I have read many times that other than the 53' models, vettes were not gel coated. The bottom side of my floor pan is unpainted fiberglass. However, upon closer inspection, it has a thin layer of resin coating it which makes it very smooth and semi-glossy. In fact, there were several areas where this coating was starting to separate. I used razor blade and found that it would come off like stripping paint off of the top side of the body.

Isn't this just a thin coat of sprayed on resin, and isn't gel coat just resin? So in effect, my '63 floorpan has gel coat

I would like to replace the resin that separated. I would like it to be clear. Can I thin standard resin and spray it on? I read that you can thin resin with Acetone. As I recall they recommended no more than 5% Acetone thinning. This does not seem like enough to make the resin fluid enough to be sprayed?

 

press molded panels are made from a sandwich of resin and mat, so i would think it would be likely that there is a bit of resin on the outside.

i see nothing wrong with spraying a protective coat of resin on the surface. too much would probably not be 'correct'...
Bill

 

Except for some pilot parts like the 63 pilot line cars and some 54 bodies, no gel-coat was used on Corvette bodies. But, as wmf62 says, the process of forming the panel left resin on some surfaces, especially those areas in depressions or corners. What you see is probably this resin.

 

The resin seems to be everywhere, not just on the corners.

Has anyone sprayed resin? What's the best way to thin it?

 

As an experiment, I added some Acetone to both Poly resin and Epoxy resin. In both cases the Acetone seems to prevent the mixtures from setting. Its been many hours and its still as viscous as when I started. I suspect that it may harden once the Acetone evaporates.
Perhaps this will not be a problem when sprayed as it will cause the Acetone to evaporate when it is atomized in the spray.
By Morning I would expect both to be hard, time will tell.

 

Let us know how it works out. I am trying to come up with a way to smooth my fire wall and inner fenders easily besides sanding them for 18 hours. I had considered that a spray gel coat may be a good start.

 

i agree with all of the above somewhat.you will need a fluid large fluid tip and a pressure pot to spray the gel do not put it on thick it will cause problems like cracking.the least amount the better.we gelcoat all corvettes from 56 to 72 after stripping and body work and some areas to 82 depending on work involved .use a sanding gel such as slicksand from evercoat it is important to gelcoat bare glass to seal it .primer of any kind is not recommended.sand the gelcoat then prime with a good 2k primer.

 

I don't understand the Slicksand comment. Slicksand is Polyester spray filler. Are you saying to use that in place of gelcoat or use the gelcoat as a substrate for your Slicksand?

 

I think you will end up with the same situation you have now if you shoot clear resin over your floor bottom. The thicker it is, the more it will tend to crack. You can add about 5% Acetone to Polyester resin just like you thin Gelcoat. You could also try 5% styrene. For shooting thick stuff like Gelcoat and Slicksand, a 2.5 tip such as with a SATA polyester primer gun.

Epoxy resin is not designed to be thinned, it will not cure properly and more than likely be a little rubbery when cured.

"Let us know how it works out. I am trying to come up with a way to smooth my fire wall and inner fenders easily besides sanding them for 18 hours. I had considered that a spray gel coat may be a good start."

I would use either Gelcoat or SPI epoxy for this job. The epoxy will sand easier and build just about as fast as Gelcoat without the orange peel. That's my 2 pesos.

I think it is fairly common to shoot gelcoat as a sealer followed by Slicksand for blocking since they are both polyester resin based products.

 

Sweet thanks!! Wow, two peso's...that's like $4 isnt it??

 

Both the poly resin and epoxy resin eventually hardened. It took days. The more acetone added, the longer it took. It does not help that its winter and cold out.
I have decided to reject both the poly and the epoxy resin. The Poly has a brown tint and the Evercoat Epoxy has a yellow tint. Neither of which I care for.

I'm told that Gelcoat is resin. Not sure why it has a unique name if its the same stuff? I found some clear gelcoat with several key features:

• UV light stability
• crack and chemical resistance
• crystal-clear
• non-yellowing

High gloss Gel Coat

But if you read the use of this product, they recommend thinning it. Ahhh, here we go again...
It seems that Styrene or Styrene with wax can be used. I have never used Styrene so I don't know how it differs from Acetone in this application. I called around to all the local hardware stores, and none carry it.
Apparently air retards the hardening of resin and the surface stays tacky. The wax is added to create a barrier. But I have found that the resin eventually hardens and the tackiness goes away.


One of the reasons I'm using resin as opposed to a urethane clear, is that I wanted something that would not disolve when exposed to gas, thinner, or paint remover. As a test, I took the hardened ingots of poly and epoxy resin and tossed them in a jar filled with Cap'n lee's Spra-strip paint remover. After a few hours, both ingots completely disolved.....Hell!

 

Gel coat is typically cured by one of two ways, the added wax barrier or by spraying a coat of PVA on it.

Since this is a Polyester based resin, it already contains styrene. Be careful not to thin more than 10% as the gel coat will become more brittle as the amount of styrene increases. You'll find styrene where fiberglass supplies are sold.

BTW, styrene is also the chemical in polyester resin that disolves the binder used to hold fiberglass mat together.

 

I have read 5%, but even 10% does not seem like it would be enough to thin the resin so that it can be sprayed. I will give it a shot.
I still can't locate any styrene. Do you know any major chain store names that might have it?

 

Your profile says Northern Ca., is there a TAP Plastics near you? They should carry some. Also try marine supply stores.

http://www.tapplastics.com/

What are you trying to spray it with, you need a 2.5 nozzle or a special Gel Coat gun.

 

years ago before new tecnology we used resin to gelcoat the bodies.it was difficult to spray and you had to make sure it was not too thick.we now use a product called slicksand . feather fill or mortons eliminator also i prefer slicksand evercoat researches all there products well and it easy to use, it is actually a sanding gel.i would stay away from spraying resin it will lead to problems just look at an older boat you will see what i mean we have repaired those also.good luck guys

 

Sent you a PM

 

I have been in business about the same as you, but I couldnt dissagree more on feather fill or mortons. I havent used slick sand, but its made by the same company as eliminator. These products have cost me so much money in the past, that I wouldnt use them on a lawn mower. They work OK on bare fiberglass, and I think that is what you are using them for, but there are better products out there to use.