sanding to the fiberglass

[Jim Hufford]

Hello Everyone,

62 corvette

I know this is a redundant subject regarding stripping or sanding. I have quite a few parts to prep before I replace panels and such. Here are my questions:

1) I found a wire type brush which attachs to a drill. I tested it on a pieces which was beyond repairable. It seemed to work if I did not apply too much pressure. Will these type of tools work without damaging the fiberglass? Is it safe to use to get past the primer? or can I use it till I get to the primer then sand it down? I do have 35-80 grit sandpaper to do the rest of the sanding.

Pitting and stress cracks
The parts are in pretty bad shape there is some pitting and cracking. What kind of filler should I use once all of the primer has been stripped?

Damaged corners and edges
What can I use to fix small areas where the fiberglass has been damages (corners and edges)? I really think I should put new fiberglass instead of filler in certain areas. Who cares a good supply of fiberglass materials for C1 cars?

Primer
What kind of primer should I use once the fiberglass has been fixed and filler has been applied?

Back side of the fiberglass
These parts have been sitting out in the weather for quite some time. Not sure how long since I purchased these parts last year. What should I apply on the back side of the fiberglass without making it incorrect?

Revets
Does anyone know where I can get the correct revets to replace witht the rusted ones?

mainly I am restoring the cars to a driver because of the condition the car is in. I figured I can build the car to a state where someone else might want to finish the restoration. I do plan on keeping the car for quite sometime? I guess I do not plan on having the car judged just want to do the job right and honest.

[Wayne C.]

Re: sanding to the fiberglass

I'd never touch fiberglass with a wire wheel, any more than I'd try sandblasting it.... too easy to cause MAJOR damage! There aren't any amazing shortcuts, only soft-media blasting comes close to being a shortcut.

Chemical paint strip or soft-media blast (only if done by a pro very experienced in stripping fiberglass) followed by sanding, or just good old fashioned sandpaper with sanding blocks. Some people say they've had success "peeling" the paint down to the primer using razorblades held at a very shallow angle to the surface, then sanding.

In the past, people have reported applying a good epoxy primer, or Slick Sand by Fiber Glass Evercoat, or "Awlgrip 545" to fill the surface, for smoothing by sanding prior to applying the color finish.

DuraGlass by USC has also been reported as a good spot "filler".

Your questions really are beyond the scope of a forum like this. NCRS sells numerous books on the subject of fiberglass repair and painting on this website.

[Wayne C.]

PS...

The backside of the fiberglass was not originally coated with anything. If you feel for some reason it NEEDS to be coated, I'd clean it very thoroughly and use a satin finish clear epoxy.

[Wayne C.]

PS again...

Here's some sites offering inspiration and info:

http://temp.corvetteforum.net/c5/richs7/index6.shtml

http://corvetteforum.com/guides/Crossgeneration/painting/painting101page1.htm

[Ray C.]

Re: sanding to the fiberglass

Hi!

We have just completed stripping a 1965 Roadster. The 65 had three layers of paint including a base-coat clear-coat. The base coat/clear coat was removed using a single edge razor blade. The second process was a chemical strip that was fiberglass safe. This process took a minimum of two applications of remover and removed all the paint except for the original red lacquer primer. I then block sanded the original red primer with 180 grit sandpaper and applied PPG Polyester Primer Filler. I am now in the process of block sanding with 320 grit sand paper. I plan on applying a second coat of the Poly/Primer and re-sanding with 400 grit paper. The body then should be ready for the red and then gray lacquer primer. This is my wifes car and she has completed 95% of the paint removal.

I hope this helps!
Ray 65-250HP and 61-270HP


hhtp://home.rochester.rr.com/carneyscorvette

[Ray C.]

Re: sanding to the fiberglass

Sorry about the URL try new one!
Ray


http://home.rochester.rr.com/carneyscorvette

[Duke W.]

Re: sanding to the fiberglass

That reddish brown primer is not lacquer. I'm not sure what base it is, but nothing short of sanding would remove it from my SWC. My take is that if the red primer is intact, you don't need to completely remove it, but just sand enough to get any top coats off. The few small cracks that I had proved to be only in the lacquer color coat, not in the primer or fiberglass.

Duke

[G B.]

Re: sanding to the fiberglass

You can get the factory primer off by soaking it in chemical striper while scrubbing with steel wool. This is far less abrasive than block sanding. It will leave your fiberglass with the exact surface the factory created, waves and all.

Of course, if you dislike a stock finish, you may want to remove the body waves. I guess it's a matter of taste.

[Wayne W.]

Re: sanding to the fiberglass

I disagree with taking that primer off with stripper. It can lead to contamination of the fiberglass and paint blisters when painted again. I will never do it. Learned my lesson the hard way many years ago. I had one that had been srtipped that way and painted it. The customer showed the car for the summer and it was perfect. We had a couple of weeks rainy spell in the spring where everything stayed soggy for a long time. When he uncovered the car it had blisters. These were in the areas where the fiberglass was most exposed from the underside. After investigation, we determined that the stripper had wicked down into the fibers, and that the moisture had come through the fiberglass strands from the underside and now being liquid had melted the paint from the underside. Each bubble was on a fiber that came to the surface and there was a little liquid juice under each. Guess who had to repaint the car, eventhough I didnt strip it?

[G B.]

Re: sanding to the fiberglass

Wayne -

I'm sorry you had that bad experience. Certainly some liquids can stay in the fiberglass and come back to ruin a paint job.

I've not had a problem with paint reaction to my stripper. But, I'm still using orange Stripeeze and lacquer paint like it was 1970. No telling what would happen if I used other products. Maybe some day I'll try to learn some new tricks.

Naaaah.

[Boyan B.]

Re: sanding to the fiberglass

I recently stripped my 63 which had 1 extra layer of paint on it. I used Kleen Strip for fiberglass and was able to remove each individual layer, one layer at a time. My body shop recommeded that I stop at the factory primer, which was easy to do. They then sanded the remainder of the primer off to just touch the bare fiberglass. Its painted now and looks fantastic. No problems.

PS, this shop has ALOT of experience with corvettes and thats what they recommend.