Braddy and Poindexter had their job cut out for them. Part of the Devin was in bare gelcoat (some of which was cracking). Fresh primer had been sprayed over unsanded gelcoat wax.
My Devin project car is finally in the shop being prepared for paint, so it's time for another installment on its progress. Although the body was basically good, it still needed quite a bit of work before it was paint booth time. If you have purchased (or are considering purchasing) a used or unfinished kit, there are a number of things you should be looking for as you examine the finish. If the car has never been painted, or if the paint is flaking off, you may have some of the same problems we encountered on the Devin paint job.
Fiberglass bodywork can present many challenges, particularly if the previous owner didn't have the car properly prepared before it was painted or primed. I took my car to master painter and bodyman David Braddy in Ennis, Texas, to have it repaired and squirted, as I had watched him work on previous KIT CAR cover cars (November 2001). David did much of the bodywork, and then master painter Chuck Poindexter took over for the actual paint job.
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Before you get started on the bodywork, tape the air cleaner element and cover the engine. There will be lots of gritty particulate flying around that will do your engine no good at all. | 
Braddy applies three layers of duct tape along exposed frame members to prevent damage from power sanders. If you haven't painted the frame yet, this won't matter as much. |
If you blow on the edge of a shiny (waxy) area with a high-pressure air gun, the primer or paint will blow off the car. You want to find this out now, not after you've applied a high-buck paint job. | 
Look for areas that are hard to reach with sandpaper and test them with the high-pressure blower. If the primer comes off, you'll have to take all the primer off down to the gelcoat or fiberglass. | 
Look for shiny places where the finish has lifted. This indicates the car has been primed over gelcoat wax. Primer adheres to the wax, but sooner or later it will begin to flake off, sometimes in sheets. |
As you sand through the primer, you can see the shiny black-waxed area. The primer won't featheredge over it, but it will chip off instead, leaving a rough edge. |  | 
Use a dual-action sander with a flexible head to carefully sand off all the old primer, paint, and wax. Use an 80-grit adhesive sandpaper pad. On the Devin, we had to remove every square inch of the primer that was on it when I got it. |
Spider cracks are usually caused by damage (like a part being dropped) or stress. Look for cracks in corners and near the edges of thin fiberglass parts like the hood and trunk. | 
As you sand, look for low areas, which the sander passes over. Low areas will have to be filled and sanded later. | 
This door panel had been half-primed over a shiny surface-this will not stick and must be removed. Any area that is shiny cannot be painted or primed over. |
Spider cracks must be completely removed. In this case, they were only gelcoat-deep, but if they extend into the fiberglass base, they must be ground out and filled with new fiberglass. | 
This low area has been filled with light fiberglass filler and sanded. It still needs more finishing before it's ready to be primed. | 
Use a small dual-action sander to work around tight areas like just below this spoiler. Try to remove the old paint and primer without damaging the area's shape. |
You may also need to hand-sand using sandpaper wrapped around a wood or plastic slat. Braddy has dozens of flats he uses to work on various areas. | 
Carefully use the dual-action sander on crowned areas like the top of this fender. Sand up to the crest from one side, then sand up to the crest from the other side. If you let the sander rest on top of the crest, it will flatten it out. | 
Medium-sized sandpaper discs (5- or 6-inch) can be worked into smaller areas to shape and remove old finishes. |
As you work down to the finer sandpaper, you will need to use long, flat sanders (either power or man-ual), not the dual action, to keep from gouging the finish. | 
Avoid using your bare hand or fingers to sand any flat surfaces (they gouge the surface). However, fingers are the only way to get into some areas like this taillight recess. | 
Match the sander's size to the job. A dual-action sander with a large disc is best for rough-sanding off old primer and paint on flat areas. Use 80-grit for the first sanding. |
This small handheld sandblaster gets into tight nooks and crannies to blast off old finishes. This is a nice-to-have tool, not a necessity. | 
Braddy shows us how to work the air file into vents. Never use a flat power sander on a curved surface. | 
Aim for a smooth, flat finish without any shiny areas. Use 180-grit sandpaper for your final sanding before primer. |