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1、- 9006379 00019bL 427 E I GENERAL MOTORS ENGINEERING STANDARDS I Materials and Processes - Paint I BUFFING COMPOUND, FOR ENAMEL 9982074 1 SCOPE. This specification covers the requiremnts for buffing compounds used to remove fine scratches, haziness and swirl marks from enamel finishes. Typically the
2、se com- pounds are used with orbital finishing machines as the last step in finesse repair operations, which consist of removal of defects by sanding, rotary polishing with 9982075 polishing compounds and orbital buffing as the final step. 2 REFERENCED STANDARDS. GM4352M GM952OP GM4465P GM9522P GM90
3、71P 9981062 9981293 9982075 3 REQUIREMENTS. Documentation covering all mate- rial properties and performance test results must be supplied in a form acceptable to the GM Engineering activity to which submission is made. Any significant change made to the mate- rial components or manufacturing proces
4、s must be assessed to determine if requalification is requited. 3.1 MATERIAL REQUIREMENT S. The folIowing require- ments am for the buffiig material as received: 3.1.1 Identification. All materials must have complete identi- fication by product code and manufacturing batch All required safety/hygien
5、e information per Section 4 must be furnished 3.1.2 Consistency. The material must be free of lumps and show no tendency to settle. Any sensitivity to freezing must be clearly identified. 3.1.3 Odor. The material s odor shall be reviewed in compari- son with current production materials, when evalua
6、ted in laboratory and production trials. Any changes in formulation must be reassessed for effect on odor. 3.1.4 Ingredients Injurious To The Paint Process. The buffing compound must not contain any ingredients which upon becoming airborne during the polishing process may cause paint rmttering or ot
7、her detrimental effect on paint or assembly processes. 3.15 Swirl Mark Filling Ingredients. The buffing compound must not contain any waxes, oils or other ingredients which temporarily fill tine scratches and swirls. Such materials hide the presence of such defects, which subsequently reappear when
8、the materd is washed away or removed 3.2 Performance Requirements. The following requirements apply to the use of tbc material in the bu!Bmg process to per- form its intended function, and its effect on the paint fish being polished. Testing shall he conducted on freshly painted panels which am aged
9、 no longer than in the intended plant pro- cess. Qualification of a polish to these requirements allows its use only with the topcoats used in the initial test program. Use with other topcoats requires retesting to the applicable perfor- mance lqukmew. 3.21 BufIing Performance. Using the intended bu
10、ffing pro- oess, equipment and allotted time, the buffing compound must be capable of removing fiisse polishing scratches and restor- ing the paint finish to specified gloss levels. When used with specified orbital fmishing equipment, the buffing operation shall leave no objectionable haziness or sw
11、irl mark patterns. Laboratory testing must always be performed in conjunction with a control buffing material to compare efficiency and observe subtle appearance differenms. Allowed buffiig tim: in laboratory tests must duplicate the intended plant process. Final approval of any material is continge
12、nt upon successful production trials. 3.2.2 Effect On Topcoat Performance. The buffing material must not affect the durability of the enamel finish in any way. The ingredients of the material will be reviewed for their potential effects on the topcoat such as surface degradation and crack resistance
13、. Appropriate testing will be initiated as required with white and light metal& colors. 3.23 Effect On The Paint Repair Process. The buffing mate- rial, used and removed in the specified polishing process, shall not be detrimental to the repair painting process. Panels shall be buffed with the mater
14、ial, between 1 h and 24 h after bake. Use the intended plant process. Prior to application of the repair paint, the buffed panel may be wiped with Naphtha (9981062) or Isopropyl Alcohol (9981293). No other solvent or cleaning procedure is allowed. The repair finish must exhibit the following: 3.23.1
15、 Appearance. No cratering or other effects d&mental to appearance is allowed. 323.2 Adhesion (GM9071P, Method A). No reduction or loss of adhesion of repair paint from original paint. 3.2.3.3 Humidity Resistance (GM4465P). Following expo- sure for 96 h, the repair paint shall exhibit no blistering o
16、r loss of adhesion per 3.2.3.2. 3.2.4 Affect On Glass Bonding. Buffing operations per- formed in the paint shop may result in deposition of residues on glass bonding surfaces. When tested as indicated below, the compound shall exhibit no adverse effect on the glass bonding process or durability. For
17、 qualification, testing shall be with representative glass bonding nimers and adhesives. Release of the buffiig material to a plant using other glass bonding mate- rials mquires retesting with the specific plant s materials Per GM4352M, Row I. 3.24.1 Panel Preparation. Monocoat (nonclearcoat) enamel
18、s require testing with white and light blue metallic colors. Basecoat/clearcoat enamels requim white only. Topcoat shall be applied at nominal film build and baked 25 minutes at tar- get tempela. Ihce buffing compound conditions on panels will be testi a. Control - no polish b. Apply 76 lrm (approx.
19、 5 cc) wet compound - air dry 30 mmutes - wipe one pass with dry cloth, leaving visible dry residue APRIL 1993 PAGE 1 9982074 Copyright General Motors North America Provided by IHS under license with GM Licensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 06/23/2008 20:49:46 MDTNo repr
20、oduction or networking permitted without license from IHS -,-,- W 9006379 0003962 363 m I GENERAL MOTORS ENGINEERING STANDARDS I Matetlals and Processes - Palnt I BUFFING COMPOUND, FOR ENAMEL 9982074 c. Apply 76 pm (approx. 5 cc) wet compound - air dry 30 minutes - wipe one pass with cloth dampened
21、with Naphtha 9981062 - wipe one pass with dry cloth Apply the glass bonding primer and adhesive and allow to age at room temperatum for 72 h before testing. 3.2.4.2 Glass Bonding Tests. There shall be no evidence of cratering or crawling of the glass bonding primer on the buffed panels. Following th
22、e tests below, bond strengths on the buffed panels shall be equivalent to those obtained on the unbuffed control panels. a. Tape Link-Up Test (GM952OP) b. Quick Knife Adhesion (GM9522P) - Initially and fol- lowing 168 h humidity exposure per GM4465P 4 SOURCE SHIPMENT RESPONSlBILlTK It will be the re
23、sponsibility of the supplier to insure that the material is not exposed to temperatures during shipment which would cause the material to fail to meet any of the require- ments of this specification. 5 INlllAL SOURCE APPROVAL No shipment shall be ma& by any supplier until representative initial prod
24、uction samples have been approved by engineering as meeting the requirements of this specification. 5.1 Completed copies of the GM Material Safety Data Sheet and Critical Material Register (available from the engineering department or laboratory). or equivalent, must be submitted with any new submis
25、sions or where a composition change has 6 INSPECTlON AND REJECTION. All shipments of material or parts under contract or purchase order manufac- tuted to this specification shall be equivalent in every respect to the initial samples approved by engineering. There shall be no changes in either fommla
26、tion or manufacturing processes permitted without prior notification and approval by engineer- ing. 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 suppli
27、er shall accept the responsibility for incoming shipments meting this specification without depen- dence upon purchaser s inspection. 7 APPROVED SOURCES. Engineering qualification of an approved source is required for this specification. Only sources listed in the GM Corporate Materials File under t
28、his specification number have been qualified by engineering as meeting the requirements of this specification. Sources are available through the on-line MATSPC System. 8 GENERAL INFORMATION. This specification was approved by the Paint Materials Specification Committee in December 1990. The latest r
29、evisions include: Rev Date Description MV A 11/92 GM4352M consistency PT 9982074 PAGE 2 APRIL 1993 Copyright General Motors North America Provided by IHS under license with GM Licensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 06/23/2008 20:49:46 MDTNo reproduction or networking permitted without license from IHS -,-,-