Gel coat please clarify it's use.
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Gel coat please clarify it's use.
Now that i have all of the paint off of my vette and am in the process of making small repairs and sanding things smooth I need to better understand the need or lack there of using Gel coat. I have read on some of the other posts that these cars were not actualy sprayed with Gel coat and that it is not neccessary to use. However, I just received Eckler's book on fiberglass repair and it states that no bonding material or filler will prevent fibers from raising up and ruining a new paint job. And if you sand to deep you will go through the gel coat and the area must have GC re- applied. Can anyone offer any insight on this to me. :confused:
Melting Slicks
Joined: Nov 2001
Posts: 2,214
Likes: 0
From: Casa Grande AZ
Re: Gel coat please clarify it's use. (wadew10)
Gel coat is not sprayed on the outside of the item unless it's being repaired (mostly). Repair Gel coat must be sanded and buffed to look good. During manufacturing gelcoat is sprayed inside a mold before the fiber layup. Then when the part is pulled it has a nice smooth colored surface that needs little if any finishing (like boats). C3's don't have a gelcoat. The smooth surface is just the fiberglass resin against the mold surface. So there is very little thickness before you hit fibers. When I did my vette, I trimmed any loose fibers first. then I went over the area with either long strand, short strand or just a coat of resin to protect the fibers. That depended on the depth of the gouge. Don't go directly over loose strands with bondo. I also used a sealer (epoxy) before and after using CATALYZED primer. I'm not sure if this is what others do but I've noticed nothing but a little shrinkage since painting.
Larry http://www.larryscars.com/71vette.html
Larry http://www.larryscars.com/71vette.html
Melting Slicks
Joined: Mar 1999
Posts: 2,845
Likes: 2
From: Apex NC
Re: Gel coat please clarify it's use. (wadew10)
There is no gelcoat on your car. The Ecklers book really pushes the use of their gelcoat. In reality you can use a combination of primer/sealer followed by a primer/surfacer to get great results. The primer/sealer will seal any bare fiberglass areas and prevent them from absorbing the top coats and shrinking the finish to show through later. Then the surfacer will smooth any imperfections and level the surface to get it nice and smooth.
If you've gotten far enough through the finish on your car, you'll see that the layer closest to the bare glass is a red oxide primer. Below that is the bare fiberglass. The surface of the bare glass was smooth originally, due to the resin in the glass itself being sprayed into the molds before they were press molded. When you sand it down past the red oxide primer, you're also sanding into this thin layer of resin that is the outermost "skin" of the panel itself. This is where the epoxy priimer/sealer will come in to seal the bare glass and stabilize the surface so it will accept the next coats without causing problems down the road.
Hope this helps,
Shannon
PS - I'm in Charlotte this weekend. Shoot me an IM if you want me to take a look and shoot the bull
If you've gotten far enough through the finish on your car, you'll see that the layer closest to the bare glass is a red oxide primer. Below that is the bare fiberglass. The surface of the bare glass was smooth originally, due to the resin in the glass itself being sprayed into the molds before they were press molded. When you sand it down past the red oxide primer, you're also sanding into this thin layer of resin that is the outermost "skin" of the panel itself. This is where the epoxy priimer/sealer will come in to seal the bare glass and stabilize the surface so it will accept the next coats without causing problems down the road.
Hope this helps,
Shannon
PS - I'm in Charlotte this weekend. Shoot me an IM if you want me to take a look and shoot the bull
Le Mans Master
Joined: Jul 2001
Posts: 9,622
Likes: 16
From: absecon nj
Re: Gel coat please clarify it's use. (lbell101)
im one of the few who actually gelcoated the entire car.my body was in real bad shape when i got errand strand coming up everywhere cracks around the entire car.This is why i did it.Long process you have to spray gelcoat on car then a release agent is sprayed on top to get it to dry,like wax of some sort,then a lot of block sanding to get it smooth,alot.Im happy with the results very staright body and no cracks have come back or strands lifting..i also repaired cracks before i gelcoated too.If you dont have to do it then dont.
Melting Slicks
Joined: May 2001
Posts: 2,215
Likes: 170
From: PA
Re: Gel coat please clarify it's use. (pats406nitrovette)
I got my car after it was all ready painted but it was gelcoated and it looks great some people say you do not need to gelcoat any more because of the new and better paint out to day but that is just what I here.
Le Mans Master
Joined: Dec 2000
Posts: 5,245
Likes: 25
From: Blue Ridge Georgia
Re: Gel coat please clarify it's use. (Stephen DeFazio)
Use the PPG DP50LF for your base sealer. Spray on a couple of wet coats, let it flash if any hairs are still standing hit these places with your grey scothbrite pad then shoot on a coat of PPG prima K36. After that block sand and repeat again then spray on the color (BC/CC)
