Issue date November 2015

Surface Preparation
Surface preparation means all activities and methods involved in preparing metal surface for paintapplication. Proper surface preparation is essential for the success of any coating scheme. The
importance of removing oil, grease and surface contaminants can not be overemphasized. The
performance of any paint coating is directly dependent on the correct and thoroughly surface preparation
prior to paint application. The technologically advanced coating system may fail if the surface preparation
is incorrect or incomplete.

1. Methods of surface preparation
There are a number of surface preparation methods and the equipment imvolved. The folowing
equipments and tools are mainly to be used. For preparation of steel surface, power tool cleaning andblast cleaning is generally applied. Recently water jetting has come to be applied for M&R.
Methods
Manualmethods

Mechanicalmethods

Equipments／Tools

・Hand tool cleaning

・Steel brushes
・Steel scrapers
・Pick hammers
・Sand / carborundum paper・Power tool cleaning・Pneumatic hammers
・Needle-guns
・Grinders・Rotary grinding disks

・Blast cleaning

・Dry abrassive blasting equipment

・Dry abrassive blasting・High pressure water jetting

Steel brush

Steel scraper

・Water jetting equipment

Pick hammer

Rotary grinding disk

2. Surface preparation for Newbuilding(1) Primary surface praparation
In the surface preparation for ship steel, a primary surface preparation is conducted to remove millscales on the steel. After that, shop primer is applied to the steel for the primary rust preventive.
(2) Secondary surface preparation
Shop-primed steel is generally used in shipbuilding yards. After constructing blocks or hull structureswith the shop-primed steel by welding and cutting, before painting, the shop-primed steel isprovided with the secondary surface preparatioin to remove the rusted / damaged parts and thecontaminants on the welds.

3. Standard for surface preparation
The internationally used standards of surface preparation is as follows. The standards including ISO,SSPC and NACE provide the degree of rust removal for the steel that is applied with no shop primer.
Regarding secondary surface preparation for the shop-primed steel, the Shipbuilding Research
Association of Japan stipulated the "Standard of Steel Surface Preparation" (JSRA-SPSS).
① ISO 8501-1 ( International Standard Organization )② SSPC (Steel Structures Painting Council)③ NACE (National Association of Corrosion Engineering)④ JSRA - SPSS (Japanese Ship Research Association)(1) Hand and power tool cleaning
Various standards（For reference）

ISO8501-1

Rust grades

AB

C

D

SSPC

NACE

JSRA

Steel surface
Steel surface
Steel surface on Steel surface onlargely covered which has
which the millwhich the millwith adhering
begun to rustscale has rusted scale has rustedmill scale butand from millaway or fromaway and on
little, if any, rust. scale has begun which it can be which generalto flake.
scraped, but
pitting is visible
with slight pitting under normal
visible underversion
normal version.

C St 2

D St 2

SP 2

-

Pt 1

C St 3

D St 3

SP 3

-

Pt 2
Pt 3

Preparation grades
Thoroughly hand and power tool cleaning
When viewed without
magnification, the surface
shall be free from visible oil,grease and dirt, and frompoorly adhering mill scale,rust, paint coatings andforeign matter.

-B St 2

Very thoroughly hand and power tool cleaning
As for St 2, but the surface
shall be treated much morethoroughly to give a metallic
sheen arising from metallic
substrate.

-B St 3

【Reference】 Hand and power tool cleaning
Rust grades

BBC CD

B St 2C St 2

D St 2B StC 3 D

C St 3

D St 3

DPeparation

(2) Blast cleaning
Various standards（For reference）

ISO8501-1

CDJSRA

B

Steel surface
Steel surface on Steel surface on
which has
which the millwhich the mill
begun to rustscale has rusted scale has rusted
and from millaway or fromaway and onscale has begun which it can be which generalto flake.
scraped, but
pitting is visible
with slight pitting under normal
visible underversion
normal version.

NACEA
Steel surface
largely covered
with adhering
mill scale but
little, if any, rust.

SSPC

Rust grades

Preparation grades

Light blast-cleaning
When viewed without
magnification, the surface
shall be free from visible oil,grease and dirt, and frompoorly adhering mill scale,rust, paint coatings andforeign matter.

-B Sa 1C Sa 1

D Sa 1SP 7 No.4--

B Sa 2C Sa 2

D Sa 2

SP 6 No.3

Sd 1

A Sa 2 1/2 B Sa 2 1/2 C Sa 2 1/2 D Sa 2 1/2 SP 10 No.2

Sd 2

Thoroughly blast-cleaning
When viewed without
magnification, the surface
shall be free from visible oil,grease and dirt, and frommost of the mill scale, rust,
paint coatings and foreign
matter. Any residual
contamination shall befirmly adhering.

Very thoroughly blast-cleaning
When viewed without
magnification, the surface
shall be free from visible oil,grease and dirt, and frommost of the mill scale, rust,
paint coatings and foreignmatter. Any remaining
traces of contamination
shall show only as slightstains in the form of spots
or stripes.

Blast-cleaning to visually clean steel
When viewed without
magnification, the surface
shall be free from visible oil,grease and dirt, and frommost of the mill scale, rust,
paint coatings and foreign
matter. It shall have auniform metallic colour.

A Sa 3

B Sa 3

C Sa 3

D Sa 3

SP 5 No.1 Sd 3

【Reference】 Blast cleaning
Rust grades

CD

Preparation grades
Not
B Sa 1C Sa 1

D Sa 1

Not applicable

B Sa 2

C Sa 2

D Sa 2

A Sa 2 1/2

B BSaSa2 21/12/2

C SaC 2Sa1/221/ 2
D Sa D2 Sa2

A Sa 3

B Sa 3

C Sa 3

D Sa 3

AB