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Is Gelcoat necessary?

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Old 08-11-2004, 03:57 PM
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FXT
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Default Is Gelcoat necessary?

My Vette is just about ready to paint, stripped down to the bare glass. I wanted to have 2 coats of Ecklers Gel Coat applied to seal the glass before anything else. One painter says he won't paint any older Vette without gelcoat, the other painter says it's not necessary....that today's primer/surfacers will seal the body ok. Seems to me spraying 2 coats of gelcoat and then blocksanding is not that much extra trouble now, I look it as cheap insurance against surprises later on after the car is painted.

My question is that....is Gelcoat no longer being used in the auto painting industry and does the primer/surfacer now take its place? Thanks for your thoughts on this.
Old 08-11-2004, 04:22 PM
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Van Steel
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I'd say it depends. GM changed fiberglass 7 times over the course of the years. Your sig doesn't specify what year you have. If you sanded it down to far to where you see fibers than I'd definelty gelcoat it. If you didn't than you'll be alright. If you have a mid year than definetly gelcoat before you paint. Most C3's you don't have to worry about unless you sanded down to far.
Old 08-11-2004, 04:40 PM
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make's sence to me Good info
Old 08-11-2004, 04:53 PM
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Originally Posted by Van Steel
I'd say it depends. GM changed fiberglass 7 times over the course of the years. Your sig doesn't specify what year you have. If you sanded it down to far to where you see fibers than I'd definelty gelcoat it. If you didn't than you'll be alright. If you have a mid year than definetly gelcoat before you paint. Most C3's you don't have to worry about unless you sanded down to far.
Yep, it's a '67 Midyear and when I bought the car it had a fresh coat of lacquer paint and you could see the glass strands sticking out of the paint. That's why I'm getting it repainted correctly. So I assume you are saying that todays primer/surfacer will not correctly seal the fibers sticking out, no? Thanks for the information.
Old 08-11-2004, 05:10 PM
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Van Steel
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Correct. Get it gelcoated 1st.
Old 08-11-2004, 05:54 PM
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lbell101
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Not to break up the gelcoat lovefest but it sucks. I wouldn't use it on any Vette ever. It's simply not a good product for the application. In the 1970's it may have been the only thing you could put over fiberglass but things have changed. Most of the time all you need or want is an epoxy sealer and a high build urethane primer. If you have really bad waves or glass that's screwed up and sticking out all over, you could use a filled polyster with better sanding properties like Z-chrome rust defender (or other similar products). Gelcoat has no real good use on a Vette anymore. Now if you're fixing a boat....
Old 08-11-2004, 06:45 PM
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Originally Posted by lbell101
Not to break up the gelcoat lovefest but it sucks. I wouldn't use it on any Vette ever. It's simply not a good product for the application. In the 1970's it may have been the only thing you could put over fiberglass but things have changed. Most of the time all you need or want is an epoxy sealer and a high build urethane primer. If you have really bad waves or glass that's screwed up and sticking out all over, you could use a filled polyster with better sanding properties like Z-chrome rust defender (or other similar products). Gelcoat has no real good use on a Vette anymore. Now if you're fixing a boat....
Like I said above, I think, is that one painter wants to skip the gelcoat and use a polyester urethane primer/surfacer. Why do you think that Gel Coat is no good to use anymore besides that it sucks and is no good? Thanks for the clarification on this.

Last edited by Patrick67; 08-11-2004 at 07:06 PM.
Old 08-11-2004, 07:18 PM
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lbell101
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I don't think it ever was a really good product for this application. It's real use is to give a waterproof color coat to boat hulls and tubs. GM never used a gelcoat on the Vette as it just didn't make sense because they knew it would be painted.
When early corvette painters discovered they were having longevity problems with lacquer systems, they had no alternative but to try gelcoat. It is compatable with fmc and would hold up better than the only other choices, bondo and lacquer primer.
Today we have a host of excellent products that do the job better and easier. While gelcoat (basically polyester resin with high density fillers and colorant) is durable, it's use was for topcoat protection rather than substrate sealing and filling. It will crack sooner than a good substrate should if given a blow or stress. Modern epoxy and urethane primers and high fill polyester products give much better flexability which is what you need in a substrate. The topcoat should provide your toughness and durability. Furthermore, the new products sand extremely easy by comparison. They are also perfectly adequate at sealing the fmc.

Larry
Old 08-11-2004, 07:24 PM
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Originally Posted by lbell101
I don't think it ever was a really good product for this application. It's real use is to give a waterproof color coat to boat hulls and tubs. GM never used a gelcoat on the Vette as it just didn't make sense because they knew it would be painted.
When early corvette painters discovered they were having longevity problems with lacquer systems, they had no alternative but to try gelcoat. It is compatable with fmc and would hold up better than the only other choices, bondo and lacquer primer.
Today we have a host of excellent products that do the job better and easier. While gelcoat (basically polyester resin with high density fillers and colorant) is durable, it's use was for topcoat protection rather than substrate sealing and filling. It will crack sooner than a good substrate should if given a blow or stress. Modern epoxy and urethane primers and high fill polyester products give much better flexability which is what you need in a substrate. The topcoat should provide your toughness and durability. Furthermore, the new products sand extremely easy by comparison. They are also perfectly adequate at sealing the fmc.

Larry
Excellent Larry, thanks! I do know that a lot of AC Cobra kit cars are hand laid and have about 5 coats of gelcoat on them in the color of your choice, so you can go without paint.
Old 08-11-2004, 10:41 PM
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i don't see the need for gelcoat on bodies if prepped properly. A good epoxy primer, body work, surfacer, and sealer should hold up just as well as anything thing else. If i recall, I don't think vettes came from the factory with a gelcoat in the first place, but i might be wrong.
Old 08-11-2004, 10:51 PM
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GDaina
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Originally Posted by Redshark6974
i don't see the need for gelcoat on bodies if prepped properly. A good epoxy primer, body work, surfacer, and sealer should hold up just as well as anything thing else. If i recall, I don't think vettes came from the factory with a gelcoat in the first place, but i might be wrong.
No gelcoat on vettes. A good two part primer is Fiber Glass Evercoat Slick Sand...I had fiber strands showing where the panels met....one good application and block sanding, thre years later looks as good as the day I laid the paint.
Old 08-12-2004, 07:02 AM
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Frank75
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As others have said, epoxy sealer, high-build primer, seal again if you wish then BC/CC.

You may also wish to post the question here: http://www.autobodystore.com/cgi-bin/config.pl?
Old 08-12-2004, 10:20 AM
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Originally Posted by Redshark6974
i don't see the need for gelcoat on bodies if prepped properly. A good epoxy primer, body work, surfacer, and sealer should hold up just as well as anything thing else. If i recall, I don't think vettes came from the factory with a gelcoat in the first place, but i might be wrong.
Redshark, I spent 2 years trying to find out who the original owner of my '67 was. If finally found him and he is (or was) from Hurricane, West Virginia. I've talked to him several times. He bought the car new in '67 when he was 18 years old from Ideal Chevrolet in Hamlin. Does Ideal Chevrolet ring a bell? They went out of business around 1992.
Old 08-12-2004, 02:51 PM
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sorry, I've never heard of that dealership....too young to know I guess. Anyways, thats cool about your car and tracing it back like that!

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