Paint (Base Coat/Clear Coat) - Polishing Techniques
Number: 93-188-0BSection: 0B
Date: MAY 1993
Corporate Bulletin No.: 111702R
ASE No.: B2
Subject:
POLISHING TECHNIQUES FOR BASE COAT/CLEAR COAT PAINT
Model and Year:
1985-1993 ALL PASSENGER CARS
1985-93 G, E, J, L, M, P TRUCKS 1988-93 C/K TRUCKS
1989-93 RN TRUCKS 1990-93 LUMINA APV
THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-166, DATED JUNE 1987 AND 91-251-0B, DATED, MARCH 1991. ADDITIONAL INFORMATION HAS BEEN INCLUDED IN THE TEXT. ALL COPIES OF 87-166 AND 91-251-0B SHOULD BE DISCARDED.
CARE OF EXTERIOR FINISHES (CLEANING AND POLISHING RECOMMENDATIONS).
APPLICATIONS:
ALL CARS AND TRUCKS WITH BASECOAT/CLEARCOAT PAINT FINISHES (EXCLUDES S/T TRUCK)
Today's basecoat/clearcoat paint finishes are very different from materials used on vehicles in the 1980's.
Materials, procedures and equipment which once worked well for polishing traditional finishes may not be acceptable for use on basecoat/clearcoat paint surfaces. The use of outdated materials, procedures and equipment may produce what appears to be acceptable results under shop lighting, but will be unacceptable to the customer when the finish is exposed to sunlight (typically, swirl marks).
While the following information can be most helpful in the new car "prep" area, it should also be made available to the "used car" area and the collision/paint repair area.
KEEP THE VEHICLE CLEAN AND DRY
- Avoid washing vehicles in direct sunlight.
- Avoid using strong soaps or chemical detergents.
- Use "brushless" type automatic car wash equipment.
- Avoid using products containing acids (unless specified to correct a condition such as "rail dust").
- Don't use brushes or brooms to remove snow or ice from vehicles in storage or on lots.
- Cleaning agents and water should be dried promptly and not allowed to dry on the surface.
- Standing rinse water should be dried promptly and not allowed to dry on the surface.
- Drying with a soft chamois is recommended.
DON'T CREATE A PROBLEM
- DO NOT polish vehicles unless a surface condition exists that can only be corrected by polishing (see chart).
- If a surface condition does exist, the repair approach should be one of "less is best" (the very least it takes to correct the condition).
- Avoid removing too much clearcoat (whenever possible, use paint gauges before, during and after polishing).
- Use ONLY the products recommended in this bulletin (or their equivalent).
- Make sure that any power polishing equipment does not exceed the requirements in the polish manufacturers recommendations or in the chart. The final process step typically uses an orbital type polisher with speeds of 1,500 to 2,000 R.P.M.
- DON'T USE WAX OR SILICONE TYPE PRODUCTS TO HIDE SWIRL MARKS (this damage will reappear later and cause customer dissatisfaction).
- Specific conditions on paint (environmental damage, rail dust, etc.) can be corrected by referring to previously published service bulletins on those specific topics.
Contact your local 3M or Meguiar's representative and ask for a demonstration of their products. Their recommended procedures should be followed to achieve the best results.
We believe these sources, their equipment, and materials to be reliable. There may be additional manufacturers of such materials and equipment. General Motors does not endorse, indicate any preference for, or assume responsibility for the products or equipment from these items or for any such items which may be available from other sources.