PAINT REPAIR WITHOUT REPAINTING- COLOR/CLEARCOAT. GMC Truck S15 Pickup

MODELS: GMC VEHICLES

Vehicles are painted for two primary reasons, appearance and protection. If a minor paint problem arises, the following procedure should be followed to reduce make-ready repair and improve owner satisfaction.

During the exterior preparation and cleanup portion of the new vehicle preparation, a paint condition that requires more than simple polishing may be identified. Many of these conditions can be repaired without sending the vehicle to the paint shop.

Minor paint problems such as light scratches, sags, runs, dirt, and orange peel can turn into costly repair bills if not handled properly. Because of the great number of highly metallic colors and the recent trend toward using a clear top coat, a simple, fast, and effective method of paint repair is needed.

CLEAR COAT

COLOR COAT

PRIMER

METAL

The paint repair system illustrated has three basic steps: 1) color sanding, 2) compounding and 3) polishing. These steps don't sound new or dramatic, but the recent improvements in materials make the difference.

Each of the problems that can be solved by this process exists only in the top coat of the vehicle paint. If the problem can be sanded out before you get down to the primer, or to the color coat on vehicles having a clear coat, there will be no need to repaint the area. This will reduce the cost of the repair by saving time, labor, and materials.

SCRATCH COLOR COAT PRIMER METAL

SAG OR RUN

COLOR COAT PRIMER METAL

DIRT

COLOR COAT PRIMER METAL

ORANGE PEEL

COLOR COAT PRIMER METAL

The procedure has three basic steps: 1) color sanding, 2) compounding, and 3) polishing.

You can adapt the procedure to the particular paint problem you are trying to correct. Color sanding is the most drastic of the steps and may not be necessary for every problem. You may be able to correct the problem just by compounding and polishing. Or maybe just by polishing alone. To begin, pick a test spot and work backwards through the process. Polish the spot; if this doesn't remove the problem, compound the spot. If compounding doesn't remove all traces of the problem, you must color sand the area to get the proper results.

Let's take a severe problem, a scratch, and go through the process step-by-step.

A SCRATCH IN THE COLOR COAT

1. Color Sanding

Select a very fine grit color sanding paper, like 3M Imperial Color Sanding Paper (or equivalent) that leaves scratches only half as deep as grade 600. Before starting, place your sandpaper in a bucket of clean water.

Soaking the sandpaper makes it more pliable. This makes it easier to fold around the sanding pad and reduces scratches from sharp sandpaper edges.

Next, wash the area to be repaired. Use a general purpose automotive cleaner and thoroughly rinse and dry the area.

Mask the area around the panel. This will protect it from sand scratches and buffing marks. This will also speed cleanup by keeping spatter off the area surrounding the repair.

Fold the color sanding paper around a sponge pad such as a 3M Wetordry Sponge pad (or equivalent). The sponge pad will give uniform support to the color sanding paper. This will help control the rate of cut and prevent finger grooves.

Flood the repair area with water while you sand. Sand, using straight strokes and only in one direction - toward the driver is best.

Sand lightly and evenly. Check the repair spot often. Remove only enough paint to eliminate the problem. If you go too far and reach the primer, the spot or panel will have to be repainted.

AFTER SANDING - Scratch is Removed and Only Sand Scratches Remain

When you think you've removed the problem, squeegee off all the water and paint particles.

Inspect the area to see if you've removed the problem. If you haven't, carefully continue sanding until you have. When you're done, the area should have a uniform dull finish.

2. Compounding

Next, apply a machine rubbing compound like 3M Super Duty Rubbing Compound (or equivalent) to the repair area. A six-inch stripe of compound is enough to begin this process.

Use the buffing pad to evenly smear the repair area with the rubbing compound.

Use a polisher, running at less than 2400 rpm, to compound the repair area. Keep the pad flat against the panel and apply only light pressure. Polishers that run at speeds higher than 2400 rpm and the use of heavy pressure may burn the paint. Panel edges and sharp contours should be compounded by hand to avoid burn-through. Check the repair area often and apply more compound if you need it.

Inspect the repair area often. When all the sand scratches are removed and you have a uniform glossy finish, you are ready for polishing.

AFTER COMPOUNDING - Sand Scratches Are Removed and Swirl Marks Remain

3. Polishing

Apply a polish like 3M Final Glaze or Prep Team Liquid (or their equivalent) to the area. Use a polishing pad to buff the area.

Keep the pad flat and allow the weight of the buffer to do the work. Use the polish sparingly; it doesn't take much to do the job.

AFTER POLISHING - All Swirl Marks Are Removed and Original Shine Is Restored

When polishing is completed, examine the repair. If the repair is satisfactory, remove the masking materials and clean the vehicle of any dripped or spattered compound or polish.

SUMMARY

This paint repair system should always be considered before spot painting or refinishing an entire panel. The procedure can save time and money, and increase customer satisfaction.

Remember that all three basic steps - 1) color sanding, 2) compounding, and 3) polishing - may not be necessary for every paint problem. Consider polishing first, then compounding and polishing, and as the last resort: color sanding, compounding, and polishing. After a little experience you'll be able to quickly decide which steps are needed to restore the paint of a particular vehicle to the desired condition.

MATERIALS REQUIRED

Color Sanding 3M Imperial Wetordry Sponge #02021 or equivalent Paper Sanding Paper Sponge Pad 3M Imperial Wetordry Sponge #05528 or equivalent Pad Rubbing 3M Superduty Rubbing #05955 (liquid) or equivalent Compound Compound #05957 (paste) or equivalent Bufring Pad 3M Superbuff Pad #05700 (buffing pad) or equivalent #05701 (2 plus 2 pad) or equivalent Polishing Pad 3M Superbuff Polishing Pad #05705 or equivalent 3M Superbuff Adapter #05710 (adapts Superbuff pad to shaft of most buffers) or equivalent

Polish 3M Final Glaze #05988 (non-silicone) or or equivalent 3M Prep Team Liquid Polish #05939 (containing silicone, should not be used in paint shop areas) or equivalent

Bucket

7" Polisher

Masking Tape and paper

Squeegee

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.