ;lHB-lto99-.

1,80-1 to 4...

I )D-1 to 113. ;3E-lto4.._ CIA-1 to 4.... PIB-1 to 100- IC-lto 4.... blD-1 to 100. pIE-lto4....

blF-1 to 100.. kCA-1 to 101. CB-1 to 104. t/CC-lto45..

A

BA

CD

EF

FG

H

K

LLM

N

O

PR

Olass-flber-reinforced polyester (FRPE)

FRPE

FRPE

FRPE

Porcelain-enameled steel

Porcelain-enameled steel Porcelain-enameled steel Porcelain-enameled steel Porcelain-enameled steel

Porcelain-enameled cast-iron Porcelain-enameled cast-iron Porcelain-enameled cast-iron. Porcelain-enameled cast-iron Porcelain-enameled cast-iron

Porcelain-enameled cast-Iron Vitreous china

Vitreous china

Vitreous china

iAxi]4-m l flats. Bathtubs.

Bathtubs.

Bathtubs.

Bathtubs.

4 x 4-in flats. Bathtubs.

4 x 4-in flats. Bathtubs.

Bathtubs.

4 x 4-in flats. Bathtubs.

4 x 4-in flats. Bathtubs.

4 x 4-in flats. 4 x 4-in flats. 4 x 4-in flats. 4 x 4-in flats.

ful in understanding various sections of this

(report.

Originally it had been expected that an extensive field survey would be made to obtain statis- tically significant results relating to various use

factors, physical properties, length of service, etc. however, this survey was not undertaken, principally because competent statisticians advised

prat a meaningful survey would be prohibitive in

ost.

1.8. Discussion of Performance Tests and

Performance Requirements

For a piece of equipment as intimately involved

! jtn family living as a bathtub, the desirable functional characteristics include not only requirements

;buch as water-tightness, drainage characteristics,

'Strength, and safety, but also the more subjective

poncepts such as ease of cleaning, appearance, durajoility, resistance to staining, burn resistance, and

resistance to chemical attack. These latter subjective requirements are likely to be expressed in

qualitative terms involving such phrases as "ac- ceptable appearance," "normal service life," and

1 'typical use conditions," that have no precise defijoition in physical terms.

1 Developing test methods that are meaningful

'[requires conception of a test procedure that simulates to an acceptable degree the kinds of physical,

• chemical, and mechanical exposure received by

;he fixtures in actual use. While simulative service

testing is not new, simulation of the interaction

between human beings and household fixtures in a

j way that will provide a basis for fair competition

l among materials of unlimited variety presents ad-

(jjiiitional complexities. It involves careful analysis

pf the important processes of use, wear, and deterioration that are brought to bear on the fixtures

(in service, and translation of these processes into

It piece of laboratory equipment that can be deli scribed and reproduced and that can measure the

jUffects of these processes in quantitative terms.

Once an acceptable test procedure and a test apparatus have been developed, the performance of

typical fixtures can then be measured under the

selected test conditions. Although fixtures or speci- mens of materials prepared especially for test purposes can sometimes be obtained on which to collect quantitative data, more frequently only commercial items are available for testing. In this latter

case, test results on the commercial items must be

used for comparison with user requirements.

The selection of acceptable performance levels involves evaluation of human aesthetic reaction as

well as the frequency and duration of exposure to a variety of human activities. In the case of properties that may be expected to deteriorate gradually

with use over a period of years, valid performance

levels cannot be set without extensive statistical data on use conditions, and on users' concepts of

long-term acceptability.

Such statistical data are usually not available

because of the prohibitive cost of obtaining them.

Where the measured values of a given property

vary over a wide range for various materials using

a selected test method, it may not always be logical to set a single performance level for all materials.

The factors of use conditions and tolerance level of users are intimately related to standard of

living, psychology, and the effect of long experi- ence with conventional materials, Thus, a given

performance level might be acceptable in the view

of some users, but entirely unacceptable to others. Similarly, after a period of experience with a new

material, users might come to accept or require a

different level of performance than formerly. For

example, it is not difficult to imagine the attitude

of users toward the introduction of glass for

windows if the material previously used had been

a transparent resilient material such as plexiglas.

It might take many years to obtain consumer

acceptance of the low impact resistance of glass

under these conditions.

In the absence of adequate statistical data on use

conditions and tolerance of users, one practical

3
approach to performance levels is to select levels that either upgrade, downgrade, or maintain the

existing quality of a class of products in current

use, based on the measured performance of a suit- able comprehensive sampling of contemporary

products. Decisions with respect to upgrading,

downgrading, or maintaining present quality re- quire the studied judgment of experienced persons

acting together. Performance levels arrived at in

this way would, of course, be subject to later adjustment as more extensive service data or user

reaction became available.

Eecommended performances levels are not in- cluded herein. However, comments on performance

requirements have been added at the end of each

section in the hope that these comments may be

helpful to code and specifications groups who may

wish to set performance levels that are based on

the recommended test procedures.

1.9. Use of Trade Names for Identifying

Instruments, Materials, and Equipment

Certain commercial instruments, materials, and

equipment are indentified in order to specify the

experimental procedure adequately. In no case does

such identification imply recommendation or en- dorsement by the National Bureau of Standards, nor does it imply that the instruments, materials, or equipment identified are necessarily the best

available for the purpose, nor that items not identified but having the necessary characteristics cannot

be used.

1.10. Test Titles

The test procedures to be discussed in what fol- lows are titled in a fashion consistent with the

identification system used by the ad hoc committee.

The word "bathtub" in parentheses indicates that

the test is limited to bathtubs in its present state of development. If the word "bathtub" does not

appear in parentheses in the test title, this signifies

the test is applicable to fixtures in addition to bathtubs. The number in parentheses signifies the test classification adopted by the ad hoc committee.

For example, S101 means test No. 101 in the Structural Series, M203 means test No. 203 in the Mechanical Series, T303 means test No. 303 in the

Thermal Series, etc.

1.11. Applicability of Findings to Various

Types of Fixtures

Since no test development was conducted in this

investigation on actual fixtures other than bathtubs, some of the recommended tests must be limited to bathtubs. In these instances, further work

will be necessary to adapt the tests to other fixtures. However, a number of the tests are applicable to more than one fixture type, because certain performance characteristics are primarily related to the material and are affected little or none by the

type of fixture the material is used in.

1.12. Statistical Limitations of Findings

Many of the test procedures discussed herein

should be looked upon as in need of further refine- ment. This is particularly pertinent from statis- tical considerations. For example, some tests are obviously affected by several sources of variation,

but limitations on the amount of work that could

be performed in the present investigation pre- cluded the collection of adequate statistical data

for the computation of the variances corresponding

to these various sources. Among the general problems that need further attention in applications of

the work reported are (1) required number of test specimens and replicate tests, (2) sampling procedures, and (3) effects of variation among observers, equipment, and laboratories. In summary,

the problem is: How much testing is required as a minimum to assure a just acceptance or rejection

of a single fixture or a lot of fixtures ? This is particularly important where the measured performance by one or a few measurements is close to specified minimum performance levels. The selection of fixtures and flat specimens for use in test development was handled by the manufacturers through the auspices of the Building

Research Advisory Board. The National Bureau

of Standards made no study regarding the extent

to which these fixtures and specimens represented

current production, and therefore makes no claim

in this respect.

Thus, in any application of the findings of the

present investigation, it is important to recognize

the statistical limitations described above, and tc recognize that a very considerable amount of additional work will be required to obtain an altogether correct solution to the statistical problems.

1.13. Units of Measurement

Results of this investigation are reported in terms of conventional units, for the most part.

This was done for two reasons : First, conventional

units are ordinarily used by those groups most

concerned with the results. Second, most of the existing standards and test methods extensively

referenced and evaluated herein utilize conventional units.

However, because of the increasing importance

of international standards in foreign commerce,

it is strongly recommended that groups which

utilize the results of this investigation in the promulgation of standards and specifications as- sume the responsibility for appropriate conver- sion to International Standard (SI) units. For

example, 0.500 in equals 1.27 cm, 2.1 lb equals 0.9E kg, 120 °F equals 48.9 °C, etc.
2. Test Procedures

2.1. Uniform Loading (Bathtub) (S101)

No test method exists for the uniform loading

of bathtubs and no test method is recommended.

This type of loading would be the result of the

weight of the bath water. The amount of water

necessary to fill each of eight different bathtubs

to the overflow outlet hole was measured. The

average weight of water was found to be 339 lbs. A 300-lb concentrated load at the center of the

sump 3 would usually be more severe than a uniform load of 339 lbs. Therefore, if the recom- mended concentrated static-load test (Sec. 2.2) is used a uniform-load test would not be needed.

Although a uniform-load test was not considered essential, some data were obtained on sump deflections from a type of load similar to

that imposed by a person sitting or standing in a bathtub partially filled with water. Load-deflection tests were made on three FRPE tubs using

150 lbs of water and three 50-lb cast-iron weights

centrally placed in the sump. Deflections with time

were measured by using the procedure recom- mended for the concentrated static-load test (sec. 2.2) . These data, for hot and cold water, were obtained for general information only.

Figure 2.1-1 presents the results of two tests on

one of the FRPE tubs. The three rectangular

weights covered a combined area of approximately

132 in 2 in both tests, but were placed slightly differently in the two tests. In Test 1, the weights were placed end-to-end along the longitudinal

centerline of the tub, but were placed side-by-side

3 The "sump" of a bathtub will be defined as the receptor comprising the inside walls and bottom of the bathtub.

T

1 1

1 1 1 11

104 "F

/8EGIN TEST I AND TEST 2

1 I I I 1 I I I II I I 0 12 3 TIME, HR.

1 Data in section 2.18 on other tubs subjected to hot-water

loading show that residual center deflections decreased substantially with time after load removal and loading. Figtjbe 2.1-1. Effect of time on the center deflection of an FRPE tub with warm- and cold- water loads.

352-020 O—70 2

with their lengths transverse to the longitudinal

centerline of the tub in Test 2. Room temperature (72 °F) water was added for

Test 1 and hot (104 °F) water for Test 2. For Test 1 the three 50-lb weights produced a

center deflection 4 of 0.039 in and the addition of

the 150 lb of cool water produced an immediate

additional deflection of 0.007 in. For Test 2 the three 50-lb weights produced a

center deflection of 0.032 in, but the addition of

the 150 lb of hot water caused an immediate upward movement of 0.026 in at the center of the

sump (indicated by a downward movement on

graph). It should be noted that the immediate

upward movement of the sump from the hot-water

load was about four times the downward move- ment from the cool water in Test 1. However, with

time the center deflections for both tests approached the same value.

Immediately upon removal of the load in Test

2 the expected upward movement occurred. However, as the tub cooled the thermal gradients

caused a downward movement. It is unfortunate

that measurements were not continued for a longer

period, but from other test results there is not

much doubt that the sump would gradually return

to a position close to the original.

2.2. Concentrated Load, Static (Bathtub)

(S102)

a. Purpose and Scope

The purpose of this test is to determine if a bathtub will support a 300-lb concentrated load

at the bottom center of the tub without excess deflections or surface damage. The service load

simulated is that of a heavy person standing in

the tub.

b. Recommended Test Method

(1) Equipment Required for Test

1. Three micrometer dial gages graduated to 0.001 in.

2. A loading device for applying a 300-lb test load without shock to the center of the tub bottom.

Note : Either calibrated weights or a suitable mechanical

or hydraulic load applicator may be used.

3. A distribution pad to distribute the load over

a 5- X 10-in area. The pad shall consist of a sheet

of %-in-thick sponge rubber (Shore Durometer

Hardness of 8 to 14) topped with a plate of plywood or stiffer material having a minimum thick- ness of % in. This plate shall be of sufficient thickness so that there is no more than 0.01 in deflection of the ends when the 300-lb load is applied

during the test.

4 The "center deflection" is defined, as the deflection at the mid-point of the longitudinal centerline of the sump.

5
(£) Support of Specimen During Test

The bathtub shall be mounted for test in a wood

frame simulating normal installation. Design of

the supporting frame shall be such as to allow for

clearance under the tub for deflection-measuring

dial gages. The manufacturer's installation in- structions when obtainable shall be used in spac- ing the 2- X 4-in stud of the frame and in fastening

the tub to the frame. In lieu of explicit manufacturer's instructions the tub shall be fastened along

the water bead to each stud of the test frame by

li^-in long No. 6 steel wood screws using %-in

steel washers. The spacing of the studs in the supporting frame shall be no greater than 16 in on

centers. The top of the supporting frame shall be at least 12 in higher than the top of the installed tub.

If legs or other component parts of the tub are within y8 in of the floor line, after installation,

rigid vertical support shall be provided for these

components.

The front apron shall be supported in a continu- ous bed of plaster of paris.

For tubs without integral wall surrounds the

back ledge of the tub shall be supported by a con- tinuous horizontal 2- X 4-in wood framing member

that is fastened securely to the studs.

(3) Test Procedure

Maintain the temperature of the testing laboratory and bathtub at 75 ± 5 °F. Before starting the

test, inspect the finished surface of the bathtub in

accordance with section 2.8 of this report. Note

all defects detected.

Center the distribution pad over the horizontal

center lines of the sump with the 10-in dimension

along the length of the sump. Determine the sump

center lines by using the average length and width

of the sump.

Place the three micrometer dial gages on a rigid

base beneath the longitudinal center line of the

sump, with one directly beneath the center of the

distribution pad and the other two within 2 in of

each end of the bottom of the sump.

Note : The areas where the tips of the dial gage bear on

the tub must be flat and smooth so that a small lateral movement of the tub will not change the gage reading by more than 0.001 in. These bearing areas can be prepared

either by grinding the under surface or by rigidly fasten- ing a small flat, level plate to the tub. In case the drain hole

of the bathtub should interfere with the placement of a

gage, a standard drain-fitting spud can be inserted in the

drain-outlet hole and a flat area on the spud used for the

dial-gage bearing.

Preload the specimen by applying the test load

of 300 lb at the center of the distribution pad and

leaving the load in place for 5 min. Then remove

the load and make the initial dial-gage readings.

Reload the tub and make the gage readings immediately following load application and also 5 mm later. Finally, remove the load and make the

dial readings immediately after removal and again

10 min later. B

Determine the average settlement of the tub and

supports by averaging the deflections measured by

the two end gages. Determine the center deflection

; of the sump by subtracting this average settlement

from the deflection measured by the center gage

After load removal, inspect the surfaces of the

tub for cracks and spalls in accordance with sec-i tion 2.8. Note any other damage that develops from

the testing.

(4) Information To Be Reported

Include the following in the test report:

1. Specimen identification;

2. Description of specimen including overall

height, width, and length

;

3. Description of test frame;

4. Method of suporting and fastening bathtub in test frame;

5. Defects, if any, prior to test; Defects, if any, after test

;

Deflection at the center of sump;

a. Immedicately after application of load ;= b. Five minutes after application of load

c. Immediately after removal of load

;

d. Ten minutes after removal of load.

I- H ;l

7.

c. Te8t Results and Discussion

(1) Discussion of Existing Methods

A test method for evaluating the structural in

tegrity of FRPE bathtubs is described in the August 1964 proposed revision of Commercial Standard CS221-59, hereafter referred to as the "proposed revision of CS 221-59" [l] 5

. This test method requires that a full-size unit be installed

according to manufacturer's directions and an ap1

plied load of 300 lb be distributed over a 3-inj diam area near the center of the bottom of the I bathtub. The applied load is allowed to remain j on the tub for not less than one nor more thani

two minutes. The maximum allowable deflection!

under the load point is 0.150 in. The residual de-|

flection which is determined 10 min after remov1

al of the applied load is not to exceed 0.008 in.]

{2) Test Data

The relationship between the applied loads and 1 deflections are shown in figure 2.2-1. Each pair of

curves represents the maximum and minimum deflections observed during tests of bathtubs manufactured from the materials designated. The observed deflections for individual units tested appear in table 2.2-1. Table 2.2-1 also includes the

results of tests performed on units using a 3-indiam disk as the applied load area. As can be ex- pected, the measured deflections are larger for

these tests. Table 2.2-2 is a summary of static load tests to

destruction. The table includes results of tests on

M.

I

6 Figures in brackets Indicate the literature references at the end of this publication.
three FRPE units, one enameled-steel tub, and

one cast-iron tub. The table is self-explanatory and

is presented for information only. Table 2.2-3 is a compilation of various dimensions of all tubs

used in these tests and is presented for information only.

An examination of table 2.2-1 shows that all tubs tested had center deflections of less than

0.125 in, and had residual deflections 10 min after

load removal of less than 0.003 in.

(3) Rationale for Test Selection

The basic concepts of the proposed revision of

the Commercial Standard were preserved in the

recommended test ; however, several modifications were incorporated. The first was to enlarge the

distribution pad from a 3-in-diam circular area to

a 5- X 10-in rectangular area. This change was

.02 OA 06 .08 .10 0 02 .04 ,06 .08 .10 J2 CENTER DEFLECTION, INCHES Figure 2.2-1. Concentrated load test (static), 50 square inches area.

Table 2.2-1. Center deflections (300-lb concentrated static load)

Specimen No. Material

5- x 10-in loaded area

Immediately

after loading5 min after loading

Immediately

after removal

of load

10 min after removal

of load

3-in round loaded area

Immediately

after loading

Immediately

after removal

of load

Ratio 3-in round to 5x 10-in areas immediately after loading

PD-1..

PC-1.. PB-4.

SE-2..

SA-4_.

SC-2_. CIE-4

CIC-4

CIA-1

FRPE...

FRPE...

FRPE...

Steel

Steel

Steel

Cast Iron Cast Iron Cast Iron

0.055 .083

. 102

.109 .107

.012

.015

.019

0.056

.084

.104

.109 .107

.012

.015

.019

0.002

.003 .005 <.001

<. 001 .001

.001

<0. 001 .001 .001 <.001

0<. 001

<. 001 0

0

0.061

.111

0.001

. 004

1.11 1.38

.107 .126

. 128

.013 .017 .022

.001 .007

.004

0

00

1.24

1. 16 1.20

1.08

1. 13

1. 16

made to more closely simulate the area covered

by a person standing in a bathtub. The larger area

also permits the use of dead weights for load application.

The test as described in the proposed revision of

CS 221-59 made no provision for correcting for

settlement of the tub in the frame when the load was applied. The present test procedure considers

I the possibility of error from this source and corj rects for it through use of three gages rather than

'' one.The length of time for the applied load to re- main on the bathtub was increased to 5 min. to coincide more nearly with service use.

d. Comments on Performance Requirements

j (1) Suggested Format for a Performance Level

The bathtub shall show no damage to either the

I visible or nonvisible surfaces from the testing.

In addition, the center deflection 5 min after

the load is applied shall not be greater than __

i in nor shall the residual center deflection 10 min

Table 2.2-2. Static load tests to destruction (5- X 10-in

area)

Specimen No. and

material

Ultimate

load, lb Results

PB-4 FRPE

4,000 At 3,000 lb, center longitudinal reinforcing member broken. Failure in top-flange screw connections to studding and transverse crack in sump between applied-load pad and front wall

at ultimate load. PC-1 FRPE

5, 100 At 2,550 lb, center reinforcing member broken. At 3,630 lb, head-end reinforcing member

broken. At 4,090 lb, drain-end reinforcing member broken. Transverse cracking of fixture across sump at maximum load. PD-1 FRPE

•8,000 Audible cracking of reinforcing member began

at 2,350 lb. No visible damage to coating. Reinforcing under sump splintered. Test

discontinued at 8,000 lb.1 SA-4

Steel 5,500 At 3,550 lb, spalling around rim. Primary struc- tural failure from buckling of flange at head

end. Spalling of coating in bottom of sump

near center and permanent set of about 1 in at point of application of load. CIA-1

Cast Iron

6,900 Crack in fixture along longitudinal center line of sump about one-half the length of the bottom

at maximum load.

1 Loading discontinued, because 8,000-lb load caused sump bottom to bear on reinforcing structure.

7
Table 2.2-3. Bathtub dimensions and weights

Material

BathtubNo.

Weight, lb Outside Dimensions:

(a) Length, in

(b) Width, in

(c) Rim Height, in

(d) Top to Floor, in

(e) Water Bead, in Sump dimensions:

(a) Depth, in.* - (b) Depth, in>

(c) Length, in.° (d) Width, at widest point, in.

J

(e) Width at drain, in. a Rim width:

at center, in

FRPE

141

6033% mi

1%

12M<

53 %

23%

21

100

591 M( 34%

16%

"74%

14Me 13Me

4922%

21% 4He

80 60Me

31 %

14%

201%

12% 11%

49%

22% 21%

Pressed Steel

83

30Me

16

1654

12% 5oy2 22% 20% 3%

96

603/16 31

15' Me

16'Me

1 13^6

13

53

22' Me

221 He 5Me

94 60%

30H<

1515%

1254 12%

5423Me 21% 3%

Cast Iron

268 60%

30Me 14% 14%%

12%

1250% 21%

18%

3iMe

293

591 Me

30%

14%

14%%

12%

11%

5022%

18Me 4%

318

291 Me

14% 14%

121 Me

12Me 48%

21% 20%

5Me

» At the center of the sump.

t At the head end of tub, 18 in. from the transverse center line of the sump.

o At mid-height of sump.

after the load is removed be greater than

in. Note: Damage to the visible surfaces of the

bathtub shall be construed as the appearance of

any of the defects described in section 2.8, while

damage to nonvisible surfaces shall be construed

as cracking or separation of reinforcing members

or any similar deterioration of the structural properties of the bathtub.

(2) Rationale for Suggested Format

There are two reasons for limiting the center

deflection of the bathtub. The first is to insure that

the bath or shower water will drain completely

from the tub even though the bather remains in

the tub. The second reason is that large deflections

may instill a feeling of insecurity in many users. The reason for limiting the residual deflection

after load removal is to provide some assurance

against accumulative permanent set from repeated

loadings, which might eventually make the fixture

unusable.

2.3. Rim Load (Bathtub) (S102A)

a. Purpose and Scope

The purpose of this test is to determine if a bathtub will withstand a 300-lb. load applied at the center of the front rim without damage. The

service load simulated is that of a person sitting or standing on the bathtub rim.

b. Recommended Test Method

( 1 ) Equipment Required for Test

1. The load-application method shall be as specified in section 2.2.b ( 1

)

.

2. The load-distribution pad shall be as specified in section 2.2.b(l) except that the area of the

pad shall be 7- X 7-in.

8

d At mid-height of sump.

• These tubs had wall surrounds extending above the rim.

(2) Preparation of the Test Specimen

The bathtub shall be mounted and supported for

test as specified in section 2.2.b(2) . The ioside sur

faces of the tub shall be inspected in accordance

with the procedure described in section 2.8.

(3) Test Procedure

Maintain the temperature of the testing laboratory and bathtub at 75 ± 5 °F. Apply the test load through the distribution pad at the center of

the front rim. Apply the center of the load to the

center of the pad, and leave in place for 5 min.

After removal of the load, inspect the finished

surfaces of the bathtub for damage.

(Ji) Information to oe Reported

Include the following in the test report

1. Specimen identification

;

2. Method of supporting and fastening specimen in frame

;

3. Description of test frame;

4. Damage noted prior to test

;

5. Damage noted after test.

c. Test Results and Discussion

(1 ) Discussion of Existing Methods

Commercial Standard CS 221-59 [2] requires

that a load of 300 lb be placed on the deck corners and at the mid-point of the rolled-over edge of the

bathtub. The load which is applied through a pad

of suitable soft material is left in position for 1 to 10 min. The loaded area is 7 in by the width of

the rim. No permanent deformation nor any cracking or crazing is allowed. The proposed revision of

CS 221-59 [1] is essentially the same except that

the no-permanent-deformation requirement was

removed.

The proposed revision also specified that the

mid-point and one end of the rim should be loaded
through a 3-in round pad. No provision was made

for loading other areas.

{2) Test Development

The basic features of the proposed revision of CS

221-59 were considered to be satisfactory. During

test development, the 300-lb test load was applied

at various positions about the rims of the tubs. Deflection measurements of the rim as well as

lateral movements of the front apron were made.

Table 2.3-1 describes some of the lateral-movement

measurements made on the various tubs. Since deflections of the rim and lateral movements of the

apron due to an applied load are partly dependent on the restraints imposed on the tub as a result of

installation, none of the measurements was considered significant. The data presented in table

2.3-1 are for information only and are not in- tended for use in evaluating the tubs. No surface

damage attributable to the 300-lb test load was observed on any of the tubs tested.

(3) Rationale for Test Selection

The recommended test procedure is similar to that outlined in CS 221-59 [2], with one exception.

The single test area, chosen as the center of the

front rim, subjects the tub to the greatest possible

flexural load and therefore is the most desirable

location for applying the test load.

The rim load is recommended as simulating the

service load from a heavy person sitting or standing on the rim. The test is needed to evaluate the

resistance to surface damage that possibly could

result from high flexural stresses.

d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

Surface finish damage that can be attributed to the test shall not be allowed. The inspection procedure prescribed in section 2.8 shall be used for

evaluation of damage.

(2) Rationale for Suggested Format

No limit on deflection or lateral movement is included in the suggested format since the struc- tural rigity of the tub can be determined by per- formance requirements for the static load test (sec. 2.2).

In addition, lateral movement and resultant

forces in service are affected by the degree of re- straint offered by the method of installation, both

of which may vary widely. The 300-lb load recom- mended approximates the weight of a very large

person. It seems reasonable to expect a bathtub to withstand a service loading of this magnitude

without surface damage.

2.4. Concentrated Dynamic Load (Bathtub)

(S103)

a. Purpose and Scope

The purpose of this test is to determine if the

bathtub will withstand, without visible damage,

an impact load simulating a person falling or jumping into a bathtub.

b. Recommended Test Method

(1) Apparatus

The falling-body test load shall consist of lead

shot in a leather bag. The total weight of the fall- ing body shall be 150 lb (±1 lb).

The bag shall be cylindrical, 9 in in diameter by

about 18 in high. The leather shall be similar to that described in Federal Specification KK-L201e for lacing leather. It shall be made from at

least two pieces of leather so that the bottom, striking, surface will be seamless. A method for closing

the top opening of the bag shall be provided to prevent.loss of lead shot. Note : As the bursting force is high, the sewing of the seams is critical. The size of thread used should be as large as practical to reduce the tendency of the thread to cut

the leather.

Table 2.3-1 Rim-load test results

Specimen No.Specimen

material

Lateral deflection at the center of apron, 2 in below rim top

300-lb load at center front300-lb load at head-end front300-lb load at drain-end front

PB-4 FRPE

in

i -0.039 -.030

-.050

-.012 -.020

-.021

in-0.010in-0. 018 PC-1 FRPE +.000 PD-1 FRPE..__ + .002 -.013 -.011 SA-4 Steel. SC-4 Steel -.007 8E-2 Steel <+.001

CIA-1 Cast Iron CIC-4. Cast Iron -.004 CIE-4 Cast Iron -.002

i Negative deflections indicate movement away from sump.

9
The method of hanging and releasing the bag

shall be such that the center of the point of impact

in the tub can be estimated to within 0.5 in and

the height-of-drop can be adjusted to within 0.1 in. Note: The buckle from an automotive safety seat belt

is satisfactory for a release mechanism.

(#) Preparation of Test Specimen

The bathtub shall be mounted and prepared for

test as specified in section 2.2 The center of

the sump shall be determined as in paragraph 2.2 b(3), and marked.

(3) Test Procedure

Maintain the temperature of the testing laboratory and bathtub at 75±5 °F. Drop the bag suc- cessively from heights of 5, 10, and 15 in, measured

vertically from the center of the bottom surface

of the bag to the point marked as the center of

the sump. Make one drop at each height. Make

certain that the center of the bag strikes within 0.5 in of the center of the sump. After the final 15-in

drop, inspect the finished surface of the bathtub

for defects in accordance with section 2.8.

{4) Information to he Reported

Include the following in the test report

1. Specimen identification;

2. Method of supporting and fastening specimen in test frame

;

3. Description of test frame

;

4. Defects noted prior to test

;

5. Defects noted after test.

c. Test Results and Discussion

(1) Test Development

A review of the literature revealed no existing

standard test method that would produce the re- quired conditions. Therefore, a simple falling-body

test was developed to simulate the type of dynamic

loading that might occur in service. A variety

of containers, weights, support conditions, shockabsorbing pads, and heights-of-drop was tried

prior to selection of the recommended dynamic

test. Metal containers proved to be too difficult to control after impact. Sand-filled bags were too bulky and also difficult to control. Lead shot in canvas bags burst the canvas when dropped. Finally a leather bag was obtained which would withstand the force from the impact.

Initially a 300-lb falling body was used. However, this was found to produce severe damage to some of the bathtubs except at unrealistically small

heights-of-drop. The 300-lb test was abandoned as

unrealistic, as field information indicated very

little or no damage from service-inflicted loads of

this type.

Electronic instrumentation was devised to re- cord the duration of impact and also the deflections. However, this was deemed too refined, costly,

and time-consuming for the information obtained.

The results of the development work indicated

that a weight of 150 lbs in a supple leather bag

dropped in increments of 6 in or less should constitute an adequate test. A relatively simple method was devised to measure deflections to 0.01 in by supporting a 6-in scale in a friction-clamping device. The scale was put

into contact with the underside of the bottom of

the tub prior to application of the load and the

initial reading made. The deflection device had to be reset prior to each drop. As for the concentrated

static-load tests (sec. 2.2), three deflection devices were used so that the observed center deflections

could be corrected for tub and support movement.

The relationships between heights-of-drop and

deflections are shown in figure 2.4—1. Each pair of curves represents the maximum and minimum observed values for each type of bathtub tested. These

data are presented for information only and are not intended for use in evaluating the dynamic

properties of the various units. However, they do

illustrate a reason for not including deflection as a performance requirement. For example, for a

24-in drop, the center deflection for the cast-iron

tubs was between 0.1 and 0.2 in, but, for the FRPE

tubs, the deflections ranged from about 0.4 to 0.75

in. It does not seem to be practical to use a limiting

deflection as a performance requirement because

of the wide variations in test results between materials and specimens.

The data presented in table 2.4-1 show that

damage to one steel tub was observed after an 18- in drop. It should be noted that damage was observed only for the steel tubs. As the tubs were

tested in height-of-drop increments of 6 in, it is not known if the observed damage would have

occurred had the weight been dropped once only

from a height of 18 or 24 in. Originally there had been some thought that,

in lieu of a dynamic test, a heavier, static concen1

trated loading might be used. However, the data

shown in figure 2.4-2 indicate that, if only deflec- tions are considered, the relationship between the

two types of tests is rather obscure for heights-ofdrop above 12 in. Furthermore, if the static load corresponding

to the first-observed damage reported in table 2.2—2

for the destruction tests is considered, it will be

noted that the damage occurred at 3550 lbs for

the steel tub. This static load is well above the

equivalent static load indicated in figure 2.4-2 for

the 18- or 24-in drop which produced damage in the

dynamic test.

(2) Rationale for Test Selection

The recommended test was selected because it represents qualitatively the type of dynamic loading which might result from a person falling in, or jumping into, a bathtub.

10
STEEL

O SPEC. WITH MIN. DEFL. D SPEC. WITH MAX. DEFL.

J I L_

.2 .3 4 .5 .6 .7 .8 0 .1 .2 .3 4 .5 .6 .7 .8 CENTER DEFLECTION, INCHES Figure 2.4-1. Concentrated load test (dynamic), 150-lb leather bag.

The possibility of using a heavier static load in

lieu of the dynamic load was discarded for the

reason stated in paragraph 2.4c ( 1

)

.

d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

The bathtub shall withstand without damage the

test conditions specified in paragraph 2.4b (3)

when the 150-lb weight is dropped from a height

of in. Damage shall be construed as the appearance of any surface defects in the bathtub,

visible damage to the reinforcing structure, or

other deterioration of structural properties as a

result of testing.

{2) Rationale for Suggested Format

It is believed that the following information

might be helpful in arriving at a realistic performance level

:

1. Field information (Appendix B) was obtained that showed a negligible incidence of

damage to pressed-steel bathtubs from falls. Since some falls did occur, it can be inferred that the

present tub designs are sufficiently strong to withstand this service condition. The pressed-steel tubs

that were tested showed no damage at heights-ofdrop of 12 in or less, and only one showed damage

at 18 in.

2. A person falling in a tub would normally

strike the tub bottom near the end opposite the

drain, where the tub has enhanced structural

stability rather than near the center, where structural stability is near a minimum. Thus, a per1

1

1 _ O FRPE O STEEL A IRON

, | I |

1 |

1

\ /

i /

V /'

note: each point represents

1 1 1

EQUAL STATIC AND DYNAMIC DEFLECTION.

, 1,1 1600 2000 2400 ;

STATIC CONCENTRATED LOAD, LBS

.

Figure 2.4-2. Correlation between height of drop in dynamic test and load in static de- structive test.

formance requirement based on impact at the

center would be more severe than if based on impact near one end. Also, the leather bag filled with

lead shot is probably more rigid than the human

body and, for this reason, could produce more

stress in the fixture at the instant of impact. Thus

a given height of fall of the 150-lb test weight

would simulate a greater height of fall for a 150-lb

person. The data in table 2.4-1 show failures in

steel tubs at heights-of-drop of 18 and 24 in, but no damage was observed at 12 in.

3. The use of successive heights-of-drop (5-, 10-,

and 15-in) in the recommended test is believed to be desirable since there is a lack of information on

11
Table 2.4-1. Results of concentrated dynamic load test with the 150-lb weight

Center de- Maximum flection at Specimen Material height-of- Defects noted maximum

drop height-of- drop

in in PB^_ FRPE 24 None -- 0. 74 PC-1 b KYsL 24 . oy PD-1- FRPE 24 None .43 SA-4 Steel _- 24 Transverse crazing . 37

at load point. SC-2 Steel. 18 Star crazing at .47 both legs. SE-2 Steel.. 24 Star crazing at . 35 both legs. CIA-1 Cast iron _ 24 None .18 CIC-4 Cast iron 24 None _ .25 CIE-4 Cast iron 24 None .10

the cumulative effects of impact loading; i.e., successive impacts of increasing magnitude might possibly lower the impact resistance of the fixture.

2.5. Concentrated Load, Sump Sidewall

(Bathtub) (S104)

a. Purpose and Scope

The purpose of this test is to determine if the

sidewalls of the sump of a bathtub can withstand

highly concentrated loads of relatively small magnitude without excessive deflection, denting, in- dentation, or other damage. The service load

simulated would be the pressure exerted by a per- son bracing himself against the side of a bathtub, or other similar load applications during normal

use.

b. Recommended Test Method

(1) Apparatus

The load-application and deflection-measuring

devices shall be essentially as shown in figure 2.5-1. The 1-in-diam steel ball shall be cemented to the arm. The lengths of the lever arms for the loading

device shall be equal to within 0.01 in to provide

for a one-to-one transfer of the load. The counter

balance shall be adjusted so that the level system

is balanced without the weight hanger.

The tripod used for holding the 0.001-in dial

gage shall have thin rubber pads mounted on its feet and shall have sufficient stiffness and weight

to prevent movement of the tripod during test. The hanger for the loading weight shall weigh

0.5 ± 0.1 lb, and the test load weight shall be

25.0 ± 0.1 lb including the hanger. The load may

be applied in increments.

(2) Test Procedure

Mount and prepare the bathtub for test as specified in section 2.2. Inspect the finished surfaces

for defects and damage m accordance with section

2.8 prior to test. Maintain the temperature of the

testing laboratory and bathtub at 75 ± 5 °F.

OEFLECTOMETER

VIEW OF LOADING RIG

\ COUNTER BALANCE

LOADING LEVER SYSTEM

. -Jr DEEP TO HOLD TOIA BALL SCHEMATIC-LOADING SYSTE Figure 2.5-1. Deflection test for unsupported area.

Apply the test load of 25 lb to the sidewall of

the sump at midheight. Test four positions, in- cluding two near the midlength of the front and

reai' side walls. The other two positions are to be

about 12 in horizontally from the original positions and on nearly vertical walls. Eead the dial

gage immediately after loading.

When setting up the testing device shown in

figure 2.5-1, take special care to ensure that:

1. The level arm with the load-application ball

is parallel to the surface being tested.

2. The stem of the dial gage over the load-application point is directly on the centerline of the

ball.

3. The stem of the dial gage is normal to the

surface on which it is resting.

The loading procedure is as follows

1. Apply the hanger and observe initial deflec- tion reading on the dial gage.

2. Apply test load and observe the deflection

reading.

3. Inspect the tested surface in accordance with

section 2.8, following removal of load. Take special care to determine if indentation of the surface at the load point has occurred.

(3) Information to be Reported

Include the following in the test report:

1. Specimen identification;

2. Description of test frame and method of

supporting and fastening

;

3. Defects and damage noted prior to test

;

4. Damage noted after test;

5. Positions of test areas;

6. Deflection readings made at each position.

c. Test Results and Discussion

(1) Discussion of Existing Methods

Commercial Standard CS 221-59 [2] includes

a requirement for a deflection test for unsupported

areas. A load of 10 lb is applied through a 1-in

12
round steel bar rounded to a i^-in radius at the

end in contact with the bathtub. The maximum

deflection allowed under this load is Ys in. No

permanent deflection is allowed. The proposed

Irevision of CS 221-59 [1] is essentially the same

except that the deflection is to be determined with

a 0.001 in deflectometer and the no-permanentdeflection requirement was withdrawn. In addition, the proposed revision specified that surface

cracking as a result of the test shall constitute

failure. Neither version of the Commercial Standard

specified methods for applying the load or for

i measuring deflection.

There are no other known standard test methods

j which are similar in purpose to that recommended

here.

: (2) Test Development

Initially a simple hand-held instrument that

would overcome the drawbacks in the method outlined in CS 221-59 was considered. A preliminary

design was developed for an instrument similar

\ in principle to the rubber-hardness-testing durom-

, eter. As time was of the essence, this idea was

dropped and the simple lever-dial-gage arrangement shown in figure 2.5-1 was adopted for the

I test.The device used in the test work was the same

as shown in the drawing except that an additional

dial gage was added to measure deflections 4%

,in from the load point. It was thought that this

! additional deflection measurement could be used

to judge the extent of the cupping effect when the

load was applied.

The load of 10 lb specified in CS 221-59 was

thought to be unrealistically low. After preliminary tests indicated that no surface damage

should be expected, the load was increased to 25 lb

for the test work.

Table 2.5-1 presents the deflection data from

both gages for all bathtubs tested. The ratio of

the two deflections can be used to judge the extent

of the cupping for flat areas without reinforcing

members or back-up material. The more flexible

FRPE tubs had stiffening ribs or back-up materials which affected the deflection ratios greatly.

For this reason the measurement of deflections

iy2 in from the load point is not recommended.

The measured deflections at the 25-lb load point

varied considerably, especially for the PB^i tub.

This bathtub had a %-in stiffener cemented to the backwall, but none on the front wall. The wall

thickness varied considerably on the FRPE tubs,

so some variation in deflections was expected. No

| visible surface damage, denting or indentation was caused by the testing.

Table 2.5-2 summarizes the deflections observed

when a 10-lb load, as prescribed in CS 221-59, was

imposed on the sidewalls. The maximum observed

deflection on any specimen was slightly less than

j half that permitted by the Commercial Standard.

352-020 O—70 3

Table 2.5-1. Deflections of unsupported areas with 25-lb load

Specimen Front

center Back

center Front head end

Front

drain end

Back

head end

Back

drain end

Deflections at load point for various positions, in »

PB-4 ... 0.145

.054 .044

.041 .020

.019

.018 <.001

<.001

.002

0. 019 .100 .062

.048

.016

0.119 0.066 0.112 0.007 PC-1 .078 PC-4i> PD-1 _ .054 .052 SA-4 .011 .008

.015

.017 SC-4 .017 SE-4 .014 .016 <.001

.009 .014 CIA-1 CIC-4

CIE-4

Deflections at i}4 in from load point

PB-4 0.085 .025

.017

.023

.007

.012

.010 <.001

<.001 <.001

0.013 .038

.032

.021 .007

0.012 0.033 0.119 0.007 PC-1 _ .029 PC-4i> ... PD-1 .020 .026 SA-4_.._ _ _ .005 .002

.007

.009 SC-4__. .006 SE-4 .009 .005 <.001.007 .004 CIA-1 __ CIC-4

CIE-4

»A11 test areas were at midheight of sump.

b This specimen tested after being subjected to 100-hr boil test described in section 2.18. Table 2.5-2. Deflections at load point with 10-lb (CS 221-

59) load, in a

Specimen

Front

center Backcenter Front head end

Front

drain end

Back

head end

Back

drain end

PB-4 0. 058 .017

.014 .013

.007

.006 .005 <.001

<.001

<.O01

0. 007 .036

.023

.018

.006

0. 052 0. 025 0.042 0.003 PC-1 .209 PC-4>> PD-1 .018 .019 SA-4 .004 .003

.004 .006 SC-4 .008 SE-4 .005 .007

<.O01

.003 .005 CIA-1..

CIC-4.. CIE-4

"Tested in accordance with section 2.5b.

•> This specimen tested after being subjected to 100.hr boll test described

in section 2.18.

(3) Rationale for Test Selection

The basic principles outlined in CS 221-59 were

preserved, but methods for applying the load and

measuring the deflection were incorporated. It was

felt that these methods should not be left to each

testing laboratory to develop.

Commercial Standard CS 221-59 originally

required that there be no permanent deflection. A

requirement for no permanent deflections seems

unnecessary because the small permanent deflec- tions resulting from the test have no aesthetic or

functional significance. These very small deflec- tions are difficult to measure and the lack of precision in measuring them might lead to difficulties in interpretation of test results. For determining

the presence of any relatively large permanent

indentations, or denting, the use of the surface in- spection routine of section 2.8 is satisfactory.

13
d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

Visible surface-finish damage including denting

or indentations shall not be present at any of the

four test positions after removal of the 25-lb load.

In addition, the deflection at any of the four test points shall not be greater than in during

load application.

(2) Rationale for Suggested Format

The reason for suggesting a limiting value for

the deflection under the load point is to limit the

flexibility of the sidewall material. A requirement

for no surface damage under a reasonable loading

is desirable, since concentrated loads are sometimes applied to sump sidewalls in service. It can be seen from the data in table 2.5-1 that

the sidewall deflections of the tubs tested were all less than 0.200 in.

2.6. Drain- Fitting Load (Bathtub) (S105)

a. Purpose and Scope

The purpose of- this test is to determine if a bathtub will withstand without damage to the

finished surface a bending moment applied to the

waste-drain fitting. The service load simulated by

this test is that produced by differential movement

between the waste-drain fitting and the vertical,

waste or soil stack as a result of shrinkage of the

floor joists supporting the bathtub. A similar service load could be caused by thermal expansion of

the waste or soil stack under certain conditions.

The recommended test applies to bathtubs only.

b. Recommended Test Method

(1 ) Equipment Required for Test

The apparatus required for this test shall be as shown in figure 2.6-1. The apparatus consists of a

rigid steel connecting device (adjustable to fit varALL PARTS ARE STEEL

Figure 2.6-1. Apparatus for drain-fitting load test.

ious configurations of the drain-hole outlets), a detachable lever arm, and a micrometer dial gage

mounted so as to measure movement of the lever arm when a bending moment is applied.

The lever arm, with the gage mounted, shall weigh 7.25 lb to produce an initial moment of 10

ft-lb. The weights and hanger shall weigh a total of 20 lb to produce an additional moment of 40

ft-lb. Four, or more, weights of approximately

equal mass shall be provided.

(2) Preparation of Test Specimen

Mount the bathtub and prepare for test as specified in section 2.2. Take special care to fasten the

specimen securely to the frame. As an additional

precaution, add at least 100 lb of weight distributed over the bottom of the sump so as to approximately cancel out the overturning moment of the

test load.

When assembling the connecting device to the

bathtub drain hole, adjust the collar so that there

will be no physical contact between the top washer

and the tub. Place a bedding of freshly mixed

plastic of Paris around the connection as illus- trated in figure 2.6-2. Plumb the vertical member

of the connecting device when the plaster is placed.

When the plaster is partially set remove excessive

plaster so that no plaster extends beyond the 3-indiam washer and collar. Finally, when the plaster is hardened the horizontal lever aim shall be attached to the connect- ing device and the deflection-measuring dial gage

shall be adjusted for indication of vertical

movement.

(3) Test Procedure

1. Before beginning the test, inspect the inside

surfaces of the bathtub for damage and defects

in accordance with section 2.8. Maintain the temperature of the testing laboratory and bathtub at 75±5 °F.

2. Make the test in at least two radial directions

90° apart, including one for which the lever arm

is parallel to the long direction of the bathtub.

3. With the lever arm in place, record the initial dial-gage reading. Place the weights individually - on the arm, and record deflection for each incre- \ ment of load. Continue loading until the indicated

deflection is equal to or greater than 1.25 in, or

until an additional load of 20 lb (40 ft-lb of moment) has been applied.

4. After application and removal of the load,

again inspect the inside surfaces of the tub for

damage attributable to the test in accordance with

the inspection procedure prescribed in section 2.8.

(4) Information to be Reported

Include the following in the test report

1. Specimen identification;

2. Description of test frame and method of

supporting and fastening specimen in frame;

14
ill

WASHER

PLASTER

<b r BATH TUB

! ADJUST COLLAR AND POSITION DEVICE SO THAT THE HARDENED

PLASTER WILL PREVENT PHYSICAL CONTACT BETWEEN THE TOP WASHER AND THE TUB.

Figure 2.6-2. Installation of connecting device for drain-fitting load test.

3. Damage and defects noted prior to test;

4. Damage noted after test

;

5. Radial direction of lever arm for each test

| position;

6. The deflections for each load increment at each test position

;

7. The weight added at each increment (including the weight hanger).

c. Test Results and Discussion

(1) Discussion of Existing Methods

A drain-fitting-connection test is described in

Commercial Standard OS 221-59 [2]. This test method requires that a 25 -lb weight be applied by means of a lever arm two ft in length connected

to the drain fitting extending horizontally in a plane parallel to the rim of the tub. The arm and

weight are placed in three radial positions, two

of which are approximately 180° apart. The per- formance requirement for this test is that no visi- ble cracks in the bathtub surface shall be evident

when inspected with the fitting in place using a standard ink test. In the proposed revision of CS

221-59 [1], the test was changed to require the

application of a 50-lb weight through a 2-ft lever arm. The performance requirement was not

changed in the proposed revision.

(2) Test Development

The test as described in CS 221-59 applies the

load through a "drain fitting connection." After

examining several drain fitting connections produced by different manufacturers it was obvious

that the rigidity of the fittings themselves would

be a factor to be considered m the test. In order

to standardize the test it was necessary to design

a "standard" drain fitting connection so that the same test conditions would apply to all tubs. The

recommended apparatus for the drain fitting test

is shown in figure 2.6-1. After the apparatus was designed, it was neces- sary to consider the magnitude of service loads

and/or movements which would be encountered

by a bathtub in service. The applied load in service would usually result from the restraint offered

by the soil or waste stack to the downward move- ment of a bathtub supported by framing members

undergoing drying shrinkage. If lumber is not

dried before installation, the shrinkage of 2- x 10- in joists can be as much as % in in the 10-in direction. An auxiliary test was performed in order to determine how much of this movement might be

transferred to the bathtub as bending moment

through the connecting assembly. This test was made with a cast-iron tub placed upside down on

the floor and weighted at each corner to offset over- turning moments. Two different drain-fitting

assemblies, complete with overflows and traps were

obtained for this test. One assembly included a

cast-iron trap and the other a lY-gage brass-tubing

trap. Otherwise the assemblies were similar. Each

assembly was installed on the inverted bathtub

and loads were applied to a pipe extension of the

trap outlet as shown in figure 2.6-3. The distance

from the drain outlet to the point at which the

load was applied was chosen as the shortest possible between the drain and the stack. This would

simulate the most severe condition occurring in

service as a result of relative vertical movement.

The movement of the outlet end of the trap was

measured by a 0.001 in dial gage supported on the

floor. The results of the tests made in this way are shown in figure 2.6^ and indicate that a load of

about 50 lbs applied at a distance of II14 in from

the centerline of the drain caused a relative move- ment of about y2 in at the point of deflection

measurement.

15
a b TRAP inches inches CAST IRON •1

BRASS M

i

ii

Figure 2.6-3. Test arrangement for evaluating rigidity of commercial drain-fitting assemblies.

Using these data as a guide the drain-fitting-load

test was performed on one specimen of each available bathtub sample. The test procedure was as recommended in 2.6b and the data are presented in

table 2.6-1. Figure 2.6-5 presents some typical

moment-deflection data obtained for one speci- men. As is indicated in this figure the initial deflection readings were with the 10 ft-lb of moment

contributed by the weight of the lever arm. Because the deflection caused by this moment was

not measured directly the moment-deflection curves

for each specimen were graphically extended back

to zero-moment. Deflections determined by this

method are entered in table 2.6-1 as the "zero-offset." The zero-offset data are considered to be ap- proximate because of the curvature of some moment-deflection curves.

(3) Rationale for Test Selection

The service load which this test method is in- tended to simulate is that resulting from a differ- ential vertical movement between the tub and waste

or soil stack. The material of the tub around the

drain outlet hole should be either (a) flexible

DEFLECTION s} IN. FROM DRAIN, IN."

1 Dimension "a" of figure 2.6-3. Figure 2.6-A. Test for rigidity of drain-fitting assemblies.

-.2 -J 0 +.1 .2 .3 4 .5 .6 .7 .8 DEFLECTION AT 30 IN. FROM CENTER OF DRAIN HOLE, IN.

Ij Figure 2.6-5. Typical moment-deflection data for

drain-fitting-load test.

16

PLfa...

k.

IK.

n.

liu

m

iouj

DUj

ly ft
Table 2.6-1. Drain-fitting-load test results

Specimen

PB-4..

PC-1-.

PD-1..

SE-2..

SC-2-.

SA-2-.

CIA-1

CIC-4

CIE-4

Direction

of loaded end of lever arm

Out end

.

Out front Out back Out end

.

Out back Out end

.

Out front Out end

.

Out back Out end _ Out front Out back Out end _ Out back Out end- Out back Out end_ Out back Out end - Out back

Deflection for 60 ft-lb » moment

At 30 in on lever arm

Meas- ured b

0.308

.533 .392

.265

.242

.103

.238

.548

.625

.567

.465 .488

.770

.257

.085

.094

.121 .100

.112

.114

Zero

offset 0

0. 105 .168

.097

.065 .062

.025

.059

. 115 .173

.132

.107

.117

.108

.043

.024 .028

.026

.026

.030

.037

Corrected

for zero

in 0.413

.701

.489

.330

.304

.128

.297

.663

.798

.699

.572

.605

.878

.300

.109 .122

.147

. 126

.142

. 151

Equivalent

for 12-in arm

Meassured b

0. 123 .213

.157

.106

.097

.041 .095

.219

.250

.227 .186

.195

.308 .103

.034

.038

.048 .040

.045

.046

Corrected

for zero

offset

tn

0. 165 .280

.196

.132

.122

.051 .119

.265

.319

.280

.229 .242

.351 .120

.044

.049

.059

.050

.057

.060

« Includes 10 ft-lb from lever-arm moment.

i> Measured increment of deflection caused by addition of 40 ft-lb moment,

e Extrapolated from moment-deflection curve (see figure 2.6-5).

enough to bend with this movement or (b) strong

enough to withstand the bending moment caused

by the movement, without damaging the tub.

Thus there is a need for a test that imposes a moment equal to the probable maximum that can

be transferred to the fixture by conventional drainfitting assemblies as a result of timber shrinkage

or building settlement. The recommended test is based on a consideration of, and data on, these

two factors.

d. Comments on Performance Requirements

(1) Suggested Format for Performance Level

The bathtub shall withstand the application of

in

? ft-lb of moment or a deflection of as described in paragraph 2.6b (3) , without exhibiting

surface damage such as cracking, crazing, spalling,

lifting of surface coating, etc. The surface damage

shall be determined by the inspection procedure

prescribed in section 2.8.

(2) Rationale for Suggested Format

A limit of 50 ft-lb of moment is about the maximum that would be transferred by the presently

used assemblies because of their inherent flexibility. A deflection limit of 1.25 in at 30 in (equivalent to 0.5 in at 12 in) would be a conservative one,

since (a) the deflection caused by the weight of the

lever arm is not measured by this method, and (b)

in many buildings, such as reinforced-concrete or steel-framed buildings, or well-constructed buildings framed with dry lumber, the differential

movements should be much less than the limit suggested for ths test. On the other hand, some factor

of safety is needed to take into account differential

movements that can develop in some high-rise sys- tems from thermal expansion of waste and soil stacks.

It should be noted that all tubs tested resisted a

50-ft-lb moment without damage and with measured deflections well below 1.25 in at 30 in. The test results suggest that presently manufactured bathtubs are capable of withstanding without damage a moment about the drain outlet equal

to or greater than the 50-ft-lb likely to be trans- ferred by the drain-fitting assemblies ordinarily

used.

2.7. Watertight-Joint Potential (Bathtub)

(S106)

No test method exists for determining the watertight-joint potential of bathtubs and no test method

is recomemnded. It would seem reasonable that some requirement be made for the water bead along

the wall. Federal Specification WW-P-541b(4),

1962 [3] and Commercial Standard CS 77-63 [4]

both specify a minimum upturn of water bead of

%6 in. The minimum upturn found on the tubs

investigated in this test program was % in. The watertightness of the joint between the floor and the tub apron is dependent upon factors other

than bathtub design. These factors are (a) installation and support techniques, (b) differential

thermal movements between tub and floor, (c) adhesion, (d) flexibility, and (e) durability of the

jointing material. An investigation into design

features of bathtubs which would affect the watertight-joint potential was beyond the scope of the

present program. However, the recommended tests for Concentrated Load, Sump Sidewall (sec. 2.5),

for Concentrated Load (Static) (sec. 2.2), and for

Hot-Water Resistance (sec. 2.18) each limit per- missible deflections under loading. These limitations should assure indirectly some protection

against excessive movement of portions of a bathtub in contact with the wall or with the finished

floor when the tub is subjected to loading. These

maximum-permissible deflections also provide some guidance on the amount of movement that

shouldbe accommodated by joint sealants.

2.8. Surface Inspection (M201)

a. Purpose and Scope

The purpose of the surface-inspection test is (a) to specify a standard procedure for inspection

of a sanitary plumbing fixture for defects and

blemishes, and (b) to define the type and number

of imperfections that are permissible in a newly

17
manufactured fixture. Although the inspection

procedure as specified can be used for all types

of sanitary plumbing fixtures, the types and per- missible number of defects and blemishes as stated

herein apply to bathtubs only.

b. Recommended Test Method

(1) Inspection Procedure

Maintain the temperature of the inspection area and fixture to be inspected at 75 ± 10 °F. Wash

the fixture with soap and water and rinse with

tap water. After drying, use a sponge to apply an

ink solution consisting of 50 percent by volume

water-soluble black ink in tap water, or use an ink

that contrasts in color if the fixture is colored. Wipe

excess ink from surface with a damp cloth and

allow fixture to dry.

Inspect the surface of the ink-treated fixture

visually at a normal reading distance for blemishes

and defects. Use a light source of partially diffused

daylight or substantially equivalent artificial light,

with a luminous intensity near the inspection sur- face of not less than 100 nor greater than 200-ft

candles. If surface blemishes or defects are observed to be segregated in a particular area of the

fixture, prepare a small cardboard sheet or thinmetal sheet with a circular viewing window three

inches in diameter. Use this inspection window

to make counts of defects within the area of max- imum concentration of defects.

(2) Suggested Surface-Finish Requirements

The surfaces of the fixtures intended to be visible

after installation shall be smooth and free from

local variations in color and texture that detract

from the appearance of the fixture. Some waviness

is typical of certain finishes, and this waviness shall not be a cause for rejection. Other imperfections

in the finish that shall or shall not be permissible

when fixture is examined as specified in paragraph

2.8b ( 1

) are listed in table 2.8-1

.

(3) Definitions

Blisters—Rounded elevations of the surface that can be penetrated by application of a localized pressure. Cracks—Visible fractures in the finish, usually of

a hairline type.

Chips—/Small damaged areas in the finish, such

as those characterized by loss of coating fragments from a localized impact.

Dents—Local depressions or raised portions in the

surface caused by an impact, or a permanent

deformation, in which no fracture occurs. Dimples—Slight depressions in the surface that

do not extend to the backing material.

Dunts—Hairline fractures extending through the

thickness of the fixture. Die marks—Visible scorings in the surface finish

caused by improper forming operations.

Table 2.8-1. Suggested surface-imperfection requirements

Defect or blemish Maximum

dimension

Mil pboo^

Max. No.

permitted within any

3-in-diam area

Max. No.

permitted

per fixture

Blisters "Won None.

None. None.

None.

8.None. None.

None.

8.

8.None below over- flow line, 8 above overflow

line. None.

None. None. Not counted.

8*.

5b. None.

None.

Cracks in coating Chips Dents Dimples 2 Dunts

Die marks None

Lifts None _ ___ Lumps 2 Molding irregularities. Pinholes

XNone below over- flow lino, 4 above overflow

line. Pores (surface) _ None _ _ Roping None

Spalls None

Specks

>He

Wrinkles

2

1None

None

a A total of 24 is permitted when a wall surround is an integral part of fixture.

b A total of 12 is permitted when a wall surround is an integral part of fixture.

Lifts—Areas of coating that are separated from

the backing material, usually over a fairly large* area. Lumps—Raised portions on a finish, such as those

characterized by an accidental application of a blob of coating material during the manufacturing operation.

Molding irregularities—Any visible distortion of

small size relating to mold imperfections.

Pinholes—Small holes in a coating that extend to the backing material.

Pores (surface) —Small voids at the surface of

the finish. Roping—Shallow ridges and valleys in a finish with no decorative pattern.

Spalls—Small discontinuities in the surface caused

by the loss of fragments after manufacture.

These discontinuities may or may not extend

to the backing material. In porcelain-enamel

coatings, spalls of this type are often referred to as fish scales. Specks—Particles of embedded foreign matter that

produce areas of contrasting color on the surface, but not including specks or flecks purposely incorporated into a finish to produce a decorative pattern.

Wrinkles—Corrugations in the finish that can be

seen or felt and which follow no fixed pattern.

(If.) Information to he Reported

Include the following in the test report

1. Identification of fixture;

2. A qualitative description of color uniformity;

3. A qualitative statement on uniformity of texture

;

18
4. A statement as to the presence or absence

of each surface imperfection listed in table

2.8-1 together with the size and number of

each, when present

;

5. A statement as to whether the fixture

passes or fails the surface-finish-requirements specified in paragraph 2.8b (2).

c. Test Results and Discussion

(1) Discussion of Test Development

Surface-finish requirements as incorporated into

Commercial Standards and into Federal Specifications were reviewed for each material that is being used for sanitary plumbing fixtures. All of

these requirements were quite similar. This permitted their consolidation into a single surface inspection test. The consolidation was done in such a way

that any currently produced bathtub fixture that now passes its own commercial standard for sur- face inspection will also pass the requirements set forth in section 2.8 (b)

.

No laboratory investigations were either possible or were they needed in the development of this

particular test. However, numerous inspections of

fixtures furnished for test were made using the

specified test procedures. All the fixtures inspected

passed the requirements of section 2.8(b).

d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

Surfaces of the fixture intended to be visible after installation shall meet the requirements for

finish quality listed in paragraph 2.8b (2) and in

table 2.8.1.

(2) Rationale for Suggested Format

Since new fixtures that pass the requirements

for surface finish specified in the commercial

standards are apparently acceptable to the general

public, there would seem to be no legitimate reason

for increasing the surface-finish requirements

from their present levels. In effect, the suggested

format as given above would insure that the present quality levels are maintained.

2.9. Water Absorption (M202)

A water absorption test for sanitary plumbing

fixture materials might serve as a control test for some material. The amount of water absorbed

might also bear some relation to performance of

given materials when subjected to other tests. No test is recommended for water absorption at

this time, because (1) existing tests for water absorption do not closely simulate service exposure,

and (2) certain other tests recommended in this

report probably provide adequate protection

against any important effects attributable to water

absorption that may occur in a service environ- ment.

A test method for water absorption of FRPE

sanitary ware is specified in section 6.2 of the proposed revision of CS 221-59 [1]. This involves

total immersion of specimens cut from an FRPE

bathtub in water at 23 °C for 24 hr. according to the procedure of paragraphs 6 ( a) of ASTM D570-

63 [5]. Water absorption is required not to exceed

0.50 percent by weight.

Other test methods for water absorption of sanitary ware are described in standards [3,6,7] . These

involve total exposure of broken specimens to boil- ing water, after which the absorption is required

not to exceed specified percentages by weight.

These tests are not considered to be an adequate

simulation of typical exposure of a bathtub to water under normal use conditions. Among the deficiencies of these tests as performance tests to evaluate the water-absorption effect on sanitary ware are the following

:

1. Some of the tests involve the unrepresentative exposure of both surfaces and cut or broken

edges of a specimen to water at unrealistically high

temperature. Furthermore, different materials

with suitable service records are known to absorb

widely varying amounts of water in immersion

tests of cut or broken specimens.

2. For the kinds of materials used for bathtubs, failure caused by water absorption is more

likely to result from flaws or defects that are widely separated rather than from effects of uniform penetration of water. The exposure of small

flat specimens cut from the fixture may not reveal

tendencies to defects that sometimes occur at the

fillets or curved areas between the bottom and

sidewalls.

3. The existing test methods for water absorption are considered useful essentially as control

tests for materials on which some service experi- ence on performance has been accumulated ; hence,

without modifications, they probably would have

limited value for new materials even as control

tests. Several of the tests recommended herein are

believed to provide the needed protection against

possible deleterious effects of water absorption

through the finished surfaces of sanitary ware. These are given in section 2.18 (hot-water resist- ance), sec. 2.10 (abrasion resistance), section 2.12

(surface-impact resistance), and section 2.16

(scratch resistance). However, it is emphasized

here that no correlation between test results and

service performance has been attempted with re- spect to water absorption per se, nor were any

measurements of water absorption made in developing the recommended tests.

2.10. Abrasion Resistance (M203)

a. Purpose and Scope

The purpose of this test is to evaluate resistance

of sanitary plumbing fixtures to the type of abrasion that occurs in normal use.

19
b. Recommended Test Method

(1) Apparatus

The apparatus for abrading specimens shall be

the Gardner Heavy Duty Wear Tester,6 shown in

figure 2.10-1. This apparatus as used herein

abrades specimens by the reciprocating action of

four hog-bristle brushes moving back and forth

across 12 specimens (three per brush) . The speci- mens are mounted at the same level on a horizontal

bed. A water slurry of scouring powder is fed

continuously through small holes in the brushes

while the equipment is in operation. The brushes,

each of which carries a load of 1,100 g, traverse the specimens at a fixed frequency of 120 strokes

(60 cycles) /min. The length of the stroke is 13 in. The velocity of travel is constant except during

the reversal at the end of each stroke. The feed

rate of the slurry through each brush is controlled

at 3.0 to 3.5 ml/min. The brushes are mounted in

brush holders, provided with fittings for plastic

tubing, Vg-in inside diameter. The slurry is con- tained in a battery jar, 8 in in diameter by 12 in

high. Four aluminum tubes extend into the jar

and plastic tubing, %-in inside diameter, is con- nected to these tubes. The slurry is kept in suspension with a motor-driven stirring apparatus. The

slurry is delivered to the four brushes through the

plastic tubing by means of a metering pump.

The apparatus for measuring abrasive-wear

depth shall consist of a dial thickness or depth

gage, graduated in 0.001-in increments with a sen- sor stem (1/4 in in diam and flat on the end). The

gage shall be mounted on a clamp above a flat plate, so that the height above the plate can be

adjusted for specimens of varying thickness.

(2) Standard Abrasive

A "standard" abrasive slurry, rather than the

slurry of household scouring powder specified in

the proposed revision of CS 221-59 [1], shall be

used for the test described herein. This slurry shall be prepared from the following ingredients

Ground quartz powder 2700 g Sodium carboxymethyl cellulose 15 g

Trisodium phosphate 60 g

Water 3000 ml

The ground quartz powder shall conform to the

following sizing,7 in accordance with Standard

Specifications for Sieves for Testing Purposes,

ASTM E 11

Through a U.S. No. 80 sieve 100 percent

Through a No. 160 sieve 98 percent

Through a No. 200 sieve 93 percent

Through a No. 325 sieve 74 percent

(3) Specimens

The specimens for testing shall consist of three

flat pieces, 3% in square, that have been cut from

the sump of each fixture. The backe of the speci mens shall be ground flat and parallel with the

face surface. Also, the edges shall be ground

smooth and square. The final size shall be 3% in square. Prior to testing, plastic specimens shall be

glued with a water-resistant adhesive to a flat 3%

in square, No. 11 gage, stainless- steel backing

plate.

(4.) Test Procedure

Maintain the temperature of the testing labora

tory and specimens at 75 ± 5 °F. Test the speci6 Available from Gardner Laboratory, Inc., P.O. Box 5728, Bethesda, Md. 20014. While this test method is described in terms of the Gardner Machine for eoocreteness, other machines

with equal or better performance in all essential respects should

be acceptable.

I

7 Ground quartz powder with this sizing is used currently inr

several popular household scouring powders and is available as |4i "No. 160 mesh pottery flint" from the Pennsylvania Glass Sand

Corp., Gateway Building, Pittsburgh, Pennsylvania.

a, battery jar for slurry ; b, motor-driven stirrer ; c, slurry metering pump ; d, brush removed from holder ; e, brushes in holder ; f, plastic tubing ; g, counter. Figure 2.10-1. Gardner heavy-duty wear tester.

20
mens using the Gardner Heavy Duty Wear Tester

following the operating procedure outlined in sec- tion 6.5 of the proposed revision of CS 221-59, but

using the abrasive slurry specified herein in paragraph 2.10b (2) in place of the Ajax brand powder specified in the proposed revision. The essential features of the test procedure are described

below

:

Dissolve the sodium carboxymethyl cellulose in

the water. Next add the trisodium phosphate and

ground quartz powder and suspend by stirring.

With the power-driven stirrer m operation, adjust the flow rate to 3.0 to 3.5 ml/min. The flow

rate can be determined for each setting by measuring the volume delivered in 10 min to a 100 ml

graduate.

Clamp 12 specimens in the two trays on the

horizontal bed of the machine, six to each tray.

This provides four rows of three specimens each,

comprising one row for each of the four brushes.

Use shims as necessary to adjust the specimens

and end plates to the same height. If there are less than 12 specimens, use specimens of the same or

similar material to fill in the blank spaces. Assemble the scrubbing apparatus, consisting of

brushes, holders, and guide plate, and connect the

plastic tubing from the slurry jar to the brush

holders. Start the pump and determine that the

slurry is flowing freely without air bubbles in the

tubing. Scrub at a rate of 60 cycles per minute for

10,000 cycles (20,000 strokes) except stop the machine at 2,500, 5,000, and 7,500 cycles to observe

specimens, to wash excess slurry from the specimen trays, and to change the brush positions (see

table 2.10-1). Also check brush blocks at each in- spection period to be certain that the holes are

free for the passage of slurry.

Table 2.10-1. Schedule for changing brushes

Position of brush in machine*

Test Period in Cycles Brush Brush Brush Brash

No. 1 No. 2 No. 3 No. 4

0-2,500.. _ _ 1 2 3 4

2,500-5,000 _ 4 1 2 3

5,000-7, 500. _ 3 4 1 2 7,500-10,000 2 3 4 1

From front to back of machine.

If the coating on any of the specimens should wear through to the backing material prior to completion of the test as evidenced by a change in

color and texture, remove the specimen from the

bed and replace it with another specimen of the same or similar material. This will prevent the

possibility of a worn-out specimen from affecting- results from the other specimens.

When the 10,000 cycles (20,000 strokes) have

been completed, remove all specimens from the

bed and measure the abrasive wear depth with the

depth gage to the nearest 0.001 in. In making this

measurement, place the specimen on the flat plate

and adjust the clamp on which the gage is mounted

so that the stem of the gage touches the speci- men. Next, move the specimen to a position such

that the stem of the gage contacts the approximate

center of the wear pattern. Set the zero of the dial

gage at the lowest depth that is observed in this

area. Finally, move the specimen so that the stem

of the gage contacts the unabraded surface. This

reading is the abrasive-wear depth for the speci- men. The abrasive-wear depth for the fixture is the arithmetic average for the three specimens.

(5) Information to be Reported

Include the following in the test report

:

1. Specimen identification;

2. Cycles required to wear through the coating, in cases where the coating is worn through to the backing material, as shown by change in color

and texture;

3. If no wear-through occurs on any of the

specimens, report the abrasive-wear depth for

each specimen and also the average for the three

specimens.

c. Test Results and Discussion

(1 ) Discussion of Existing Methods

Three test methods for evaluating the abrasion

resistance of sanitary plumbing fixtures were in- vestigated. One of these is described in the ASTM

test for abrasion resistance of porcelain enamels

[8]. The method of abrading specimens consists

of placing fixed weights of alloy steel balls, abrasive, and water in a cylindrical container with a rubber ring at the bottom to serve as a gasket. The

balls and abrasive rest on the surface of the speci- men. The container is clamped to the specimen

and the assembly placed on the platform of an

oscillating shaker ("RoTap" machine with no

tapper) . The treatment time is calibrated through

use of standard specimens of plate glass.

Two types of abrasion are measured. For sur- face abrasion, the abrasive is the fraction of Pennsylvania glass sand (quartz) passing a No. 70

sieve and retained on a No. 100 sieve. For subsurface abrasion, the abrasive is No. 80 electric corun- dum. Surface abrasion is measured by changes in

45° specular gloss and subsurface abrasion is measured by changes in weight.

Although both surface- and subsurface-abrasion tests by this method have been shown to be

reproducible, it has not been shown that this type

of abrasive action simulates that which occurs in

the normal use of sanitary plumbing fixtures. Abrasion of installed fixtures occurs largely from

the use of scouring powder for cleaning. The ac- tion of oscillating steel balls moving over an abrasive on the surface of a specimen does not generate

the same type of abrasive action as that of a per- son cleaning the fixture with a commercial scour352-020 O—70 4 21
ing powder that has been applied to a brush,

sponge, or cloth. Another method which was investigated was

the Schiefer Abrasion-Testing Machine, originally

designed for testing textiles [9]. In modifying

the machine for testing floor covering [10], a brass cup was added to hold the specimen and a nylon brush and alkaline soap solution were used

to provide the abrasion. Both cup and brush were

rotated at 250 rpm with axes of rotation one inch

apart. In the present investigation, trials were made using this modification on specimens of por- celain-enameled steel, circularly cut to fit the brass

cup. A slurry of Ajax brand scouring powder and

water was used as the abradant. The same nylon

brush used to test floor covering was employed

with four pounds of force being applied to the

brush. After 10,000 revolutions, the center region

of the specimen was worn, rather than the outer

portion, although the brush covered the entire

specimen. Apparently only the "high spots" on the

specimens were affected by the treatment. In an

attempt to eliminate this difficulty, the bristles were removed from a nylon brush and replaced with

sponge rubber. This pad was then used with Ajax

slurry to abrade a second porcelain-enameled steel specimen. Again the specimen was worn near the

center but not on the outer portion. In other tests, a cellulose sponge with Ajax slurry showed practically no effect on a specimen after 10,000 cycles.

Also, Pellon non-woven cloth was cemented onto

the nylon brush holder and another porcelainenameled-steel specimen abraded with Ajax for

10,000 cycles at a 4-lb force. Although this treat- ment resulted in a more uniform abrasion, the

surface being dull over most of the test area, the

abrasion was still not sufficiently uniform, nor was

it measurable with the depth gage.

It was apparent that a good deal of additional

work is necessary to determine whether the

Schiefer machine can be adapted to testing sanitary ware. Its use in testing of sanitary ware is time-consuming largely because of the difficulty in

preparing the circular specimens required in

present applications of the machine.

The one test method in current use for sanitary

fixtures that apparently simulates actual cleaning

practices for sanitary ware is that specified in sec- tion 6.5 of the proposed revision of CS 221-59

[1]. The abrasion requirement in this proposed

standard for FRPE fixtures is that the coating

shall not wear through to the backing material

after 10,000 wear cycles in the Gardner Heavy

Duty Wear Tester, modified as described in the

proposed revision. This test, with minor modifications, is the one recommended as a performance

test for abrasion resistance based on the present

study. Results of tests using this method are given

in section 2.10d(2) of this report.

Other tests that have been used for abrasionresistance testing of sheet or plate materials were

reviewed but no tests were made [11, 12, 13, 14]. It was obvious that none of these tests closely

simulated the action of cleaning a fixture with

scouring powder.

(0) Test Data

Table 2.10-2 compares the results obtained when

sanitary ware materials were tested in accordance

with (a) section 6.5 of the proposed revision of

CS 221-59 and (b) the method specified in section

2.10b herein. The agreement in the results between

the two test procedures is good. This might be

expected, since the only differences between the

two tests is in the abrasive slurry. The data indi- cate that the "standard abrasive slurry" specified

in section 2.10b (2) gives approximately the same

abrasive action as does the Ajax scouring powder

specified in the proposed revision of CS 221-59.

Coating-thickness contours across the surfaces

of an FRPE and a porcelain-enameled-steel specimen after 10,000 wear cycles (20,000 strokes) with

"standard abrasive" are shown in figure 2.10-2. Results with a porcelain-enameled cast-iron specimen, although not shown, were similar to those for

porcelain-enameled steel. The loss in thickness for

porcelain-enameled surfaces after the 10,000 cycle

treatment was approximately 0.0002 in, although

accurate measurements could not be made owing

to the uneveness of the surfaces.

Table 2.10-2. Results of abrasion tests with Gardner heavy duty wear tester

Material a

Results of test using Ajax slurry Results of tests using standard abrasive slurry

45° specular gloss Percent

gloss retained

Abrasive wear

depth

45° specular gloss Percent

gloss retained

Abrasive wear

depth

Initial After

10,000 cycles

Initial After

10,000 cycles FRPE o, e FRPE a, 63 12 19 0.009 in. 57

5164

71

11

1166

59

1922

10083

0.009 in. Porcelain-enameled steel c Porcelain-enameled cast iron ° 65

75 6673

100

97

(»)

( b)

(")

( b

)

=> Three specimens were used for each material in each test.

*> The abrasive-wear depth on the porcelain-enameled specimens was too small for measurement by the method used. Some loss was indicated, however, since an increase in roughness occurred from the test treatment.

0 Flat specimens supplied by manufacturer.

d Specimens cut from bathtub.

» Wear-through to fiber-glass backing occurred on one specimen of the

three.

22
Figure 2.10-^2. Profiles of original and abraded surfaces of porcelaimenameled steel and FRPE specimens.

(3) Rationale for Test Selection

The reason for recommending the abrasion test specified in section 2.10b are as follows

:

1. The recommended test method simulates

the abrasive wear that occurs in service through

the common practice of cleaning sanitary fixtures

with abrasive scouring powders. Another potentially applicable method (the Schiefer test) re- quires further development work for application

to sanitary fixture materials.

2. The basic equipment necessary to make the

test is available commercially and the necessary

modifications can be made in any well-equipped

laboratory. A similar test using this equipment

is already in use for FRPE fixtures ; thus laboratories are familiar with the equipment and its use.

3. The differences in abrasion resistance

between the various materials currently used for

sanitary ware as evaluated by the recommended

procedure appear to be of the same order of magnitude as indicated both by qualitative handrubbing tests and field observations.

d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

Wear-through to the backing material as evi- denced by a change in color and texture shall not

occur on any of the three specimens. Also, in those

cases where no wear-through occurs, the average wear depth for the three specimens shall not

exceed in.

(2) Rationale for Suggested Format

_ It was not possible in the present study to establish a relation between the number of cycles in the wear tester and the abrasive wear in service. To

suitably investigate a relation of this type would

require an expensive and time-consuming survey

of both porcelain-enameled and FRPE fixtures. Since both time and budget were limited, such a survey could not be made during the contract year. In attempting to set a realistic wear depth requirement the following factors need to be considered

:

1. It seems to be the consensus of the FRPE

sanitary ware industry that gel-coat thickness

should be greater than 0.010 in, both from the

manufacturing and end-use standpoints. Presumably this is a sound consensus based on industry

experience accumulated over the past 5 years. It should be pointed out that a polyester gel-coat

applied at a thickness of greater than 0.010 in

would not wear through to the backing material

in 10,000 cycles.

2. The introduction of new materials having an

abrasion resistance appreciably lower than the current gel-coats would be prevented if the aver- age wear depth was set at 0.010 in. This might

be desirable since until such time as it can be

demonstrated that household scouring powders

will not be used on plastic fixtures, a high per- formance level for abrasion resistance would seem

to be almost mandatory.

3. Wear-through to the base material in less than 10,000 cycles should not be permitted, since

exposure of the base material would be highly

undesirable from the standpoint of sanitation and

overall appearance.

4. Selection of 10,000 cycles for the test duration is based on the requirements specified in the

proposed revision of CS 221-59. A shorter testing

period would not seem advisable until such time

as the relation between wear rates in the test and wear rate in service can be investigated

adequately.

23
2.11. Cleanability and Soilability (M203A)

a. Purpose and Scope

The purpose of this test is to evaluate both the

aesthetic soilability and cleanability of sanitary

plumbing fixtures. Soilability is defined as the

degree to which a surface accumulates and retains

the kinds of soiling materials associated with sanitary plumbing fixtures. Cleanability refers to the

ease of removal of these same soiling agents. Retention and removal of bacteria are not included

in the scope. The discussion of this test is related

specifically to bathtubs and shower receptors

although it has some applicability to lavatories,

sinks, and water closets.

b. Selection of Test Method

A specific test method is not recommended. An

acceptable test procedure for soilability should be

comprised of two major elements: (1) a reproducible soiling agent that suitably simulates actual

soiling materials in the bathtub with respect to chemical composition, color, adherence properties,

hardening and drying properties, etc., and (2) a

suitable method for evaluating the accumulated

soiling material in terms of some physical property such as weight, volume, reflectance, etc. An acceptable test procedure for cleanability

should be comprised of three major elements:

(1) a soiling agent that suitably simulates actual

soiling materials in a bathtub (see above), (2) a

scrubbing procedure that suitably simulates techniques, and materials used under actual service

conditions, and (3) a suitable method for evaluating the aesthetic cleanliness of the surface in

terms of some physical property such as reflec- tance or retention of some tracer material, the

presence of which can be detected in quantitative

fashion.

A number of existing methods, laboratory investigation of some of these methods, and development work on new standard soiling agents and

measurement techniques are described. Additional

laboratory work is summarized that is needed to develop a suitable standard soiling agent, scrubbing procedures, and procedures for evaluation of

accumulation of soil and cleanliness of the sur- faces of sanitary plumbing fixtures.

c. Discussion of Existing Test Methods

(1) Soilability

Laboratory investigation indicated that the soil- ing agents developed for published test procedures did not suitably simulate the soiling materials in a bathtub. While there is no scientific evidence to support it, the common idea is that

the ring in the bathtub is the most difficult cleaning problem. No publications were discovered that

described attempts to study or duplicate "bathtub

ring."

Most of the research work on soilability has been

done with textiles. Certainly, human soil is one

of the ingredients of the soiling materials deposited on bathtub plumbing fixtures and is probably an important constituent of bathtub ring. Undoubtedly shirts and pillowcases are soiled chiefly

from persons wearing or using these items. Dorothea Marra and Lloyd I. Osipow [15], on the basis

of analyses of the material from such soiled

fabrics, proposed a soil with the following

composition

Percent

by weight

Carbon ( Darco S-51 ) 25.

2

Coconut oil 32. 4

Coconut oil fatty acids 16. 2

Mineral oil, heavy 16. 3

Benton 34 10.

0

Actually, a standard soiling agent for test purposes in relation to sanitary fixtures should in- clude other representative materials, as discussed

in section 2.1 le.

{2) Cleanability

A number of different test methods have been

used to evaluate the cleanability of surfaces. These

are described briefly together with a discussion

of their relevance to performance teste for

sanitary plumbing fixtures.

(i) Cleanability Test for Fiber-Glass-Reinforced Polyester Bathtubs [7 ] The soiling agent used in this test is a "standard

dirt" formulated of specified percentages of car- bon black, magnetic iron oxide, calcium stearate,

motor oil, a wetting agent, and water. In section 4.4.1 of the proposed revision of CS

221-59 [1], a test method involving the use of the

"standard dirt" for detection of voids in the sur- face is described. Section 6.5 describes the use of

the test method as a criterion or measure of cleanability after a 10,000 cycle abrasion treatment of

the surface. In testing for cleanability as in section

4.4.1, surfaces to be evaluated are first conditioned

by hand scrubbing with wet sponge and scouring

powder. About 5 g of "standard dirt" per 16 in2 of surface is then rubbed into the surface with a dampened chamois, using heavy thumb pressure. The dirt is allowed to dry for at least 1 hour and

then washed with a clean, dampened chamois and

liquid detergent before visual inspection of the

surface for dirt retention.

In evaluating abraded surfaces, as prescribed

in section 6.5, 10 g of the "standard dirt" are ap- plied to the abraded specimens and rubbed into the

surfaces with a dampened chamois, using heavy

thumb pressure. After the dirt has dried for at least one hour, the specimens are washed with a liquid household detergent cleanser for about 50

cycles or until no more dirt appears to be removed.

Evaluation of the dirt remaining after this clean24
ing treatment is accomplished by comparing the

white-light reflectance before the dirt is applied

with that after the dirt is removed by the specified

cleaning treatment. Since this test is already in use for sanitary ware materials, data were obtained

in the present investigation following the procedures in the proposed revision of CS 221-59 and

also using a modified procedure. The results are given in section 2.11d.

The "standard dirt" in the proposed revision of

CS 221-59 is not recommended, principally because

of its ease of removal. The findings on this characteristic will be discussed further in section 2. lid

herein. As discussed in section 2.11e, it would be

desirable to use a more representative, standard

soiling agent in both the soilability and the cleanability tests.

(ii) Pencil Test

In the field measurements described in Appendix

A, marks made with a 3B drawing pencil were used

as a "standard soiling agent" on fixtures of various

materials. Cleanability was categorized by ease of

removal of these marks using a dry cloth, a damp

cloth, a damp cloth with soap, or a damp cloth

with household cleaner. While this simple test provides a four-step rating or classification of

cleanability, the pencil marks cannot be said to simulate agents in a bathtub in service.

(Hi) Washability Tests for Paints

1. A washability test for painted surfaces is prescribed in a Federal Specification [16]. A soil- ing medium of raw umber, petrolatum, and mineral spirits is applied to the panel with a doctor

blade. The coating is dried for % hr at 105-110 °C

and then cooled. The panel is then tested in a windshield-wiper type of washability apparatus

with wet sponge and abrasive soap for 35 cycles

(70 strokes). The "apparent daylight reflectance"

and 60° specular gloss are determined before and

after this treatment. In considering the suitability of this test for

sanitary plumbing fixtures, it should be noted that

the soiling medium specified is unlike that encountered in sanitary plumbing fixtures. The use of a

liquid detergent for cleaning, rather than an abrasive soap, should be explored since the abrasive

soap might cause a change in the surface during

the test . 2. The effectiveness of cleaning agents for

gainted surfaces was investigated by Wesley E.

helberg, James L. Mackin, and Ross K. Fuller

[17].

The specimens were soiled with "synthetic dirt,"

formulated to resemble urban and shipboard dirts. The formulation for urban dirt was based on pre- vious chemical and physical analyses of street sweepings from six large eastern U.S. cities, that

passed a No. 200 sieve. The following formulation was used to represent urban dirt

:

Percent by weight

Humus 38.0

Portland cement 16. 3

Silica Powder 16. 3

Diesel oil 0. 9

Used automobile lubricating oil 1. 3

Carbon 1. 6

Iron oxide,8 magnetic, Fe3 04 0. 3

Sodium chloride 5. 4

Clay, "average grade" 16. 3

Stearic acid 1. 8 Oleic acid 1. 8

8 The iron oxide was probably in powdered form.

This formulatjton for a soiling agent probably

merits investigation since it includes some of the

materials likely to be found in soils on sanitary

plumbing fixtures. However, some of the elements

of human soiling materials, such as body oils and

skin particles, are not present.

(iv) Tests for Bacterial Cleanability [18]

Glass, china, stainless steel, and aluminum

plates were seeded with bacteria tagged with

radioactive phosphorus, P32

. The dishes were washed under various conditions in a commercial

dishwasher and radioactive counts performed on

the dishes. The above test is not considered applicable to sanitary plumbing fixtures since it is concerned with bacterial cleanability whereas the

present study is concerned with evaluating

aesthetic cleanability.

( v ) Washability of Dinnemoare

1. The National Sanitation Foundation at the

School of Public Health, University of Michigan,

has developed a Use and Wear Machine for simulating use and wear on materials and finishes for

chinaware, as mentioned in Western Plumbing

Official for May-June 1964. One method for measuring the effectiveness of cleaning procedures is the "salt-shaker" test, described by E. H. Armbruster and G. M. Ridenour [19]. A mixture of

85 percent talc and 15 percent Safranine-0 dye

is dusted on the surface and rinsed with water. Residual red dye is an indication of remaining

fatty oil or grease, protein, and starch. This is a simple method but not quantitative

and applies more to food soil than to the soils likely to be deposited on sanitary plumbing fix- tures in bathrooms.

2. Louis E. Wells, Jr. [20] described a method

for evaluating liquid detergents using soiled din- ner plates and a weighted brush, operated by

hand. This might be a good method for preliminary testing but a machine-operated brush would

give a more uniform and reproducible cleaning

action.

25
(vi) Cleanliness of Floors

The cleanliness of floors has been measured by

Robert J. Weatherby [21]. A predetermined area

of the surface is wiped in a controlled manner

with a standard area of a standard fabric and the

amount of dirt picked up measured by light trans- mission, using a portable densitometer. In order

to test the procedure in the laboratory, a standard

soil was applied to glass plates and test wipes

made on these plates. The formulation of the

standard soil is as follows

Lamp black 0. 5 g

Bentonite clay 10- 0 g

Nonionic wetting agent, ethylene oxide-octyl phenol con- densate 2. 0 drops

Ethyl alcohol 2. 0 ml

Water 100- 0 ml

This method might be used to evaluate the

amount of dirt remaining on sanitary plumbing

fixtures and thus to evaluate soilability and cleanability but the amount of residual dirt is probably

much less than that found on floors. The soiling

medium probably does not resemble bathroom

soil.

d. Laboratory Studies of Soilability and Cleanabllity

Laboratory studies of cleanability of bathtubs were made in the present investigation on speci- mens abraded by the Gardner Heavy Duty Wear

Tester using two different abrasive slurries. One

slurry was the mixture of 50 percent commercial

Aj ax cleanser and 50 percent water by weight

specified in the proposed revision of CS 221-59.

The other slurry was prepared at the National

Bureau of Standards using nonproprietary materials as described in section 2.10 on Abrasion

Resistance herein. The soiling medium used on

the abraded specimens was the "standard dirt" of

the following composition, specified in the proposed revision of CS 221-59

Percent by weight

Carbon black, pigment grade 20

Iron oxide, magnetic, Fe3 04 , powered 20

Calcium stearate 10

Motor oil, 30W viscosity 5 Nonionic wetting agent, ethylene

oxide-octyl phenol condensate 1 Water 44

The liquid detergent used on the specimens

abraded with Ajax slurry was the commercial detergent, "Mr. Clean," as specified in the proposed

revision of CS 221-59. The liquid detergent used on the specimens abraded with the nonproprietary NBS slurry vas a liquid detergent of the

following composition, prepared at the National

Bureau of Standards

26

Percent by weight

Tetrapotassium pyrophosphate 8.0 Biodegradable nonionic nonyl phenolethylene oxide detergent 7.0 Ethylene glycol monobutyl ether, also known by the trade name "Butyl

Cellosolve" 1.5 Sodium xylenesulfonate 8.0 Distilled water 75.5 The results of the cleanability tests are summarized in table 2.11-1. The results show that the

modified test procedure, using nonproprietary

abrasive slurry and- liquid detergent, yielded

greater loss in reflectance (see note b, table 2.11-1)

for the FRPE specimens than did the procedure

described in the proposed revision of CS 221-59.

This was probably due principally to differences in

the detergents, since the data on abrasion resistance

in section 2.10 herein show that the abrasion produced by the two slurries was about equal for the

FRPE specimens.

Table 2.11-1. Cleanability of abraded sanitary ware

specimens a

Material

Percent loss in white-light reflectance, Rd b

Specimens abraded by

Gardner heavy duty wear

tester

Specimens

abraded as in ASTM C

448-61

with Ajax

slurry »

with NBS

abrasive

slurry f with Ajax

slurry 8

FRPE = 0.2 e.h2.7

*->3. 1 0.4 FRPE <i, e Porcelain-enameled steel .2

0

0.1 0.9

.5 Porcelain-enameled cast iron .4

» Each value is the average of values for three specimens.

b After soiling with "Standard Dirt" and cleaning with liquid detergent. Measurements by Gardner Color-Difference Meter according to thaprocedure

of ASTM D 1365-60T [38].

° Flat specimens supplied by the manufacturer.

<> Specimens cut from bathtub.

» Mr. Clean was used for the cleanabilty test.

' NBS nonproprietary detergent used for cleanability test.

8 One of the specimens wore through the gel-coat.

h After cleaning with abrasive slurry, Rd increased 4.4 percent. After cleaning with abrasive slurry, Rd decreased 4.2 percent.

The losses in white-light reflectance, shown in

table 2.11-1 for the porcelain-enameled specimens, were largely independent of the abrasive slurries

and detergents used. The measurements were made

with the Gardner Color-Difference Meter as specified in the proposed revision of CS 221-59, according to the procedure of ASTM D 1365-60T [38].

Some of the abraded specimens were coated with

"standard dirt," the excess wiped off with paper

wiping tissue 'and the specimens examined with a

linear-traverse microscope. An FRPE specimen

abraded by the Gardner Wear Tester showed

numerous long scratches in the direction of wear

pattern, with no pits. Porcelain-enameled oast-iron

and steel specimens, abraded in like manner,

showed very few pits on the oast-iron and about

iff
76 pita per linear inch on the steel specimen. Specimens abraded as by ASTM C 448-61 [8] method

: showed many pits. The entire surface of the FRPE

! specimen was pitted with little or no space be-

| tween pits. The porcelain-enameled oast-iron speciI men had 357 pits per linear inch, while the steel

; specimen had 378 per linear inch. From these observations and the foregoing data in table 2.11-1,

it appears that deep scratches may affect clean

ability much more than do pits.

Limited laboratory studies were made on soiling

media. The studies made on cleanability showed

that it was not necessary to use scouring powder

( to remove the "standard dirt" specified in the proI posed revision of CS 221-59, unless the surface was badly worn. This was true even when the

standard dirt was allowed to dry for 24 hours before removal.

J Common experience with bathtubs indicates that

"bathtub ring" adheres rather tenaciously to enj; ameled surfaces if allowed to dry overnight. Many

! brands of toilet soap will also stick tightly to an

enameled surface if allowed to dry in contact with

hthe surface. The field survey of installations of

FRPE fixtures revealed that most housewives

1 1 used scouring powder for cleaning their bathtubs.

| \ Comparison of these observations with the laboratory experience indicated that the standard dirt

specified in the proposed revision of CS 221-59

;was more easily removed than actual bathtub soil. In an attempt to develop a soiling medium more

J like that encountered in bathtubs, "synthetic bathitub ring" was produced on a number of flat speci- mens of sanitary ware in the stainless- steel tank

ijused for the Water-Resistance Test, section 6.1 of the proposed revision of CS 221-59.

j A soiling medium was first formulated from the

1 following ingredients

Mineral oil 10 g

i

! Anthracene 10 g

Carbon black, pigment grade 10 g

Iron oxide, magnetic, Fe304, powdered 10 g

Titanium dioxide, 100 percent rutile__ 10 g

Sodium Bentonite 30 g

The stainless- steel tank was filled with distilled

1 water and solutions of calcium and magnesium

chlorides and sodium bicarbonate added to pro-

' duce hardness equivalent to 300 ppm as OaC03

.

; The water was then heated to 120^130 °F and 1

I percent neutral soap powder contain 'ng no addij tives and 0.1 percent soiling medium was added,

i The mixture was stirred and allowed to stand in

' contact with the specimens for about 30 min. The

tank was drained and the specimens allowed to dry

overnight. Another experiment was tried, using a

j superfatted soap in place of the soap powder,

j However, in both cases, the "synthetic bathtub

ring" was easily removed by dry wiping, as shown

visually and by examination under ultraviolet

light, which fluoresces the anthracene. This did not

appear to be a promising approach, because of the

ease with which the soil could be removed.

e. Recommendations for Future Development

(1) Soiling Agents

An essential starting point for the development

of test procedures for both soilability and cleanability is a reproducible soiling agent that suitably

simulates actual soiling materials in sanitary

plumbing fixtures. Actually, typical soiling agents

may differ for bathtubs, lavaboratories, sinks,

water closets, etc. Based on the laboratory experience obtained

during this investigation, it is considered neces- sary to explore actual bathtub soiling materials

involving hard water, bath soap, and human subjects. Analysis should be made of bathtub soil to determine the nature and proportions of various

constituents as a basis for synthesizing a representative standard soiling medium. Consultation

with the manufacturers of toilet soap and detergents is desirable as a means for identifying the

principal ingredients in soaps and to reduce the

amount of research and analysis required. It is considered possible to develop a standard soiling

agent that will suitably simulate the chemical

composition, color, adhesion properties, hardening

and drying properties, etc., of actual soiling

agents, and which can serve as a basis for per- formance tests on soilability and cleanability.

(2) E'valuation of Accumulation

It is probable that, with some initial experimentation in whole bathtubs, the soiling process can be adequately studied on flat samples cut from

bathtubs or shower stalls, using a small-scale apparatus. In this event, the accumulation of soil CDuld probably be determined by weight, with or without removal from the surface.

(3) Soil Removal by Scrubbing

It is probable that the essential measure of

cleanability is the amount of energy or work re- quired to remove the soiling agent and produce an appearance of aesthetic cleanliness. This in- volves the cleaning device (brush, sponge, cloth,

etc.), the cleaning agent (detergent or scouring

powder) , the pressure used in scrubbing, the force

required to move the scrubbing element across the surface of the specimen, and the number of

strokes over the surface. Existing methods do not

attempt to evaluate cleanability in these terms. These parameters of the scrubbing process all vary

widely in actual practice. It would be highly desirable to standardize the

elements of the scrubbing process if meaningful

comparisons are to be made for different materials.

If the soiling process can be effectively produced on flat samples in a small-scale apparatus, it would

27
be possible to use the Gardner Heavy Duty Wear

Tester, equipped with suitable brushes or sponges,

under a standard pressure, and a standard nonproprietary detergent or scouring powder, to determine the amount of scrubbing effort required

to clean a surface or to compare the cleanaoility

of various surfaces. It might be desirable to use a liquid detergent as the cleaning agent rather than

a scouring powder, to avoid possible problems of

particle imbedment in the scrubbing element, and

to magnify any differences that might exist in the

number of strokes or work required to attain a given level of cleanliness.

(A) Evaluation of Aesthetic Cleanness

White-light reflectance is presently used (sec. 2.11d) to indicate the amount of soiling medium

remaining on a surface after cleaning. The soiling

medium used in the test contains black pigments

which reduce the reflectance of a white or lightcolored surface, which has a high white-light re- flectance before soiling. In attempting to correlate

this method for evaluating cleanability with

aesthetic cleanness, it must be established that

natural dirt also reduces white-light reflectance

of the surface and that the change in reflectance

is related to the amount of dirt. The test described in section 2.11d gives an in- dication of the amount of soiling medium retained

in the scratches on the surface resulting from

abrasion. Hence it is an indication of abrasion as well as cleanability and soilability and was designed as an indicator test for abrasion. It seems

likely that, with further work to correlate visual

response, type and quantity of soil, and reflectance,

white-light reflectance could be used as a measure

of aesthetic cleanness of white sanitary ware. The

apparatus is commercially available, it is suffi- ciently sensitive to simulate visual resolution, and

a fairly good correlation between white-light

reflectance and visual response has already been

established.

The white-light reflectance of a dark-colored

surface is low and there may not be sufficient contrast between the surface and the soiling medium

or natural dirt to indicate the amount of soiling.

Hence the method outlined in section 2.11d may

not be valid and white-light reflectance may not

be a good indication of cleanness or abrasion of

colored sanitary ware. Some additional research

work would be needed to develop suitable modifications of the procedure for colored plumbing fix- tures. This might take the form of a different

coloring agent in the standard soiling medium.

Correlation between reflectance measurements on

colored surfaces with various degrees of soiling

and visual responses would also be needed.

Soilability and cleanability tests should be car- ried out on both new specimens and abraded

specimens.

2.12 Surface-Impact Resistance (Bathtub)

(M204)

a. Purpose and Scope

The purpose of this test is to determine whether

or not the finished surface of a bathtub will withstand certain impact loads on critical areas without suffering mechanical damage. The impact

load imposed by the recommended test is a blow

on a rounded edge of the rim by an aluminum

tube mounted on the end of a pendulum.

b. Recommended Test Method

(1) Apparatus

The apparatus shall be as shown and described

in figure 2.12-1. Essentially it is a pendulum-type

impact device made so that the tup (striking part)

strikes the inside convex corner of the front rim of

the bathtub at an angle of 45° from the horizontal.

(2) Preparation of Test Specimen

Place the bathtub on the floor and level it. Use

framing and/or shims when required to prevent

rocking or shifting of the specimen when tested. In addition, distribute sufficient weights in the

bottom of the bathtub to provide approximately

250 lb of total weight including the weight of the

bathtub.

Inspect the test area prior to the test using the

procedure outlined in section 2.8. Test only those areas without defects. Make certain that each test point is at least 2 in from any defective or damaged area.

(3) Test Procedure

Maintain the temperature of the testing laboratory and bathtub at 75 ±5° F. Position the test apparatus so that the center of the tup will strike

the test surface at an angle of 45° with the horizontal. This procedure is illustrated schematically

in figure 2.12-1. Select the area for test along the

inside convex corner of the front rim. Test a total of 10 points.

Drop the pendulum against the test surface in

1-in increments of height-of-drop until cracking,

chipping, or other damage in the surface is observed, or until a 30-in height-of-drop is achieved.

Inspect for damage to the surface using the proce- dure outlined in section 2.8. Rotate the tup slightly

after each point is tested so that a new area of the

tup strikes the test point. Record the height-ofdrop of the pendulum when the damage occurs, and describe the damage.

(4) Information to be Reported

Include the following in the test report:

1. Specimen identification;

2. Location of the 10 test points indicating the

distance of each from the drain end of the tub

;

28
Figube 2.12-1. Surface impact-resistance test apparatus.

3. The height-of-drop for cracking, chipping,

( or other damage at each point;

4. Description of the damage.

c. Test Results and Discussion

(1) Test Development

Several test methods were tried prior to the

'development and selection of the recommended

method. The first method tried (table 2.12-1) in- volved the use of a %-lb steel ball iy2 in in diameter

as the striking object. This method was essentially

as described in the proposed revision of CS 221-59

[1] except that a plastic cylinder fitted with bubble-type plumb devices was used as a guide tube.

! The steel ball was allowed to fall free from various

^heights on both flat and curved surfaces of the

Specimens. The results of these tests indicated that

Table 2 12-1. Results of drop-impact tests on bathtubs using }i-lb steel ball, iy% in-diam

Location of

test areas Specimen

No.

Height

of drop,

in

No. of damaged

areas

No. of

tests

! Bottom or ledge SA-3 36 al 3

(horizontal flat). SC-3 36 0 3 CIC-3 36 0 4 PB-2 36 bl 3 Inside rim (convex SA-3 12 ° 6 8

radius)

.

SC-3 6 d 1 3 CIC-3 6 °3 3 PB-2 24 ' 1 3

* Bmall chip.

b Small gouge.

° Chips ranging from \U to Vi in maximum dimension.

d Chip, %-in maximum dimension.

0 Faint mar.

' Fine scratches.

the convex surfaces of the tubs were most susceptible to damage. It was also noted that the precise

point of impact was critical. The steel ball test was

abandoned because of difficulty in controlling the

point of impact on the convex surfaces, and also

because the high rigidity of the steel ball was not

characteristic of objects likely to be dropped on

bathtubs after installation. A second series of tests was tried with a pendulum apparatus similar to the recommended apparatus except that the tup

used was a glass bottle. Variations in weights and

dimensions of bottles of the same nominal size

plus the danger from glass breakage led to the use

of an aluminum cylinder as the striking object.

(Jg) Test Data

The results of tests on a number of porcelaihenameled-steel tubs are presented in table 2.12-2. The reported results are confined to porcelainenameled-steel tubs only although porcelain-enameled cast-iron and FRPE tubs were also tested. The results of tests on cast-iron units are not in- cluded in table 2.12-2 as no failures occurred at the maximum height-of-drop. The same was true

for the FRPE tubs with one exception. Specimen

PB-2 at a point of double curvature failed at an

average height-of-drop of 18% in for eight test points. Nine test points located at areas of single

curvature withstood the maximum height-of-drop

without damage.

The results tabulated for other test areas in

table 2.12-2 are included to show that a definite

test area must be specified since differences in

impact resistances among different areas of the same specimen are significant.

29
Table 2.12-2. Surface impact-resistance test results a

Location of test area Specimen

No.

Avg. ht. of drop to

failure

Number

of drops Standard

deviation

Inches Inside front rim SE-4 13.8 13 3.37 SA-4 8.2 9 1.64 SC-2 & 7. 6 8 1. 51 SC-2.._ 7.

3

9 1. 00 SC-4 7. 0 3 1. 00

Outside front rim SE-4 10.3 9 1.73 SA-4 7.8 13 1. 16 SA-2 7. 7 11 1. 27 SC-2 -.- 6.

6

9 . 88 SC-4.._ 5.

9

13 1. 06

Inside back rim SE-4.. 17. 7 9 7. 97 SE-4 o 16.2 9 5. 30 SC-4 12.0 7 2. 52 SC-2 t> 10.9 8 1. 46 SC-2 10.7 9 1.42 SA-4 7.6 8 1.19

Inside head-end SA-4 8.3 3 1.53

* Apparatus used as shown in figure 2.12-1.

b 2d Set.

° 2-in x 4-in timber under ledge.

(S) Rationale for Test Selection

The primary reason for the selection of this

method of test was that the height-of-drop and the

point of impact can be easily controlled and

reproduced. The selection of aluminum as the

material for the tup -was prompted by the similarity of its modulus of elasticity to that of glass.

The inside radius of the front rim was chosen as the test area because this area is vulnerable to impact blows in normal service, and is con- veniently located for testing with the apparatus

developed for this test.

d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

The average of the heights-of-drop at first cracking, chipping or other damage for the 10 test points shall be not less than in. The minimum value for any one point shall be in.

{2) Rationale for Suggested Format

That chipping occurs on some steel tubs is indicated by the results of the telephone survey

(Appendix B). In setting height-of-drop limits,

however, it should be kept in mind that about

% of the chips occurred during, or prior to, instal- lation. More care during handling and installation

probably would have reduced the observed damage by a sizable amount.

2.13. Dimensional Stability (M205)

This characteristic was defined by the ad hoc

committee as the ability of a plumbing fixture to withstand the conditions of environmental ex- posure in service, and the conditions of normal

handling and storage prior to installation without

excessive distortion. There is no existing test method applicable to the determination of this

property for sanitary plumbing fixtures and no

test method is recommended. Extensive experimentation would be required to devise accelerated

tests to evaluate permanent distortion in service

in relation to time of use. Some data on per- manent distortion after exposure to concentrated

load separately and in combination with a water

load are presented herein. Some data on per- manent deflection during the hot-water resistance

test are also presented.

2.14. Bond Maintenance (Mechanical)

(M206)

Commercial Standard CS 221-59 specifies that

FRPE specimens exposed to the ASTM B 117

salt spray test for 4000 hr [22] shall not exhibit

any "apparent" blistering, delamination, or other

surface defects. No work was done on a test for

this property in the present investigation. The

tests recommended in sections 2.2, 2.4, 2.18, and

2.20 covering concentrated static load, concentrated

dynamic load, hot-water resistance, and radiantheater resistance, respectively, are believed to expose the fixture to some of the more severe service conditions that are likely to produce delamination or loss of bond. These tests should indicate

the ability of the fixture material to maintain the

bond between the structural back-up and the sur- face finish under service conditions.

2.15. Surface Slip Resistance (Bathtub or Shower Receptor) (M207)

a. Purpose and Scope

The purpose of this test is to evaluate the sur- face slip resistance of bathtubs and shower receptors. This property obviously is related to safety

in the use of these fixtures.

b. Selection of a Test Method

No test method can be recommended at this time,

because none of the existing test methods appear

to be suitable, and it was not possible to develop

a suitable method within the resources available in

the present investigation. Three major elements

would be pertinent to a suitable method

(1) The sliding element of the test apparatus

should effectively simulate the surface properties

and resilience of some part of the human anatomy

likely to be involved in slipping in a bathtub or a shower receptor. These properties would have to be determined through further study.

(2) The method of initiating slippage, i.e., dynamically or statically induced, would have to be selected from further information on falls in

service (or other simulated service conditions) so

1

30
as to effectively simulate the mechanisms of slippage in bathtubs and shower receptors.

(3) The nature of the fluid film to be used on

j the test surface should be selected from further

study so as to simulate service conditions.

Finally, a relation between slip-resistance values

determined in tests and actual slippage by human

subjects (suitably protected against injury) in a

service or simulated-service environment, using the same materials, would be highly desirable.

c. Discussion of Existing Test Methods

Two reports [23, 24] relating to test methods and

I apparatus for determining slipperiness of walkways were studied.

In horizontal-track methods, the sliding coefficient of friction at constant velocity is the ratio

of the force required to drag the specimen to the

weight of the sliding body, neglecting intermolecular forces between the surfaces. In inclined-track

methods, the coefficient of friction is determined by

the tangent of the angle of incline of the plane

! surface to the horizontal. The angle is adjusted

until constant velocity is attained. The Sigler Slip

Tester, a pendulum-impact machine, developed

at the National Bureau of Standards for testing

slipperiness of walkway surfaces, was based on

the premise that, in the process of walking, slipping is most likely to occur when the rear edge

of the heel contacts the walkway surface. The value

obtained from use of the machine, the energy loss in a measured distance of movement across the surface, is called the "anti-slip" coefficient. The simplest method, a horizontal-track method

for floor surfaces, used by the Research Department of the Hospital Bureau, Inc., employs a 15-

lb spring scale and an 8- X 10-in canvas bag con- taining 10 lbs of lead shot. The bag is placed on two layers of clean cheesecloth with the scale at- tached. If less than a 3-lb drag will pull the bag

j across the floor, the surface is considered too slip- pery. If a drag of 5 lbs or more is required, the

floor is considered safe. However, it was reported

that the results depend on operation and technique. Possibly a modification would be suitable

I for testing the slipperiness of bathtubs and shower

j receptors.

j Another horizontal-track method is the Egan

Slip Tester, manufactured by the Thwing-Albert

Instrument Co., Philadelphia, Pa, Friction is measured between two specimens, one secured to a moving platform and the other attached to a weighted sled connected to a spring dynamometer

or electric load cell. This would not be suitable for

measuring the slipperiness of sanitary ware, be- cause only one surface of the sanitary ware is involved in slipping in a bathtub or shower re- ceptor, while two surfaces are involved in the

Egan Slip Tester. Friction of floors has been studied by means of

; a household floor scrubbing and polishing unit,

the power supply of which is connected to an ammeter. Increased current indicates greater friction

and vice-versa. However, the brush is not similar

in surface properties to the human foot or other

part of the anatomy which might slip in a bathtub or shower receptor.

Another type of horizontal-track method, measuring static friction instead of kinetic friction, is represented by the Hunter Machine, the James

Slip Tester, and the Dura Slip-Resistance Tester,

all similar in principle. The Hunter Machine consists of a slotted weight, placed between two verti- cal guide bars of the frame, and a thrust arm

pivoted at one end near the center of gravity of

the weight and at the other end through the center of a shoe. The sliding specimen, a footwear material, is attached to the underside of the shoe and

rests on the track, a flooring material. Initially

the shoe is placed with the thrust arm close enough

to the vertical so that the specimen will not slip on the track. By means of a screw and lug, the shoe can be drawn forward by small increments, in- creasing the horizontal component of the shoe until

the specimen slips on the track and the weight

drops. The position of the lug at the instant of

slippage is an indication of the frictional force. This method seems deficient because the relationship between frictional properties of footwear materials and the sole of the human foot is unknown,

and the method of initiating slippage seems unlike that involved in falls in bathtubs and shower

receptors.

The Sigler Slip Tester is essentially a compound

pendulum which sweeps a shoe material over the

walkway surface to be tested. A mechanical shoe,

forming the lower end of the pendulum, is so ar- ranged that a test piece of rubber, leather, or other

heel material, iy2 in square, can be attached to the underside of the shoe at an angle of 10, 20, or 30 degrees to a horizontal plane. A helical spring

is used to press the edge of the heel against the

walkway surface. The pendulum, released from a predetermined fixed height, is allowed to sweep

over the floor specimen or surface to be tested. A pointer attached to the framework at the pendulum's center of rotation records the heights to which the pendulum swings beyond the floor specimen after contact, From the data, an anti-slip coefficient between the two materials is determined.

Deficiencies of this method are similar to, but possibly less serious than, those of the Hunter method.

The British Portable Skid-Resistance Tester

[25] is an improved modification of the Sigler

Slip Tester, designed for measurements on walkways and roadways. It is also the basis of a proposed ASTM method for measuring surface fric- tional properties. The slider assembly consists of an almninum backing plate to which is bonded a y4 X 1- X 3-in rubber strip. The rubber compound

is synthetic rubber as specified in ASTM E249-

64T [26] and must not be more than 2 years old.

31
c. Test Results and Discussion

Three bathtubs were evaluated for surface slip

resistance, using the British Portable Skid-Resist- ance Tester, one of the available existing test machines. The procedure adopted for these trial tests was as follows:

Clean the fixture with synthetic detergent and

water and thoroughly dry interior surfaces, taking

care to remove mold-release wax from new FRPE

surfaces. Level and adjust the test machine for

5-in contact area (±}4 in). Take four readings.

Record the first reading in parentheses and dis- regard. Move to another location, readjust the machine, and take readings as before. Average the

second, third, and fourth readings at the two loca- tions for measuring dry slip resistance, Stopper

the drain of the fixture and add enough water to make a pool in the lower portion. Perform meas- urements as before but slosh water onto the test area immediately before making each observation.

Average the corresponding six readings for measuring wet slip resistance.

Measurements as shown in table 2.15-1 were made on one each of porcelain-enameled steel, porcelain-enameled cast-iron, and FRPE bathtubs,

using the British Portable Skid-Resistance Tester. There was a noticeable difference between wet and

dry slip resistance, the wet surfaces being much

more slippery. There was no significant difference

in wet slip resistance between any of the bathtubs

tested. There were some differences in dry slip

resistance, porcelain-enameled cast-iron and steel tubs being somewhat less slippery than FRPE

tubs when dry. However, further study should be

made, taking special care to remove any mold-release wax from FRPE tubs.

Table 2.15-1. Measurement of slip resistance of bathtubs with the British portable skid-resistance tester

Material

Slip resistance, average

of six readings

Dry Wet FRPE 35

45

51

13

1013 Porcelain-enameled steel Porcelain-enameled cast iron

e. Recommendations for Future Development

Further work on a suitable test method should

include attention to nature of the sliding element,

the method of initiating slippage, and correlation

between service experience and test results, as re- ferred to in paragraph 2.15b. Other parameters that should be evaluated, if possible, are

(1) Resilience of fixture material, and of

force between sliding element and fixture surface.

If any substantial local deformation occurs in the

material beneath the feet of a bather, the resulting

"depression" might reduce the tendency to slip due

to a shift in body position. This effect, if it is appreciable, might be affected by unit force between

the surfaces in contact, area of contact, and re- silience or flexibility of the fixture material.

(2) Amount, temperature

? and composition

of liquid over test surface. It is conceivable that

slip resistance may be different for' hot and cold

wetted surfaces, and may be different when soap

is used than when only clean water is used. Opinions have been volunteered by some persons that

wet slip resistance may be least when only a film

of water remains in a bathtub.

Performance limits should be based on a rela- tion between test results and data from a service or simulated service environment, so that the limits set can be looked upon as reasonable in the

interests of safety in use. The above suggestions are made principally be- cause opinions have been volunteered (see Appendix A) that some materials feel less slippery when

wet than others, and because these variables were

not studied in the present investigation.

j 2.16. Scratch Resistance (M208)

a. Purpose and Scope

The purpose of this test is to provide a method

for evaluating the resistance of sanitary plumbing fixture materials to the type of scratches that

detract from the aesthetic appearance of the fix- tures. Scratches that cannot be seen with the un- aided eye, either before or after accumulating soil, are not considered to be objectionable.

b. Definitions

(1) Scratch

For the purpose of this test, a scratch is defined

as a permanent, elongated groove or a linear se- ries of intermittent discontinuities in a surface

caused by the mechanical movement of an object

in contact with the surface. A scratch is characterized by great length with respect to both width

and depth and is further characterized by dis- placement of material, without restriction on the . method or manner of displacement. The displacement can be caused by any of the following

(a) Plastic deformation (the plastic flow

and piling up of material on either side of the

groove)

.

(b) Cutting or tearing (the breaking of

molecular bonds)

.

(c) Micro-melting (liquid flow resulting

from frictional heat generated by a large force on

a small localized area)

.

(d) Crushing and/or plowing (the dislodging of material from the surface, such that it either sloughs off spontaneously or accumulates as loosely adhering particles that can be easily

brushed off)

.

32
(2) Visual Scratch Damage

Visual scratch damage is denned as the marring

or disfigurement of a surface by scratching to such an extent that either the scratch itself or foreign

material retained in the scratch is readily visible to persons with 20-20 vision.

c. Recommended Test Method

(1) Apparatus and Materials

The basic instrument used for this test is the

Porcelain Enamel Institute Gouge Test Apparatus [27], modified for scratching. The essential

features of the apparatus are shown schematically

in figure 2.16-1. The reversible motor drives a screw shaft which slides the carriage across the

top of the elevating table at a fixed velocity of 4

in per min. A specimen placed on the carriage is contacted from above by a scratching tool mounted

on the underside of the counterweighted lever

beam. The beam rests on a knife edge ait its ful- crum and the working end of the beam has a sus- pended weight pan for varying the load on the

scratching tool. The scratching tool is a rightcircular conical diamond with a vertex angle of

90° and a 3-mil radius point.9 The diamond tool

is inclined 3° off the vertical axis in the direction

opposite to the movement of the carriage. The load on the diamond tool is calculated from the load on the beam and the lengths of the lever arms. Any other instrument capable of making a

straight scratch under a constant, controllable load

may be used. However, the diamond scratching

tool shall be as specified above.

The apparatus required for evaluation of

scratches is a special viewing box which provides

uniform viewing distance and angle, and uniform

specimen illumination. A schematic diagram of

the box is shown in figure 2.16-2. One of the following soiling agents shall be

used:

(a) The "standard dirt" specified in the proposed revision of OS 221—59. The formulation of

this material is: 20 parts iron black (iron oxide,

9 Diamond points of this geometry are available from the Tabor Instrument Corp., North Tonawanda, N.Y., Catalog No.

139-55.

COUNTERWEIGHTED BEAMz

DIAMOND

SCRATCHING TOOL 7

KNIFE EDGE 3

7-

WEIGHTS

ELEVATING

Figube 2.16-1. Scratch test apparatus.

16"-

40 WATT LIGHT BULBS

INTERIOR FINISHED IN FLAT WHITE

Figure 2.16-2. Specimen viewing box.

black, powdered) , 20 parts carbon black (pigment

grade), 10 parts calcium stearate, 5 parts 30W

motor oil, 1 part wetting agent (Triton X-100,

Rohm and Haas, or equivalent) , and 44 parts tap

water.

(b) A white paste made by mixing 5 g of

titanium dioxide (pigment grade) with 10 cm3 mineral oil (clear and extra heavy).

(2) /Specimens

Specimens shall consist of flat, 4 in X 4 in pieces

of the material cut from the fixture except that

separately prepared specimens may be used if they

are certified to be identical to the material used

in the fixture.

(3) Procedure

(a) Application of Scratches

Maintain the temperature of the testing laboratory between 68 and 78 °F, and the relative humidity between 45 and 65 percent. Precondition

specimens in the laboratory atmosphere for at

least two hours before test. When using the instrument shown in figure

2.16-1, first balance the beam in the horizontal

position by adjusting weights in the pan. Next,

place a trial specimen on the carriage and raise

the elevating table until the specimen makes contact with the point of the diamond scratching

tool and then place additional weights in the pan

so as to give a small load on the diamond. The

load, in grams, on the diamond is calculated from

the weight in the pan and the lever ratio. When

the carriage is started, allow the diamond to tra- verse about 2.5 in across the face of the specimen.

After making the scratch, lower the elevating

table and return the carriage to the original

position.

Repeat the above procedure with increasing

loads on the diamond until the approximate load

is found that causes a visible scratch. This load

shall be called the "estimated critical load." Next,

select a series of loads such that five are greater

33

352-020 O—70-
than the estimated critical load, by increments

of 5 percent, and five are less than the estimated

critical load, by decrements of 5 percent.

After the estimated critical load has been determined, prepare a fresh specimen for testing by

marking eleven reference points, spaced %6 in

apart, along an edge of the specimen. Place this

specimen on the carriage and position it so that

the diamond scratching tool starts its movement

at the first reference point. With one of the preselected loads in the pan, make a scratch (or pass)

across the specimen. Eepeat this procedure for

each of the other pre-selected loads; however, the

order of applying the loads shall be randomized

so as to preclude a regular pattern which might

tend to bias an observer, who later rates the

specimen.

(b) Application of Soiling Agent to Scratches

In order to allow for elastic recovery and for

any other delayed effect of scratching, do not apply soiling agent until at least 18 hr have elapsed

after scratching.

When testing white- or light-colored fixtures

apply a generous quantity of the black soiling

agent to the specimen and rub it on by hand with a

soft cotton cloth. Rub in random directions at first, but finally in a direction approximately normal to the scratches. Continue the rubbing until it appears that no additional dirt is being retained in

scratches. The excess dirt is then wiped off the

specimen surface with wadded paper towels. All

wiping is done in a direction normal to the

scratches. Several towels are used until no more

dirt shows on a towel. One to 2 minutes of

vigorous rubbing with wadded towels is quite

sufficient. In the case of black fixtures, use the white soil- ing agent. The procedure is the same except that

the excess soil shall be wiped off until no more is visible on the unscratched surface.

When fixtures of other colors are to be evaluated, select the soiling agent that shows the greater

contrast with the fixture color.

(c) Visual Examination of Specimens

The scratched and soiled specimen is placed in

the bottom of the viewing box and positioned under a holding frame so that the 11 reference marks

on the specimen coincide with 11 numbered refer- ence positions on the frame. An observer (other

than the operator) looks down through the viewing port and searches for evidence of scratches.

He records the number corresponding to each ref- erence position on which he finds a scratch.

The operator determines from his records the

loads on the diamond at which observable

scratches occurred. The visual scratch damage rat- ing assigned to the fixture is taken as the smallest

load on the diamond, in grams, that caused a vis- ible scratch on the specimen.

In the case of a fixture with a surface pattern

that is directionally oriented, the rating assigned

to the fixture is taken as the average rating obtained from two specimens, one scratched in the

pattern direction and one scratched in a direction

forming the maximum possible angle with the

pattern direction.

(If.) Information to be Reported

Include the following in the test report

1. The color of the fixture.

2. Identification of the soiling agent that was

used to detect scratches.

3. The visual scratch damage rating of the

fixture.

d. Test Results and Discussion

{!) Discussion of Existing Methods

Scratch tests have been in existence for many

years. Perhaps the oldest is the Mohs Scale for | determining the relative hardness of minerals.

Like the Mohs test, many of the later scratch tests are also intended to measure hardness and are of- ten designated "scratch-hardness" tests. Generally,

scratch resistance is correlated with hardness, but

not always. All of the known scratch-resistance or scratch-hardness tests depend on the material

being scratched by a hard object under controlled

conditions. The hard object (herein designated

"scratching tool") may be pointed, such as a diamond-tipped or hardened-steel phonograph needle, or it may be sharp-edged, such as a knife edge or

a diamond-cube edge. In some cases the specimen

is rated by adjusting the load on the scratching

tool until the first visible scratch appears. In other

cases the scratch is made under a constant load and

the rating is determined by measuring the width

or depth of the scratch.

Each of the known scratch tests was evaluated,

but none was found to be entirely suitable for rat- ing the performance capabilities of all classes of

sanitary plumbing fixtures. A common objection

to most of these tests is that they were designed

for a limited class of materials and are not readily

adaptable to a group of materials with widely

different scratch resistances.

(2) Test Development

The first attempt at developing a scratch test that would be suitable for all fixture materials was based on determining the smallest load that

would produce a scratch on the specimen surface.

The starting point of the scratch was determined

with the aid of a microscope. Although this particular test appeared to rate materials in the proper

order of scratch hardness, a valid objection to the

test as it applies to sanitary plumbing fixtures was

that a scratch which cannot readily be seen is not

aesthetically objectionable.

34
A reappraisal of the original purpose of a

scratch test led to the conclusion that a better defi- nition of the property that was desired to be

measured might be stated thus : "The resistance of

a fixture to the type of scratching in which either

the scratch itself or soil retained in the scratch

becomes unsightly." Consequently, the above-mentioned threshold scratch test was rejected and the

"Visual Scratch Damage Test" described in section

2.16c was developed.

(a) Test Data

Data obtained during development of the Visual

Scratch Damage Test are given in table 2.16-1. All

of the porcelain-enamel, vitreous-china, and gel- coat specimens tested were white.

(b) Discussion of Test Data

Variation in visual acuity among individuals naturally leads to some scatter in ratings. However,

the data in table 2.16-1 show that the variations

are not serious when materials of widely differing

properties are rated. Furthermore, it is believed

that scatter in results can be reduced significantly

when more experience is gained in conducting the

test. Table 2.16-1 includes some preliminary reTable 2.16-1. Visual scratch damage ratings

Minimum load on diamond tool to cause visible scratch (after soil- ing), gm

Material Average

of 10 observers Standard

deviation

Minimum

and maximum

values

Porcelain enamel on steel: Mfr. A 980 152 855-1230 Mfr. B:

Spec. 1 _ 790 24 740-798 Spec. 2 __ 800 102 618-930

Porcelain enamel on cast iron: Mfr. A 780 32 760-836 Mfr. B:

Spec. 1 750 62 665-855 Spec. 2 620 44 551-703

Vitreous china: Mfr. A _ 700 "0 700 Mfr.B:

Spec. 1 --. 590 40 570-665 Spec. 2 570 29 523-626

Gel coat on FRPE:

Mfr. A:

Spec. 1... 41 3.3 37-48

Spec. 2 47 2.0 38-48 Mfr.B:

Experimental 1 57 "0 57 Experimental 2 ... 65 4.0 57-67 Experimental 3 Plate glass: 74 5.9 57-76 Black background - 810 "0 810 White backgromd 820 20 808-855

Stainless steel, type 304 (280-mesh

abrasive finish)

:

Scratched parallel to grain. __ Scratched perpendicular to grain.

.

285 »0 285

19 *0 19

• Each observer made an independent determination of the minimum load

that produced visual evidence of a scratch. The loads employed ranged in

steps of 5 percent of the estimated critical load. Thus, potential variations between results reported by different observers within the range bounded by

one step above to one step below the reported scratching load could not be

detected by the procedure used, and in such instances the computed standard

deviation was zero.

suits; i.e., data accumulated before the test prece- dure had been firmly set. The scratches on plastic and vitreous materials

have different appearances. The scratch on a plastic

specimen is usually a continuous, nearly uniform

groove. On the other hand, a light scratch on porcelain enamel or vitreous china may be observable

in this test only as a series of discontinuities caused

by the scratching tool breaking through sub-surface bubbles. This led to variations among observers, particularly in borderline cases where there were only two or three damaged areas observable

along the line traversed by the diamond point.

(3) Rationale for Test Selection

There is no other known test that rates materials

according to their resistances to being visibly

scratched and to retaining visible soil in the

scratches. It is believed that the recommended test simulates a condition that occurs frequently in

service, i.e., a fixture is scratched by a sharp or pointed object such as a grain of sand, a tool, edge

of a soap dish, etc. Subsequently, the scratch ac- cumulates foreign matter and becomes unsightly.

e. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

The visual scratch damage rating of the ex- posed surface of the fixture shall be not less than

grams.

{2) Rationale for Suggested Format

Inasmuch as all currently manufactured sanitary plumbing fixtures have apparently received

public acceptance with respect to their scratch re- sistance, it might be reasonable to set the performance level at a value slightly below the minimum

value found for materials used in contemporary

fixtures. Such a performance level would disqualify any future fixture material with a scratch re- sistance substantially lower than the minimum

value found for the presently used materials. In

addition, the mere presence of a scratch-resistance

requirement should tend to encourage improvement in this property of fixtures. The data on scratch resistance obtained in this

investigation show a wide range in the values for

the different materials. This set of results illus- trates the essential difficulty that arises when

widely different levels of performance are ex- hibited by different materials for a given characteristic, and indicates that it may not always be

logical to set a single performance level for all materials.

2.17. Drainability (Bathtub) (M209)

a. Purpose and Scope

The purpose of this test is to evaluate the ability

of a bathtub to drain quickly and completely.

35
b. Recommended Test Method

(1) Apparatus

The essential apparatus for this test is shown in

figure 2.17-1, consisting of supporting structures,

slope gage, graduated glass cylinder, and receiving

vessel. Requirements are as follows

(a) Fixture support

The supporting structure shall be stable under

the load imposed by a bathtub, and shall be

equipped with facilities for careful adjustment of

level such as leveling screws or thin shims.

(b) Outlet fitting

The fitting shall be a standard drain-outlet

fitting of diameter appropriate to the drain opening in the bathtub.

(c) Slope gage and base

The slope gage shall be an instrument having

a calibrated accuracy to within ±0°5' and finest scale graduations of 0°10' or less. Base of gage

shall be at least one third of length of bathtub,

or the instrument shall be placed on a stiff metal

straight edge of this length.

(d) Vessels

The 1,000-ml graduated glass cylinder shall

have finest scale graduations of 10 ml or less, a height-to-diameter ratio of at least 5.0, and a cali- brated accuray to within ±5 ml at any depth. The

receiving vessel shall be cylindrical, shall have a volume not exceeding twice the tangent-depth

V 90' TO TUB BOTTOM V \ WATER S URFACE

SEE NOTE J/

OUTLET FITTING- BATHTUB

MOUNTED ON SUPPORTING STRUCTURE AS REQUIRED TH 1

DEPTH TO WHICH 98% OF TANGENTDEPTH VOLUME

FILLS VESSEL

MEASURE

1000 ml GRADUATED GLASS

CYLINDER

' .»T'.,'.t. V- RECEIVING VESSE L PLACED ON LEVEL, STABLE SUPPORT

> 2.0 u fmJ^lu s

JlrfacV°lnci<ies wlth P°int of tangency between nllet and bottom of tub. Figure 2.17-1. Apparatus for drainaUUty tdst. 36

volume for the bathtub,10 and shall have a heightto-diameter ratio of at least 2, based on the depth

to which 98 percent of the tangent-depth volume

fills the vessel. The receiving vessel shall either be

transparent or shall be fitted with a transparent

sight tube of at least y2 in diam to facilitate precise determination of water surface elevation.

(e) Timing device

The timing device shall have the finest indicating scale graduations not exceeding 1.0 sec and a

calibrated accuracy to within ±1.0 percent when

measuring a 60-sec period.

(2) Procedure

Maintain the temperature of the testing laboratory, bathtub, and water used for testing at 70 ±

10 °F. Place the bathtub to be tested on the supporting structure and install the drain outlet fit- ting without overflow fittings but with drain plug

so that no leakage occurs when the plug is in place

and water is introduced into the bathtub. Adjust

the top rim of the bathtub so that it is level from

front-to-back at the drain end of the fixture, and

so that the longitudinal dimension of the front

rim slopes away from the drain to the extent of

0°30' (±0°5') as determined by averaging three

measurements taken at the left, center, and right

positions along the length of the front rim. After

establishing the specified rim slope, adjust the

nominally horizontal outlet tube of the drain

fitting to a slope of at least 0°30' in the direction

of discharge.

Thoroughly clean the entire inside surfaces of

the bathtub, graduated cylinder, and receiving

vessel with water and soap or synthetic detergent,

rinse, scrub out with alcohol, and air dry. Insert drain plug and, using graduated cylinder, fill fix- ture with clean tap water to tangent depth as determined and marked with the aid of a straight

edge at least 24 in long. Carefully record volume

of water required, and calculate 98 percent of

tangent-depth volume. Remove drain plug and

allow bathtub to drain completely, discarding the

water discharged.

Using the graduated cylinder, determine and

mark the receiving-vessel depth corresponding to 98 percent of tangent-depth volume for the bathtub being tested. In making this determination,

place the receiving vessel on a stable, level surface

beneath the bathtub drain outlet. Mark both

lateral and angular positions so the position can be

duplicated in successive measurements.

In order to wet inside surface of bathtub pre- paratory to making measurements, replace drain

plug and fill bathtub with water to tangent-depth

line as previously marked. Remove drain plug and

10 See figure 2.17-1 for illustration of tangent-depth volume. Tangent-depth volume is defined as the volume of water required

to fill the bathtub to a depth such that the water surface coincides with the point of tangency between the inside bottom surface of the bathtub and the curved area at the end opposite the drain, as determined on the longitudinal centerline of the bathtub by means of a straight edge placed on the bottom.
allow tub to drain until continual dripping ceases,

at which time repla.ce the drain plug.

Refill bathtub with tangent-depth volume of

water, empty receiving vessel and replace in

marked position, remove drain plug, and measure

time duration of discharge required to bring water

level in receiving vessel up to the mark corres- ponding to 98 percent of the tangent-depth

volume.

Replace drain plug immediately after cessation

of continual dripping, and collect water clinging to inside surface of bathtub bottom with a

flexible, non-absorbent squeegee. By use of the

graduated cylinder, determine volume of water

collected. Repeat the three last-mentioned steps, obtaining

measurements in triplicate for drainage time and

retained water. Compute average values from the

measurements in triplicate.

In using the graduated cylinder, wet inside sur- face immediately before using, shake out and dis- card excess water. If repeated uses of cylinder

are necessary to determine marking level on receiving vessel or to fill bathtub to tangent depth, shake

inside surface water into receiving vessel or bathtub, as appropriate, after each such use. Immediately before each use of the receiving vessel, first wet inside surface and then, holding upside down,

shake vigorously, so as to dislodge excess water

or foreign matter clinging to inside surface of

vessel.

(3) Information to he Reported

Include the following in the test report

:

1. Tangent-depth volume;

2. Time for discharge of 98 percent of tan- gent-depth volume

;

3. Volume of water retained after cessation

of dripping.

c. Test Results and Discussion

(1) Discussion of Existing Methods

A review of standards for plumbing fixtures did

not yield any reference to a test for drainability.

REGIME I, ORIFICE FLOW UNDER SMALL HEAD

(2) Test Development

In developing a test, measurements were first made to determine the nature of the discharge curve near the end of the period of drainage for

a bathtub (the last 3 gal). In addition, the effect of bottom slope on the amount of water retained

after cessation of dripping was investigated. These

data are shown in figures 2.17-2 and 2.17-3. From

these data it was concluded that a bottom of near

zero slope, a slope away from the drain, or a wavy

or warped bottom could be detected by measuring

the water retained after cessation of dripping.

In further development work, five bathtubs were

tested using the procedure prescribed under sec- tion 2.17b (2), and the data are shown in table

2.17-1. In these tests, specimen SC-1 retained

somewhat less water after dripping than shown

in figure 2.17-2: this was apparently because it was not thoroughly cleaned before the test repre- sented in the figure. The data of table 2.17-1 show

reasonably good repeatability and agreement be- tween results by different observers.

Table 2.17-1. Results of drainability tests

Specimen material and

identification

Tangentdepth volume

Time to discharge

90 percent tdv

Volume

retained on bottom

surface

ml sec ml

Enameled steel (SC-1) 3, 300 i>43.7 °35

"42.9 "28 Ml. 8 °30

"45.4 °30 Enameled cast iron (CIA-1) 8,600 20.2 18 19.2 15 19.7 15 FRPE (PC-4)d_„_ 10, 710 14.3 44

15.5 38

15.4 41 FRPE (PB-3)d 12, 000 19.9 109 19.3 107 22.0 94 FRPE (PB-2) 12, 000 23.9 67 25.0 84

25.1 72

"Tangent-depth volume, as indicated in figure 2.17-1.

b Observer A.

0 Observer B.

d Test made after completion of 100-hr boil test. SPECIMEN SC-1 BOTTOM SLOPE l°-40'

ll,840ml ADDED TO WETTED TUB

APPROXIMATELY 120ml RETAINED AFTER END OF DRIPPING

30 TIME, SECONDS

Figure 2.17-2. Discharge pattern for bathtub. a7
SPECIMEN SC-I

II, 840ml ADDED TO WETTED TUB

I2r

AVERAGE VALUES

•4O-0' SLOPE A 3" -10' o |°-40' FLAT SLOPE A FLAT

430ml RETAINED

INCLUDING 0BVI0US"P00LING"

40

TIME, SECONDS

100

Figure 2.17-3. Bottom slope effect in bathtub drainage test, regime 2. The test on specimen PB-3 yielded a value of

retained surface water slightly in excess of 100 ml.

This was not surprising in view of the appearance

of the test specimen which had previously been

subjected to a 100-hr boil test. Apparently some

permanent warping of the bottom had occurred,

and the surface was roughened with many blisters. These conditions probably contributed to the re- tention of excessive water.

(3) Rationale for Test Selection

Since important properties to be evaluated by

this test are duration of drainage near the end

of the discharge period and retention of water on

the bottom after cessation of continuous dripping,

it was considered sufficient to base the tests on the

quantity of water required to barely cover the bottom surface, referred to as the tangent-depth vol- ume. By measuring the quantity of water retained

after dripping, the "pooling" that might result

from improper design or manufacturing errors can be detected. As a practical indication of the

duration of time for the discharge of the tangentdepth volume, the time for discharge of 98 percent

of the tangent-depth volume was used. While this

percentage value was somewhat arbitrary, it was

about the maximum value at which good repeatability could be obtained in the measurement of

the time values and yet gave a meaningful comparative indication of duration of discharge for

the amount of water required to cover the bottom

of a bathtub. The requirement that the tests be

made with a rim slope of 0°30' opposite to the

drain end of a bathtub is based on field measure- ments of rim slope of installed fixtures. In these

measurements the maximum deviation of rim slope

from the horizontal approximated 0°30', although

most fixtures were set very nearly horizontal. A

rim slope opposite to the drain end of the fixture was selected for test purposes since this condition

imposes a more critical requirement than a slope

toward the drain.

d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

The maximum allowable time for discharge of

98 percent of tangent-depth volume shall be , sec (average of three measurements), as determined in accordance with the procedure in section

2.17b (2). In addition, the maximum allowable

quantity of water retained on the fixture surface

below the tangent-depth plane shall not ex- ceed ml (average of three measurements),

as determined in accordance with the procedure in

section 2.17b (b).

{2) Rationale for Suggested Format

All bathtubs which were tested for drainability

discharged 98 percent of the tangent-depth volume

in less than one minute, and when new retained

less than 100 ml of water on the surface below the

tangent-depth plane. A limitation on drainage

time 'is of interest to the user since many persons

prefer to scrub and rinse a bathtub immediately

after bathing. Likewise, excessive retention of

water' oh the surface due to surface irregularities

and puddling makes cleansing and rinsing more

difficult and time consuming, and may be aesthetically objectionable.

2.18. Hot-Water Resistance (Bathtub) (T302)

a. Purpose and Scope

The purpose of this test is to evaluate the ability

of a bathtub to withstand exposure of the interior

38
surface to hot water without blistering, cracking,

checking, or loss of bond between surface coating

and base material. Although development work on

the test has been carried out only on bathtubs, with

further development work the test could probably

be adapted to other fixtures.

b. Recommended Test Method

(i) Apparatus

The apparatus required comprises a heat source, an immersion heating element, a water-circulating

pump, a temperature control, and a dial gage graduated to 0.001 in for measuring displacements. One

such system is shown in figures 2.18-1 and 2.18-2. The system shall be capable of maintaining a water

temperature of 120 °F (± 5 °F) at any point in

the tub.

{2) Supporting Structure

A supporting structure as specified in section 2.2

shall be provided that is stable under the weight of

STEAM T „T ,.,,„ SUPPLY ^ 1

HOT-WATER

CIRCULATING PUMP

Clearance ^ l" t £

TO

DRAIN OR

RECEPTACLE

ELEVATION

17

h — 27 n - r i I-* < C

O 16-j 4" '~T « 16"

I 4

.

32" »B ' J PLAN

PLACEMENT AND DIMENSIONS OF HEAT ELEMENT IN TEST TUB

MATERIAL1 Type L Copper Water Tube

A, steam trap safe for use at line pressure—opens to dis- charge condensate into test tub ; B, thermostat and recorder

sensor location approximately mid-depth and mid-length, 2

to 4 in from wall: C, riser, %-in copper or brass pipe; D,

solenoid-operated steam valve, nominal % in diam ; H, pump

capable of circulating 10 gpm through suction and discharge

lines.

Figtjbe 2.18-1. Apparatus for hot-water resistance test.

—(^Wrj— —^^^L_

D, solenoid-operated steam valve, nominal % in diam : B

45-sec time-delay relay, contacts N.O. ; F, 2-sec time-delay

relay, contacts N.C. ; G, bi-metallic thermoregulator, 3-wire

control, for use in water, range —100 to +350 °F. Figure 2.18-2. Temperature-control wiring diagram.

a bathtub filled to the overflow outlet with water,

and that will allow clearance under the bottom of

the bathtub for deflection measurements with a dial

gage. The bathtub shall be secured to the supporting structure as specified in section 2.2. In addition, a drain-fitting assembly shall be installed complete with overflow fitting and stopper. A flat sur- face shall be provided on the under-surface of the

central point at the sump determined as specified

in section 2.2, paragraph b(3), so that center deflections of the sump can be measured normal to bottom.

(3) Test Procedure

Clean the inside surfaces of the bathtub with

water and mild soap or synthetic detergent, rinse

with water, dry, and then inspect for surface defects using the procedure described in section 2.8. Fill the fixture to the overflow outlet with water at cold-water supply temperature, drain and within

10 min after emptying determine the dial-gage

reading representing the elevation of the center of

the underside of the sump. This reading constitutes

the zero reference for subsequent deflections. Next,

fill the bathtub to the overflow outlet with clean

tap water, set temperature control to 120 °F, turn on heat source and start temperature recorder and

hot-water circulating pump. After water temperature stabilizes, adjust thermostat so that temperature of the water at recorder sensor (point B in

fig. 2.18-1) as measured with a calibrated thermometer is maintained at 120 °F within range of

±2 °F. Temperature measured with the thermometer approximately 1 in from the fixture surface at eight points (two points near the bottom at approximately the third points of the longitudinal

centerline, also two points each near front and

rear walls and one point near each end wall at approximately halfway depth) shall not vary from

120 °F by more than ± 5 °F.

Note : Nonuniform temperature distribution may be cor- rected by adjusting circulating-pump discbarge rate or

position of free ends of suction and/or discbarge lines. Stop the test at intervals of 100 hr, drain the tub,

and inspect the fixture for damage in accordance

with the procedure described in section 2.8. Also,

30 min after draining, determine the center deflec- tion of the sump. After the final 100-hr interval of

exposure terminate the test, inspect the fixture for

the final time, and make the final dial-gage reading.

Note : Tbe test may be terminated after any test interval

if tbe inspection shows tbat tbe fixture bas failed the re- quirements specified in paragraph 2.18c.

(3) Information to oe Reported

Include the following in the test report:

1. Specimen identification, including overall

dimensions

2. Description of test frame and method of

fastening tub to frame

3. Results of visual inspections at beginning

of test and at each successive inspection interval

39
4. Deflection of center of sump 30 min after

draining, at each 100-hr interval

c. Test Results and Discussion

(1) Discission of Existing Methods

Hot-water exposure tests have been prescribea

for several sanitary plumbing fixture materials.

Among these are the 100-hr boil test for small spec- imens of FRPE materials described in the proposed revision of CS221-59 [1], and the total immersion test of a complete fixture in boiling water

described for vitreous-glazed earthware in CSlll43 [7]. Hot-water exposure of small specimens by

total immersion is involved in the tests of thermal

shock and water absorption for vitreous china

described in OS20-63 [6] and FS WW-P-541b-54

[3]. However, none of these tests subjects the fix- ture to the type of exposure encountered in service

;

i.e., partially filling the fixture with hot water.

(2) Test Development

Three FRPE bathtubs were tested first as described in section 2.18b, with the test temperature maintained at 200-212 °F. The tests were

terminated after an aggregate of 100 hr of ex- posure. The data are shown in table 2.18-1. Blistering occurred in all three tests at exposure

times of 25 hr or less. Cracking was observed in

two of the three tests at 50 and 75 hr. Subsequently

boi) tests for 100 hr as prescribed in the proposed

revision of CS221-59 were made using specimens,

4 in sq, prepared by cutting from the undamaged

areas of the tested fixtures; i.e., from above the

water line. The results of these tests are shown in

table 2.18-2. Blistering, but not cracking, was obsen^ed with these specimens. The relatively early

blistering observed on specimens PB-3(1) and

PB-3(2) indicates that the thermal insulation

provided by backing naterials may reduce the

resistance of gel-coats to blistering. This increased

thermal insulation could easily result in a higher

temperature in the coating as well as at the coat- ing-substrate interface.

Deflections of the bathtub sumps due to prolonged exposure to water at or near the boiling

point are summarized in table 2.18-1. In all three

tests appreciable deflection recovery occurred

upon empting the bathtub, and recovery continued

for some time afterwards. However, some residual

deflection existed after periods of up to 72 hr. In

one test, the lower rear wall of the sump assumed a

noticeable permanent rearward set. This particular area was not supported by a reinforcement

backing.

In preliminary development work, a porcelainenameled-steel bathtub was tested at a temperature

approaching the boiling point for 53 hr, including

50 hr of exposure essentially as described in sec- tion 2.18b, and the balance from the hot-water

phase of 25 cycles of the thermal-shock test described in section 2.21. No noticeable effects were

observed aside from a very slight dulling of the

finish. Two additional tests using whole FRPE bathtubs were made, one exposed to 160 °F (±5 °F)

water and one to 120 °F (±5 °F). The results of

the 160° test are shown in table 2.18-1. As in the

tests at the higher temperature, deflection recovery

in the 160° test continued for at least 90 hr after

emptying the tub. Blistering, however, did not appear until the 74-hr inspection.

In the 120° test (specimen PC-2), inspections were made at the beginning, and at 74, 146, 241,

355, 500, 600, 796, and 1000 hr of exposure to 120 °F

(±5 °F) water. Blisters were not observed until

the 500-hr inspection. At that time, the defects

comprised less than half a dozen slightly raised areas of circular (up to % in diam) or needle

shape (up to % in long). As in the earlier tests at higher temperatures, the blisters were less prominent after the bathtub had cooled. The 600-

hr inspection showed little if any further change in

the surface condition. However at 796 hr, fiber

and blister prominence had increased, and a number of new raised areas were observed. Still further deterioration was noted at 1000 hr. As

before, some degree of recession was noted after

cooling. Residual sump deflections taken immediately after draining the tub at the various inspection intervals ranged up to approximately 0.11 in,

with some characteristic deflection recovery after

remaining empty for a period of hours at room

temperature.

In short-time load tests on FRPE bathtubs with

150 lb of water at approximately 115 °F on which was superimposed a 150-lb concentrated load at the center of the sump bottom, maximum deflec- tions of the sumps did not exceed approximately

0.05 in. These data are presented in section 2.13. While these trials showed that the particular

FRPE bathtubs furnished for test were incapable

of withstanding exposure to hot water for long

periods at temperatures of 160 °F, or higher,

without exhibiting surface defects, bathtubs in

service are probably only rarely exposed to such

temperatures and then probably for very short

intervals of time.

Two series of 100-hr boiling water tests were performed on 4-in X 4-in flat specimens provided

by manufacturers or specially prepared in the

laboratory. Equipment was used conforming to that specified under paragraph 6.1.1 of the proposed revision of CS 221-59 [l]. The results of

the first series of tests are summarized as follows

Material Appearance After Boiling

Porcelain-enameled cast-iron, Dull and etched. SD105.a

Porcelain -enameled- steel, Slightly dulled; slight CID.a yellowing.

FRPE: Same as before treat- Sanitary ware gel coat" ment.

See footnotes at end of table.

40
Appearance After Boiling

Same as before treat- ment. Badly checked and peeling. Numerous blisters ; dis- colored to a dirty

yellow.

" Specimen from bathtub manufacturer.

b Laboratory specimen, specially prepared by gel-coat producer.

Material Experimental sanitary ware

gel-coat. b

Conventional boat gel- coat." Sanitary ware gel-coat."

In the above tests, the specimens were not pre- conditioned except by cleaning with 1 percent tri- sodium phosphate solution.

In the second series of tests on 4-in x 4-in flat specimens, the specimens were preconditioned

with Bon Ami for 20 full strokes in a lapping

machine. Gloss measurements were made before

and after the boiling tests with careful cleaning

Table 2.18-1. Results of hot-water exposure tests of FRPE bathtubs at 205 °F and 160 °F

Specimen

identification Approximate

water

temperature

Period

of exposure

Center Deflection

of sump bottom

Surface condition

Filled" Empty

PB-3

o p

205

hT0

525

in

>>0. 082 .130

.326

in No defects.

0. 163 Many blisters approx. Yi-Yia in diam X 0.01 in high.

.105 Time lapse approximately 5 weeks. Deflections indicated below for specimen PB-3 referenced to "zero" reading at later date.

PC-4.

PD-2.

PC-3.

205

205

160

tart b. 095

. 211

50 .268 .055

75

100 .290 .047

0 K 059 .077

1 .093 .024

3 .106 .027

6 .101 .031

9 .109 . 036

25 .109 .038

«.033

'.030 50 .119 .045

e.030 75 .143 .058

h .037

100 .143 .062

i.038

0 >>.034 .034

25 b.048 .003

. 021 i. 012

50 >>. 045 . 0

.021 k.012

75 . 010

100 .0

0 . 122 20 .146 .053

25

50 .155

72 .266

74 .080

". 063

054 -.049

101

A number of blisters in diam, especially in area of front radius. Longitudinal

cracks in rear radius on both sides of overflow opening. Greater number of blisters, ranging up to H in diam. Largest blisters in corners.

Blisters tended to recede upon cooling. Fiber impressions evident. Additional

cracks especially at ends, some in branching pattern. More blisters than at 75 hr, some up to Me in across. Recede somewhat on

cooling. Bottom warped outward near edge of reinforcement at back of sump.

Cracking worse than at 75 hr, length of cracks ranging up to approx. 12 in No defects. Two small blisters near center of bottom. A number of additional bisters. ABC (Hot Tub)

31 4 0 ABC3 (Hot Tub)

40 4 0 A B C° (Hot Tub)

45 6 0 (Cold Tub)

(Cold Tub)

B C°

Many large blisters just below water line. Size di- minished on cooling. Two hours after draining, blister counts of 20 to 80 were obtained from randomly spaced 6-in circular areas on sidewalls, ranging up to Vi6 in diam (up

to fs in on bottom). Needle-shaped raised areas approx. Vi to 3a. in long, particularly on sidewalls. Two small areas on lower sidewall contained numerous short, parallel cracks. (Hot Tub)

(Cold Tub) No defects.

Surface below water line covered with numerous tiny blisters, except in front

corners.

Blisters increased in number (He in to Ys in) All areas below water line blistered, many blisters joined with adjacent blisters.

Blisters flattened out considerably, many having burst open. No defects. No defects. No defects. Approx. 20 blisters on finished surface of tub bottom, ranging from y$ in to \i

in diam. Blister prominence decreased upon cooling.

Blisters noticeably less prominent. Three new blisters approx. \i in diam on

concave surface of an inside corner slightly below water line. Outlines of numerous filaments of fiberglass.

Notes:

» Water at temperature in column 2 except where otherwise noted.

b Water at cold water supply temperature.

° Measured immediately after emptying except where otherwise noted.

d Measured after tub had been empty for 25 min.

• Measured after tub had been empty for y2 hr.

' Measured after tub had been empty for V/2 hr.

* Measured after tub had been empty for 24 hr.

h Measured after tub had been empty for 3 hr.

1 Measured after tub had been empty for 1 hr.

i Measured after tub hadbeen empty for 42 hr.

k Measured after tub had been empty for 72 hr.

1 Measured after tub had been empty for 2 hr. m Measured after tub had been empty for 25 hr.

" Measured after tub had been empty for 90 hr.

° Designations A, B, and C identify 6-in circular areas on longitudinal

centerline of finished surface of bottom of bathtub. A was at mid-point, C

adjacent to drain, and B at opposite end of tub. Numbers indicate blister counts in the respective areas.

41
Table 2.18-2. Results of 100-hr boil test of J+-in x 4-in FRPE specimens cut from above waterline of whole bathtubs previously

subjected to 100-hr boil test

Specimen identification Surface condition at indicated time

25 hr 50 hr 75 hr 100 hr

PB-3(1), plywood backed

PB-3(2), plywood backed

PB-3(3), no backing

Many small blisters Many small blisters _ Few blisters _._

Blisters slightly enlarged

Blisters slightly enlarged Same as at 25 hr

Some bursted blisters Some bursted blisters Same as at 50 hrMany bursted blisters, resembling peeling paint. Many bursted blisters, resembling peeling paint. Many blisters pinpoint size to ]4 in diam.

Several additional small

blisters. Approx. 12 blisters ranging up to 3A in diam. Approx. 12 blisters not as pronounced as spec. PC-4(2), receded upon

cooling. Blisters burst on all specimens, leaving surface

similar to peeling paint.

PB-4(1), no backing

PC-4(2), no backing— _.

PC-4(3), no backing

PD-2 (6 specimens, no

backing)

No noticeable change

No noticeable change No noticeable change

No noticeable change at

24 hr.

No noticeable change..

No noticeable change __ _ No noticeable change

Gel coat on all specimens

covered with tiny blisters, similar to pebble-finish paint surface (48 hr.)

Three blisters ys in-M 6 in diam, fiber impressions prominent.

Fiber impressions beginning

to develop. Fiber impressions beginning

to develop.

Blisters on all specimens

larger than 48 hr.

and drying preceding the gloss measurements in

each case. The results were as follows:

iS° Specular

Gloss

Before After

Material Appearance After Boiling Boiling Boiling Vitreous-china a Slightly dulled 56. 1 21. 6 Porcelain-enameled

cast-iron

CID 84 a Dull and etched 70. 9 2. 3

S U. I*fSL cg X 1

b Dull, etched, some 70. 4 20. 8 yellowing.

Porcelain-enameled- Dull and etched 63. 6 19.

steel, SD 110. a surface. FRPE, sanitary ware gel-coat:

A105 ° Same as before 14. 9 22. 1 boiling.

PA 83 a Numerous blisters 8. 8 5. 6 over entire

surface.

» Specimen from manufacturer of sanitary plumbing fixtures.

b Acid resistant, class AA, dry process specimen obtained from manufacturer of sanitary plumbing fixtures.

« Laboratory specimen from gel-coat producer.

Tests at low temperatures require long testing

times. However, there was at least an indication

from the data that low-temperature performance

might be predicted from high-temperature data.

The possible existence of an exponential relationship between water temperature and time-tofailure was indicated from the results of tests on

three bathtubs of the same make, one specimen

at each of the three temperatures. If this corre- lation could be satisfactorily established, a test temperature greater than 120° could be selected

so that test duration could be reduced. However,

there are not sufficient data at this time to rec- ommend the higher test temperature.

(3) Rationale for Test Selection

An exposure test of the entire bathtub (inside

surface below over-flow-outlet level) is recom- mended for two reasons:

1. The detection of susceptibility to deterioration on exposure to hot water is more certain with

the use of a whole fixture than if only a few small

specimens cut from the fixture were tested.

2. Any possible effects of unequal stress dis- tributions and other characteristics that might be

associated with curved surfaces in whole fixtures

probably cannot be detected in hot-water tests of

small flat specimens.

It is recognized that the recommended test in- volves a prolonged exposure, whereas in service

the exposure is typically intermittent. Thus, the

recommended test does not incorporate thermal

shock, nor does it allow for possible effects caused

by alternate wetting and drying. Some consideration was given to the desirability of combining

both termal-shock and hot-water resistance into a single test. A discussion of this possibility ap- pears in section 2.21. However, this will require

further development work.

d. Comments on Performance Requirements

(1) Suggested Format for Performance Level

The bathtub shall withstand exposure of the

interior surface to water at a test temperature of

120 °F for ,

, hr without blistering, cracking,

loss of bond between surface coating and base

material, or other damage as detected by the sur- face-inspection test of section 2.8. In addition,

residual deflection after hr of exposure when

measured 30 min after emptying bathtub shall not exceed in.

(2) Rationale for Suggested Format

The requirement of the appearance of no defects

in a bathtub surface after a given exposure to water at 120 °F is believed to be a reasonable re- quirement. A bathtub is meant for bathing and

if blisters and cracks or other defects that seri- ously affect its usability appear after only short

42
periods of service, the fixture is not performing

the function for which it was intended. It was

assumed that a total of 400 hr of exposure might

occcur in eight years of service. However, since

most baths are probably taken at water temperatures appreciably less than 120 °F, and since timeto-failure appears from the test results to be

lengthened by lowering the temperature, 400 hr

of exposure at 120 °F could represent a normal

service hot-water exposure of much longer than

eight years. Hence, 400 hr without the appearance

of defects might be considered as a fairly reasonable test requirement.

It should be pointed out that the blisters that

first appeared in the tests were not of a type that

would have made the tubs immediately unusable in

service, although their presence would have been

undesirable. The observed tendency of these blis- ters to recede on cooling, however, does not suggest

that their appearance is of no significance. When

a blister occurs the original bond of the coating

to the substrate is destroyed, and for this reason

the coating may be subject to spalling at these

blister points during later service. In fact, it is even possible that the small spalls observed on some of the older tubs in the field inspection of

FRPE fixtures could have originated from this

cause. A possible limit on center deflection of the sump

30 min after draining the hot water from the bathtub would be y8

in. This value is based on the fol- lowing considerations

:

1. A center deflection of % in that uniformly

diminishes with distance from the center should

not present a drainability problem in bathtubs

with bottom slopes comparable to those of cur- rent production. The deflection limit recommended

may include an inherent safety factor, since the

intermittent loading occurring during use would

tend to cause less sump deflection in some materials

than continuous hot-water loading for the same

period of exposure, and also because many polymeric materials (such as FRPE) will continue to recover for much longer periods than the 30 min

specified in paragraph 2.18c.

2. Field information on bathtubs did not show

a significant incidence of drainability problems;

hence, it may be inferred that sump-bottom deflec- tion from hot-water exposure has not been a problem with the current materials. The FRPE

bathtubs tested pass the suggestion deflection re- quirement. Because of their particular properties,

porcelain-enameled metal bathtubs are not subject

to permanent deflection from exposure to hot

water. However, the same sort of a deflection limit

is proposed as both necessary and desirable so as

to prevent possible future use of materials that

may have permanent deflections sufficiently high

to affect adversely their drainability.

2.19. Cigarette-Burn Resistance (T303)

a. Purpose and Scope

The purpose of this test is to evaluate the ease of removal of chars or stains caused by lighted

cigarettes that are left in contact with a flat sur- face of a sanitary fixture.

b. Recommended Test Method

(1) Test Procedure

Maintain the temperature of the testing laboratory at 75 ± 5 °F. Store the fixture in the laboratory at least 4 hours prior to testing to permit it to reach temperature equilibrium.

Select any three contemporary but popular

brands of cigarettes and designate them Brands

A, B, and C, respectively. Remove three cigarettes

from a freshly opened package of Brand A, light

each one, and immediately after lighting, place

each burning cigarette on any flat horizontal sur- face of the fixture, with the burning end in contact with the surface and not less than 14 in from

a fixture edge. If the fixture has no suitable flat, horizontal areas, the fixture may be tilted so that a flat area, will be horizontal, or alternatively,

flat specimens may be cut from the fixture. Separate the burning ends of the cigarettes during test by a distance of at least 6 inches. After 2

min (±2 sec), remove each cigarette from the

fixture and allow the tested area to cool to room

temperature. Repeat the same operations and procedures with three cigarettes of Brand B, placing

each one on an area of the fixture adjacent to the

earlier test areas. Finally, repeat the same operations and procedures with cigarettes of Brand C. After all test areas have cooled to room temperature, assign a burn rating to each test area on the

basis of the rating method shown in table 2.19-1. To evaluate burn ratings of 80 and lower, use

a ^-in wide strip of 220-mesh abrasive paper

(6/0) fastened to a rigid backing strip to abrade

away the coating at the test areas until a depth is reached where no more than a faint trace of dis- coloration remains. Measure thickness of coating

removed with a depth gage that can be read to

0.2 mils (0.0002 in). Record these readings and,

in addition, on any three of the test spots, continue

to abrade the coating until the substrate becomes

visible. Measure these depths and designate the

average as the coating thickness. Compute for each

spot the percent of the coating thickness that must

be removed to a point where only a faint trace of

the discoloration remains.

After burn-resistance ratings have been assigned

to each test area in accordance with the rating

method, add all of the nine burn-resistance ratings

and divide the sum by nine to obtain the burnresistance rating of the fixture.

43
JL /V Jj iJ Jj £i, A.XJ I - W» HO/ CU ill J Ul 1 Lbl> u fty C ty (X/ CttC U HI It / Co fcofcl* f fcOt/

Cigarette- Criteria burn rating

100 Stain removable by dryrubbing with a soft cotton cloth. 90 Stain removable by wet rubbing with a soft cotton cloth. 80 Stain removable by any scouring treatment that does not measurably decrease the coating thickness. 70 Stain eliminated by removal of not more than 10 percent of coating thickness.*

60 Stain eliminated by removal of not more than 20 percent of coating thickness. 50 Stain eliminated by removal of not more than 30 percent of coating thickness. 40 Stain eliminated by removal of not more than 40 percent of coating thickness. 30 Stain eliminated by removal of not more than 50 percent of coating thickness. 20 Stain eliminated by removal of not more than 60 percent of coating thickness.

10 Stain eliminated by removal of not more than 70 percent of coating thickness.

0 Stain not eliminated by removal of 70 percent of thickness.

a For molded fixtures with no coating, burn ratings of 70 and lower are based more than 8 mils, 40; by not more than 10 mils, 30; by not more than 12 mils, on measured char depths only. If, for these fixtures, the stain is eliminated by 20; and by not more than 14 mils, 10. If the stain is not eliminated by removal removal of not more than 2 mils of material from the surface, the burn re- of 14 mils from the surface, the burn rating is zero, sistance is 70; by not more than 4 mils, 60; by not more than 6 mils, 50; by not

(2) Information to be Reported

Include the following in the test report

1. The three brands of cigarettes that were

selected for testing

2. Total thickness of coating

3. Depth of coating removed at each test spot and average of the three depth measurements

for each of three cigarette brands. Do not identify

test data with cigarette brand names.

4. The assigned cigarette-burn-resistance rat- ing for the fixture.

c. Test Results and Discussion

(1 ) Discussion of Existing Methods

A search of the literature disclosed only one

test method for cigarette-burn resistance. This

appeared as one part of ASTM D 1300-53T [11].

This particular test uses a calibrated automobile

cigaxette lighter with a controlled wattage input

placed 0.313 ± 0.003 in from the surface of the

specimen. Heating of the surface is by radiation.

Failure is defined as evidence of blistering, per- manent discoloration, or charring after 110 sec of exposure for the standard grade of material and

10 mm for the cigarette-proof grade.

(2) Test Development

Consideration of the aforementioned ASTM test procedure indicated that (a) it might be unnecessarily complex and involved as a test for sanitary ware, and (b) the small cigarette-lighter source might not simulate an actual burning cigarette

since the heating of the test surface is almost entirely by radiation, whereas, when a lighted cig- arette is placed on a surface, some of the heating

is by conduction. As a result of these considerations

the development of a new cigarette-burn test was

initiated which led to the recommended test method

described in paragraph 2.19 (b)

(a) Effect of time of contact

Figure 2.19-1 shows the results of a series of

tests made on one FRPE specimen with a gel- coat thickness of 22 mils. It can be seen that char

depth goes up rapidly with the time of contact. Partly on the basis of these results, but mostly from

considerations of the average time of contact that

might be expected in service, a contact time of 2

min was proposed for the standard condition.

( b ) Effect of cigarette brand

Four cigarette brands were tested on the same

specimen. The results are summarized in table

2.19-2.

The differences in the char-depth averages for

the various brands are not statistically significant

at the 0.05-probability level except for Brand D,

which gave significantly lower char-depth than

Brand A and Brand C. The burn-test rating of the

specimen for all four brands, however, was 60.

(c) Burn ratings of porcelain enam-els and

vitreous china

Burn ratings of both porcelain on steel and cast

iron, and of the glaze on vitreous china were 100

when measured according to the system outlined

in the table. This rating might drop for abraded

surface since condensed tars would undoubtedly

be more difficult to remove from the roughened

finishes.

(d) Effect of gel-coat thickness

Although not studied systematically, there was some evidence that char-depth increases with gel- coat thickness. A char-depth of 4.6 mils was meas- ured with Brand A cigarettes for a 22-mil thick

gel-coat as against a char-depth of 1.9 mils for

what was presumably the same gel-coat with a thickness of 10.2 mils. The burn-resistance ratings

of the two specimens would, according to table

2.19-1, be 50 and 60, respectively.

(e) Comparison of cliar-depths determined by

two operators

Two different operators evaluated the burn

resistance of a 4- by 4-in FRPE specimen with a r 10-mil thick gel-coat. Brand A cigarettes were j used. The results follow

44
14

12

10

GEL- COAT SPEC. F-l

BRAND A CIGARETTES FRESH PACK

TIME OF CONTACT WITH BURNING CIGARETTE-MIN.

Figure 2.19-1. Char depths for a 22-mil polyester gel coat on a 0.10-in FRPE backing.

Char Depth in Mils

Spot No.

12

3

4

5

6

Avg

S.D.

Operator No. 1 Operator No. 2

2.6 1. 8

2. 2 2.0

1.5 2. 0

1.8 2. 2

1.8 1.4

1.9 2.0

1. 97 1. 90

0. 35 0. 25

charring was observed at any of the three test areas. The condensed tars present at each area were

removable by dry rubbing; hence, the cigaretteburn-resistance rating for this particular Formica

specimen was 100. The average char depth on a %-in-thick specimen of clear Lucite was measured as 2.1 mils.

Since no coating was present, the burn-resistance

rating was determined as specified in the footnote

of table 2.19-1. The burn-resistance rating was 60

for this particular specimen.

Table 2.19-2. Summary of cigarette burns tests on two FRPE specimens with polyester gel coats

There is not significant difference between the two

averages at the 0.05-probability level.

(/) Burn resistance ratings for specimens of

Formica amd Lucite

A small specimen of laminated thermoplastic

sheet (Formica-mottled grey) was tested with

Brand A cigarettes. The coating thickness was

10.7 mils while the backing sheet was 0.050 in thick.

No metal foil was laminated into the structure. No

Specimen No.

PA-1 b PA-1-.

PA-1.. PA-2 c PA-2. PA-2.

Coating

thick- ness

mils

10.2

10.2 10.2

10

10

10

Cigarette brand

letter A

A

BA

CD

Test

operator No. of

tests

Average

char depth

mils

1.97

1.90

1. 72

1.90

1.90

1.63

Standard

deviation

»See table 2.19-1 for procedure used to assign rating.

b Thickness of fiber-glass-resin backing. 0.14 in.

° Thickness of fiber-glass-resin backing, 0.11 in.

45
(g) Bum-resistance ratings of FRPE -fixtures The burn-resistance ratings were obtained on two FRPE bathtubs. No difficulties were encountered in performing the tests. Both units gave a burn-resistance rating of 70.

(3) Rational for Test Selection

Admittedly, the proposed test tends to be some- what qualitative, especially with respect to the end

point, which depends both on the judgment and

visual acuity of the observer. However, since nine

burned areas are evaluated, and since char depths

obtained over a relatively wide range of percentage loss in thickness yield the same burn-resistance

rating, high scatter in results among the observers

would not be expected. One desirable feature of

the test is that it exactly simulates the service ex- posure involved in this performance characteristic.

d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

The burn-resistance rating of the fixture shall

be not less than , , when measured as prescribed

in paragraph 2.19 (b)

(£) Rationale for Suggested Format

Lighted cigarettes are occasionally placed on the

flat ledges of bathtubs. The field survey made near

the beginning of the project showed that burns

from this practice were not uncommon on bathtubs with organic finishes. At the same time, however, it was found that once a burn had occurred, a polyester gel-coat could be restored to almost its original appearance without the need for an ex- pensive or complex repair operation or of the re- moval of an excessive amount of coating material.

Other future organic finishes might not have this

property. Therefore, it would seem desirable to re- quire that the cigarette-burn resistance be approximately as great as the currently produced polyester gel-coat. A burn-resisting rating of not less than 50 would accomplish this purpose.

2.20. Radiant-Heater Resistance (T303A)

a. Purpose and Scope

The purpose of this test is to evaluate the resis- tance of a sanitary plumbing fixture to permanent

damage caused by a radiant heater placed near the

fixture.

b. Recommended Test Method

(1) Apparatus

Radiant Heater. The radiant heater to be used

shall be a 650-watt 120-volt heater. The heating

element shall be a wire-wound annulus of conical

shape that operates in an air atmosphere. A 10-in

bright metal parabolic mirror placed behind the

heating element collimates the radiant flux. The

front safety grill of the heater shall be removed

prior to testing. Also, the heater shall be operated

at the same voltage to ±2 volts for all tests de- scribed herein. In addition, the reflector shall be

cleaned of accumulated dust and dirt prior to each

use. The heater used in the present test was a Sears

Roebuck Model 135. 71600.

Black-Panel Radiometer. A black-panel radiometer is required. This shall be constructed as

specified in figure 2.20-1 (Part A). A null-type

potentiometer (or a millivoltmeter) readable to

0.1 mV is required to measure the response of the

radiometer thermocouple.

Figure 2.20-1 specifies that a flat black paint

shall be applied at a thickness of 0.002 in to the

sensing area of the radiometer probe. This paint

film may blister if the temperature of the probe

is raised too rapidly during the first heat-up.

Therefore, the paint film shall be cured prior to the test by moving the probe very slowly toward

the radiant heater until a probe temperature of

250 °F is indicated. The probe shall then be maintained at this temperature for 15 min to complete

the curing, after which the painted surface shall be inspected for the presence of blisters. If blisters are present, the probe shall be repainted, and the

paint film cured with a slower heating cycle. In no case shall the probe be used for the testing

described herein unless the paint film is completely

free of blisters. The paint used as the probe coating shall be 3M

Brand Black Velvet Coating (101-C10 Black), or

equivalent. This is available in 6-oz spray cans from the Reflective Products Division, 3M Co.,

St. Paul, Minn. The required 0.002 in thickness is achieved with this paint by spraying as two coats but without permitting complete drying between

the two applications. Film thickness can be determined by micrometer measurements before and

after application.

(2) Test Procedure

A. Calibration of Radiant-Heater Response

with Black-Panel Radiometer : Mount the heater

and radiometer on a flat, horizontal surface using an arrangement such as that suggested in figure

2.20-1 (Part B). Then, with the temperature

in the test room at 75 ± 3 °F, place the probe at a distance of 27 in from the face of the heater.

Position the probe with the painted surface facing

the heater and also, with the center of the probe

at the same height as the center of the reflector,

and, in addition, center the probe with respect to the horizontal axis of the heater.

After positioning the heater, turn on the heating element and, after 5 min, measure the millivolt

response from the probe thermocouple. Then,

without turning off the heater, move the probe

y2 in in a lateral direction and after 2 min, again measure the millivolt response. Repeat this operation moving the probe y2 in in a lateral direction

after each measurement until a position is reached

46
(A) BLACK-PANEL RADIOMETER

Black

Paint

4-

18-Gage (.052") AISI

Type 321 St. Steel

Separate-Wire

Spot Welds

20-Gage (.032")

Chrome 1-Alumel

Thermocouple Leads

1/4" Diam. , 2-Hole

Porcelain Insulator

Note ; Black paint to be sprayed to a thickness of 0.002". Abrade

surface with 400C silicon carbide paper prior to spraying.

(B) SUGGESTED TEST ARRANGEMENT

Wooden Frame

30" Long by 8" Wide

\

To Millivoltmeter

650-Watt

Radiant Heater

Figure 2.20-1. Black-panel radiometer probe and suggested arrangement for calibration of radiant heater.

tha/t is approximately coincident with the outer rim of the reflector on the heater. Take the maximum reading obtained during this lateral scan as

the millivolt response of the radiometer at the

27-in distance.

Next, repeat the procedures outlined in the pre- ceding paragraph with the probe placed 24, 21, 18,

15, 12, 9, and 6 in from the heater face, being cer- tain in each case that the probe face is parallel

to the front edge of the reflector on the heater.

After completing these measurements, convert the

maximum millivolt readings obtained at each dis- tance to temperature in °F using the standard

conversion tables for Chromel-Alumel thermocouples given in ASTM Procedure: E230-63. In

effect, these temperatures at each distance repre- sent a maximum flux density calibration for the

radiant heater.

Note : These maximum temperatures are referred to later as equivalent black-panel radiometer temperatures.

47
B. Testing of Fixture : Place the fixture to be

tested in its normal use position permitting it to

rest freely on a horizontal heat-resistant surface.

Use no closures at the fixture ends.

Next, select a vertical area near the center of

the fixture that might be exposed in service to the

flux from a portable radiant heater. For a bathtub

with a front apron, select the test area near the

center of the apron while for other fixtures, such

as a shower stall, select any outer vertical surface

as the test area. Note : On fixtures other than bathtubs, only a part of the

collimated flux may strike the test area. Maintain the temperature of the testing laboratory at 75 ± 5 °F. Store the fixture in the laboratory for at least four hours prior to testing to permit it to reach temperature equilibrium. As

soon as this equilibrium has been established,

position the reflector of the heater so that the front

edge of the reflector is parallel to the test area and at a distance of 27 in from the fixture when

measured from the outer rim of the reflector to the area to be tested. Also, adjust the height of

the heater so that the collimated flux strikes

approximately midway between the top and bottom of the test area. After completing this positioning, turn on

heater and expose the test area for 15 ± *4 min

to the radiant flux. Note : Start timing when the heater is turned on rather than when it reaches its operating temperature. If no damage to the fixture is observed when examined within

2 min after turning off the heater, move the heater 3 in closer to the test area (24-in distance) and repeat all operations specified above. Note : For the purposes of this test, damage consists of any cracking, blistering, and discoloration of the test surface as well as any distortion or buckling of the fixture. Next, continue the testing by moving the heater

three inches closer to the test area after each

15-min exposure period until a distance is reached

where the 15-min treatment causes some observable damage to the fixture. The radiant-heater re- sistance rating of the fixture is then taken as the

equivalent black-panel radiometer temperature

for this distance. Note: If no damage occurs at the six-inch distance, the radiant heater resistance rating is reported as greater

than the equivalent radiometer temperature at six inches. Likewise, if damage is observed at the 27-in distance, the

resistance rating reported is less than the equivalent

radiometer temperature at 27 in.

(3) Information to he Reported

Include the following in the test report

1. Type of radiant heater, including manufacturer's name and number

2. Type and thickness of paint used on blackpanel radiometer probe

3. Type of instrument used for measuring milli- volt response of probe thermocouple

4. Distance between heater and fixture at which

first damage was observed

5. Type of damage, if any, that resulted from

the radiant-heater treatment

6. Radiant-heater-resistance rating of fixture.

c. Test Results and Discussion

(1) Discussion of Existing Methods

A search of the test literature failed to reveal

any earlier tests for the resistance of a fixture material to damage from radiant heaters.

{2) Test Development

The first tests were made with 4-X4-in speci- mens of FRPE mounted, face forward, in a small

backing enclosure of %-in plywood. A small wire

thermocouple was cemented into a hole drilled

from the back of the specimen to the gel-coat interface. The hot junction was positioned so as to be

touching the gel-coat. Indicated temperatures were

recorded as the specimens were moved inward

toward two types of radiant heaters. Results obtained with two FRPE specimens for this type of

testing are shown in figure 2.20-2. The only per- manent damage observed in these tests was a dis- coloration (yellowing) of the specimen after

exposure at 6 inches to the 650-W heater.

Because of difficulties involved in standardizing

the treatment described above, and also because

thermal stresses encountered in a fixture would

not be duplicated in a 4- X 4-in specimen, further

work on this method was terminated. Instead,

emphasis was placed on the exposure of actual

fixtures to the radiant flux from a commercial

heater. However, since no two heaters could be

depended upon to give the same radiant flux per

unit area at the same distance from the heater, it was necessary to devise a simple method of cali- bration. The method devised is described in section

2.20(b). Although a more sophisticated calibrate

300

50

1

1 1 1 1 1 1 1 PA SPECIMENS VERY STRONG \\ FUMES

10 MIL GEL COAT ON v 1/8" FIBERGLASS \ BACKING ^650 WATT RADIANT HEATER

^^^^(VERY STRONG ODOR

MILD ODOR

^-250 WATT INFRARED ^^rT f HEAT LAMP

'VERY^'^X

STRONG ODOR \\

V-rSLIGHT ODOR ^\>-VERY SLIGHT ODOR

^/ROOM TEMP ~° 0

1 1 1 1 1 1 1 1 4 8 12 16 20 24 28 32 DISTANCE FROM FRONT OF HEATER — IN. Figure 2.20-2. Results of preliminary radiant-heater

tests with 4-in square specimens^

48
tion approach might have been used that would

involve, among other things, expensive calibrated

radiometers with infrared windows, such an ap- proach was not believed justified for the radiantheater test. Results of measurements made with

thre^ different probes are given in table 2.20-1.

It will be noted that the three probes are in reason- ably good agreement. The maximum difference

between probes was 13 °F. This occurred at the

closest distance of approach to the heater.

Table 2.20-2 lists the results of radiant-heater

tests made on four FRPE bathtubs. Position No. 1

is the test area specified for bathtubs in section

2.20(b) 2. Of the three tubs that could be tested

in this area (PB-2, PB^t and PD-1), two had

radiant-heater-resistance ratings of greater than

215 °F while one (PB-2) showed a blister at 18 in

(203 °F rating) . This blister almost completely re- ceded on cooling. Nevertheless, the bond between

coating and substrate had been ruptured by the

treatment and this could easily lead to later deterioration.

(3) Rationale for Test Selection

Numerous alternative approaches might be

used to evaluate the radiant-heater resistance of a

fixture. One might be to place a specimen cut from

Table 2.20-1. Results with three black-panel radiometer

probes prepared in accordance with section 2.20b{l).

Maximum Radiometer-Probe Temperature

Distance from Heater « Probe Probe Probe No. 1 No. 2 No. 3 Average

- 1 in ° F o p ° F ° F

27— 156 156 160 157

24 _ _ 169 173 173 172

21 195 186 186 189

18... _ 208 203 199 203

15... 221 212 214 216

12 _._ _._ 230 225 230 228

9 243 238 247 243 6 278 265 278 274

° Sears Model 135.71600, 650-W heater.

the fixture into an oven and determine the temperature at which deterioration was first observed.

Such a method would not be simulative, however,

since when a fixture is exposed to the flux from a radiant heater, heating is from one side only. Also,

the temperature reached by a given material during radiant heating is strongly dependent on its infrared absorptance and emittance while in an

oven all specimens will reach the same temperature irrespective of the thermal radiation properties of the surface layer.

The particular test recommended is believed to

closely simulate the conditions that exist when

a portable radiant heater is placed on the floor of a bathroom in such position that it faces a bathtub. Exposure for 15 min seems a reasonable

time, although longer times might have been

specified. Built-in panel heaters (either gas or electric) might operate almost continuously in a bath- room during cold weather. Heaters of this type,

however, are normally positioned further from

the fixture and hence the flux per unit area falling on the fixture would not reach the high values

encountered with the portable heaters.

d. Discussion of Performance Requirements

(1) Suggested Format for a Performance Level

The radiant-heater resistance rating of the fix- ture shall be not less than when measured by

the methods and procedures specified in section

2.20(b). This rating is the equivalent black-panel

radiometer temperature for the heater distance at which first damage to the fixture is observed.

{2) Rationale for a Suggested Format

In attempting to arrive at an equivalent blackpanel radiometer temperature for a performance

level, one might consider a value of 215 °F. This

represents the condition that exists when a typical

portable heater with a power of 650 W is placed

approximately 15 in from an exposed area of the

fixture. This distance appears to be a reasonable

Table 2.20-2. Results of radiant-heater tests on FRPE bathtubs

Tub No.

Location

of test area a

Damage

distance b Description of damage

Rad.-heater

resistance rating

PB-2

PB-4

PC-1

PD-1

One blister, 2y2 in. diameter

Slight discoloration

Slight discoloration

Slight discoloration

Blister, 2)4, in. diameter

Blister, 2}4 in. maximum dimension

Slight discoloration.

Slight discoloration

Slight discoloration _ Slight discoloration Slight discoloration

" No. 1—on apron midway between ends of tub. No. 2—on apron near drain end. No. 3—on apron at end opposite drain.

b Measured from front rim of reflector on heater to tub apron.

0 Test made on fixture that had been cut in half for other testing.

49
one since, if the heater was placed closer than about

15 in to one of the current FKPE fixtures, a per- son in the bathroom would be forewarned of impending damage to the fixture by a rather strong

odor of styrene.

Long-time effects from radiant heat at lower

flux densities than that represented by a 650-W

heater at 15 in were not investigated because of

time limitations. However, it seems unlikely that

any damage from this type of treatment would be

of especially serious nature. The 15-min time period specified in section

2.20b (2) B is admittedly arbitrary. It was selected

as being reasonably representative of the time that

a portable heater might be left on in a bathroom.

2.21. Resistance to Thermal Shock (T304)

a. Purpose and Scope

The purpose of a thermal-shock performance

test for a sanitary plumbing fixture is to evaluate

the ability of the fixture to withstand (1) intermittent exposure of the finished surface to hot

water, and (2) alternate exposure to hot and cold

water, without exhibiting surface damage. Some

degree of thermal-shock resistance is desirable in

all sanitary plumbing fixtures. The need is probably least for water closets and urinals, since

typical service exposure for these fixtures involves

cold water at temperatures not far below normal room temperatures. The limited amount of work

reported here was carried out only on a bathtub.

b. Selection of a Test Method

An apparatus was assembled for exposing a bathtub to repetitive cycles of thermal shock. This

apparatus was tried out on one specimen of an

enameled-steel tub. This apparatus would probably

be suitable for use in thermal-shock tests with some further development and refinement, as described in paragraph 2.21e. No test method is recommended at this time, because (1) the. existing

published test methods reviewed impose conditions of exposure unrepresentative of service, (2) no correlation appears to have been established

in the existing tests between number-of-cycles-tofailure and temperature, and (3) the limitations

of the present investigation did not permit complete development of an adequate test. A recommended test method should be relatively

simple, and should effectively simulate the conditions imposed in service. Correlation between the

effects produced in the test and the effects from

service exposure would be needed.

c. Performance Requirements

Performance requirements cannot be stated

precisely because more work is required on test development and more data are required on per- formance. However, it can be stated that a plumbing fixture should be capable of a reasonable period

of service exposure, without exhibiting surface

damage that can be detected by the inspection

procedure described in section 2.8.

d. Test Results and Discussion

(1 ) Discussion of Existing Methods

A few tests involving thermal shock have been

developed by other groups for use with vitreouschina and vitreous-glazed earthenware plumbing

fixtures. The degree of correlation between the re- sults obtained from these test procedures and from

actual service exposure is unknown.

Among the tests referred to in existing plumbing fixture standards are the following

1. Autoclave Test for Crazing of Vitreous

Glazed Earthenware, Par. 11, CS 111-43 [7].

Flat pieces broken from a fixture (approx. 16

in2 area on one side) are subjected to 75-psi steam

pressure in an autoclave for one hour, after

which the pressure is released and the specimens

are allowed to cool to room temperature in the

autoclave. The specimens are then examined for

cracking or crazing after applying a dye solution

to the finished surface. Cracking or crazing after

being subjected to four cycles of this treatment

indicates failure.

2. Thermal Shock Test for Vitreous Glazed

Earthenware, Par. 12, CS 111-^3 [7].

A complete fixture is filled with boiling water

which is maintained at the boiling point until the

material is heated throughout, followed by rapid

emptying and immediate refilling with ice water

at a temperature of 38 °F. The ice water is maintained at 38 °F by addition of ice until the fixture

material is thoroughly cooled, after which the fix- ture is quickly emptied and the cycle repeated.

Visible injury of the specimens upon exposure to 25 cycles of this treatment indicates failure.

3. Crazing Test for Vitreous China, Par. 6.4 of CS 20-63 [6] and Par. 10.11.4 of FS WW-P541b (4), 1962 [3].

Test specimen 4 to 5 in2 is suspended in a solution of anhydrous calcium chloride and water

(equal portions by weight) and boiled for iy% hr. ! Then the specimen is removed and immediately

plunged into an ice-water bath and allowed to cool. Following this, the specimen is soaked for 12 hr

in a concentrated solution of methylene-blue dye,

and finally examined for craze lines. Visible evi- dence of crazing after this treatment indicates

failure.

(2) Test Development

Apparatus was constructed and tried out which t subjected the inside surface of a bathtub to thermal

shock with a differential in water temperature approximating 160 °F. Figure 2.21-1 is a schematic

representation of the apparatus. The bathtub was

filled with hot or cold water to the overflow outlet

in about three minutes, and emptied in about four

50
-1X1—DRAIN

-tXh O TEST TUB

l-in. nom. dia. galvanizedsteel pipe, bronze gate valves

used in circulating circuit. Reservoirs were steel.

Heating element in hot-water reservoir capable of reheating water withdrawn from tub to boiling point

in less than 20 min. Two cold-water reservoirs were necessary to provide a supply of ice water every 20 min. Figure 2.21-1. Schematic of thermal-shock test apparatus for complete bathtub.

minutes. A boiling-water reservoir with steam

heating was provided, as well as an ice- water reser- voir using ice cubes for coooling. A circulating

pump and a pipe network with necessary valves

provided the means for introducing and removing

water from the fixture. A multi-channel temperature recorder provided a continuous record of the

temperature of the water at the entrance to the

tub, in the central area of the tub, and of the outside surface of the lower portion of the fixture at four points.

Based on trials with a porcelain-enameled steel- bathtub, approximately 20 min per cycle was re- quired to permit the outside surfaces of the sump

to attain a maximum or minimum temperature,

respectively, in the alternating hot and cold ex- posures. Cycle frequency was selected on the basis

of these temperature measurements. Approximately 40 lb of ice were required per cycle.

Table 2.21-1 summarizes some aspects of the operation of the apparatus shown in figure 2.21-1

in an 18-cycle trial test of a porcelain-enameledsteel tub. A six-channel temperature recorder was

employed. Observations made on the porcelainenameled-steel bathtub after a 50-hr continuous

boil test and 25 cycles of the thermal-shock test described here showed no surface effects other than

a very slight dulling of the finish.

(3) Comments on a Performance Level

Since the test development was incomplete, no

b. Recommended Future Test Method

It is recommended that further work be carried

out with apparatus patterned after that shown in

figure 2.21-1 with some modifications and refine- ments, such as automatic flow-control valves, mechanical chilling equipment, corrosion-resistant

reservoirs and circulating equipment, and an improved temperature-control system. The criterion

and method used for selecting cycle frequency

should be considered further. It might be desirable

to base this selection on the minimum and maximum temperatures attained within the fixture material rather than on outside surface temperatures.

Table 2.21-1. Characteristics of thermal-shock test* in

trial run on porcelain-enameled-steel tub

Cycle time..

Cold-to-hot peaks

Hot-to-cold peaks Incoming water temperature differ- ential. Water temperature differential in tub

(1 in above bottom of tub, centrally

located)

.

Outside skin temperature differential.

Approximately 20 min. Approximately 10 min. Approximately 10 min. Approximately 175 °F. Approximately 158 °F.

Approximately 150-155 °F, depending on location.

comments regarding

possible. a performance level are

*See figure 2.21-1.

Tests should be made on a statistically adequate number of specimens of several materials to

establish the relation between number-of-cyclesto-failure and temperature differential and/or

water temperature. Finally, it would be neces- sary to determine what constitutes a reasonable

set of use conditions as they relate to frequency of

51
use and temperature differential or water temperature, so that this set of conditions could be considered in recommending test procedures. The

performance level could then be set from test results on materials with known service

performance.

Further development work should be planned

with a view to the possible recommendation of an

alternate hot-and-cold-water exposure test that

could be used to combine the prolonged hot-water

exposure test recommended in section 2.18 and the

thermal-shock test discussed above.

2.22. Resistance to Household Chemicals

(C501)

a. Purpose and Scope

The purpose of this test is to evaluate the resist- ance of bathroom plumbing fixtures to chemicals

with which they are likely to come into contact during normal use.

b. Recommended Test Method

(1) Equipment

The test for resistance to household chemicals

shall be made using test equipment prepared in

accordance with figure 2.22-1.

(2) Chemicals

The resistance to attack by 20 different chemicals shall be evaluated. The chemicals that shall be used together with their required purity, concentration, and method of preparation are listed

in table 2.22-1. Note: Such items as soap, mineral oil, and pine oil are

considered as chemicals for the purpose of this test.

(3) Test Procedure

Cut five flat 4-in square specimens from the

fixture to be tested and number these specimens

from one through five. Clean each specimen with

1 percent by weight tri-sodium phosphate solu- tion and cellulose sponge, rinse thoroughly with

water, and dry.

Next, position specimen No. 1 into the testing

assembly as illustrated in figure 2.22-1 (F).

Tighten screws with a firm pressure to prevent

leaking. Then, with the cell in a horizontal position, add 0.5 ml of chemical No. 1 to cell No. 1, 0.5 ml of No. 2 to cell No. 2, 0.5 ml of No. 3 to cell No.

3, 0.5 ml of No. 4 to cell No. 4. Use a hypodermic

syringe to introduce the chemical into the cell through the needle holes in the Teflon cover sheet

(fig. 2.22-1, part C). Insert Teflon plugs into

each of the four holes in the top plate (fig. 2.22-1,

part A)

After 2 hr ± 5 min at 75 ± 5 °F, dismantle

equipment, remove specimens, and rinse with

water. Immediately after drying, inspect test

-4-

DRILL 4 HOLES (£" I»4.)

- DRILL -* TAP < HOLE* i£ -20 tpi) 4- +

-4- -f-

(A) TOP PLATE

THICK ST..L)

IC) TEFLON COVER SHEETC £ THKK TEFLo«)

DRIU 4 HOLES (£' o.»o

(B) BOTTOM PLATE

( i" THKK STEEL)

TEFLON

PLUG

(D) TEFLON RING C£ THICK TEFLON -4 RSO'O)

(E) TEFLON PLUG

OIA., 20 TPI, l u L0N6-, 4 R£Q*D)

TOP PLATE

sc«ewi \\ LON« WITH NUTS TO f IT.

WOTE: TfFLON

cover SHEET- TEFLON N0T SHOWN. RING BOTTOM PLATE

(F) ASSEMBLY

SPECIMEN

Figure 2.22-1. Apparatus for testing resistance to household chemicals.

areas for evidence of attack and assign a chemical-resistance rating to each test area in accordance

with the rating system specified in table 2.22-2. Next, repeat the same test procedure with speci- mens No. 2, and chemicals No. 5, 6, 7, and 8. After

assigning resistance ratings, follow the same procedure with specimens No. 3, 4, and 5 and thus

obtain a resistance rating for all 20 chemicals

listed in table 2.22-1. The household chemicals re- sistance rating for the fixture shall then be the

arithmetic average of these 20 individual ratings.

(4-) Information to oe Reported

Include the following in the test report

1. Effect observed for each test area.

2. Household chemicals resistance rating for

each of the 20 chemicals.

3. The household chemicals resistance rating

for the fixture.

c. Test Results and Discussion

(1) Discussion of Existing Methods

Few tests exist for evaluating the resistance of

sanitary ware materials to common household

chemicals. The commercial standards for porcelain-enameled bathtubs (OS 77-63, cast iron [4] ; and CS 144-47, pressed steel [28]) include a re- quirement for resistance to citric acid, a chemical

52
Table 2.22-1. Chemicals to be used in household chemicals test and reasons for their selection

Chemical No.

Principle chemical

ingredient

Grade

or purity

Concentration and

preparation Reason for selection

Acetone Benzene

Ethyl acetate Ethyl alcohol Carbon tetrachloride.

.

Isopropyl alcohol Petroleum naphtha _ .

.

Mineral oil- - Pine oil _ Soap, mild

Lanolin Phenol. Hydrogen peroxide

Oxalic acid.. -- Sodium bisulfhate Sodium carbonate Ammonium hydroxide

Sod. dod. sulfonate d _. Sodium hydroxide Sodium nitrate -

Reagent Reagent

Reagent USP

Reagent

Reagent Comm." Comm."

Comm.' Comm.b USP

Reagent Comm."

Reagent

Reagent

Reagent

Reagent

Det.°__. Reagent

Reagent

Full strength

Full strength Full strength - 95 percent by vol (5 percent H2O)

Full strength

Full strength _ Full strength Full strength Full strength _ (See footnote c)

Full strength _. 2 g in 100 ml water

6 percent by vol in water

5 g in 100 ml water

5 g in 100 ml water _..

5 g in 100 ml water

50 percent by vol in water...

5 g in 100 ml water

5 g in 100 ml water

5 g in 100 ml water

In finger nail polish & polish removers. (Same as above). (Same as above). In hair tonics. Sometimes used as cleaning solvent (haz- ardous substance). Rubbing alcohol. In household cleaners and insecticides. In baby oil and hair oils. In disinfectants. To simulate wet soap on fixtures. In shampoos and hair tonics. Derivatives used in disinfectants. In hair bleaches. In rust-removing scouring powders.

In toilet bowl cleaners. In water softeners. In household cleaners. In scouring powders.

In drain cleaners. In drain cleaners.

a Commercial grade.

b Ivory flakes, or equivalent.

0 0 1 g of soap shall be placed in Teflon ring before adding cover; 0.5 ml of

water shall be added after equipment is assembled.

d Sodium dodecylbenzene sulfonate.

0 Detergent grade.

that is not found too often in bathrooms. ASTM

Procedure: D1300-53T [11] contains a section on

"stain resistance" in which at least one household

chemical (vinegar) is included. In this test each

of eight reagents is applied to the specimen in an

unspecified amount and a cover glass is placed over

the reagent. The test is made for 16 hr at 24 °0.

The grading is based mostly on the presence or

absence of stains.

(2) Test Development

Preliminary tests in which watch glasses were

used to cover reagents indicated that this method

was unsuitable because of uncontrolled evaporation rates. Volatile organic solvents such as acetone, benzene, ethyl acetate, and alcohol disappeared from under the match glass, sometimes in a matter of minutes. A tight seal was essential

for reproducible results and this led to the design

and use of the equipment shown in figure 2.22-1.

Table 2.22-2. System for assigning ratings in household

chemicals test

Appearance of tested areas a Rating to be assigned

No visible effect - 100

Fiber pattern in coating or indentation mark in coating from 75 penetration of Teflon ring.

Etching, dulling, pitting, or discoloration 50

Flaking, blistering, or peeling of coating 25 Exposure of substrate material 0

' If more than one effect is present after treatment, the effect giving the

lowest rating shall be the one used for assigning a rating to the test area. Also, all effects listed for one rating need not be present on the same test

area. Thus, if a specimen showed a slight dulling of the surface with no evi- dence of pitting, etching or staining, the assigned rating would be 50. Likewise, if all three effects (etching, pitting, dulling, and staining) were present, the rating would be 50.

Trials with the equipment showed that evaporation could be held to low levels even when such a

volatile solvent as acetone was used as the test reagent.

The test procedure that was devised through use of this equipment is described in section 2.22b(3).

Test results when this procedure was used for

three current fixture materials are listed in table

2.22-3. The household chemicals resistance rating

Table 2.22-3. Results of household chemicals test for

three sanitary ware materials

Chemical No. Type of chemical

Acetone. _ Benzene

Ethyl acetate Ethyl alcohol Carbon tetrachloride

Isopropyl alcohol. Petroleum naphtha

Mineral oil Pine oil Soap

Lanolin Phenol Hydrogen peroxide

Oxalic acid Sodium bisulfate Sodium carbonate Ammonium hydroxide.. Sodium dodecylbenzene

sulfonate Sodium hydroxide Sodium nitrate Household chemicals

resistance rating

FRPE

b o 75

d 50

o d 50

d 50 100

100 100

100

100

100

100 d50

100 100

100

100 "50

100

100

100

Assigned chemicalresistance rating

Porcelain- enameled

cast iron

100

100 100

100 100

100

100

100 100

100

100

100 100

100 100

100

100

100

100 100

100

Porcelain- enameled

steel

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100 100

100

100

» PA Series.

b Indention mark in coating from penetration of Teflon ring.

» Fiber pattern in coating.

d Dulling of coating.

6 Slight stain.

53
of the FRPE fixture material was 86 and that of

both porcelain-enameled materials (cast iron and

steel) was 100.

(3) Rationale for Test Selection

A test for resistance for household chemicals

should incorporate a representative range of those

reagents with which a bathroom fixture might come into contact during service. In selecting these

reagents, staining media were not considered since a staining test is incorporated elsewhere herein

(sec. 2.23).

The selection of test chemicals was established on the basis of recommendations by members of

the BRAB ad hoc committee. Some of the selec- tions may be questioned. For example, the list includes pairs of chemicals of the same type but

with different reactivities or solvent properties.

One such pair is ethyl and isopropyl alcohols, and

another is sodium hydroxide and sodium carbonate. Also, the list does not include chlorine

bleaches, which are present in scouring powders

and bleaching products.

Another possible objection to the test method is that the chemical exposure occurs in a closed sys- tem. Under service conditions such volatile sol- vents as acetone, benzene, ethyl acetate, ethyl alcohol, and carbon tetrachloride would normally

evaporate before attacking the surface. However,

the rationale considered the possibility that such

solvents, as well as other chemicals, might be

trapped between the fixture surface and the bottom of a container. The chemical might be spilled

initially on the surface of the fixture, the container

might leak, or the bottom of the container might

become wet due to carelessness in pouring. The

container might then be set down on the surface,

trapping the chemical underneath and maintaining

a ring of pressure around the contour of the bottom of the container.

The test time of two hours is arbitrary. Either a longer or shorter time might have been used. However, two hours is believed to be realistic since

only on very rare occasions would household

chemicals (with the possible exception of wet soap)

be in contact with a fixture for a longer period.

The method of grading the test areas assigns a

resistance rating based on the severity of the at- tack. A material that shows no effect from a given

chemical should obviously have a higher rating

than one that shows an effect. Likewise, a material that shows only a very slight effect (fiber pat- tern in coating or a softening as evidenced by penetration of the Teflon ring) should be rated higher

than one in which the attack is so severe that the

substance is exposed after treatment. The rating

system specified in table 2.22-2 incorporates this

concept of differences in the degree of attack.

d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

The household chemicals resistance rating for

the fixture shall be not less than In addition

the individual resistance rating to chemical No. 10

(soap) shall be not less than 100, nor shall the rat- ings be less than for chemicals No. 6 (isopropyl alcohol), No. 12 (phenol), No. 13 (hydrogen

peroxide), No. 17 (ammonium hydroxide), No. 19

(sodium hydroxide), or No. 20 (sodium nitrate).

(%) Rationale for Suggested Format

The household chemicals resistance rating of

the FRPE specimens tested was 86. The field sur- vey, made at the beginning of the investigation,

indicated that the present gel-coat materials have a

sufficient resistance to household chemicals since

there was no evidence of chemical attack on any of

the fixtures nor were any complaints offered by

homeowners about the lack of chemical resistance.

Future sanitary ware materials may not have as

| good a resistance as current FRPE fixtures. Therefore, some considerations should be given to setting

the performance requirement at 75 to insure that

newly introduced materials will not be seriously

deficient with respect to their resistance to common

household chemicals.

Consideration of the 20 chemicals listed in table

2.22-1 will suggest that some of these chemicals

are much more frequently encountered than others

and therefore more important to the test. This is the reason for suggesting specific levels for specific

chemicals. It would be unreasonable, for example,

to permit the use of a fixture material that had poor

resistance to attack by wet soap. A performance

level requiring a resistance rating of 100 for wet

soap would prevent the use of such a material. The

levels for chemicals No. 6, 12, 13, 17, 19, and 20

might be set lower ; possibly as low as 50.

2.23. Stain Resistance (C502)

a. Purpose and Scope

The purpose of this test is to evaluate the ease of I removal of stains from both "new" and "abraded" o surfaces of such sanitary fixtures as bathtubs,

shower stalls, and lavatories.

b. Recommended Test Method

(1) Equipment and Staining Agents

The following equipment is required for per- forming the stain test as herein described

1. Brass cover blocks prepared in accordance

with figure 2.23-1.

2. One-inch diameter watch glasses.

3. Rubber O-rings, % in O.D. by "/16 in I.D. In addition the following staining solutions are required

54
Figure 2.23-1. Brass cover Mock for stain testing.

Stain No. 1. Five-percent solution (by weight)

of reagent-grade potassium permanganate in distilled water. Stain No. 2. One-percent solution (by weight)

of iodine in ethyl alcohol. Stain No. 3. Mercurochrome in ammonia; pre- pare by mixing one volume of a two-percent aque- ous solution of Mercurochrome (merbromin) with

two volumes of concentrated ammonium

hydroxide.

Note : The Mercurochrome solution may be that com- monly sold in pharmacies as a general antiseptic.

Stain No. 4- Iron-staining medium; two in- gredients are required: (1) Chemical-grade ironmetal filings, degreased, 20 mesh and finer, Allied

Chemical Company, Code 1810, or equivalent, and

(2) A one-percent solution (by weight) of sodium

chloride in water. These two ingredients are combined immediately prior to use as specified in

paragraph 2.23b (2).

(2) Test Procedure

Select at random eight li^-in-diam areas of the

fixture that are substantially flat and horizontal.

If the fixture has no such areas, the fixture may

be tilted, or alternatively, flat specimens may be

cut from the fixture. Abrade four of the selected

test areas with 400 C silicon carbide abrasive paper

(Carborundum Company A955R, or equivalent).

Use strips of the paper that are approximately

y% in wide and 1 in long. Place one end of the

paper under the index finger and with a firm pres- sure (force of approximately 10 lb) abrade the

area to be tested for a total of 10 strokes (five

forward and five backward) in one direction, and

then with the index finger over the opposite end

of the strip, abrade for 10 strokes in a direction at right angles to the first direction. The area where

the two abrasion treatments intersect (roughly l/2 in2 ) is the area to be used for evaluating the stain

resistance of an abraded surface. Prior to application of the staining solutions wash all test areas (abraded and unabraded) with soap and water,

rinse thoroughly, and dry. Place approximately

0.5 ml of Stain No. 1 solution on unabraded area No. 1, cover with a 1-in-diam watch glass, and

finally cover with the brass cover block (fig.

2.23-1) to prevent excessive evaporation. After 2

hours at 75 ± 5 °F, remove the brass block and

watch glass, and also remove excess staining solution by blotting. (Note : If the test area is dry on

removal of watch glass, the test is void and shall be repeated). Allow the test area to stand after

blotting until it is visually dry and then grade for

ease of removal of residual stain in accordance

with the rating system specified in table 2.23-1. Next, repeat all operations specified in the pre- ceding paragraph for Stains No. 2 and No. 3. Note: For Stain No. 3 cover inside surfaces of brass cover block with a layer of stop-cock grease to prevent

corrosion of the brass by the ammonia vapor. Table 2.23-1. Grading procedure for assigning stain ratings

(A) NUMERICAL RATING SYSTEM

Numerical Treatment Treatment required for stain removal

rating identification

100 A Dry rub (20 strokes)

.

90 B Wet rub with water (20 strokes). 80 C Mild soap a and water rub (20 strokes). 70 D Ethyl alcohol rub (20 strokes). 60 E Abrasiveb and water rub (10 strokes)

.

50 F Abrasiveb and ethyl-alcohol rub (10 strokes). 40 G Abrasiveb and water rub (20 strokes)

.

30 H Abrasiveb and ethyl-alcohol rub (20 strokes). 20 I Slight staining after Treatment H.

10 J Moderate staining after Treatment H.

0 K Severe staining after Treatment H.

a Ivory soap or equivalent.

b Finely ground quartz mixed with 10 percent by weight of trisodium phos- phate powder that has been screened through a U.S. Standard No. 100 sieve. The finely ground quartz shall conform to the following size fractions to within ±5 percent. Percent by

Size fraction weight On U.S. Std. No. 60 sieve. __ 0 Thru 60, on 100 0.2 Thru 100, on 200 11.4 Thru 200, on 325. _ 19.8 Thru 325 68.6

100.0 Note: Material meeting the above size requirements is available from the Pennsylvania Glass Sand Corporation, Pittsburgh, Pa.

(B) REQUIREMENTS FOR GRADING SPECIMENS

(1) Use a fresh, unused pad of soft, lint-free cheesecloth for each rubbing

treatment specified in table 2.23-1 (A). Each pad shall be approximately one inch square and shall consist of not less than five layers of the cloth.

(2) For each rubbing treatment, place the pad under the index finger and

with a firm pressure (approximately 10 lb total force), rub for the

specified number of strokes. One stroke shall consist of either one for- ward or one backward movement of the pad over the stained area.

(3) In all wet rubbing teatments, excess fluid shall be removed from the pad

prior to use.

(4) Each treatment specified shall be applied to the stained area in sequence

until there is no further visual evidence of discoloration, or until Treat- ment H has been completed. The numerical rating shall correspond with

the final treatment that removed the discoloration, or if some discolora- tion remains after Treatment H, it shall correspond with the intensity of the residual staining.

(5) Stains retained in small scratches that may accidentally be present on

the unabraded specimens shall not be considered in assigning stain

ratings.

55
For Stain No. 4 (iron stain) , spread 0.1 g of the

iron filings uniformly over a 3^-in.-diam area of the

test surface and surround the iron with a %-indiam O-ring that has been cleaned with scouring

powder prior to use. Wet the iron with 0.1 ml of

the 1-percent sodium chloride solution and cover with a brass block (fig. 2.23-1). Apply an excess of stop-cock grease to the brass block O-ring to insure a tight seal. After 20 hrs at 75 ±5 °F, re- move the brass block and %-in-diam O-ring, and

allow residual solution to dry without blotting.

If test area is dry on removal of the brass block,

improper sealing has occurred and the test shall be repeated. Grading of the iron stain shall be

done within one to four hours after removal of

the brass block. Prior to grading, remove excess iron from test area by brushing. Assign stain rat- ing as specified in table 2.23-1. Evaluate the stain

ratings of the abraded areas by the same test procedures and the same rating system used for the

unabraded surfaces.

For the abraded-area tests, the watch glass (or

the O-ring for the iron stain) shall be so positioned that the outer edge of the watch glass (or

O-ring) falls on the center of the abraded area. The combined stain rating shall be the sum of the

rating for the eight individual stains (four stains on the unabraded and four on the abraded areas)

divided by eight. This combined rating need not

be reported to more than two significant figures.

(3) Information to be Reported

Include the following in the test report

1. Assigned rating for each stain on the un- abraded areas.

2. Assigned rating for each stain on the

abraded areas.

3. Combined stain rating for the fixture.

c. Test Results and Discussion

(1) Discussion of Existing Tests Two test procedures have been used for evaluating stain resistance. The first, which is for the

"Formica" type of material, is included in ASTM

Designation: D1300-53T [11]. It specifies that

the material shall be unaffected by tea, beet juice,

vinegar, bluing, dye, ink (washable), iodine (1

percent), and Mercurochrome (2 percent) except

for superficial staining which can be easily re- moved by a light application of a mild abrasive.

The test is highly qualitative and vague in its wording. In addition, it gives the test operator

considerable leeway in selecting the particular

proprietary products that he chooses to use. The proposed revision of CS 221-59 [1] contains a stain test specifically designed for FRPE

sanitary fixtures. Although this test has some desirable features, it was not believed suitable for a performance test since (1) it uses proprietary

materials for stains, (2) the abrasive pretreatment is not sufficiently severe to have any measurable effect on porcelain-enamel or vitreous-china

finishes, (3) the material with the poorest stain

resistance is assigned the highest stain rating, and

(4) iron stains, which are quite common on sani- | tary fixtures, are not included as one of the stain- i ing media.

(2) Test Development and Rationale for Test

Selection

The premises used for devising a staining test j that would be free of most of the aforementioned

objections were as follows

1. Since it would be impractical to test a fixture 1 material with every conceivable stain with which

it might come into contact, it seemed necessary to

select several representative types of stain for the ! standard test method.

2. Because proprietary products could change

in composition at any time depending on the ! needs of the manufacturer to maintain a market,

and also because these products could at some t future time disappear completely from the mar- j ket, the specified staining agents should be ' well-specified chemicals rather than proprietary E

- products of uncertain composition.

3. With the possible exception of iron and copper discolorations, stains on fixtures are usually ! not the result of long-time contact but rather are caused by accidental spills or other short-time ex- posure to the staining agent.

4. Because the surfaces of all fixtures become

roughened to varying extents during normal use, the stain resistance after a roughening treatment

is of considerable interest to the user. However, it

is only logical that the same roughening treat- ment be applied to all materials. Also, it seems

logical that the selected treatment should be suffi- 1 ciently severe to cause at least some roughening of 1 the most abrasion-resistant finish.

5. The stain rating should be related to the ease

j with which a stain can be removed through use of

common household cleaning agents.

6. The stain test should be so designed as to provide numerical ratings for stain resistance so that [ (a) performance levels can be more easily as-

"

signed, and (b) manufacturers can more readily - ascertain when they have improved the overall ! stain resistance of their product.

( a) Selection of Staining Agents

One of the major problems encountered in the | development of a stain test was the selection of the

staining agents. The following stains were in- ' vestigated

1. Iron stain. Trials with solutions prepared

from soluble iron salts all gave negative results. } In no case was an adherent stain formed on any ; of the materials. However, when metallic iron was

permitted to rust while resting on the fixture, sur- face stains were produced that closely resembled

those that are sometimes observed on installed fix- tures. The problem then became one of generating

56
i controlled corrosion of the iron so that reproducible stains could be obtained. After much experimental work the conditions specified in paragraph

8.23b (2) were selected. A chemical grade of iron

ilings was used together with a one-percent solu- ion of sodium chloride. The relative amounts of

:ach were found to be important and the amounts

ipecified in the recommended test method must be

Larefully adhered to in order to generate a reproducible stain.

2. Copper stain. Copper stains are oftentimes

observed on fixtures in rural or suburban areas

Ivhere (a) copper piping is used for the water

kipply, and (b) the water supply is either neutral

pr slightly acid. Tenacious blue stains appear on

[he fixtures under these conditions, especially if ;here is a small leak from the hot-water faucet.

, Considerable difficulty was encountered in the

(laboratory in reproducing these copper stains. After many trials a procedure was devised

Lvhereby copper turnings were wet with ammolium hydroxide and left on the test surface for 20

jar in a closed container. This treatment created

oenacious blue stains on porcelain enamel and viti :eous china that closely resembled those observed on fixtures; however, on FRPE specimens the

popper stain was found to penerate deeply into

the gel-coat. Additional tests showed that the ammonia was the cause of this penetration; hence,

jthis particular test could not be considered realistic for gel-coats since any significant amount of

.ammonium hydroxide would never be encountered

jin a water supply.

Sufficient work was done with the copper stain

[test to show that the stain rating for enamel and

vitreous china was the same for copper stains as

Jfor iron stains. Therefore, it was decided to in- clude only the iron stain in the recommended test since the iron stain would probably give the re- iquired indication of the resistance of a material to the metal-ion type of discoloration.

3. Hair dye. The most severe staining medium

in the CS-221 stain test for FRPE was the black

Ihair dye [1]. Since this is a proprietary product,

efforts were made to simulate its action through

fuse of some easily prepared chemical solution. The

[hair dye was found to contain ammonium hydroxide and it was believed that the presence of this

'ammonium hydroxide was responsible for the

severity of the stain on FRPE fixtures. Stain

i|No. 3 (Mercurochrome in NH4OH) yielded the

! same stain ratings on FRPE specimens as did the

: black hair dye. Hence, it was included in the test

i as one of the standard staining media,

j 4. Iodine. Iodine is a stain that might well come

I into contact with fixtures. Therefore, it seems logiIcal to include this stain as one of the staining

j agents. Also, the iodine can be considered representative of many types of staining media that

contain alcohol.

5. Potassium permyonganate. This chemical is used occasionally in bathrooms for therapeutic

purposes. A second reason for its selection is that

is should be representative of the most aggressive

types of water-soluble stains that might be encountered during the normal service life of a fixture.

6. Lipstick and black crayons. Stains of this

general type could be removed easily from all candidate materials even after 20 hours of contact. Hence, a simulated stain of this general type was

not included as one of the selected staining agents.

7. Water-soluble ink and liquid shoe polish.

These stains were also removed easily. Any material that received a high rating with respect to KMn04 (Stain No. 1) should also be highly resist- ant to ink and shoe polish.

8. Rubber stains. It has been observed that some

types of rubber when in contact with a plastic sur- face may stain the finish due to migration into the

plastic of such compounding ingredients as antioxidants and sulphur that are present in the

rubber.

Consideration of this problem indicated that it would be difficult, if not impossible, to simulate

this type of staining by a simple laboratory test. Two ASTM tentative test methods exist for evaluation of the resistance of plastics to rubber staining; (1) ASTM Designation: D1712-60T [29]

with reference to sulfide stains, and (2) ASTM

Designation: D2151-63T [30] with reference to staining by rubber compounding ingredients.

Since both of these tests are quite complex and

since rubber stains are not reported to be a serious

problem in FRPE fixtures, no requirements with

respect to rubber staining were included in the

recommended staining test procedure. However,

if rubber staining should become a serious problem on future fixtures it would be possible at that

time to incorporate the two ASTM tests into the

performance requirements.

(b) Test Results

Table 2.23-2 lists the results obtained when the

staining test, specified in the proposed revision

of CS 221-59, was made on five fixture materials.

When the same staining agents were used and the

testing conducted as specified in section 2.23(1),

the ratings were those listed in table 2.23-3. Table 2.23—4 gives the results obtained with

four fixture materials using the staining agents

and test procedures specified in section 2.23(b).

In all cases, the combined stain ratings were lower

for the abraded specimens than for those that were

not abraded. This was not the case, however, for some of the individual stains. For example, porcelain-enameled steel, porcelain-enameled cast iron,

and vitreous china received a rating of 60 against

iron stains in both the abraded and unabraded

condition. A more severe abrasion treatment

would probably have lowered the iron-stain rating

of the abraded specimens; however, a more severe treatment was not indicated in view of the mild

abrasion effects that are normally observed on

finishes of this type after a number of years of

57
Table 2.23-2. Stain ratings of five sanitary ware specimens when tested in accordance with the proposed revision of CS-221 [1

One percent iodine Liquidshoe

polish

Blue

ink Gen.

violet Rev.

lipstick Black

hair dye

Black

crayon

i

i Comr. Specimen No. Specimen type Pre-treatment 5 min 30 min 4 hr 16 hr 16 hr 16 hr 16 hr 16 hr 16 hr 16 hr

stain

ratini

C U C U C U C U C U C TJ C u C U C U C U

PA-lOO Gel-coat _ None b 2 2 2 1 2 1 3 1 1 1 1 1 3 2 1 1 5 3 12

1 PA-5 Gel-coat Bon Ami scrub °_. 2 2 4 3 4 2 5 3 3 3 3 3 4 3 3 3 5 4 2 CID-100 P/E-cast-iron Bon Ami scrub d . 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 VCA-99 Vit.-china Bon Ami scrub 1 d _. 1 1 1 1 1 1 1 1 1 1 1 1

e 4 1 1 1 1 1 1 I SD-79... P/E-steel Bon Ami scrub 2 d_. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

» Ratings assigned on the following basis: No. 1, stain removed with tap water and cheesecloth by 20 scrub cycles with normal hand pressure; No. 2, stain removed by washing for 20 cycles with cheesecloth moistened with

either (a) rubbing alcohol, or (b) lighter fluid; No. 3, stain removed by 20 scrub cycles at normal hand pressure with moistened cheesecloth and Bon

Ami; No. 4, slight stain remains after Bon Ami treatment; No. 5, severe

stain remains after Bon Ami treatment. Letter "C" indicates stain solution

was covered with a microscope cover glass during test; "TJ" indicates it uncovered.

b Specimen tested with its initial glossy surface.

Initial gloss mostly destroyed by pre-treatment of 20 scrub cycles wit] Bon Ami.

d No visual change in initial gloss by 20 scrub cycles with Bon Ami.

» Stain penetrated pinholes in glaze.

Table 2.23-3. Stain ratings of specimens to CS-221 stains [1] when tested in accordance with the method specified in section ' 2.23(b)

Spec. No. Spec, type Surface treatment

Individual stain ratings »

Iodine Liquidshoe polish Blue ink Gentian

violet Rev.lipstick Black

hair dye

Black

crayon

705090

60

10060

70

40 10070

20

20

10060

100

100 9090

1009090

70

10070

100 100100

100

100 100 90

90

10090

90

80

90

90

100

100 100100

100 100 90

90

10090

9070

9090

100

100

100 100

Comb,

stain rating

PA series

.

FRPE (gel-coat)

.

CID series. P/E-cast-iron.

VCA series. Vit.-china.

SD series. P/E-steel.

None

Abraded

None

Abraded

None

Abraded

None

Abraded

7t51 Avg 65

9789 Avg 93

9693 Avg 94

9691 Avg

» Treatment time 2 hr.

Table 2. 23-4. Stain ratings of sanitary ware specimens to the four recommended stains when tested by the method specified in section 2.23(b)

Individual stain ratings

Spec. No. Spec, type Surface treatment Stain No. 1 Stain No. 2 Stain No. 3 Stain No. 4 Comb,

stain KMn04 Iodine Mer.— NHiOH

Iron

rating

PA series FRPE gel-coat.. None _ 80 70 20 80 63 Abraded 50 50 20 60 45 Avg. 54 CID series P/E on cast-iron None 80 100 90 60 83 Abraded... 60 100 60 60 70 Avg. 77 VCA series Vitreous-china . None -. 80 100 90 60 83 Abraded 60 100 a 40 60 65 Avg. 74 SD series P/E on steel None 80 100 90 60 83 Abraded 60 100 60 60 70 Avg. 77

- Stain penetrated pinholes in glaze.

58
service. It should also be pointed out that the

specified abrasion treatment with the 400 C silicon

cafbide paper roughens the surface of these

materials to an extent that is comparable to the

10,000 cycle abrasion treatment in the scrub tester

as specified in section 2.10.

d. Comments on Performance Requirements

(1) Suggested Format for a Performance Level

The combined stain-resistance rating shall be

not less than __ when determined as specified

in section 2.23(b).

(2) Rationale for Suggested Format

The field inspection of FKPE fixtures made in

July 1964 (Appendix A) indicated that staining was not a serious problem with the FRPE

material ; hence, one might wish to place the per- formance requirement for stain resistance at a

level that would permit the use of materials with

a stain resistance comparable to the current types

of polyester gel-coats. This purpose would be

accomplished if the requirement was set at 50.

2.24. Color Stability (C503)

a. Purpose and Scope

The purpose of this test is to evaluate the resist- ance of sanitary fixture materials to changes in

color caused by exposure to solar radiation.

b. Recommended Test Method

(1) Apparatus

A 6000-W, water-cooled xenon- arc apparatus

with a 37% in-diam specimen rack shall be used.

This apparatus shall be that specified in ASTM

Designation: E 240-64T [31].

(2) Procedure

Cut four 4- x 4-in flat specimens from the fixture

to be tested. Wash with soap and water, rinse

thoroughly, and dry. Designate these specimens

Nos. 1, 2, 3, and 4. Place specimens Nos. 1, 2, and 3 in the xenon-arc apparatus that has been adjusted to give a blackpanel temperature of 125 °F ± 3 °F, and operate

the apparatus with no water spray for a total of

200 hr. Humidity need not be controlled.

At the end of the 200-hr exposure time, remove

the three specimens, clean them by the same procedures specified above, and then place them adjacent to specimen No. 4 (untested specimen).

Finally, have an observer with normal color

vision examine the specimens visually at normal

reading distance and with illumination as described in section 2.8 for an immediately apparent

color difference between the tested specimens and

the untested specimen. If no color difference is immediately apparent, the specimens are adequate in

color stability.

In the event of an apparent color difference by

the visual examination, or in the event of a dis- agreement, determine color differences according

to ASTM Designation D 1365-60T [38], reporting

the color difference determined for each of the

three tested specimens and the average of these

three values, in NBS units.

(3) Information to be Reported

Include the following in the test report:

1. Type and model of xenon-arc apparatus;

2. Age of both the xenon burner and the glass

filters at the time of testing. Also, the wattage used

during testing

;

3. Operating black-panel temperature

;

4. A statement as to the degree of color differ- ence between the tested specimens and the untested

specimen, in the case of visual examination. If

the examination is made by the method of ASTM

D 1365, report color difference measurements in

NBS units.

c. Test Results and Discussion

(1) Discussion of Existing Methods

Numerous arc tests exist for evaluating the

resistance of materials to the photodegradative

effects of natural sunlight. Examples are ASTM

Designations: E 188-63T [32], E 42-57 [33], D

822-60 [34], and E 240-64T [31]. In general, these

tests attempt to simulate rainfall as well as sunlight, since they all include a water-spray cycle as part of the test condition.

The proposed revision of CS 221-59 [1] for

FRPE fixtures contains a requirement for "color

fastness." A xenon arc is specified. The test time is 200 hr. The performance requirement (paragraph

6.3.2) states that the "tested specimens shall show

no appreciable change in color when compared to the 'control' specimen." No explanation is given

as to the interpretation to be placed on the term

"appreciable change in color."

(%) Test Development

Triplicate specimens of four fixture materials were tested under both carbon-arc and xenon-arc

exposure. The measured changes in color from

these respective treatments are given in tables

2.24-1 and 2.24-2. In all cases the measured color

changes were small.

(3) Rationale for Test Selection

The recommended test procedure is a modification of that specified in the proposed revision of

OS 221-59 for FRPE fixture materials. Both the

equipment and the exposure times are the same as

in the test specified in the proposed revision of CS

221. The main difference in the two tests is that

the test recommended herein provides an instru59
Table 2.24-1. Change in color of white sanitary ware

specimens after exposure to two carbon-arc treatments

Fixture material

Dry exposure—

808 Hr » Wet exposure—

814 Hr b

Spec. No.

Color change 0 Spec. No.

Color change 0

Porc.-Enamel on Steel (SB Series).

Avg

252634

NBS

units

1.4

1.0

0.

5

131920

NBS

units

0.7

.6

. 8

0. 97

1.4

1.5

1.

9

.70

1.8 2.8

2.

0

FRPE 272833

14

15

16 (PA Series).

Avg 1. 60

1 4 L4

1.6

2.20

1. u

1.3

1.1

Porc.-Enamel on Cast-Iron (CID Series).

Avg _

2930

36

17

18

21

1.47 1.2

1.6

1.6

1. 10 1.8 1.9

1.7

Vitreous- China (VCB Series).

Avg

31

32

35

22

23

24

1.47 1.80

a Carbon arc operated in accordance with ASTM Procedures D 822-60 and E 42-57.

b Same as dry exposure except for a water spray striking specimens for 9 min out of each hour of operation.

0 See NBS Circ. 429 (1942) [35]. Measurements made by procedure of ASTM D 1365-60T [381.

Table 2.24-2. Change in color of white sanitary ware

specimens after 200 hours exposure in xenon-arc apparatus*

Spec. Specimen type Change in Average color No. color change NBS units t> NBS units b

1 Porce.-Enamel on Steel (SB Series) ... 0.5

2 .3

3 .3 0. 37

4 FRPE (PA Series) 0.7

5 1.1 6 .6 0. 80

7 Porce.-Enamel on Cast-iron (CID 0.2

8 Series)

.

.6

9 .5 0.43

10 Vitreous-China (VCB Series).. 1.0

11 .7

12 1.0 0. 90

6000-W, water-cooled xenon arc with a 37K-in-diam specimen rack. Apparatus operated dry. Black panel temperature was 125 °F.

b See NBS Circ. 429 (1942) [35]. Measurements made by procedure of ASTM

D 1365-60T [38].

mental method for determining the degree of color

change.

The following reasoning influenced the selection

of the recommended xenon-arc test method

:

1. Sanitary fixtures in normal installations are exposed to only very short periods of sunlight. This

would occur when the fixture was installed near

a window. Some exposure to direct sunlight occurs when fixtures are stored temporarily out-of-doors

by manufacturers, distributors, or plumbing contractors. Thus, a test exposure to simulated sunlight seems reasonable. Because of window shades,

translucent glass, cloudy days, and dirty windows,

200 hr seen a reasonable testing time.

2. The xenon-arc has been shown to have a spectral energy distribution, when properly filtered,

that more closely simulates sunlight at the earth's,

surface than does the distribution from any otheri; available light source. Hence, the filtered xenon

arc is preferable to the carbon arc.

3. A xenon-arc test is already specified in the

proposed revision of CS 221-59. There does not

appear to be any good reason to change to a com-

!

pletely new test for color stability except to be more specific about the magnitude and measure- ment of the color change that will be permissible

after the 200-hr treatment.

d. Comments on Performance Requirements

(1 ) Suggested Format for a Performance Level

The average color difference between three untested specimens and three specimens from the' same lot exposed for 200 hr to the xenon arc specified in section 2.24b shall be less than ___ NBS

unite.

(2) Rationale for Suggested Format

The largest average color change reported in

table 2.24-2 is 0.90 NBS unite. This is not a noticeable change, since 1.0 NBS unit, as described in

NBS Circ. 429 [35], is generally considered to be an excellent color match. This means that the pres- ently manufactured white-fixture materials have

acceptable color stability with respect to solar

radiation. Colored fixtures, however, might not

have this same stability. Also, future candidate

materials might be lacking in this respect. Therefore, it seems desirable to include a color-stability

requirement. Possibly the performance level should

be set higher than 1.0 NBS unit. A color change of

5.0 NBS units would be readily dectable, but would

not detract from the serviceability of the fixture.

2.25. Surface Texture Aging (C4)05

The purpose of this test is to evaluate the ability

of a sanitary plumbing fixture to maintain its original appearance and other important surface

properties without deterioration from natural

changes through passage of time under normal

ambient conditions, as contrasted to changes from

external influences associated with use. The principal difficulty in developing a suitable

aging test is the correlation between effects observed in an accelerated laboratory test and the

anticipated changes over a long period of time

under normal conditions. If it is anticipated that

normal temperature, humidity, daylight, etc., cause aging, it is impossible, without extensive

experimentation, to compress the time scale by a known factor using selected increases in the severity of these environmental factors. A test for color fastness of FRPE sanitary ware

is described in paragraph 6.3.1 of the proposed re- vision of OS 221-59 [1], involving exposure for

60
!• 200 hr to ultraviolet radiation. A similar test for

U evaluating color stability, using apparatus speciI fied in ASTM E 240-64T [35], is recommended

II in section 2.24 herein. However, it is not the purii ij pose of either of these tests to evaluate surface

texture aging effects,

es Weatherometer tests, such as described in

i) ASTM D 1499-59T [36], generally combine ultra- • violet radiation and water spray. Other acceler-

!s ated tests for plastics, such as ASTM D 756 [37],

- employ cycles involving different degrees of hu-

>5 midity and heat. Still other accelerated tests in- volve exposure to elevated temperatures in an

oven. None of the existing tests referred to approximates the conditions of service exposure for sanitary plumbing fixtures sufficiently well to warrant

,'. their recommendation as performance tests for

i< surface texture aging without correlation with

effects observed in service.

j The ad hoc committee was of the opinion that

I the development of an aging test for sanitary

plumbing fixtures was not practical during the

present investigation.

2.26. Odor (C505)

1 The ad hoc committee established a functional

' requirement on odors that stated that sanitary

plumbing fixture materials should not emit ob1 jectionable odors, either their own inherent odor

' or others which they might acquire during normal

J use. While evaluation of odors is not within the

I scope of technical investigations of the National

Bureau of Standards, the problem of odor emis-

!

| sion by materials used for sanitary plumbing fixj tures was brought to the attention of the Chairman of ASTM Committee E-18 on Sensory

j Evaluation of Materials and Products. Although

no formal reply was received from this Commit3. Tests Requiring

I Several needed test methods discussed in section

2 herein are not sufficiently complete for recomI mendation in their present stage of development

i for application to the bathtubs in particular, nor

1 to sanitary plumbing fixtures in general, as per-

' formance tests. Special attention is directed to three of these tests requiring further work.

3.1. Cieanability and Soilability (M203A)

A suitable test method for these characteristics

cannot be recommended at this time, principally

j because of (1) the lack of a representative soiling

i medium, and (2) inadequacies in the means for

simulating scrubbing procedures and for evaluating residual soil. These deficiencies and recom- mendations for further development work are discussed in section 2.11. Cieanability and soilabil- ity may be considered as separate characteristics.

tee, it is recommended that further contact be

made with this ASTM Committee for assistance

and guidance in the evaluation of this property.

It was observed during the study of FRPE

bathtubs at the National Bureau of Standards,

that some specimens produce a pronounced odor

when stored in a confined space. Flat specimens,

stored overnight in closed glass jars, caused odors

to develop in the jars; some specimens having more pronounced odor than others. The odors were

generally characteristic of styrene, a constituent

used in manufacture of the FRPE material. The

same odor was detected during the Hot-Water

Resistance Test (sec. 2.18) and the RadiantHeater Resistance Test (sec. 2.20).

2.27. Noise Control (Bathtub) (N401) and

(N402)

The damping characteristics of a bathtub for

the noise generated by falling water and the

sound-attenuation characteristics of an integral

surround were considered to be significant functional characteristic of a bathtub. However, study

of these factors was not included in the approved

project proposal.

2.28. Biological Characteristics (B601) (B602)

(B603)

There was general agreement in the ad hoc committee that a sanitary plumbing fixture should be

cleanable with respect to micro-organisms, that

the materials in the fixture should not sensitize

human skin on repeated contact, and that the materials should be resistant to attack by rodents or

insects. However, investigation of these characteristics was not included in the approved project

proposal.

Further Development

However, they are closely related and could probably be evaluated, in sequence, during a single test procedure.

3.2. Surface Slip Resistance (M207)

A suitable test method for this characteristic

cannot be recommended at this time, principally

because of (1) poor simulation of use conditions

in the existing tests, and (2) lack of correlation

between test results and slipping in service. These

deficiencies and recommendations for further development work are discussed in section 2.15.

3.3. Resistance to Thermal Shock (T304)

A test method for resistance to thermal shock was not recommended herein, principally because

of (1) poor simulation of service temperature ex61
posure in existing tests, and (2) lack of information to correlate temperature levels and the

number of cycles to produce failure. It is recom- mended that further work be directed toward the

development of a suitable test that would replace

both the hot-water resistance tests described in sec- tion 2.18 and the existing thermal-shock tests described in section 2.21. A discussion of these

matters is given in section 2.21. The blistering of FRPE bathtubs observed during the hot-water resistance tests described in sec- tion 2.18 was probably not the result of thermal

shock. It may have been the caused by differential

expansion of the gel-coat and the substrate, or more

likely by volatile products given off by the substrate at the elevated temperatures. Therefore, the

combination test procedure proposed above should

incorporate a cumulative long-term exposure of a bathtub to warm water, together with a cyclic

thermal-shock test at different temperatures.

4,

[I] Standard for gel-coated glass-fiber reinforced poly- ester resin bathtub units, a proposed revision of Commercial Standard CS 221-59 (Aug. 1964).

[2] Gel-coated glass-fiber reinforced polyester resin bathtubs, Commercial Standard CS 221-59.

[3] Plumbing fixtures, land use, Federal Specification

WW-P-541b(4) (1962).

[4] Enameled cast iron plumbing fixtures, Commercial

Standard CS 77-63.

[5] Method of test for water absorption of plastics,

ASTM designation : D 570-63.

[6] Vitreous china plumbing fixtures, Commercial Stand- ard CS 20-63.

[7] Earthenware (vitreous-glazed) plumbing fixtures, Commercial Standard CS 111-43.

[8] Standard methods of test for abrasion resistance of porcelain enamels, ASTM designation : C 448-61.

[9] Schiefer, H. F., Crean, L. E., and Krasny, J. F, Improved single-unit Schiefer abrasion testing machine, Research Paper RP 1988, NBS J. Research,

42 (May 1949).

[10] Richey, G. G., McKenna, E. H., and Hobbs, R. H.

;

Methods and equipment for testing printed-enamel

felt-base floor covering, NBS Building Materials

and Structures Report No. 130 (1952).

[II] Tentative specifications and methods of test for laminated thermosetting decorative sheets, ASTM

designation : D 1300-53T.

[12] Standard method of test for mar resistance of plastics, ASTM designation : D 673-44.

[13] Standard method of test for abrasion resistance of

paint, varnish, lacquer, and related products by

the falling sand method, ASTM designation

:

D 968-51.

[14] Standard method of test for abrasion resistance of coatings of paint, varnish, lacquer, and related products with the air blast abrasion tester, ASTM

designation : D 658-44.

[15] Marra, Dorothea, and Osipow, Lloyd I., A review

of Snells's soiled cloth, Detergent Age (Oct. 1964,

p. 52).

[16] Enamel ; interior, semigloss, tints and white, Federal Specification TT-E-508(4) (1953).

3.4. Other Characteristics Requiring Test

Development

There was a number of performance character-" ^

istics for sanitary plumbing fixtures that wereconsidered important by the ad hoc committee, but;! pi]

'

which were excluded from the present test develop- j ment effort either because (1) accounting for all

j the relevant parameters made the investigation too,] 'm complex and costly or (2) the particular scientific '', discipline principally involved was not available at the National Bureau of Standards. These characteristics include the following

:

Dimensional Stability (M205)

Noise Control (N401) (N402)

Surface Texture Aging (C504)

Odor (C505)

Biological characteristics (B601) (B602)

(B603)

These characteristics should be considered in any i future program of test development for sanitary

plumbing fixtures.

[17] Shelberg, Wesley E., Mackin, James L., and Fuller, Ross K., Artificial surface dirts for detergency

studies with painted surfaces, Ind. Eng. Chem.,

46, No. 12, 2572 (Dec. 1954).

[18] Ridenour, G. M., and Armbruster, E. H., Bacterial j cleanability of various types of eating surfaces,

Am. J. Public Health, 43, No. 2, 138 (Feb. 1953).

[19] Armbruster, E. H., and Ridenour, G. M., Field test procedures for cleanliness measurement of multi- 1 pie use of eating utensils, The Sanitarian 23, No. 2, 103, (Sept.-Oct. 1960).

[20] Wells, Louis E. Jr., A progress report, Part II, Test i methods for evaluating liquid detergents for hand

dishwashing, Proc., 43rd Annual Meeting, Chem- i ical Specialties Manufacturers Association, Washington, D.C., (Dec. 3-5, 1956). pages 189-191.

[21] Weatherby, Robert J., The measurement of floor

dirt, J. Environmental Health, 26, No. 4 (Jan.-

Feb. 1964).

[22] Standard method of salt spray (fog) testing, ASTM ! designation : B 117-61.

[23] Causes and measurement of walkway slipperiness,

Federal Construction Council Technical Report

No. 43, Report of Task Group T-41, Building Research Advisory Board, National Academy of Sciences-National Research Council, Washington,

D.C., 1961.

[24] Causes and measurement of walkway slipperiness, i Publication No. 899, National Academy of I Sciences-National Research Council, Washington,

D.C., 1961. [25] Giles, C. G., Sabey, B. E., and Cardew, K. H. F., Development and performance of the portable

skid-resistance tester, Road Research Paper

No. 66, Department of Scientific and Industrial Research, London, England (1964).

[26] Tentative specifications for standard tire for pave- j ment tests, ASTM designation : E 2A9-MT.

[27] Test for resistance of porcelain enamels to gouging, ; Bulletin T-l, Porcelain Enamel Institute, Inc., t

1 Washington, D.C. (1942).

[28] Formed metal porcelain-enameled sanitary ware, Commercial Standard CS 144-47 (under revision).

References

62
[29] Tentative method of test for resistance of plastics

to sulfide staining, ASTM designation D 1712-

60T.

[30] Tentative method of test for staining of poly- (vinyl

chloride) compositions by rubber compounding

ingredients, ASTM designation: D 2151-63T.

[31] Tentative recommended practice for operating

water-cooled xenon-arc type apparatus for artificial light exposure tests, ASTM designation

:

E 240-64T.

[32] Tentative recommended practice for operating en- closed carbon-arc type apparatus for artificial light exposure tests, ASTM designation : E 188-63T.

[33] Recommended practice for operating light- and

water-exposure apparatus (carbon-arc type) for

artificial weathering test, ASTM designation: E

42-57.

[34] Recommended practice for operating light- and

water-exposure apparatus (carbon-arc type) for

testing paint, varnish lacquer, and related products, ASTM designation : D 822-60.

[35] Hunter, R. S., Photoelectric tristimulus colorimetry

with three filters, NBS Circular C429 (1942).

[36] Tentative recommended practice for operating lightand water-exposure apparatus (carbon-arc type)

for exposure of plastics, ASTM designation : T> 1499-59T.

[37] Standard methods of test for resistance of plastics

to accelerated service conditions, ASTM designation : D 756-56.

[38] Method of test for color difference using color- difference meters of the Hunter-lab or Gardner

types, ASTM designation : D 1365-60T.

63
Appendix A. Inspection of FRPE Manufacturing Processes, Installed Fixtures,

and Test Facilities

a. Purpose and Scope

A live-man inspection team from NBS, assisted by

BRAB consultants and FHA representatives, visited three

plants engaged in the manufacture of FRPE sanitary

plumbing fixtures and made on-site field inspections of 37 fixtures that had been in use for periods ranging up

to three years. Test facilities were also observed. The

field observations on FRPE fixtures were limited to bath- tubs and shower receptors. The purpose of the trip was twofold: (a) to become

familiar with current manufacturing and testing processes

for FRPE plumbing fixtures, and (b) to inspect as many

installed fixtures as time would allow. The overall goal was to permit the NBS team to obtain a background on FRPE plumbing fixtures before embarking on the BRABsponsored program to select or develop performance tests for sanitary plumbing fixtures fabricated from any

material.

b. Manufacturing Processes There were many similarities in the operations ob- served at the three plants that were visited. All three used

a highly-polished black plastic mold, which is a male

image of the desired fixtures. A wax parting compound was first rubbed on the mold surface, after which a poly- ester gel-coat was applied by hand-spraying with a special spray gun to a thickness of approximately 0.020 in. The

required amount of catalyst was metered in the gun so as

to provide hardening of the gel-coat within 30 to 45 min

after spraying. The white gel-coats appeared to be opacified with titanium dioxide. The appearance of the finish was similar to porcelain enamel. Its smoothness and gloss

depended on the polish imparted to the mold prior to spraying. After the gel-coat hardened, the fiberglass backing was

applied. Two of the three plants used the sprayed-glass

process. In this process, glass yarn was fed into a special spray gun where it was chopped into fibers % to % in long before being propelled along with the polyester and

catalyst against the previously gel-coated mold. The resin- coated fibers did not flatten out against the back of the

gel-coat, but rather deposited as a loose mat. This required a hand-rolling operation in which the operators used steel rollers to compact the layer. This was done periodically

throughout the spraying operation. The thickness of the backing as well as thickness uniformity appeared to de- pend to a considerable extent on the skills of the spray- gun and roller operators with the methods and equipment

being used. In the glass-fabric process the gel-coated mold was first brushed with a polyester varnish to which the proper amount of catalyst had been added. Sheets of glass mat

and glass fabric were then placed over the polyester and

hand rolled into position.

The total thickness of the walls of the fixtures manufactured at all three plants was of the order of % to % in. Since this was insufficient to provide the required rigidity,

reinforcements were glued to the back surfaces before re- moval of the fixtures from each mold. Each manufacturer

used a different type of backing reinforcement such as plywood, pressed hardboard, gypsum wallboard, or plastic

ribs. Mold removal occurred as a final operation. This was

done by applying air pressure at the edges.

All three plants manufactured bathtubs of the same

basic design, i.e., a tub with an integral front apron and a wall surround extending above the top of the tub to a maximum of approximately 4 feet. The wall surround was

flanged with an edging strip about % in wide for nailing to the studs during installation. A few bathtubs with no wall surround were being produced, but this type of fixture rep- resented only a small percentage of the total production.

c. Inspection of Installed Fixtures

A total of 37 plastic fixtures was inspected in the geo- graphical areas adjacent to the manufacturing plants.

However, all units inspected in a given area were not necessarily manufactured by the plant that was visited in: that area. The age of the fixtures inspected ranged from"

a few months to approximately three years. Production^

methods and quality control procedures had been changed

in some instances since the first of these fixtures was manufactured. The inspections were intended as spot checks. They

were not arranged by the manufacturers except in one midwestern area where time limitations prevented a more:

objective selection of installations. The help of local FHA officials was used in locating nous-" ing developments where plastic fixtures had been installed. The selection of installations was largely random after the development was reached. Normally, three teams of two

persons each made the inspections. Arrangements for the

inspections were made in most cases by one of the team members talking to one of the occupants of each of the

selected houses. Detailed observations were recorded by

the NBS team for the information of BRAB staff and the project staff. From this information, several comments

can be made

:

(1) Installation Method

The plastic bathtubs were attached to the wall studding

by nailing through the edge strip provided for this purpose on both the front apron and on the wall surrounds. In" some cases cracking of the edge strip was observed The : observed cracks did not extend into the part of the fixture | intended to be visible after installation of the bathroom!

walls. One manufacturer recommended screws for this pur- < pose and predrilled the edging strip. However, one such

fixture inspected in a house under construction showed

that the installer had nevertheless used nails rather than

screws.

All of the plastic fixtures inspected had a bottom slope

adequate to provide complete draining of cold water intro- duced into them. The bottom slopes varied from 0.2 to 4.2 percent with a median of 2.5 percent. The top ledges

showed slopes of —0.6 to +1.1 percent, but most were

installed level.

(2) Cleaning Methods and, Cleanability

Although all manufacturers recommended that the tubs not be cleaned with harsh scouring powders, about 80 per- cent of the occupant interviewed reported that they used

proprietary brands of scouring powders. A cleanability

test convenient for field use was made during each inspection in which a 3B drawing pencil was used to make marks

on the surface of the fixture. On a newly installed bathtub

64
the pencil marks could normally be removed by dry rubbing. Once the gloss had disappeared, however, it was

necessary to use soap (Ivory) and water to obtain re- moval. On about 19 percent of the fixtures it was necessary

to use scouring powder (Bon Ami). In no case was it impossible to remove the marks with the scouring powder.

(3) Scratching of Gel-Goat Almost all of the fixtures inspected had one or more

visible scratches. In general, these scratches were visible

!only on close inspection and did not appear to affect clean-

[ability as determined by the 3B pencil test.

(4) Cracking of Gel-Goat About half of the fixtures showed one or more fine cracks

in the gel-coat. The depth of the cracks was not ascer-

!

| tained.

(5) Gouging of Gel-Coat Small gouges in the gel-coat were observed in three of 37

fixtures.

j (6) Chemical Stains

Chemical staining was observed on four of the 37

fixtures. In one case the staining apparently had resulted from use of a rubber mat in the bottom of the tub, while

in the other three, the stain had probably been caused by

rusting of iron objects (possibly bobby pins or metal

toys)

.

(7) Cigarette Bums

Three tubs showed cigarette burns on the outer ledge.

Two of these were in motel units and the third in a pri- vate home. It was found in the home fixture (FHA

repossessed ) that the discolored area could be removed by

a vigorous and prolonged localized scouring with "Bon

Ami."

(8) Impact Damage

There was no positive evidence in any of the inspected

plastic fixtures of complete loss or penetration of gel-coat

from impact of a falling object. However, one fixture was

found where a star-shaped crack pattern in the gel-coat on the wall surround suggested that an impact from the reverse side might have occurred previously.

(9) Rigidity and Strength

Several fixtures (two or three years old) exhibited considerable flexibility, especially in the wall surround,

and some fixtures exhibited a "cracking noise" when

pressed firmly with a foot or a hand. This condition sug- gested either a possible separation of the reinforcement

strips from the fiber-glass-resin backing, or insufficient rigidity of the reinforcement as designed. No structural

failures were observed in any of the fixtures.

(10) Spalls and Pits Small spalls or pits, approximately Yiq in to %-in diam, were detected on the bottom of about 80 percent of the bathtubs which had been installed for periods of two to three years. This percentage decreased to 35 percent on

the fixtures installed from one to two years while none of these defects was observed on the fixtures installed for one year or less.

(11) Lifting of Gel Layer (Bexamination)

Several examples of separation of the gel layer from

the fiberglass-resin backing were observed. In one case water could be squeezed out of a break in the coating by

pressing down on the raised portion of the gel-coat.

(12) Apparent Slip Resistance of Gel-Coat Two members of the inspection team who took baths in FRPE tubs installed in their motel rooms reported a feel- ing that the tubs were less slippery than conventional

porcelain-enameled fixtures. The manager of a development for retired people

reported no injuries from falls in bathrooms since the development started. He ascribed this absence of injury to the plastic fixtures. All of these homes (est. 1,000 completed) were equipped with deep shower receptors with

integral seats.

(13 ) Field Repairs of Plastic Fixtures

Several field-repaired fixtures were inspected. Some

owners reported reappearance of defects after a relatively short period of service following repair.

(14) Comments on Customer Acceptance

Although no comments from occupants were solicited during the field inspections, opinions and comments were

nevertheless frequently volunteered. Some dissatisfaction was evidenced in a number of cases where defects requiring field repairs had appeared. One comment, volunteered during many of the inspections, was that the FRPE

fixtures were not only more difficult to clean than porce- lain-enameled fixtures, but that even after cleaning they

did not look as "clean" as a porcelain-enameled fixture. On the other hand, many favorable comments were heard

on the absence of a tub-to-tile seam with the FRPE fix- ture. Some users commented favorably about apparent

slip resistance.

d. Suggestions Regarding Needed Test Based on Field

Observations

The comments given below regarding needed tests for sanitary plumbing fixtures were developed immediately

following the field inspection trip as a result of the field observations, and preceded the initiation of laboratory

work. In fact, the substance of these comments was later found quite useful as guideline material in actual test development work and in formulating recommendations. For these reasons, it is appropriate to present the com- ments here.

(1) Delamination

Separation of the gel-coat from the fiber-glass-resin

backing, if it occurs, is a serious defect from the stand- point of sanitation and fixture usability. A suitable hot- water resistance test might reveal tendencies to delamination and spalling of the gel-coat.

(2) Cracking or Crazing of Gel-Coat Cracking of crazing of the gel-coat is undesirable from

the standpoint of sanitation and ease of cleaning, and may

permit water entry into the fiber-glass-reinforced plastic.

A hot-water resistance test might reveal susceptibility

to crack or craze.

(3) Gel-Coat Thickness In a performance specification a gel-coat thickness requirement does not seem appropriate. Instead it might be

better to require that the coating withstand a minimum

number of abrasion cycles under specified conditions.

(4) Bond Between Fiber-Glass-Resin Backing and Reinforcing Strips

A test of the bond strength of reinforcing strips should

not be a part of a performance specification. The integrity of the bond could probably best be evaluated by specify65
ing maximum permissible deflection during localized load- ing and measuring the deflection with respect to the immediate vicinity of the loading point.

(5) Abrasion Resistance

This is an important property, since the field inspection indicated that owners continue to use scouring powder for cleaning in spite of instructions to the contrary from the manufacturer. A suitable abrasion test should take into account the portable number and severity of scouring treatments during the desired period of service life.

(6) Stain Resistance

The field inspection indicated that stains had not been

a serious problem with FRPE tubs except possibly stains from cigarette burns. The criterion for stain resistance might possibly be related to the thickness of coating that would have to be removed to eliminate the stain.

(7) Aging

No installations were inspected that had been in service for longer than three years. It might be desirable to have an accelerated test to indicate whether or not the properties of the material would change appreciably with time at approximately room temperature.

(8) Hardness and Scratch Resistance

One of the unexpected findings from the field inspection was that scratches, while present, were not especially noticeable and, furthermore, they had little effect on the

pencil cleanability test employed in the field inspections.

Nevertheless, it seems important that a scratch test be included in a performance specification.

(9) Cleanability

The field inspections indicated that cleanability is im- portant to the user. A suitable test should measure the ease with which a standard soiling agent can be removed.

e. Test Facilities The NBS inspection team visited one commercial test- ing laboratory, one industry research laboratory, and

one fixture manufacturer's laboratory. The impression

obtained was that each of these laboratories had been

conducting several of the tests called for under OS 221-

59, and had become familiar with these tests. The manufacturer's laboratory was set up for the primary purpose

of quality control of FRPE fixtures, and was well equipped for this purpose. The industry research labora- tory was concerned with evaluating or developing tests for a broad spectrum of building products and materials,

and was well equipped for making several of the important tests called for by OS 221-59. The commercial test- ing laboratory visited evidently made only certain tests on plumbing fixtures, principally the structural and mechanical tests. Two of the three manufacturing plants visited evidently did not make on the premises the test described in OS

221-59, but conducted inspection and made empirical process control adjustment. These two plants did not conduct routine tests on the quality of the gel-coat materials, but purchased the product from well-known suppliers according to specification.

This brief inspection of test facilities should not in any

sense be construed to indicate an evaluation of the lab- oratories visited. The only purpose was to obtain some

familiarity with the test apparatus and procedures used

in evaluating FRPE fixtures made to existing standards.

66
Appendix B. Telephone Survey of Pressed- Steel Bathtubs

In two of the performance tests for bathtubs (Dynamic

Load, Sec. 2.4, and Surface-Impact Resistance, Sec. 2.12), relatively low values were obtained in the laboratory

tests for the pressed-steel bathtubs. Therefore, it ap- peared desirable to conduct a survey of field damage due

to impact for tubs of this type. However, since available resources were limited, it became necessary to select a type of survey that could provide statistically significant data in a reasonable time and at a reasonable cost. The procedure decided upon was a telephone survey. Two housing developments were first selected from the Washington, D.C., area, where it was known with cer- tainty that only porcelain-enameled pressed-steel bathtubs had been installed by the developers. The two devel- opments selected were

:

1. Development "A" : This is a very large mediumpriced housing development located approximately 15

miles from the District of Columbia. Occupancies from

1 to 3 years.

2. Development "B" : This is a medium-sized develop- ment located almost adjacent to the District of Columbia.

Homes, which are from 6 to 15 years old, are in the medium-price range. Telephone numbers were chosen at random from the

street names and house numbers known to be a part of these two developments. Secretaries in the NBS Building Research Division then placed the calls requesting the information specified on a survey sheet, a sample of

I which is included- with this Appendix ( table B-l )

.

I Table B-2 lists the results of the survey. In interpreting the results the following comments appear to be

pertinent

:

(1) The homes contacted in Development "A" were

built by mass-production techniques. Information was ob- tained indirectly indicating that extra precautions against

chipping damage were not exercised when installing bathtubs, since the builder had found that it was more economical to repair chipped areas after installation than to require elaborate protective procedures by the workmen.

This may account for the high incidence of damaged areas

reported at the time of occupancy (see table B-2).

(2) The survey indicated that a serious fall had oc- curred in only 0.9 percent of the pressed-steel bathtubs. The falls that did occur were reported to have caused no

noticeable damage to the fixtures. (3) A total of 20 percent of the 324 tubs was reported

to have one or more chips, while 80 percent (258 tubs) were reported as having no impact damage. Most of the chipped areas were small ; 60 per cent of the damaged

areas were described as less than V^-in in diameter.

(4) No field inspections were made by the project

personnel. A few spot checks would have been desirable, but these could not be made because of time limitations. Therefore, since the results were based entirely on the

replies of the housewives, the reference level for judging

damage probably varied and, for this reason, uncertainties exist in the data. On the other hand, it seems very

unlikely that the reported percentages could be in error by any sizable amount since there would appear to be no

logical reason for a housewife to supply either a dishonest

or an incorrect answer to the questions.

67
Table B-l. Survey Sheet Used in Making Calls for Telephone Survey.

NBS TELEPHONE SURVEY OF SHEET STEEL BATHTUBS

Date of Call Initials of NBS Interviewer

Name Telephone No.

Subdivision . 1. How old is your house? years.

2. How many bathtubs in house?

3. Does your bathtub have any chipped areas: places where the white finish has come off and you can see the

black material underneath? Yes , . No

3.b. If so, how many places are there like this?

3.c. Are they on one tub only? Both tubs

3.d. Are they on bottom? Rim? . 3.e. About how large are they?

3. f. Were they present when you moved into house? Yes No

4. Has anyone ever fallen while taking a bath or shower in your tub? Yes No

4. b. If so, were they injured? Yes No

4.c. Was there any damage to the tub? Yes No

If no chipping or falls are reported, complete the call by thanking them for their assistance. If either chipping or a fall has occurred, ask if it would be all right for a team of two people from the Bureau

of Standards to stop by to look at the tub sometime during the next month. These people would not come

without first calling and making an appointment.

Volunteered comments of interest (if any)

Table B-2. Summary of results of telephone survey of pressed-steel bathtubs

Development "A"" Development "B"b Both developments

Question Description Number Percentage Number Percentage Number Percentage

1. Bathtubs reported __ 273 100 51 100 324 100

2. Serious falls reported __ <= 2 0.7 » 1 1 3 0.9

3. Bathtubs with no chips. . 218 80 40 78 258 80

4. Bathtubs with one or more chips __ 55 20 11 22 66 20

a. Chips present when dwelling was occupied 40 15 d

b. Chips occurred after occupancy 15 5 d

c. Average number of chips per fixture 1.15 1. 36

d. Location of chips: Bottom

.

. . _ . 39 61 5 33 44 56 Rim _ 23 36 9 60 32 40 Outside apron _ 2 3 1 7 3 4

Total _ 64 100 15 100 79 100

e. Approx. size of chips: <M in diam 40 63 7 47 47 60 About Yi in diam - 9 14 0 0 9 11 About J/2 in diam _ 8 12 5 33 13 16 About 1 in diam 4 6 3 20 7 9 >1 in diam- 3 5 0 0 3 4

Total 64 100 15 100 79 100

» Medium-priced homes that had been occupied from 1 to 3 years. age of fixture 9.8 years).

b Medium-priced homes that had been occupied from 6 to 15 years (average ° No damage reported to fixture.

d In most cases, occupant was unable to answer this question.

68 U.S. GOVERNMENT PRINTING OFFICE : 1970 O—352-020
Announcement of New Publications in

Building Science Series

Superintendent of Documents,

Government Printing Office,

Washington, D.C., 20402

Dear Sir: Please add my name to the announcement list of new publications to be

issued in the series: National Bureau of Standards Building Science Series. Name

Company

Address

City State . . . Zip Code

(Notification key N-339)



NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards ' was established by an act of Congress March 3, 1901. Today,

in addition to serving as the Nation's central measurement laboratory, the Bureau is a principal

focal point in the Federal Government for assuring maximum application of the physical and

engineering sciences to the advancement of technology in industry and commerce. To this end

the Bureau conducts research and provides central national services in four broad program

areas. These are: (1) basic measurements and standards, (2) materials measurements and

standards, (3) technological measurements and standards, and (4) transfer of technology.

The Bureau comprises the Institute for Basic Standards, the Institute for Materials Research, the

Institute for Applied Technology, the Center for Radiation Research, the Center for Computer

Sciences and Technology, and the Office for Information Programs.

THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United

States of a complete and consistent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essential services leading to accurate and

uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of an Office of Measurement Services and the following technical

divisions:Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic and Molecular Physics—Radio Physics -—Radio Engineering 2—Time and Frequency - —Astrophysics -—Cryogenics.2 THE INSTITUTE FOR MATERIALS RESEARCH conducts materials research leading to im- proved methods of measurement standards, and data on the properties of well-characterized

materials needed by industry, commerce, educational institutions, and Government; develops,

produces, and distributes standard reference materials; relates the physical and chemical properties of materials to their behavior and their interaction with their environments; and provides

advisory and research services to other Government agencies. The Institute consists of an Office of Standard Reference Materials and the following divisions: Analytical Chemistry—Polymers—Metallurgy—Inorganic Materials—Physical Chemistry.

THE INSTITUTE FOR APPLIED TECHNOLOGY provides technical services to promote

the use of available technology and to facilitate technological innovation in industry and Government; cooperates with public and private organizations in the development of technological

standards, and test methodologies; and provides advisory and research services for Federal, state, and local government agencies. The Institute consists of the following technical divisions and

offices: Engineering Standards—Weights and Measures — Invention and Innovation — Vehicle Systems Research—Product Evaluation—Building Research—Instrument Shops—Measurement Engineering—Electronic Technology—Technical Analysis.

THE CENTER FOR RADIATION RESEARCH engages in research, measurement, and application of radiation tjo the solution of Bureau mission problems and the problems of other agencies and institutions. The Center consists of the following divisions: Reactor Radiation—Linac Radiation—Nuclear Radiation—Applied Radiation. THE CENTER FOR COMPUTER SCIENCES AND TECHNOLOGY conducts research and

provides technical services designed to aid Government agencies in the selection, acquisition, and effective use of automatic data processing equipment; and serves as the principal focus

for the development of Federal standards for automatic data processing equipment, techniques,

and computer languages. The Center consists of the following offices and divisions: Information Processing Standards—Computer Information — Computer Services — Sys- tems Development—Information Processing Technology.

THE OFFICE FOR INFORMATION PROGRAMS promotes optimum dissemination and

accessibility of scientific information generated within NBS and other agencies of the Federal government; promotes the development of the National Standard Reference Data System and a system of information analysis centers dealing with the broader aspects of the National Measure- ment System, and provides appropriate services to ensure that the NBS staff has optimum accessibility to the scientific information of the world. The Office consists of the following

organizational units:

Office of Standard Reference Data—Clearinghouse for Federal Scientific and Technical Information ' —Office of Technical Information and Publications—Library—Office of Public Information—Office of International Relations.

1 Headquarters and Laboratories at Gaithersburg, Maryland, unless otherwise noted; mailing address Washington, D.C 20234.

- Located at Boulder. Colorado 80302.

'> Located at 5285 Port Royal Road. Springfield. Virginia 22151.
U.S. DEPARTMENT OF COMMERCE

Washington, D.C. 20230

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U.S. DEPARTMENT OF COMMERCE