Gelcoat Question

[Kurt B.]

Gentlemen:
Did 1968 Corvettes have gelcoat?
When repainting such a vehicle that has been strippedof all paint chemically, does it need to be gelcoated before repainting?
I am getting conflicting answers from "professional body shops". Some say yes some say no.
I am confused.
Thank you,
Kurt Bunting

[Terry F.]

Re: Gelcoat Question

If your car is original, there is no gellcoat on it. I think the uninformed body shops get confused on the subject. The simple answere is NO. There are definitely other on this board that can comment on what the pannels of the car are made of. I think some people see a heavy layer of resin that was sprayed into the panel molds and then the fiberglass resin was added. This gave the appearance that the panel had a gellcoat.

After years of multiple paint jobs (sanding on the outer surface if the panel), flexing (stress cracks smaller than you can see or detect), repair work, and errand strands of fiberglass etc you can have the potential for a lot of problems. The intent of gellcoat is to seal all that stuff up and provide a layer that is more stable for painting because it bonds nicely to the panel. The idea being that all the nasty stuff that is soaked into the panel will have a harder time getting out and forming bubbles in the paint. Fiberglass is not steel, it absorbs everything including the hummidity in the air. Later, as the temperature changes, these substance will try to take the path of least resistance sometimes forming bubbles under the paint. Putting a ton of paint products on your car can contribute to this. But the types of paint that you apply is also inportant so you can't just blame it on the thickness in my opinion. Original primers were laqure based and they burned into the surface of the paint. They were good at sealing the surface of the panels. The paint was put on thin compared to what most people do today. My opinion is that it might have been more breathable. Just my opinion on all this stuff. I am not an expert. The professionals develop habits based on success. They don't want you to come back to them. It sounds like Voodo most of the time because people develop strong opinions on why things work out and they really might not even have a clue about what is going on at the surface of the paint. All they know is that it seems to work.

In my opinion, purchase a system for painting your car and adhear to that system. Don't force dry the paint at any stage. I personally believe you should clean the surface of the glass, cover the car with a breathable car cover and let it sit out in the sun on warm days to force the volitile products out of it and shrink the repairs. I also believe in using heat lamps to shrink the any repairs that have been done and blow off the volitile component. Paint on a low humidity day and make sure the surface of the fiberglass is bullit proof clean. Some people say you can use epoxy primers on bear glass instead of gellcoat but I don't think they burn into the surface of the glass like laquer did (I gladly stand to be corrected on this). I suspect they still bond very well to the surface and can seal up errand strands of glass. I will stop here because I don't want to add to the already conflicting information out there. I would like anyone else to comment on what I said. I am not at all an expert on this. Terry

[Terry F.]

Re: Gelcoat Question

If your car is original, there is no gellcoat on it. I think the uninformed body shops get confused on the subject. The simple answere is NO. There are definitely other on this board that can comment on what the pannels of the car are made of. I think some people see a heavy layer of resin that was sprayed into the panel molds and then the fiberglass resin was added. This gave the appearance that the panel had a gellcoat.

After years of multiple paint jobs (sanding on the outer surface if the panel), flexing (stress cracks smaller than you can see or detect), repair work, and errand strands of fiberglass etc you can have the potential for a lot of problems. The intent of gellcoat is to seal all that stuff up and provide a layer that is more stable for painting because it bonds nicely to the panel. The idea being that all the nasty stuff that is soaked into the panel will have a harder time getting out and forming bubbles in the paint. Fiberglass is not steel, it absorbs everything including the hummidity in the air. Later, as the temperature changes, these substance will try to take the path of least resistance sometimes forming bubbles under the paint. Putting a ton of paint products on your car can contribute to this. But the types of paint that you apply is also inportant so you can't just blame it on the thickness in my opinion. Original primers were laqure based and they burned into the surface of the paint. They were good at sealing the surface of the panels. The paint was put on thin compared to what most people do today. My opinion is that it might have been more breathable. Just my opinion on all this stuff. I am not an expert. The professionals develop habits based on success. They don't want you to come back to them. It sounds like Voodo most of the time because people develop strong opinions on why things work out and they really might not even have a clue about what is going on at the surface of the paint. All they know is that it seems to work.

In my opinion, purchase a system for painting your car and adhear to that system. Don't force dry the paint at any stage. I personally believe you should clean the surface of the glass, cover the car with a breathable car cover and let it sit out in the sun on warm days to force the volitile products out of it and shrink the repairs. I also believe in using heat lamps to shrink the any repairs that have been done and blow off the volitile component. Paint on a low humidity day and make sure the surface of the fiberglass is bullit proof clean. Some people say you can use epoxy primers on bear glass instead of gellcoat but I don't think they burn into the surface of the glass like laquer did (I gladly stand to be corrected on this). I suspect they still bond very well to the surface and can seal up errand strands of glass. I will stop here because I don't want to add to the already conflicting information out there. I would like anyone else to comment on what I said. I am not at all an expert on this. Terry

[Kurt B.]

Re: Gelcoat Question

Terry,
Thanks for the input. I am presently going to various body shops to find someone to paint the car as I do not have the equipment or the knowledge to do this. I am getting conflicting opinions from these shops and am trying to separate fact from fiction. I appreciate the info you provided.
Kurt Bunting

[Kurt B.]

Re: Gelcoat Question

Terry,
Thanks for the input. I am presently going to various body shops to find someone to paint the car as I do not have the equipment or the knowledge to do this. I am getting conflicting opinions from these shops and am trying to separate fact from fiction. I appreciate the info you provided.
Kurt Bunting

[Jeff M #42706]

Re: Gelcoat Question

Kurt,

You will definately get 1000 different answers on this. After doing a few myself. I have had good luck using epoxy primer and polyester primers AS a gel coat. Terry is right, you have to seal off the fiberglass or the paint may lift (this has happened to me also before I started using the epoxy or polyester primers) The bad thing is it may not happen untill a car show next summer. Most manufactures have these types designed to work with thier system. As far as ordering the "gel coat" from Ecklers, I have never done it.
JM

[Jeff M #42706]

Re: Gelcoat Question

Kurt,

You will definately get 1000 different answers on this. After doing a few myself. I have had good luck using epoxy primer and polyester primers AS a gel coat. Terry is right, you have to seal off the fiberglass or the paint may lift (this has happened to me also before I started using the epoxy or polyester primers) The bad thing is it may not happen untill a car show next summer. Most manufactures have these types designed to work with thier system. As far as ordering the "gel coat" from Ecklers, I have never done it.
JM

[Donald T.]

Re: Gelcoat Question

I've used spray gelcoat and lived to regret it. It's very difficult to work with. I also ruined a very nice Devilbiss gun when it set off in the cup. I've never used gelcoat since. Had very good luck using DP40 as a sealer on the bare glass, followed by K36 for blocking, and then a final coat of DP40 to prep for color. JMHO

[Donald T.]

Re: Gelcoat Question

I've used spray gelcoat and lived to regret it. It's very difficult to work with. I also ruined a very nice Devilbiss gun when it set off in the cup. I've never used gelcoat since. Had very good luck using DP40 as a sealer on the bare glass, followed by K36 for blocking, and then a final coat of DP40 to prep for color. JMHO

[Terry F.]

Re: Gelcoat Question

I have heard some nasty stories about applying gellcoat. Long time ago I heard it dried very hard and was difficult to sand smooth/flat. I remember Eckler's product being complained about back then. There are other types out there now and I believe they work nicely. Corvette Image makes body panels and sells a gellcoat that sounds easy to work with (1-800-550-1200). I have no affiliation to them. Srays like a heavy primer. You need someone that will take the time to experiment with it to get it right. You need to be prepared to work with it. Experience counts in these sorts of things. You can shoot section by section without problem. When it is dry, you use regular sand paper to block it. They don't recomend wet sanding it as I recall. Terry

[Terry F.]

Re: Gelcoat Question

I have heard some nasty stories about applying gellcoat. Long time ago I heard it dried very hard and was difficult to sand smooth/flat. I remember Eckler's product being complained about back then. There are other types out there now and I believe they work nicely. Corvette Image makes body panels and sells a gellcoat that sounds easy to work with (1-800-550-1200). I have no affiliation to them. Srays like a heavy primer. You need someone that will take the time to experiment with it to get it right. You need to be prepared to work with it. Experience counts in these sorts of things. You can shoot section by section without problem. When it is dry, you use regular sand paper to block it. They don't recomend wet sanding it as I recall. Terry

[Jim T.]

Re: Gelcoat Question

Kurt are you going to use base coat/clear coat?

[Jim T.]

Re: Gelcoat Question

Kurt are you going to use base coat/clear coat?

[Joe M.]

Re: Gelcoat Question

Shot Ecklers gel coat a few times, once on a canoe. Had it start to set up once when the air temp was a bit high but got it out of the gun on time. It does set up waxy and will clog sandpaper. I used a bucket of water mixed with Joy dish detergent and wet sanded without problems. Never had a problem with it failing even years down the road. Needs to be fresh product. Sands hard but that gives me the impression of integrity. Select the appropriate grit paper to get good mechanical bond for primer. A Dupont rep recently told me a vette must be gelcoated. I have painted other vettes using just lacquer primer. One local guy who has painted a couple of magazine vettes, claims dupont epoxy primer followed by PPG K-36 primer and then bc/cc or acrylic lacquer. Another guy shoots K-36 on bare glass, no sealer, then bc/cc. The recipes are endless and the final product is more directly related to sound fiberglass repairs rather than relying on primer or other topcoat to remove all sins. Familiarity and experience with a line of products makes for the best paint results. It is better to ask what doesn't work. Legendary fiberglass, located in south east PA, has a product it recommends to cover bare fiberglass. Not sure if it a polyester or urethane primer. A friend used it on a 59 a few years ago, topped with Dupont bc/cc with no problem.

[Joe M.]

Re: Gelcoat Question

Shot Ecklers gel coat a few times, once on a canoe. Had it start to set up once when the air temp was a bit high but got it out of the gun on time. It does set up waxy and will clog sandpaper. I used a bucket of water mixed with Joy dish detergent and wet sanded without problems. Never had a problem with it failing even years down the road. Needs to be fresh product. Sands hard but that gives me the impression of integrity. Select the appropriate grit paper to get good mechanical bond for primer. A Dupont rep recently told me a vette must be gelcoated. I have painted other vettes using just lacquer primer. One local guy who has painted a couple of magazine vettes, claims dupont epoxy primer followed by PPG K-36 primer and then bc/cc or acrylic lacquer. Another guy shoots K-36 on bare glass, no sealer, then bc/cc. The recipes are endless and the final product is more directly related to sound fiberglass repairs rather than relying on primer or other topcoat to remove all sins. Familiarity and experience with a line of products makes for the best paint results. It is better to ask what doesn't work. Legendary fiberglass, located in south east PA, has a product it recommends to cover bare fiberglass. Not sure if it a polyester or urethane primer. A friend used it on a 59 a few years ago, topped with Dupont bc/cc with no problem.