ASTM D1731-09

Standard Practices for Preparation of Hot-Dip Aluminum Surfaces for Painting

ABSTRACT
These practices describe procedures for the preparation of hot-dip aluminum surfaces for painting. Two types of surface preparation are included: solvent cleaning and chemical treatments. Solvent cleaning of the surfaces may be done by any of the following methods: manual swabbing or dip washing with a solvent such as mineral spirits or high flask solvent naphtha, solvent spray cleaning, and vapor degreasing in special equipment. On the other hand, surface preparation of aluminum for painting may be achieved by any of the following chemical treatment methods: use of alkaline cleaners, use of alcoholic phosphoric acid cleaners, use of acid fluoride deoxidizer, crystalline phosphate treatment, amorphous phosphate treatment, carbon chromate treatment, amorphous chromate treatment, and acid-bound resinous treatment.
SCOPE
1.1 These practices describe procedures for the preparation of hot-dip aluminum surfaces for painting.
1.2 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 14-Apr-2009
• ICS: 87.020 - Paint coating processes
• Technical Committee: B08 - Metallic and Inorganic Coatings
• Drafting Committee: B08.07 - Conversion Coatings

Relations

• Replaces: ASTM D1731-03 - Standard Practices for Preparation of Hot-Dip Aluminum Surfaces for Painting
• Effective Date: 15-Apr-2009
• Replaced By: ASTM D1731-09(2014) - Standard Practices for Preparation of Hot-Dip Aluminum Surfaces for Painting
• Effective Date: 01-Nov-2014
• Referred By: ASTM B905-00(2021) - Standard Test Methods for Assessing the Adhesion of Metallic and Inorganic Coatings by the Mechanized Tape Test
• Effective Date: 15-Apr-2009
• Referred By: ASTM D6577-15(2019) - Standard Guide for Testing Industrial Protective Coatings
• Effective Date: 15-Apr-2009
• Referred By: ASTM D3322-23 - Standard Practice for Testing Primers and Primer Surfacers Over Preformed Metal
• Effective Date: 15-Apr-2009
• Referred By: ASTM D3451-06(2017) - Standard Guide for Testing Coating Powders and Powder Coatings
• Effective Date: 15-Apr-2009
• Referred By: ASTM D2454-23 - Standard Practice for Determining the Effect of Overbaking on Organic Coatings
• Effective Date: 15-Apr-2009

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D1731 − 09
StandardPractices for
1
Preparation of Hot-Dip Aluminum Surfaces for Painting
This standard is issued under the fixed designation D1731; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Solvent Cleaning
1.1 These practices describe procedures for the preparation 4.1 The surfaces may be prepared for painting by any of the
of hot-dip aluminum surfaces for painting. methods for solvent cleaning described in 4.2 and 4.3.
1.2 This standard may involve hazardous materials,
4.2 Method 1—Manual swabbing or dip washing with a
operations, and equipment. This standard does not purport to
solvent such as mineral spirits or high flask solvent naphtha. It
address all of the safety concerns, if any, associated with its
is extremely difficult to produce a clean metal surface by this
use. It is the responsibility of the user of this standard to
method. Accumulated contaminants in the solvent or on the
establish appropriate safety and health practices and deter-
swab are frequently redeposited on the surface being prepared.
mine the applicability of regulatory limitations prior to use.
4.3 Method 2—Solvent spray cleaning in accordance with
Method A, Procedure 1 of Practice D609.
2. Referenced Documents
2
4.4 Method 3—Vapor degreasing in special equipment in
2.1 ASTM Standards:
accordance with the latest revision of Method A, Procedure 2
D609 Practice for Preparation of Cold-Rolled Steel Panels
of Practice D609, employing trichlorethylene or perchloreth-
for Testing Paint, Varnish, Conversion Coatings, and
ylenevapor.Solventcleaningdoesnotdisturbthenaturaloxide
Related Coating Products
3
film on the metal and may prove adequate for some applica-
2.2 Military Standards:
tions.
MIL-DTL-5541 Chemical Conversion Coatings on Alumi-
num and Aluminum Alloys
5. Chemical Treatment
MIL-C-15328 Specification for Acid Wash Primers
MIL-M-10578B Metal Conditioner and Rust Remover
5.1 The surfaces may be prepared for painting by any of the
(Phosphoric Acid Type)
methods for chemical treatment (Note 1) described in 5.2 to
5.9:
3. Types of Surface Preparations
NOTE 1—Materials and procedures employed in these methods of
3.1 Two types of surface preparations are covered as fol-
treatment are available from a number of sources as proprietary com-
lows:
pounds or methods. Selection may be made from available sources. The
hexavalent chromium methods given are not recommended as hexavalent
3.1.1 Solvent Cleaning, and
chromium is a known carcinogen.
3.1.2 Chemical Treatments.
5.2 Method 1, Alkaline Cleaners—Etching alkaline
3.2 These two types cover several methods as described in
solutions, such as caustic soda, should be avoided because of
Section 5. Variations in surface treatment produce end condi-
the possibility of dissolving away the aluminum coating
tions which differ and which do not necessarily yield identical
thereby exposing the base metal. Since inhibited alkaline
results when paints are applied. Service conditions will dictate
cleaners do not etch the surface, they can be used to remove
the type of surface preparation that should be selected.
grease, oil, and other organic solids from hot dip aluminum.
After alkali cleaning, the surface should be thoroughly rinsed
1
ThesepracticesareunderthejurisdictionofASTMCommitteeB08onMetallic
with clean water. Most often alkaline-cleaned surfaces are
and Inorganic Coatingsand is the direct responsibility of Subcommittee B08.07 on
subsequently processed by one of the following methods,
Conversion Coatings.
described in 5.3-5.9.
Current edition approved April 15, 2009. Published May 2009. Originally
approved in 1960. Last previous edition approved in 2003 as D1731 – 03. DOI:
5.3 Method 2, Alcoholic Phosphoric Acid Cleaners —This
10.1520/D1731-09.
2
treatment involves the use of an aqueous solution of phos-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
phoric acid with alcohol or other organic solvents, together
Standards volume information, refer to the standard’s Document Summary page on
with wetting agents, emulsifying agents, etc. The solution may
the ASTM website.
3
be applied by swabbing or dipping (preferably at a temperature
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098 of 70 to 90°F (21 to 32°C)). The solution should remain on the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D1731–03 Designation: D 1731 – 09
Standard Practices for
1
Preparation of Hot-Dip Aluminum Surfaces for Painting
This standard is issued under the fixed designation D 1731; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 These practices describe procedures for the preparation of hot-dip aluminum surfaces for painting.
1.2 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all
of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate
safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D 609 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and Related
Coating Products
2.2 Military Standards:
3
MIL-C-5541 Military Standards:
MIL-DTL-5541 Chemical Conversion Coatings on Aluminum and Aluminum Alloys
MIL-C-15328 Specification for Acid Wash Primers
MIL-M-10578B Metal Conditioner and Rust Remover (Phosphoric Acid Type)
3. Types of Surface Preparations
3.1 Two types of surface preparations are covered as follows:
3.1.1 Solvent Cleaning, and
3.1.2 Chemical Treatments.
3.2 These two types cover several methods as described in Section 5. Variations in surface treatment produce end conditions
which differ and which do not necessarily yield identical results when paints are applied. Service conditions will dictate the type
of surface preparation that should be selected.
4. Solvent Cleaning
4.1 The surfaces may be prepared for painting by any of the methods for solvent cleaning described in 4.2 and 4.3.
4.2 Method 1—Manual swabbing or dip washing with a solvent such as mineral spirits or high flask solvent naphtha. It is
extremely difficult to produce a clean metal surface by this method. Accumulated contaminants in the solvent or on the swab are
frequently redeposited on the surface being prepared.
4.3 Method 2—Solvent spray cleaning in accordance with Method A, Procedure 1 of Practice D 609.
4.4 Method 3—Vapor degreasing in special equipment in accordance with the latest revision of Method A, Procedure 2 of
Practice D 609, employing trichlorethylene or perchlorethylene vapor. Solvent cleaning does not disturb the natural oxide film on
the metal and may prove adequate for some applications.
5. Chemical Treatment
5.1 The surfaces may be prepared for painting by any of the methods for chemical treatment (Note 1) described in 5.2 to 5.9:
NOTE 1—Materials and procedures employed in these methods of treatment are available from a number of sources as proprietary compounds or
1
These practices are under the jurisdiction of ASTM Committee B08 on Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee B08.07 on
Chromate Conversion Coatings.
Current edition approved Sept. 10, 2003. Published Sept. 2003. Originally approved in 1960. Last previous edition approved in 1998 as D1731–67(1998). on Conversion
Coatings.
Current edition approved April 15, 2009. Published May 2009. Originally approved in 1960. Last previous edition approved in 2003 as D 1731 – 03.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book ofASTM Standards
, Vol 06.01.volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

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D1731–09
methods. Selection may be made from available sources. The hexavalent chromium methods given are not recommended as hexavalent chromium is a
known carcinogen.
5.2 Method 1,Alkaline Cleaners—Etching alkaline solutions, such as caustic soda, should be avoided because of the possibility
ofdissolvingawaythealuminumcoatingtherebyexposingthebasemetal.Sinceinhibitedalkalinecleanersdonotetchthesurface,
they can be used to remove grease, oil, and other organic solids from hot dip aluminum. After alkali cleaning, the s
...