SIST EN ISO 8504-2:2020

SLOVENSKI STANDARD
oSIST prEN ISO 8504-2:2019
01-februar-2019
Priprava jeklenih podlag pred nanašanjem barv in sorodnih premazov - Postopki
priprave površine - 2. del: Peskanje z abrazivi (ISO/DIS 8504-2:2018)
Preparation of steel substrates before application of paints and related products -
Surface preparation methods - Part 2: Abrasive blast-cleaning (ISO/DIS 8504-2:2018)
Vorbereitung von Stahloberflächen vor dem Auftragen von Beschichtungsstoffen -
Verfahren für die Oberflächenvorbereitung - Teil 2: Strahlen (ISO/DIS 8504-2:2018)
Préparation des subjectiles d'acier avant application de peintures et de produits
assimilés - Méthodes de préparation des subjectiles - Partie 2: Décapage par projection
d'abrasif (ISO/DIS 8504-2:2018)
Ta slovenski standard je istoveten z: prEN ISO 8504-2
ICS:
25.220.10 Priprava površine Surface preparation
87.020 Postopki za nanašanje Paint coating processes
barvnih premazov
oSIST prEN ISO 8504-2:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 8504-2:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 8504-2
ISO/TC 35/SC 12 Secretariat: BSI
Voting begins on: Voting terminates on:
2018-12-17 2019-03-11
Preparation of steel substrates before application of paints
and related products — Surface preparation methods —
Part 2:
Abrasive blast-cleaning
Préparation des subjectiles d'acier avant application de peintures et de produits assimilés — Méthodes de
préparation des subjectiles —
Partie 2: Décapage par projection d'abrasif
ICS: 25.220.10
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 8504-2:2018(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2018

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COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Abrasives . 3
4.1 Materials and types . 3
4.2 General requirements . 4
4.2.1 Technical . 4
4.2.2 Health and safety . 5
4.3 Selection considerations . 5
5 Abrasive blast-cleaning methods . 6
5.1 Dry abrasive blast-cleaning . 6
5.1.1 Centrifugal abrasive blast-cleaning . 6
5.1.2 Compressed-air abrasive blast-cleaning . 6
5.1.3 Vacuum or suction-head abrasive blast-cleaning . 7
5.2 Wet abrasive blast-cleaning . 7
5.2.1 General. 7
5.2.2 Moisture-injection abrasive blast-cleaning (compressed-air moisture-
injection abrasive blast- cleaning) . 7
5.2.3 Compressed-air wet abrasive blast-cleaning . 8
5.2.4 Slurry blast-cleaning . 9
5.2.5 Pressurized-liquid blast-cleaning . 9
6 Procedure.10
6.1 Preparation before blast-cleaning .10
6.2 Blast-cleaning .10
6.3 After blast-cleaning .10
7 Assessment of the blast-cleaned surface.11
Annex A (informative) International Standards for metallic and non-metallic blast-cleaning
abrasives .12
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Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee
SC 12 ,Preparation of steel substrates before application of paints and related products.
This third edition cancels and replaces the second edition (ISO 8504-2:2000), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— Normative references updated;
— Editorially revised.
ISO 8504 consists of the following parts, under the general title Preparation of steel substrates before
application of paints and related products — Surface preparation methods:
— Part 1: General principles
— Part 2: Abrasive blast-cleaning
— Part 3: Hand- and power-tool cleaning
Further parts are planned.
A list of all parts in the ISO 8504 series can be found on the ISO website.
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Introduction
The performance of protective coatings of paint and related products applied to steel is significantly
affected by the state of the steel surface immediately prior to painting. The principal factors that are
known to influence this performance are:
the presence of rust and mill scale;
the presence of surface contaminants, including salts, dust, oils and greases;
the surface profile.
International Standards ISO 8501, ISO 8502 and ISO 8503 have been prepared to provide methods
of assessing these factors, while ISO 8504 provides guidance on the preparation methods that are
available for cleaning steel substrates, indicating the capabilities of each in attaining specified levels of
cleanliness.
These International Standards do not contain recommendations for the protective coating system
to be applied to the steel surface. Neither do they contain recommendations for the surface quality
requirements for specific situations even though surface quality can have a direct influence on the
choice of protective coating to be applied and on its performance. Such recommendations are found in
other documents such as national standards and codes of practice. It will be necessary for the users of
these International Standards to ensure the qualities specified are
— compatible and appropriate both for the environmental conditions to which the steel will be exposed
and for the protective coating system to be used;
— within the capability of the cleaning procedure specified.
The four International Standards referred to below deal with the following aspects of preparation of
steel substrates:
ISO 8501 — Visual assessment of surface cleanliness;
ISO 8502 — Tests for the assessment of surface cleanliness;
ISO 8503 — Surface roughness characteristics of blast-cleaned steel substrates;
ISO 8504 — Surface preparation methods.
Each of these International Standards is in turn divided into separate parts.
The primary objective of surface preparation is to ensure the removal of deleterious matter and to
obtain a surface that permits satisfactory adhesion of the priming paint to steel. It should also assist in
reducing the amounts of contaminants that initiate corrosion.
This part of ISO 8504 describes abrasive blast-cleaning methods. It should be read in conjunction with
ISO 8504-1.
Abrasive blast-cleaning is a most effective method for mechanical surface preparation. It is widely
applicable because this method of surface preparation has a number of versatile features listed below.
a) The method allows a high production rate.
b) The equipment can be stationary or mobile and is adaptable to the objects to be cleaned.
c) The method is applicable to most types and forms of steel surface.
d) Many different surface states can be produced, for example different preparation grades and
surface profiles.
e) Effects such as cleaning, peening, roughening, levelling and lapping can be produced.
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f) It is possible to remove selectively partly failed coatings, leaving sound coatings intact.
g) Abrasive ricochet (rebound) enables the cleaning of otherwise inaccessible areas.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 8504-2:2018(E)
Preparation of steel substrates before application of paints
and related products — Surface preparation methods —
Part 2:
Abrasive blast-cleaning
1 Scope
This part of ISO 8504 describes abrasive blast-cleaning methods for the preparation of steel surfaces
before coating with paints and related products. It also contains information on the effectiveness of
the individual methods and their fields of application. It describes the equipment to be used and the
procedure to be followed
ISO 8504 is applicable to new and corroded steel surfaces and to steel surfaces that are uncoated or
have been previously coated with paints and related products. For limitations, see note 2.
NOTE 1 These methods are essentially intended for hot-rolled steel to remove mill scale, rust, etc., but could
also be used for cold-rolled steel of sufficient thickness to withstand the deformation caused by the impact of
abrasive.
NOTE 2 There are several items that should be included in the purchaser's procurement documents
to supplement this part of ISO 8504. Items that should be considered as a part of surface preparation before
coating are edge grinding, removal of grease and oil, porosity of welds, removal of weld spatter, removal of
burrs and other sharp edges, grinding of welds, filling of pits and other surface imperfections that may cause
premature failure of the coating system (see ISO 8501-3 for more information) and the removal of water-soluble
contaminants.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4628-3, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and
size of defects, and of intensity of uniform changes in appearance — Part 3: Assessment of degree of rusting
ISO 8501-1, Preparation of steel substrates before application of paints and related products — Visual
assessment of surface cleanliness — Part 1: Rust grades and preparation grades of uncoated steel substrates
and of steel substrates after overall removal of previous coatings
ISO 8501-2, Preparation of steel substrates before application of paints and related products — Visual
assessment of surface cleanliness — Part 2: Preparation grades of previously coated steel substrates after
localized removal of previous coatings
ISO 8501-3, Preparation of steel substrates before application of paints and related products — Visual
assessment of surface cleanliness — Part 3: Preparation grades of welds, edges and other areas with surface
imperfections
ISO 8501-4, Preparation of steel substrates before application of paints and related products — Visual
assessment of surface cleanliness — Part 4: Initial surface conditions, preparation grades and flash rust
grades in connection with high-pressure water jetting
ISO 8502-2, Preparation of steel substrates before application of paints and related products — Tests for
the assessment of surface cleanliness — Part 2: Laboratory determination of chloride on cleaned surfaces
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ISO 8502-3, Preparation of steel substrates before application of paints and related products — Tests for
the assessment of surface cleanliness — Part 3: Assessment of dust on steel surfaces prepared for painting
(pressure-sensitive tape method)
ISO 8502-9, Preparation of steel substrates before application of paints and related products — Tests for
the assessment of surface cleanliness — Part 9: Field method for the conductometric determination of
water-soluble salts
ISO 8503-1, Preparation of steel substrates before application of paints and related products — Surface
roughness characteristics of blast-cleaned steel substrates — Part 1: Specifications and definitions for ISO
surface profile comparators for the assessment of abrasive blast-cleaned surfaces
ISO 8503-2, Preparation of steel substrates before application of paints and related products — Surface
roughness characteristics of blast-cleaned steel substrates — Part 2: Method for the grading of surface
profile of abrasive blast-cleaned steel — Comparator procedure
ISO 8504-1, Preparation of steel substrates before application of paints and related products — Surface
preparation methods — Part 1: General principles
ISO 8504-3, Preparation of steel substrates before application of paints and related products — Surface
preparation methods — Part 3: Hand- and power-tool cleaning
ISO 11124 (all parts), Preparation of steel substrates before application of paints and related products —
Specifications for metallic blast-cleaning abrasives
ISO 11126 (all parts), Preparation of steel substrates before application of paints and related products —
Specifications for non-metallic blast-cleaning abrasives
ISO 12944-4, Paints and varnishes — Corrosion protection of steel structures by protective paint systems —
Part 4: Types of surface and surface preparation
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
abrasive blast-cleaning
impingement of a high-kinetic-energy stream of abrasive on to the surface to be prepared
Note 1 to entry: The abrasive is typically propelled either by centrifugal force or by a high-velocity stream of fluid
such as air or water to remove rust, mill scale, existing coatings and other contaminants and expose the substrate.
The cleaned surface has a characteristic secondary profile dependent on the blast-cleaning conditions, the
properties of the abrasive, the initial condition of the surface and the properties of the steel being blast-cleaned.
The initial surface roughness or primary profile may be altered by the abrasive blast-cleaning procedure. Surface
profiles are assessed using the method described in ISO 8503-2. When selecting a surface preparation method,
it is necessary to consider the preparation grade required to give a level of surface cleanliness and, if required, a
surface profile (roughness), such as coarse, medium or fine (see ISO 8503-1 and ISO 8503-2), appropriate to the
coating system to be applied to the steel surface. Since the cost of surface preparation is usually in proportion to
the level of cleanliness, a preparation grade appropriate to the purpose and type of coating system or a coating
system appropriate to the preparation grade which can be achieved should be chosen.
3.2
blast-cleaning abrasive
solid material intended to be used for abrasive blast-cleaning
3.3
shot
particles that are predominantly round, that have a length of less than twice the maximum particle
width and that do not have edges, broken faces or other sharp surface defects
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3.4
grit
particles that are predominantly angular, that have fractured faces and sharp edges and that are less
than half-round in shape
3.5
cylindrical particles
sharp-edged particles, having a diameter-to-length ratio of 1:1, cut so that their faces are approximately
at right angles to their centreline
4 Abrasives
4.1 Materials and types
4.1.1 A wide variety of natural and synthetic solid materials and several liquids are used for abrasive
blast- cleaning. Solid materials commonly in use for the preparation of steel surfaces before coating are
given in Table 1. Each material provides a characteristic performance and surface finish.
When selecting a blast-cleaning abrasive, the following factors relating to its initial condition shall be
considered:
— sub-group and type (see Table 1);
— indication of chemical composition;
— range of particle size (see 4.1.2);
— particle hardness (for example Vickers, Rockwell or Mohs, or as measured by another appropriate
method). International Standards for metallic and non-metallic blast-cleaning abrasives are listed
for information in annex A.
4.1.2 The size and shape of the particles of an abrasive may change during use or re-use and this
change can affect the resultant surface texture of the blast-cleaned steel.
Table 1 — Commonly used blast-cleaning abrasives for steel substrate preparation
Type Abbrevia- Initial parti- Compara- Remarks
a
tion cle shape tor
(see Table 2)
Metallic (M) Cast iron Chilled M/CI G G Mainly for
blast-cleaning compressed-
c
abrasives air blast-
cleaning
b
Cast steel High-carbon M/HCS S or G S or G Mainly for
centrifugal
Low-carbon M/LCS S S
blast-clean-
b
Cut steel — M/CW C S
ing
wire
a
Comparator to be used when assessing the resultant surface profile. The method for evaluating the surface profile by
comparator is described in ISO 8503-2.
b
Certain types of abrasive rapidly change their shape when used. As soon as this happens, the appearance of the surface
profile changes and becomes closer to that of the "shot" comparator.
c
International Standards for the range of abrasives given here are listed in annex A: the ISO 11124 series for metallic
blast-cleaning abrasives and the ISO 11126 series for non-metallic blast-cleaning abrasives.
d
Certain types of abrasive, depending on hardness, rapidly change their shape when used. As soon as this happens the
appearance of the profile changes and becomes more similar to that of the “shot” comparator.
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Table 1 (continued)
Type Abbrevia- Initial parti- Compara- Remarks
a
tion cle shape tor
(see Table 2)
Non-metallic Natural Olivine N/OL G G Mainly for
(N) blast- compressed-
Staurolite N/ST S G
cleaning air blast-
Almandite garnet N/GA G G
c
abrasives cleaning
Synthetic Iron slag (Calcium N/FE1 G G Mainly for
silicate) compressed-
G
air blast-
Steel slag (Calcium N/FE2 G/S
cleaning
silicate)
Copper (Iron sili- N/CU G/S
refinery cate)
slag
Nickel (Iron sili- N/NI1 G
cate)
refinery
slag
Ferro nick- (Magnesium N/NI2 G/S
el smelting silicate)
slag
Coal fur- (Aluminium N/CS G
nace slag silicate)
Fused aluminium oxide N/FA G G —
a
Comparator to be used when assessing the resultant surface profile. The method for evaluating the surface profile by
comparator is described in ISO 8503-2.
b
Certain types of abrasive rapidly change their shape when used. As soon as this happens, the appearance of the surface
profile changes and becomes closer to that of the "shot" comparator.
c
International Standards for the range of abrasives given here are listed in annex A: the ISO 11124 series for metallic
blast-cleaning abrasives and the ISO 11126 series for non-metallic blast-cleaning abrasives.
d
Certain types of abrasive, depending on hardness, rapidly change their shape when used. As soon as this happens the
appearance of the profile changes and becomes more similar to that of the “shot” comparator.
Table 2 — Initial particle shape
Designation and initial particle shape Symbol
Shot — round S
Grit — angular, irregular G
Cylindrical — sharp-edged C
4.2 General requirements
4.2.1 Technical
Abrasives shall be dry (except when added to pressurized liquid or slurry blast-cleaning systems) and
shall be free-flowing to permit consistent metering into the blast stream.
Abrasives shall meet the requirements specified in the ISO 11124 and ISO 11126 series of standards and
be free from corrosive constituents and adhesion-impairing contaminants. Because of their deleterious
effect on the blast-cleaned steel surface, permanently contaminated abrasives (for example those that
cannot be cleaned before recycling and those produced from slag that has been granulated by the use of
saline water, i.e. sea water, for cooling) are not permitted.
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4.2.2 Health and safety
The procedures described in this part of ISO 8504 are intended to be carried out by suitably trained and/
or supervised personnel. The substances and procedures used in these methods may be injurious to
health if adequate precautions are not taken. Attention is drawn in the text to certain specific hazards.
This part of ISO 8504 refers only to the technical suitability of the methods and does not absolve the
user from statutory obligations relating to health and safety.
Equipment, materials and abrasives used for surface preparation can be hazardous. It is important to
ensure that adequate instructions are given and that all required precautions are exercised.
4.3 Selection considerations
4.3.1 Selection of a suitable abrasive, together with an appropriate blast-cleaning method and
operating conditions, is necessary to achieve the required standard of surface preparation.
The type of blast-cleaning abrasive — i.e. its particle size distribution, shape, hardness, density and
impact behaviour (deformation or shatter characteristics) — is important in determining the standards
of cleanliness, the cleaning rate and the resulting surface profile of the blast-cleaned surface.
NOTE The particle size distribution of abrasives should be determined using the methods specified in
ISO 11125-2 and ISO 11127-2 respectively (see annex A).
4.3.2 Preliminary blast-cleaning tests are recommended to determine the most effective abrasive, the
resulting surface preparation grade and the resulting surface profile (see ISO 8501-1 or ISO 8501-2 and
ISO 8503-2 ). If recycled abrasive is to be used for the surface preparation work, it is essential that a
preliminary test be carried out with the same material, as new abrasive may give misleading results [see
also 4.3.3 c)].
4.3.3 When selecting an abrasive, it is essential that the following considerations be taken into account:
a) The influence of a particular particle size on the resulting surface profile is normally greater for
metallic abrasives than for non-metallic abrasives. This is because the shatter characteristics differ
and because differences in density affect the kinetic energy of the abrasive particles.
b) A balanced mixture of particle sizes will produce the optimum level of cleanliness, cleaning rate
and surface profile.
c) In blast-cleaning plants where the abrasive
...