Primer-What's your opinion
 

I committed to doing everything to build my car when I started. I am now starting the bodywork and have been reading everything I can on working on glass cars. I have done several completes years ago but never a fiberglass car. I have also talked to a couple of professional guys that have done a fair amount of Cobras. Yes, as always opinions vary and most guys seem to stay with what works for them.

One issue I am trying to resolve is do you need to epoxy primer or not when you end up sanding through the gelcoat in the seam areas. One guy says yes because the gelcoat is harder than the regular glass and you want to seal the whole car. You can then use Evercoat Featherfill G2, Slicksand, or other various 2K primers over the epoxy. I have read the tech sheets on Featherfill and Slicksand but they don't address the issue if the gelcoat was sanded through in spots. Perhaps it may be recessary to spot spray epoxy on only the seams areas

The other issue I need some help on is both the tech sheets for Featherfill and Slicksand say you can spray the base coat right over them without a sealer. Does anyone have experience with this?

I have read tons of threads of the FFR site but they don't seem to address these issue conclusively.

Thanks.
Wayne

Painting glass
 

The important thing is to make sure you have not sanded parting wax into the body. Use a good prep-sol de-waxer and then sand that gelcoat so there are NO shinny spots. Use water to help spot the unsanded spots by removing all the sanding dust. Glass bodies are not very even. A surface may look flat but can hide valleys and hills. After you have done the car with 220-240 give it a coat of 320. The car is now ready to shoot with Evercoat high buildup, resand using long boards with 220-240. If you are doing it correctly the car will look like a pinto as you will probably go through the Evercoat in spots back down to the gelcoat. Now use Evercoat finishing filler coating. This is not high buildup and has a lot harder finish and is harder sanding. Pin holes should be filled with an expoy filler not fender fillers. Two, part filler, Evercoat makes these also. The 220-240 again and then I coat with Dupont Corlar epoxy primer. If you feel at this point you need a sealer then apply, I don't and have never had a problem. Match the color of the primer to your final color. The primer has an affect on the final color. Sand with 220-240, wash follow with 320-360, wash followed by 400-600 wash and pre-sol, hit it with a wax rag and you should be ready to paint final color. The paint job on a Lambo takes 250 man hours!!! The secret is
PREPARATION PREPARATION

bill k

Bill, thanks for responding. I washed the car down three times with Acetone before sanding. That's what Evercoats tech sheet said. I really don't think there was any wax on the body. Is that good enough? I have sanded most of the seams. Your process is to use the epoxy the last to seal everything after all the bodywork and sanding is done.

Good detailed information.

Thanks.
Wayne

Three times with acetone should more than do it. Look into the pre-sol, not as bad to work with as acetone. I have never had anything bleed through in numerous cars in the past. But it is important to use the two part putty for the pin holes, regular tube type finishing putty tends to separate from the body under the paint giving the affect of a blister. This really shows up in the heat as glass bodies expand an contract more with temperature than metal. I actually shoot the car the final color and then sand the car again but not through the color coat, then finish with a couple of coats of the final color and then clear over it. Let dry completly and sand with 1200 and use 3-M three stage finishing system of compounds. A lot of work, yes but usually something that would have cost a fortune if you were to have someone else do it.

Bill K

What he said.

Slicksand will adhere just fine if you have sanded thru the gelcoat. No need to spray epoxy first.

And yes, you can lay the base directly over those high build primers if you haven't sanded thru them.

You will probably end up laying on another coat of high build primer anyway after you block sand the first time. It's not uncommon to have to do that a few times, depending on how good the body is to begin with.

So what purpose does epoxy serve. In the tech sheets Evercoat only recommends the epoxy for metal cars and then they want it installed on bare metal before the Featherfill. I am guessing the epoxy is for a good stick to the metal. What does it do if installed over the Featherfill for glass cars?

Wayne

I've never heard of anyone spraying epoxy before they spray the high build primer. I don't know what purpose that would serve. Some spray it over the high build primer to get a good base for their color.

No pro here, but epoxy is very stable, inert, and works well to prevent any solvents of the undercoats and topcoats from influencing each other/bleeding through.

On a bare metal resto, it is comon practice to apply an epoxy primer to the newly cleaned/exposed metal, do the body work with filler, followed by highbuild primers, then go back and seal the whole mess again with epoxy (sometimes thinned a bit).

Tough stuff.

I recently read a how-to article in Auto Restorer on painting a Cobra and he did shoot the raw body first with epoxy, then high build and then with epoxy as a final seal coat. His explanation was that it sandwiched all filler within inert epoxy primer and prevented any possible reaction by something coming through the fiberglass. It makes sense but typically you need filler in low areas and in the initial blocking of the body your not going to take the gel coat off in low areas - except where you grind down seams. Might make sense to spray a coat of epoxy over the prepared mold seams prior to starting filler work. However, his article was published too to do me any good.