gelcoat??

[Kenneth G.]

Hello all!

Just heard from the shop that is redoing the body and paint work on my 69. It seems the body work is just about finished, all the panels, bumpers, grills etc are all aligned and the body should be ready for primer/paint in a short while. Then the shop owner said "but first the body has to be sprayed with a gelcoat". Not wanting to sound ignorant , i didnt ask him about the gelcoat, but what exactly is it?? My car had mostly new panels put on it and i thought you needed the gelcoat only if you stripped the panels down completely. Forgive my lack of knowledge in this area and i would appreciate any explanation on the gelcoat process. On a side note, does anyone have an opinion on my original color "fathom green"??

Kenny- savings account is having a heart attack due to my 69

[Chuck S.]

Re: gelcoat??

Kenny,

Think of gelcoat as primer-sealer from HELL. It seals all errant glass fibers, and fills any pinholes or minor depressions in the fiberglass surface. It is applied over bonding adhesive and body filler, and after block sanding, gives a smooth body surface for the perfect paint job (not always desireable for the "perfect" NCRS car). I have heard many knowledgeable Corvette owners say "Forgettaboutit" concerning gelcoat, but the "experts" swear by it.

Actually it is closer to resin than it is to paint. There are two different types, but the gelcoat I am familiar with has to be mixed with a catalyst. After that the working time is about a half hour before it begins to set up on the fiberglass, in the gun, and on you. It is very difficult to apply, so, UNLESS your body man is desperate for work, I don't think he would recommend it unless he thought you needed it. Ask him any questions you need answered; you're the one paying the bill. Besides, don't worry about not knowing the answers; if you were an "expert", you would be doing it yourself (well, maybe not).

After the gelcoat is applied to the car, HELL Part 2 starts. In order for gelcoat to cure completely, it has to sealed from ambient air. In the oldest type gelcoat, this is accomplished by a wax which migrates to the surface during application. In order to block sand the cured gelcoat, this wax has to be removed with lacquer thinner, or your sanding is "gummy" and difficult. The second type of gelcoat, sometimes disparaged as a "boat gelcoat" by those selling the other type, doesn't have the wax, but is sealed by a spray-on coat of "PDA" (?) sealer. I believe the second type is easier to work with, but beyond that, I have no knowledge of the advantages/disadvantages of the two types of gelcoat.

Chuck Sangerhausen

[Roger]

Re: gelcoat??

Kenny DO NOT USE GELCOAT. Instead have them first spray it with a polysurfacer. I just finshed painting my '63 after stripping it down to the fiberglass. I used Sikkens paint and their recommendation was to use Polysurfacer and it came out as smooth as a baby's behind. Polysurfacer is a type of primer which does the same thing as gelcoat without the problems. If you have any further question E-Mail me. Regards Roger

[Shannon Burgess]

Re: gelcoat??

Kenny,

I agree with what was said about using a modern urethane primer/surfacer rather than gelcoat. I'd suggest having the painter first prime the body with some epoxy primer. This will seal any bare fiberglass and keep the next coats from soaking in to any exposed glass. Then have him shoot the primer/surfacer over the epoxy and block it smooth. Modern primer/surfacers do a fantastic job in filling minor imperfections and levelling the panels once they are sanded smooth. They sand easily and will provide an excellent base for the paint.

This assumes, however, that you're painting the car with urethane paint. If you're planning to use laquer, I'm not sure what kind of products you can use.

Shannon


My '69 Corvette

[Mike in AZ]

Re: gelcoat??

With the advent of catalyzed polyester-based primer surfacers, there is no need to even consider using spray gelcoat, IMHO.

[Mark L.]

Re: gelcoat??

Kenny,

All good advice here, and I agree with Shannon about the new primer surfacers.

When I painted my '58 I used white epoxy primer (about four coats) lightly sanded and applied light grey laquer primer over it (about four coats).

After sanding I applied sixteen coats of color (laquer), four coats, sand, four coats, sand.......you get the idea.

No problems whatsoever.

BTW: I got the epoxy primer from a boat guy as well as all the other fiberglass materials, worked great and at half the cost of the Corvette specialty shops!!

Hope this helps, Best Regards from Connecticut...........Mark

[Mike]

Re: gelcoat??

Started my '62 in gelcoat. Best excercise in body prep I ever had. There have to be better modern day coatings available today, as listed in this thread. I will never do it again.

[Bill W.]

Re: gelcoat??

the least amount of material you can put on you car the longer it will last. less is best.the more material you have between your fiberglass and your pain the more problems youll have in the future.

[Chuck S.]

Re: gelcoat??

Bill,

Does that mean you are Fer' It, or Agin' It, gelcoat that is? I'm thinking you said "more material=gelcoat=future problems".

It doesn't seem like gelcoat is an experience anyone wants to repeat again, but this thread started with the statement of a professional body man that a car should have gelcoat applied before paint. Is he just old-fashioned, and refuses to take advantage of modern primer-surfacers that could make life easier for him? I've never had the pleasure of applying gelcoat, but this strong difference of opinions is puzzling me.

Chuck Sangerhausen

[Bill W.]

Re: gelcoat??

i would not use gel coat. ive made my living in a body shop sense 1968 it doesnt matter what kind of material you use. but on a corvette the least amount you can put on the longer it will last. fiberglass expands and contracts and when the finish does guess what. cracks