Restoring old fiberglass

rustbucket · Post by **rustbucket** » Wed Aug 04, 2004 3:15 pm

I just picked up an old baja kit for a couple of bucks. The problem is its old and slightly crazed in a few places and cracked in a few spots. So my question is, what is the best way to remove paint off of old glass? Also, what is the best way to refinish the glass? Finally, what is the best way to reinforce the parts where they bolt up?

I have seen restorations of old Corvettes where they just put new resin over the old glass and sand it to the desired finish. I've also thought about putting new cloth over the old and then sanding. I will have to do it where there all cracks.

Thanks

letterman7 · Post by **letterman7** » Thu Aug 05, 2004 6:38 am

Baja-
If the fiberglass has been painted, any chemical stripper would work. 'Glass is pretty durable when it comes to stripping. Once you get it down to the gelcoat (original color), fix any cracks from underneath with a few layers of chopped mat 'glass. Sand the surrounding area first for adhesion. For crazing, there's not much you can do. It's what 'glass does over the years. Stress cracks are a different story. You can reinforce those areas from underneath as well to keep the flex down. When you bolt parts together, make a backing plate for the part out of thin stainless or aluminum so the pressure of the bolt and nut is spread over a wider area. There's a technique called 'potting' a through-bolt, but it only works of the 'glass is thicker than 1/4". If you are going to refinish the entire body, I would probably repaint it rather than shooting a new layer of gel coat. Shooting gels is a pain, and you sometimes wind up with more problems than you started with. With paint, you can do all the ugly body work you have to, then hide it!

rustbucket · Post by **rustbucket** » Thu Aug 05, 2004 7:41 am

I thought I could use stripper, but I didn't want to go spray it without being sure.

As for the reinforcement, should I glass in the metal strips, or just bond them to the glss via epoxy?

As for painting, is there a special primer I should use, or just regular primer (i.e. high build, self-etching etc.)

Thanks

letterman7 · Post by **letterman7** » Thu Aug 05, 2004 9:37 am

Always try the 'lightest' grade strippers first. The trick is going to be seeing what the paint is that's already existing. If it's a basecoat/clearcoat, you might be in for a battle. If it's just a simple single coat of enamel, like from a Maaco body place, it should be easy. Try some of the stripper on a very small area first to see what happens. As for reinforcement, if t he cracks aren't too severe, you can just re-glass over them. Try to get as much loose stuff out as you can. I'm not a fan of glassing in metal strips, but that's me. As the body heats and cools, the strips expand at a different rate and can cause problems.
For a primer, sand the entire body first, then you can shoot just about any generic epoxy primer. Hence, try the stripper in a small area. It might be easier to do minor body work and then primer and paint the whole thing rather than stripping and redoing everything. If the paint's not flaking off, I wouldn't touch it.
Have fun!

Guest · Post by **Guest** » Mon Aug 09, 2004 4:51 am

L7 is dead on with all of his suggestions. Follow them and you'll be pretty much all set.

When the time comes for final paint, you might ask for a little flex additive to be mixed into the paint. Ask them to treat the car as though it were an early Corvette. As L7 mentioned, the fiberglass will heat and cool, changing shape way more than metal will. The paint needs to have a little more "flex" than average. Whatever they put in the paint mixed for Corvettes or even fiberglass bumper covers and ground effects ought to work just fine for your car.

Luck,

TC

eureka · Post by **eureka** » Tue Aug 10, 2004 2:28 pm

Remove any 'shine' off the gelcoat by sanding. Then fix any small defects in the surface of the fibreglass with marine filler (doesn't shrink as much as normal filler) then sand again before applying a primer / surfacer then more sanding before your colour coat goes on. The biggest tip is to use products all from the same manufacturer as they are designed to work together. Composite boat building suppliers are a good source (eg fibreglass yatchts and ski boat builders/suppliers).

rustbucket · Post by **rustbucket** » Thu Aug 12, 2004 7:35 pm

Well the paint is flaking. Horribly. So I decided to take it off.

I've only done the nose and part of one fender so far, but it comes off pretty easy with Auto-Strip. The top coat was a dark green. After it came off, there was a layer of dark brown that seems to be immune to the stripper. I am assuming this is the gelcoat. Underneath that it is bright white. So I'll just get the green off and go from there.

Thanks for the paint tip. I wouldn't have thought of that. Can I spray the whole car with the more flexible paint?

Thanks again

Dairdevil9 · Post by **Dairdevil9** » Fri Aug 13, 2004 11:58 am

Here is a really great web site that has a "learning section" full of great info on fiberglass work http://www.fibreglast.com/. I thought it was pretty helpful.
Brad

Guest · Post by **Guest** » Fri Aug 13, 2004 2:34 pm

The backing plate that letterman7 is talking about is not bonded to the fibreglass, but rather it's used like a big washer to distribute the pressure of the fastener over a larger surface area.

wolfgang · Post by **wolfgang** » Sat Aug 21, 2004 3:42 pm

Instead of washers you can also use plywood gussets. they can be fiberglassed right to the old fiberglass. Use marine grade for best results if exposed to weater at all.