69 Front Support

[George D.]

I recently had my 69 repainted and there were rusted metal rivets pushing up the fiberglass from the front support surround(the metal support under the fiberglass by the horns) which I have seen on many Corvettes. The body shop ground out the fiberglass and replaced the rivets. Once the rivets were replaced they fiberglassed in the holes. You can now see the area where they reglassed over the rivets. It looks like the fiberglass shrunk and there is now a slight indentation. I spoke with the body shop guy and now he tells me the only way to fix it is to remove the entire support and fiberglass in in rather than using rivets. Anyone have this same problem and what was the solution? This sound rather complicated and I'm concerned about causing more problems.

Thanks,

[Terry F.]

Re: 69 Front Support

These cars have certain issues with them. The rivets you described are one of them. The way they cause the fiberglass to bulge slightly, I consider part of the character of the car. The result of trying to fix it can leave the fiberglass weakened and in your case a poor repair. Personally, I would have taken great care in doing the repair. I probably wouldn't have replaced the rivets. I wouldn't have glassed over them with with regular resin and matting. I would have used something like what corvette image sells called "pigmented reinforced polyester putty." I think ekler's sells the same stuff as "original formual". It is real close to what was used to bond panels together on 53 to 72 corvette. I would have mixed it and layed it in the repair area. Another option would have been to mix it up and smash it into some random fiber matting and then lay it in the ground out area. If they didn't bevel the repair area well enough that will also contribute to the problem you are having. After I made the repair, I would have roughed it out and then baked it with a infrared heatlamp to shrink the repair material (be very carefull doing this, no need to burn your car to the ground. This is best done after it has cured for a couple of days or weeks or so. Letting it sit in the sun will help too. Basicly, you need to shrink it as much as possible so that it will be stable and not shrink anymore before you paint it. The problem with using regular resin and matting is that it is impossible to achieve the same character (density) as the fiberglass in the area around the repair. As the temperature of the car changes you start to get shadows and repairs start to show up. The product I mentioned seems to approximate the same density as the original pressed fiberglass panel when cured. Time is a big element to making repairs so that the repair can shrink itself as much as possible before you paint over it. I also believe in using a gellcoat. Helps hide all the boo-boos. I am not a painter or body man. I have talked to a lot of people on this stuff though. I am sure there are others that can comment about this.

[Bill B.]

Re: 69 Front Support

Hope you receive several responses on this as I too am contemplating repairing my son's 72 convertible. To me, any rusting of the support which is below the fiberglass will eventually surface again in "dimples" unless that rust is totally removed. Although it sounds like a lot of effort, I am leaning towards removing the support, blasting and rerivet. I just glanced at the car and seems that support would come out reasonably "easy" (or would that be resaonably difficult). And, like all this repair work, repair would just take some thought and patience. We have the headlights, bumpers/brackets, and radiator out. In your case, I have to believe that the repair could have been accomplished to a higher standard using the procedure that was used. I think you are getting some excuses for poor workmanship rather than a qualify result.

[David H.]

Re: 69 Front Support

George and Bill; I have been there on my 69, the aluminum rivets are what is rotten and they oxidize causing the glass to bulge. They hold another FG panel on to the steel reinforcement which usually lives quite well. What I did was to grind through the top panel about 1.5" in diameter until you grind to bellow the old rivet head, this cuts through the top panel and well into the reinforcement panel, you will also see the factory panel bond matterial between the panels. Then change the rivets or leave them out, the old rivets will still hold the steel reinforcement where they are crimped over for a stock appearance. Then fill with West Marine epoxy resin, not the polyester kind that will shrink, this bonds the 2 panels together and will not shrink latter.
George; the man should offer to repair your car now useing evercoat (polyester) short strand kitty hair or epoxy resin with one of the many fillers that are sold to go in it and reprime and paint. The sinking feeling should at least be felt by him as well!! David

[Klaus Friedrich #33362]

Re: 69 Front Support

Hi George,

David is right - it is a simple chemical reaction. To use aluminum rivets on steel mixed with humidity will start this reaction. The aluminum will corode and bulge the fiberglass. Try using steel rivets instead (I know it is hard work!).

Hope it helps

Klaus Friedrich
#33362