GMW 14885

WORLDWIDE ENGINEERING STANDARDS

General Specification Paints

GMW14885

Painted Aluminum Road Wheels

1 Introduction Note: Note: Nothing in this specification supersedes applicable laws and regulations unless specific exemption has been obtained. Note: In Note: In the event of conflict between the English and domestic language, the English language shall take precedence. precedence.

GME 60203 GMW3001 GMW3059 GMW3286 GMW14333 GMW14334 GMW14458

GMW14829 GMW14873 GMW15282 GMW15287 GMW15487 HN 0278

1.1 Scope. This specification defines the pretreatment, paint materials and processing required to paint/coat aluminum road wheels. In some cases, this specification might be applied for aluminum wheel trim. Coating/Paint durability requirements are also included.

3.1.1 Calibration. The equipment used at the test facilities shall be in good working order and shall have a valid calibration label.

1.2 Mission/Theme. This specification applies for all painted cast and forged aluminum wheels. This specification applies to all surfaces that are designated on the engineering part drawing to meet these requirements. requirements.

3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuring variables as specified in this specification shall be determined correctly with respect to its physical definition.

Painted parts must meet these requirements prior to going into the field, and must also satisfy GM’s and GM’s customers’ expectations for appearance and cosmetic durability.

3.1.3 Facilities. All Non Tier 1 facilities shall have ISO17025 accreditation for General Motors to accept data. Where applicable, proficiency data shall be kept current and made available at the request of the GM Materials Engineer. All Tier 1 facilities are expected to operate test facilities to the intent of ISO 17025, and shall have ISO 16949 accreditation.

All deviations from this specification must be agreed upon by GM and must be documented in the validation agreements. agreements. 1.3 Classification/Wheel Classification/Wheel types. 1.3.1 Type A. Wheels with only clear paint(s) over sections of the disc outer and/or rim flange, for example, bright polished wheels. 1.3.2 Type B. Fully or partially color painted wheels with or without areas of bright metal.

2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ISO 16949 ISO 17025 SAE J2020

SAE J2633 SAE J2635

2.2 GM Standards/Specifications. GM9509P GM9525P

GMW14700 GMW14729

3 Requirements 3.1 Resources.

3.1.4 Equipment. Equipment. All equipment and test procedures utilized to supply data to this specification shall be documented on the Scope of Accreditation for the the facility. 3.1.5 Test Vehicle/Test Piece. Test pieces wherever possible shall be the finished part. If size, shape, etc. of the finished part is impracticable, tests shall be conducted on specially prepared coated test panels, as agreed upon by the appropriate GM Materials Engineer. 3.1.6 Test Time. There shall be no deviations from the test times documented in this specification unless it is agreed upon by the GM Materials Engineer. 3.1.7 Test Required Information. These test requirements are intended for routine acceptance and control of production painted parts using materials and processes previously found to be

© Copyright 2006 General Motors Corporation All Rights Reserved

December 2006

Originating Department: North American Engineering Standards

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GMW14885

GM WORLDWIDE ENGINEERING STANDARDS

satisfactory. These test requirements do not represent the complete testing necessary for engineering approval.

drawings, test certificates, reports, and in validation agreements, etc.

3.1.8 Personnel/Skills. Not applicable.

4 Validation

3.2 Preparation. Not applicable.

4.1 Appearance.

3.3 Conditions. Tests with parts should commence earliest 72 h after final bake, unless other specified in a reference specification.

4.1.1 The surface shall be smooth and free from any surface blemishes prejudicial to serviceability, appearance or subsequent processing. Runs, sags, dry spray and other surface imperfections are unacceptable.

A shorter aging time may be used provided it is recognized that it represents a more severe condition of test. 3.3.1 Environmental Conditions. Not applicable.

4.1.2 No Coating is to be applied to the mounting surface or lug nut/screw face areas.

3.3.2 Test Conditions. Laboratory conditions such as humidity and temperature should be recorded to help understand any test anomalies.

4.1.3 Overspray is allowed if it does not affect the paint performance, and if it does not degrade in a manner that dissatisfies the vehicle owner.

3.4 Instructions. All tests should be performed to the intent of ISO 17025.

4.1.4 Appearance of the clear and color must compare favorably to the approved engineering standards. For matching caps/trim and wheel counterparts, each supplier is responsible for utilizing production parts from his process and from the other supplier’s process as an ongoing QC procedure to assure color/texture match. The frequencies shall be included in the control plans. GM shall be consulted to review discrepancies.

3.5 Data. Proficiency data should be included in the test reporting format if it is required by the customer. 3.6 Safety. This procedure may involve hazardous materials, operations, and equipment. This method does not propose to address all the safety problems associated with its use. It is the responsibility of the user of the method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 3.7 Documentation. Samples of components or material released to this specification shall be tested for conformity with the requirements of this specification and approved by the responsible GM Department prior to the start of delivery of production level components or materials. Any change to the component or material, e.g., design, function, properties, manufacturing process and/or location of manufacture requires a new release of the product. It is the sole responsibility of the supplier to provide the customer, unsolicited, with documentation of any change or modification to the product/process, and to apply for a new release. If not otherwise agreed to the entire verification test shall be repeated and documented by the supplier prior to start of delivery of the modified or changed product. In some cases a shorter test can be agreed to between the responsible GM Department and the supplier. 3.7.1 Test Results. Not applicable. 3.7.2 Deviations from Test Procedure. Deviations from the requirements of the test procedures shall have been agreed upon. Such requirements shall be specified on component

4.1.5 Production Part Approval Process (PPAP). Color/appearance submissions shall be produced with production processing equipment and materials, and the processing parameters shall be documented at the time of color/appearance approval. All deviations from production intent shall be identified at the time of color/appearance approval. 4.2 Pretreatment. Clean and pretreat with appropriate procedure. All products must meet GMW3059 and final coatings shall be Chrome VI free. In regions where the parts are PPAP approved and there are approved materials requirements, approved products as documented by GM Materials Engineering have to be used. Note: Production pretreatment processes that use more than one chemical supplier are unacceptable. De-ionized (DI) water chemical companies are excluded from this requirement. 4.2.1 Pretreatment coatings for bright metallic surfaces must be uniformly water clear and not change the color or appearance of the aluminum. There should be no evidence of a loose or powdery surface following coating application. There should be no visible stains or discoloration on the part subsequent to the final pretreatment stages.


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GM WORLDWIDE ENGINEERING STANDARDS 4.2.2 Parts should not be touched or handled in any way following pretreatment and prior to painting unless clean cotton gloves are used. 4.2.3 Each pretreatment system is required to contain a deoxidization process. 4.3 Organic Coating Requirements. 4.3.1 Applying clear organic coatings on parts designed with only areas of bright metal on the exterior. (Type A wheels per section 1.3.1.) In regions where the parts are PPAP approved and there are approved materials requirements, approved products as documented by GM Materials Engineering have to be used. 4.3.1.1 The selection of powder, or powder and liquid clear paint systems for this application is left to the discretion of the wheel/trim supplier, providing all requirements of this specification are met. 4.3.1.2 Accent color coatings, inks, etc. must be compatible with the primer and clear topcoat materials used on the part. They shall have no detrimental effects that might alter the appearance or durability of the part assembly. All pigments used in paints, inks, etc. must have sufficient UV resistance. 4.3.1.3 Apply (acrylic) powder or liquid, or (polyester) powder and (acrylic) liquid clear coatings to areas specified on the part drawing. Dry film thickness shall be controlled to produce a part that meets all of the color and appearance requirements. All color paints, inks, etc. shall be coated with a clear topcoat in order to meet the cosmetic durability requirements. 4.3.1.4 Wheels and trim that are machined, polished, etc. after paint material has been applied must be reprocessed through the pretreatment steps prior to any subsequent clear coat application. 4.3.1.5 Apply clear topcoat(s) to areas specified on the part drawing. Dry film thickness for an acrylic powder or liquid film, is to be 40 microns minimum. Dry film thickness for two coat, polyester powder and acrylic liquid is to be 80 microns minimum. Edge film thickness data should be submitted with the validation (PPAP) data. 4.3.1.6 For trim parts that are located in the center of the wheel and are not in the car wash tire/wheel brush area, the clear topcoat paint minimum thickness requirements may be excepted if the parts are validated at the minimum production thickness. Trim parts shall be tested after all forming and subsequent heating processes are performed.

GMW14885

4.3.2 Colored organic coatings on surfaces of parts that may or may not have bright surfaces on the exterior. (Type A or Type B wheel styles per section 1.3). All sections of 4.3.1 apply for any bright areas on these painted wheels. In regions where the parts are PPAP approved and there are approved materials requirements, approved products as documented by GM Materials Engineering have to be used. Wheels must be coated with powder or liquid primer, liquid or powder color paint, and acrylic liquid or acrylic powder clear topcoat paints. The total dry film thickness is to be 100 microns minimum. 4.3.3 Organic coatings on brake and tire sides of the wheel surfaces. If designated on the engineering drawing that these surfaces must be coated, the dry film thickness must be 40 microns minimum. The coating must meet the requirements of sections 4.4.1, 4.4.2 and 4.4.3. 4.4 Finished part durability requirements. The durability requirements pertain to finished parts, after all painting, heating and forming operations. All combinations of coatings (paints, inks, etc.) as they appear on the finished parts are required to meet these requirements. When submitting for part approval, the supplier shall identify that the cosmetic surfaces with the least corrosion protection were validated to meet these requirements. 4.4.1 Tape adhesion test. Cross hatch test according to GMW14829 in the as received conditions and after humidity exposure for 120 h per GMW14729 with a minimum of 99% paint adhesion or rating 0. There shall be no evidence of blistering or other appearance changes at end of humidity exposure. 4.4.2 High humidity exposure. Expose painted parts per GMW14729. There shall be no evidence of blistering or other appearance changes at end of humidity exposure after a) 96 h and b) 240 h. 4.4.3 Salt spray fog test. Painted parts must pass a salt spray and adhesion test when evaluated at 336h and at 1000h exposures. Painted parts must pass GMW3286 (336 h and 1000 h) with no more than 1 mm of creep back (see GMW15282) from edges and scribes, and no other loss of adhesion after air blow-off. All coated surfaces must be scribed per GMW15282. If there is ample space on the section, multiple scribes could be made before the exposure so that one could be evaluated at 336 h and the other at 1000 h. The evaluation can


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be realized by blowing with compressed air or by using scalpel or adhesive tape. There shall be no evidence of blistering or other appearance changes at the end of the 336 h or 1000 h. 4.4.4 CASS Test. An optional salt spray testing method is acceptable to expedite approvals if it is specified in the validation agreement. Painted parts must pass 168 h of CASS test exposure (per GMW14458) with no more than 3 mm of creep back (see GMW15282) from edges and scribes, and no other loss of adhesion after evaluation. The evaluation can be realized by blowing with compressed air or by using scalpel or adhesive tape. All coated surfaces must be scribed per GMW15282. There shall be no surface corrosion or coating degradation, excluding the scribes and cut edges. If air blow-off is used, it shall be performed with a rapid scraping of the scribe by the nozzle. 4.4.5 Filiform Resistance. Painted parts of disc outer must meet a filiform resistance requirement of no more than 4 mm maximum length of any filament from the scribe line, when tested per GMW15287, for a period of 672 h in humidity. Furthermore, there shall be no filament growth on the non-scribed test surfaces at the end of the test, because this is an indication of insufficient coating coverage at that site. (Excluding sample prepared cut edges.) SAE J2635 is an alternate procedure that could be used to meet this requirement, if agreed upon by GM Materials Engineering.

Storage 1 h ± 5 minutes at -30°C Storage 1 h ± 5 minutes at +120°C Storage 1 h ± 5 minutes at -30°C Storage 1 h ± 5 minutes at +120°C Storage 44 h at 23 ± 5°C to GME 60203. 4.4.8 Resistance to Cleaning Agents. Resistance to on-the-shelf tire and wheel cleaners according to GMW14334 - Rating 2 or test method shown in Appendix A. 4.4.9 Resistance to Fuel. All paint products must have acceptable fuel resistance according to GMW14333 Rating 2. 4.4.10 Thermal Shock. If the validation agreement requires thermal shock adhesion testing, paint adhesion must meet the requirements of GM9525P, Thermal Shock Test for Paint Adhesion, with 99 % adhesion along the scribe as shown in GMW15282, Figure 5. All coated surfaces must be scribed per GMW15282. Any paint appearance change as a result of this test should be characterized as a nonconformance to the requirements. Humidity pick-up in the coating, or “Blushing”, is a nonconformance unless it disappears at room temperature within 24 h. 4.4.11 Delamination Test. 4.4.11.1 At least 24 h after final bake of the painting, test pieces shall be immersed in a bath of fully de-mineralized water and stored in an oven at +63 ± 2°C for 48 h.

4.4.6 Stone impact resistance. Painted parts must pass the stone impact resistance test per GMW14700.

After regeneration time of 1 h adhesion of painting should fulfill cross hatch test according to GMW14829- classification 0 or 1.

Requirements:

4.4.11.2 The following alternate delamination test could be substituted if agreed upon by GM Materials Engineering.

•

method A or B: ≥ 8 (GM8) and

•

method C: ≥ 8 (GM8)

Note: This procedure replaces SAE J400 and the respective SAE chip ratings. 4.4.7 Corrosion resistance to cyclic alternating conditions. Painted parts of disc outer shall undergo a cyclic corrosion test. Type B: salt spray fog-climate testing, per GME 60203-F-Grade 3 (W d ≤1 mm) shall be performed. Type A: parts are tested in a modified salt-fogclimate test based on GME 60203-F but after removal from exposure to high humidity environments a temperature storage is performed twice. The detailed procedure for this modified test GME 60203–F modified is: •

24 h salt spray fog test to GMW3286.

96 h exposure to high humidity environments according to GMW14729.

•

Delamination/watersoak GM HN 0278. 4.4.12 Abrasion Resistance. Abrasion resistance to GMW15487 1.4 L/µm minimum. 4.4.13 Weather Resistance. Depending on the geographic location of the approving GM materials group, various weathering procedures are used to approve materials. The regional materials group approving the materials will select from the following methods: 4.4.13.1 Florida Exposure. All coatings (paints, inks, etc.) for aluminum wheels and trim are required to have resistance to long-term weathering in Florida (GMW14873). Painted parts or panels must show minimal gloss and color change or any other deleterious effects when subjected to two years of Florida exposure @ 5 degrees from horizontal, facing south.


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GMW14885

A light polish could be used to restore the appearance of the paint. Paint suppliers shall provide parts and/or panels after exposure, to GM Materials Engineering for initial product approval.

6 Notes

4.4.13.2 Accelerated Weathering. (Xenon-Arctest). The test shall be performed with an apparatus of Atlas SFTS, B. V. Company.

ASTM

American Society for Testing Materials International

CASS

Copper Accelerated Acetic Acid Salt Spray

CTS

Component Technical Specifications

DI

Deionized water

GM

General Motors

GME

General Motors Europe

h

hour(s)

ISO

International Organization Standardization

PPAP

Production Part Approval Process

ppm

Parts per million

QC

Quality Control

QUV

Q-Lab Ultraviolet Cabinet

SAE

Society of Automotive International

SPC

Statistical Process Control

VTS

Vehicle Technical Specifications

4.4.13.2.1 Apparatus type Atlas Ci-65A, CI 4000 or CI 5000 Weather-Ometer (Xenon Arc WeatherOmeter). 4.4.13.2.2 Inner- and external filter: Borosilicate 2 radiation exposure: 0.27 W/m (at calibration point 340 nm). 4.4.13.2.3 Radiation energy: 1944 kJ/m

2

4.4.13.2.4 Use a continuous test cycle of 17 minutes light only, 3 minutes light and spray. The relevant surface of the test piece shall face the light source during test. 4.4.13.2.5 Black panel temperature (during light only period) of +63 ± 3°C. Tested after cooling down. After exposure painted parts or panels must show minimal gloss and color change or any other deleterious effects. 4.4.13.2.6 Q-Lab Ultraviolet Cabinet (QUV) per SAE J2020 (1000 h). After exposure painted parts or panels must show minimal gloss and color change or any other deleterious effects. Note: Similar types of commercial apparatus meeting the requirements described above may also be used.

5 Provisions for Shipping 5.1 Inspections and Rejection. All shipments of materials or parts under contract or purchase order manufactured to this specification shall be equivalent in every respect to the initial samples approved by engineering. There shall be no changes in formulation or manufacturing process permitted without prior notification and approval by engineering. Lack of notification by the supplier constitutes grounds for rejection of any shipment. While samples may be taken from incoming shipments and checked for conformance to this specification, the supplier shall accept the responsibility for incoming shipments meeting this specification without dependence upon purchaser’s inspection. 5.2. Source Shipment Responsibility. It will be the responsibility of the supplier to ensure that the material is not exposed to temperatures or environments during shipment which would cause the material to fail to meet any of the requirements of this specification.

6.1 Glossary. Not applicable. 6.2 Acronyms, Abbreviations, and Symbols.

for

Engineers

6.3 Paint Rework Processes. GM Design, Quality, Materials and Appearance Engineering must approve all paint rework processes. The affect of paint rework bake temperatures on the mechanical properties of the alloy wheel should be validated. 6.4 Approved Sources (only GMNA). Engineering qualification of approved materials is required for this specification. GM Materials Engineering is responsible for documenting the materials that have met these requirements.

7 Additional Paragraphs 7.1 All materials supplied to this specification must comply with the requirements of GMW3001, Rules and Regulations for Material Specifications.

8 Coding System This standard shall be referenced in other documents, drawings, VTS, CTS, etc. as follows: GMW14885-type B.

9 Release and Revisions 9.1 Release. This standard originated in December 2005, replacing 9985586. It was first approved by the Global Materials Engineering Center in June 2006. It was first published in December 2006.


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GM WORLDWIDE ENGINEERING STANDARDS A3 Procedure.

Appendix A A1 Qualitative Test Procedure for the Chemical Resistance of Clear Coatings A1.1 Purpose: This procedure establishes the methods for testing and evaluation of aluminum wheel and wheel trim surface coatings for compatibility with various types of tire and wheel cleaners. Test data for this requirement are to be on file at the raw coating material supplier.

A2 Test Materials and Equipment. A2.1 Various types of tire, wheel, chrome, and whitewall cleaners that can be found in aftermarket retail stores. GM Materials will provide guidance on the types of cleaners for testing. A2.2 Containers to hold coated panels and testing solutions. A2.3 Type of panel used for the trial – Aluminum or steel panels with appropriate pretreatment for paint adhesion (phosphate, chromate, etc.). A2.4 The paints that are to be evaluated with production-intent cures and thickness. Studies should also include minimum cure and maximum thickness conditions. All new coatings shall be evaluated in parallel with a currently approved production materials.

A3.1 After panels have been coated, allow 72 h controlled temperature and humidity `age’, and submerge them into the cleaner solution. Record all production intent data relative to film thickness and cure. Cure checks should be included. Panels shall be left in the solution for 24 h. A3.2 Rinse the panels with water and dry with a cloth. If there is no visible degradation and no hardness change, proceed with additional testing as described in section A4. Testing shall be conducted until some type of degradation occurs. Record procedural details.

A4 Test Procedure. A4.1 Accelerated heat. Place the panels in an electric oven for 14 days @ 49 °C. A4.2 Water Immersion. – 24 h test exposure. A4.3 Weathering. Expose the panels per one of the methods in SAE J2633. A4.4 100% Relative Humidity. 96 h test exposure per GMW14729. Test and solutions may be changed as long as they are documented in the final written report. The procedure should be repeated until the onset of coating degradation. Record the type of degradation of the paint system for each test cleaner.


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