I have a fiberglass cowl that I need to repaint. Should I strip the old paint (Lustrekote) off with some sort of paint stripper or should I sand it down to the original primer? If I strip it I am kind of concerned about the chemicals that will be left behind that may eventually damage the new paint job.

Any suggestions???

If it was me, I'd sand it smooth then just re-prime and paint
not really nessasary to sand or strip all the old paint off, unless the old paint is not sticking well.

Chemical stripper could affect/soften the resin little lone the new paint job, you need to think of the resin as really thick paint.

If you need to remover all the old paint, I'd stick with sand paper

While I have never repainted fiberglass on any of my models, I have done a lot of fiberglass work on my full size boat. Chemicals around the fiberglass are a definate no-no. The chemicals can seep into the resin layer (especially if there are any cracks in it) and weaken the resin which can lead to failure later on down the road. I know it's a lot of work, but elbow grease is the only real way to get it off. A great help in this area is the Black & Decker Mouse sander. It's small enough to fit in one hand and does a great job of doing the elbow grease work for you. You can get one at Wal-mart, and I think they are less than $50.

Sand it smooth, reprime with a primer compatable with the paint you will be using, it will be fine.

Vince

Wet sanding takes very little time. If the existing paint has a lot of old defects(scratches, dings, paint application imperfections)... I would use some 400 3M Wet/Dry - wet to remove all the imperfections. You do not need to remove 100% of the old paint unless the old/new paints are imcompatable. I would then lightly sand out any 400 sized scratches with 600 3M Wet/Dry. Then just prime/sand/paint as normal. Good luck!