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User Guide
Elcometer 108
Hydraulic Adhesion Tester

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CONTENTS
SectionPage

1

Overview

en-2

2

Box Contents

en-2

3

Getting Started - Digital Pressure Gauge

en-3

4

Securing the Dolly

en-4

5

Preparing the Gauge for Test

en-5

6

Performing the Test

en-6

7

Assessing the Results - Destructive Testing

en-7

8

After Test

en-7

9

Using a Dolly Plug

en-8

10

Spares & Accessories

en-9

11

Warranty Statement

en-14

12

Technical Specification

en-14

13

Legal Notices & Regulatory Information

en-15

For the avoidance of doubt, please refer to the original English language version.
Tester Length:
520mm (20")
Tester Weight:
1.4kg (3lb)
Material Safety Data Sheet for the adhesives supplied by Elcometer can be downloaded via our website:
Cyanoacrylate Adhesive:www.elcometer.com/images/MSDS/elcometer_cyanoacrylate_adhesive.pdf
Araldite® Standard Two Part Epoxy Adhesive:www.elcometer.com/images/stories/MSDS/araldite_epoxy_adhesive.pdf© Elcometer Limited 2009-2019. All rights reserved. No part of this document may be reproduced, transmitted,
transcribed, stored (in a retrieval system or otherwise) or translated into any language, in any form or by anymeans (electronic, mechanical, magnetic, optical, manual or otherwise) without the prior written permission of
Elcometer Limited.

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1 OVERVIEW
Available with an analogue or digitalpressure gauge, the Elcometer 108
Hydraulic Adhesion Tester is an easy tooperate and fully portable Type III
adhesion gauge for measuring the bondstrength of a range of applied coatings.
The surface under examination is preparedand then a test dolly is attached byadhesive. When the adhesive is cured, thetester is attached to the dolly and a force isapplied by turning the handle.
When the stress exceeds the adhesion of the coating, the dolly andcoating detach from the substrate. The maximum value of hydraulicpressure during the test is recorded and is equivalent to the adhesionof the coating to the substrate.

2 BOX CONTENTS
<
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<
<
<
<
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<
<

a

Elcometer 108 Hydraulic Adhesion Tester
Heating Tongs (if ordered )Standard Flat Dollies (x5)
Dolly Plugs (x5)
Dolly Tool
Cyanoacrylate Adhesive (50g)
2 x AA Batteries (digital gauges only)
Transit Case
Calibration Certificate (if ordered)User Guidea

The Elcometer 108 is supplied with or without heating tongs depending on the part number ordered.
Heating tongs are also available to purchase separately, see Section 10.7 on page en-13 for details.

www.elcometer.com

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3 GETTING STARTED - DIGITAL PRESSURE GAUGE
3.1 FITTING THE BATTERIES
1Peel the protective rubber boot forward to expose the battery
compartment cover at the rear of the gauge.
2
Rotate the battery compartment cover anti-clockwise to the‘unlock’ position.
3
Identify correct polarity and fit 2 x AA alkaline dry batteries.
4
Replace battery compartment cover and rotate clockwise to the‘lock’ position.
5
Replace protective rubber boot taking care not to damage thefront panel of the display.
The battery symbol at the bottom right hand side of the display
indicates the battery condition.
Note: Batteries must be disposed of carefully to avoid environmental contamination.
Please consult your local Environmental Authority for information on disposal inyour region. Do not dispose of any batteries in fire.

3.2 SWITCHING THE GAUGE ON AND OFF
To Switch On: Press. The gauge displays the version ofsoftware fitted (e.g. 1.04.03 IDENT) followed by the MIN and MAX
range in MPa.
To Switch Off: Press
and hold for a second. The gauge willswitch off when the button is released.
Note: When the digital pressure gauge is switched off, “OFF” is permanently
displayed.

Automatic Switch Off: The gauge has a timer function and can be set
to switch off automatically after 1, 5 or 20 minutes of inactivity. The
gauge default setting is NONE.
1

Press

2

Press
or
to toggle between the options; NONE, 1 MIN,
5 MIN, 20 MIN.

3

Press

en-3

MENU

MENU

until TIMER is displayed followed by

to select.

MAX

to select the setting required.

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3 GETTING STARTED - DIGITAL PRESSURE GAUGE (continued)
3.3 SELECTING THE UNITS
The gauge can display readings in MPa (Megapascals) or PSI(Pounds per Square Inch).
1

Press

MENU

until UNITS is displayed followed by

2

Press

MENU

or

3

Press

MAX

to select.

to toggle between MPA and PSI.

to select the units required.

3.4 RESETTING THE GAUGEThe gauge has a gauge reset function which restores the original
factory settings.
1

Press

2

Press
again to confirm the reset. The gauge will reset andswitch off.

3

To cancel the reset request, press‘CANCL’ followed byto confirm.

MENU

until RESET is displayed followed by

MENU

or

MAX

to select.

to toggle to

4 SECURING THE DOLLY
1
Identify the dolly test surface.
2
Ensure test surface of dolly is clear ofold adhesive - see Section 8.2‘Cleaning the Dolly’ on page en-7.
3
Wipe dolly test surface and sample
area with a solvent to remove oil andgrease.
4
Apply a thin, even coat of adhesive todolly test surface. If adhesive is low
viscosity, see Section 9 ‘Using a Dolly
Plug’ on page en-8.
5
Press dolly on to sample for about 10
seconds.
6
Leave dolly undisturbed for at least 15 minutes (preferably for 2
hours or more), to allow the adhesive to harden.
7
If required, score the coating around the dolly using a dolly cutter- see Section 10 ‘Spares & Accessories’ on page en-9.
www.elcometer.com

ü

û

ü

ü

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5 PREPARING THE GAUGE FOR TEST
5.1 PREPARING THE GAUGE FOR TEST
1
Turn the handle anti-clockwise until it is fully unwound to release
any pressure in the tester.
2
Zero the pressure gauge, see Section 5.2.
3
Select the measurement units; MPA or PSI (digital pressuregauge only) - see Section 3.3 on page en-4.
5.2 ZEROING THE PRESSURE GAUGE
To zero the analogue pressure gauge:
Rotate the knob on the front of the pressuregauge to turn the red drag indicator to ‘0'.
To zero the digital pressure gauge:
1

Press

to switch the gauge on.

2

Fully unwind the handle (anti-clockwise) to release all pressure.

3

Press
to zero the gauge and set the gauge to store themaximum force recorded during test, known as ‘Max Hold’.
MAX

MAX

Max Hold: The display holds the maximum value until the
buttonis pressed for a second time. ‘Max Hold’ should be switched on before
undertaking an adhesion test, signified on the display by either MAXMPAor MAXPSI. The ‘Max Hold’ feature is switched off when the gauge isswitched off.
Note: “RLOCK” will be displayed if the gauge zero has failed. This is due to the pressure
not being fully released from the instrument. If this occurs, release all the pressure
by turning the crank handle followed by the coarse adjustment screw anti-clockwise
until fully unwound and press MAX to repeat the gauge zero.

5.3
1
2
3

ATTACHING THE GAUGE TO THE DOLLY
Ensure the pin is pushed fully upwards towards the coupling.
Pull coupling sleeve up and insert pin into centre of dolly.
Release coupling sleeve.
4 The instrument should grip the dolly firmly. If the coupling does not grip the

dolly firmly, there may be excess adhesive in the centre of the dolly. Use thedolly tool supplied to remove excess adhesive.

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6 PERFORMING THE TEST
1
Hold the gauge steady with one hand and turn the handle
clockwise slowly and evenly to apply an increasing force to thedolly and hence stress to the coating.
4 The rate at which the force is applied (the speed of rotation of the handle)

should be in accordance with the relevant Standard.

Continue until either;
(a)
(b)

2

the coating fails and the dolly is removed from the surface(destructive testing) or;
the minimum specified pressure value is reached(non-destructive testing).

Record the pressure indicated on the display and unwind thehandle.
The operating range of the Elcometer 108 is 2 to 18 MPa (290 to 2600psi).
DO NOT exceed the operating range as overloading could damage
the gauge.

Note: The oil inside the Elcometer 108 is incompressible and therefore any leakage
due to catastrophic failure of the gauge will result in an almost instantaneous
drop in pressure to atmospheric level.
Note: Dollies can be reused after cleaning until either the top of the dolly is severely
deformed or the dolly surface is no longer flat, see Section 8.2 ‘Cleaning the
Dolly’ on page en-7. Additional dollies are available from Elcometer or yourlocal supplier - see Section 10 ‘Spares & Accessories’ on page en-9 for details.

7 ASSESSING THE RESULTS - DESTRUCTIVE TESTING
Once pulled from the surface, examine the bottom of the dolly toassess the results.
a)a)Successful Test: In most cases the coating
will fully adhere to the dolly and the test can
be claimed as 100% valid.

b)Partial Failure: In some cases, the coating
will cover only part of the dolly face. A partial
adhesion / coating failure should be recorded
if the coating covers more than 50% of thedolly face.
Cohesive Failure: When the coating fails inthe body of the coating layer leaving somecoating on the surface and some coating on
the dolly face.

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b)

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7 ASSESSING THE RESULTS - DESTRUCTIVE TESTING (cont.)c)c) Adhesive Failure: If no coating is present on
the dolly this must be recorded as a failure of
the adhesive (or glue). This is normally due toincorrect or insufficient mixing of thecomponent parts of the adhesive,incompatibility of the adhesive and the coatingor the dolly and / or test surface has not been
properly prepared before test - see Section 4‘Securing the Dolly’ on page en-4.
8 AFTER TEST
8.1 AFTER TEST
Analogue pressure gauge:
1
Fully unwind the handle (anti-clockwise) to decrease the pressure
to zero.
2
Pull up the coupling sleeve to release the dolly.
Digital pressure gauge:
1
Fully unwind the handle (anti-clockwise) to decrease the pressure
to zero.
2
Pull up the coupling sleeve to release the dolly.
3
Press
to release the ‘Max Hold’.
MAX

4

Press

MAX

again to zero the gauge and reset ‘Max Hold’.

Note: Failure to release the ‘Max Hold’ and zero the gauge before each adhesion test
will result in an invalid adhesion measurement.

8.2 CLEANING THE DOLLY
Cleaning the dolly produces unpleasant fumes - ensure that thework area is extremely well ventilated. DO NOT inhale thefumes.
HOT! Exposed very hot surfaces. Use great care when handlingor placing the tongs. Allow to cool before storing.

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8 AFTER TEST (continued)
1
Plug the heating tongsa into the mains supply and leave to warm
up for 5 minutes.
2
Heat the dolly with the tongs for 3 to 5 minutes. This will soften
the adhesive.
3
Using a sharp blade, remove the adhesive/coating from the test
surface of the dolly.
4
Drop the dolly into water or allow to cool naturally. Do not put theheating tongs into water.
5
To remove any remaining adhesive, rub the dry, cool dolly withfine sandpaper or similar.
6
Use the dolly tool to clear any adhesive from the dolly centre.
7
Wipe the dolly test surface with a solvent to remove oil andgrease.
9 USING A DOLLY PLUG
Particularly in the case of low viscosity adhesives it is advisable toplace a nylon plug in the centre of the dolly before gluing it to thesurface.
This dolly plug stops glue going up the centre of the dolly, which can
impede the pin and prevent the test being carried out properly. Carefulcleaning of the centre hole increases the adhesion values for tests on
a given coating.
Each gauge is supplied complete with five dolly plugs. Additional plugs
are available to purchase separately, see Section 10.4 ‘Dolly Plugs’ on
page en-13.
To use the dolly plug:
1
Place the dolly plug through the centre hole on the dolly so thatthe tip protrudes just below the test surface.
2
Apply the adhesive to the dolly test surface, see Section 4‘Securing the Dolly’ on page en-4, taking care not to get adhesiveon the plug.
3
Press the dolly and dolly plug onto the sample area for about 10
seconds.
4
Remove the dolly plug from the centre of the dolly and wipe theend clean using tissue soaked in a suitable solvent. If the dollyplug becomes stuck to the dolly, use pliers to remove it.
5Complete the test as described in Sections 5 to 6.
a

The Elcometer 108 is supplied with or without heating tongs depending on the part number ordered.
Heating tongs are also available to purchase separately, see Section 10.7 on page en-13 for details.

www.elcometer.com

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10 SPARES & ACCESSORIES
10.1 ADHESIVES
The adhesive supplied with the Elcometer 108 is Cyanoacrylate
Adhesive.
Cyanoacrylate adhesives are normally recommended for gluing dollies
to the sample area due to their relatively quick curing time. However,there are a number of coatings for which the cyanoacrylate adhesives
may not be suitable. These are:1

Thermoplastics, celluloses, vinyl, chlorinated rubbers and someacrylics, due to the possibility of the glue reacting with the coating.

2

Porous coatings e.g. some metal spraying, in which case theglue, due to its low viscosity will travel into the coating, sticking
particles together and possibly altering its adhesion.

A two-pack epoxy such as Araldite® or a modified acrylic gel-typeadhesive should be used with the coatings described in (1) and (2)above.
If in doubt as to the type of adhesive to use, please contact the coating
manufacturer for advice.
Description
Cyanoacrylate Adhesiveb, 50g
Araldite® Standard Two Part
Epoxy Adhesive; 2x15ml Tubes

Part Number
T99911135
T99912906

Material Safety Data Sheets for the adhesives supplied by Elcometer can be downloaded via our
website:Cyanoacrylate Adhesive:www.elcometer.com/images/MSDS/elcometer_cyanoacrylate_adhesive.pdf®

Araldite Standard Two Part Epoxy Adhesive:www.elcometer.com/images/stories/MSDS/araldite_epoxy_adhesive.pdf®

®

®

Note: Other suitable adhesives include Loctite Hysol 907 and Araldite Standard.
The suitability of any adhesive should be determined by the user. Somecoatings can be adversely affected by adhesives. Some adhesives can becontaminated by coating environments, solvents etc.

b

Supplied as standard with each gauge.

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10 SPARES & ACCESSORIES (continued)
10.2 DOLLIESThe Elcometer 108 is supplied with five standard flat dollies with anoutside diameter of 19.4mm (0.76"). Additional dollies are available topurchase separately together with dollies for measuring on curved
surface - see Section 10.3.
Description
Standard Flat Dolly, 1 off

Part Number
T9999646-

10.3 DOLLIES FOR CURVED SURFACES
Using a flat dolly on a curved surface can produce misleading results.
The gap between the flat and curved surfaces will not be filled by theadhesive, resulting in one or more of the following effects:ŸŸŸThe dolly may peel or twist off instead of being pushed off.
The surface area to which pressure is applied, will be modified.
This will lead to results from different curvatures not being
comparable.
The amount of adhesive may not be sufficient to withstand theexerted force, resulting in the adhesive breaking before thecoating separates from the substrate.

These difficulties are overcome by using curved dollies on diameters ofless than approximately 2m (6' 7"). An extensive range of curved
dollies is available.
Curved and flat dollies are all used in the same way, matching themarks on the dollies with the longitudinal axis on the curved surface.
CONVEX DOLLIES FOR CONCAVE SURFACES
Internal Diameter

Dolly
Radius (mm)Min (mm)

Max (mm)

T999122741

940

1880

FLAT

T999122742

470

940

1880

T999122743

313

626

940

T999122744

235

470

626

T999122745

188

376

470

Part Number

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10 SPARES & ACCESSORIES (continued)
CONVEX DOLLIES FOR CONCAVE SURFACES
Internal Diameter

Dolly
Radius (mm)Min (mm)

Max (mm)

T999122746

157

314

376

T999122747

135

270

314

T999122748

118

236

270

T999122749

105

210

236

T9991227410

94

188

210

T9991227411

85

170

188

Part Number

CONCAVE DOLLIES FOR CONVEX SURFACES
External Diameter

Dolly
Radius (mm)Min (mm)

Max (mm)

T999121401

940

940

1880

T999121402

470

626

940

T999121403

314

472

628

T999121404

236

378

472

T999121405

189

316

378

T999121406

158

272

316

T999121407

136

238

272

T999121408

119

212

238

T999121409

106

192

212

T9991214010

96

174

192

T9991214011

87

160

174

T9991214012

80

148

160

T9991214013

74

138

148

T9991214014

69

130

138

T9991214015

65

121

130

T9991214016

61

116

121

T9991214017

58

110

116

Part Number

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10 SPARES & ACCESSORIES (continued)
CONCAVE DOLLIES FOR CONVEX SURFACES
External Diameter

Dolly
Radius (mm)Min (mm)

Max (mm)

T9991214018

55

104

110

T9991214019

52

100

104

T9991214020

50

96

100

T9991214021

48

92

96

T9991214022

46

88

92

T9991214023

44

84

88

T9991214024

42

80

84

T9991214025

40

77

80

T9991214026

38.5

74

77

T9991214027

37

71

74

T9991214028

35.5

68

71

T9991214029

34

66

68

T9991214030

33

64

66

T9991214031

32

62

64

T9991214032

31

60

62

T9991214033

30

58

60

T9991214034

29

56

58

T9991214035

28

54

56

T9991214036

27

52

54

T9991214037

26

51

52

T9991214038

25.5

50

51

Part Number

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10 SPARES & ACCESSORIES (continued)
10.4 DOLLY PLUGS
Each gauge is supplied complete with five dolly plugs. Additional
plugs are available to purchase separately. For information on whenand how to use dolly plugs, see Section 9 ‘Using a Dolly Plug’ on
page en-8.
Description
Dolly Plug, Pack of 5

Part Number
T99911136

10.5 DOLLY CUTTER
A dolly cutter is available which cuts through the coating to isolate thecoating area under the dolly. It should be noted that some coatings will
be damaged by such an operation, which may cause micro-cracks.
Use of a dolly cutter should be agreed before testing starts.
Description
Dolly CutterPart Number
T99914009

10.6 DOLLY TOOL
Supplied as standard with each gauge, the dolly tool is used to remove
excess adhesive from the centre of the dolly.
Description
Dolly Tool

Part Number
T9994586-

10.7 HEATING TONGSa
Heating tongs are used to soften the adhesive and remove the dolly
from the test surface, see Section 8.2 ‘Cleaning the Dolly’ on pageen-7 for further information.
Description
Heating Tongs; EU 220V / UK 240V
Heating Tongs; EU to UK Converter Plugc
Heating Tongs; US 110V

Part Number
T99923147
T99923102
T99923103

a

The Elcometer 108 is supplied with or without heating tongs depending on the part number ordered.
Heating tongs are also available to purchase separately, see Section 10.7 on page en-13 for details.
cSupplied with T99923147.

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11 WARRANTY STATEMENTThe Elcometer 108 is supplied with a one year warranty against
manufacturing defects, excluding contamination and wear.
12 TECHNICAL SPECIFICATION
Elcometer 108
Standard Flat
Dolly

DigitalAnalogueOutside Diameter: 19.4mm (0.76")
Inside Diameter: 3.7mm (0.15")
Area: 284mm2 (0.44 sq. inch)

Scale Range

0 - 25MPa(0 - 3600psi)

0 - 25MPa(0 - 3600psi)

Operating Range(Certiﬁed)

2 - 18MPa(290 - 2600psi)

2 - 18MPa(290 - 2600psi)

Scale Resolution

1MPa (100psi)

0.1MPa (1psi)

Accuracy

1MPa (150psi)±3% or 0.4MPa(60psi)d-

2 x AA alkaline
dry batteries

Power Supplye
Tester Length

520mm (20")

Tester Weight

1.4kg (3lb)

Kit Dimensions

497 x 411 x 140mm (19.6 x 16.2 x 5.5")

Kit Weight

4.9kg (10.8lb)

Can be used in accordance with:ASTM D 4541, ISO 16276-1, NF T30-606
Note: The Elcometer 108 Hydraulic Adhesion Tester is a Type III adhesion tester as
defined by ASTM D4541.

deWhichever is the greater.
Rechargeable batteries can be used.

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13 LEGAL NOTICES & REGULATORY INFORMATIONThe Elcometer 108 meets the Electromagnetic Compatibility Directive.
The Elcometer 108 is Class B, Group 1 ISM equipment according to CISPR 11.
Group 1 ISM product: A product in which there is intentionally generated and/or used conductively
coupled radio-frequency energy which is necessary for the internal functioning of the equipment itself.
Class B product: Suitable for use in domestic establishments and in establishments directly connected
to a low voltage power supply network which supplies buildings used for domestic purposes.
Applicable Patents:
UK: 2,166,875A & 2,166,876A
Germany: P3676087.0 & P3676088.9
Norway: 165,938 & 165,937

US: 4,586,371 & 4,606,225
Canada: 1,272,395 & 1,272,394
Sweden, France and Italy: EP0244518 & 0244519

The Elcometer 108 is packed in a cardboard package. Please ensure that this packaging is disposedof in an environmentally sensitive manner. Consult your local Environmental Authority for further
guidance.
is a registered trademark of Elcometer Limited, Edge Lane, Manchester, M43 6BU.
United Kingdom
All other trademarks acknowledged.
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