Hi Everyone,

Ed, I have several friends with early C3s that have original paint and they have rivets showing through.  I know it is a common problem in the early c3s and have been told that they will eventually show through even after a repaint.  Im no authority, some here are but I do know that your problem is very common.  The front rubber bumper C3s, 73-82 did not have that problem but replaced the rivet problem with the urethane bumper getting wavy after time.

It is a common problem, tho not all will have it. The issue is the rivets corroding, and pushing up thru the fiberglass and paint. There is a metal reinforcement bar across the front, in front of the hood. That bar is first riveted to a bonding strip, and then the bonding strip/reinforcement is bonded to the upper surround. Over time, moisture gets in there, and the rivets and the metal reinforcement will start to corrode....this causes the corrosion to force it's way thru the body and paint.
Just sanding the paint down, and re-painting will NOT "fix" this. The only real fix is to remove the reinforcement bar, re-rivet, and then re-bond it back to the body....not an easy task.
Some have just drilled thru the rivets, and then filled in the holes. This is the most common solution, but it also leaves the drilled/filled holes to show thru eventually. It's a vicious cycle.

The real point is, this is not someone's half baked attempt at body repair...it is a fairly common dilemma.

Up here in the North East we see it alot. as joel stated not the body mans fault. Remember GM never intended these cars to be around so long. When looking for an older C3 that is one thing I would be checking for, for originality. I'd leave it myself unless they are broken right out. Your call let us know what you decide. ebo

I have a '68 Rally Red Roadster that was repainted in 1999 76XXX original miles.  Like your subject line I have one bump in the paint about the size of a quarter.  I had head the cause before but all the guys chimming in on your entry just confirms it.  I was also at a get together last week and there were also 2 other '68s there and you could see the rivets to varying degrees.

The Black Widow is in the paint shop and I just saw this very issues last week. My painter mentioned everything above and is fixing it by drilling it out and repairing the metal bar underneath and resealing it before finishing the body work. Someone tried to fix it before and did a very bad job. They used body filler and the paint callaposed around and in the holes. Very pain the in A$$ work to fix it, but he's done it many times before so I have confidence in his abilities. We'll see if it comes back one day but hopefully not for a LONG time! 😄😄

|UPDATED|12/14/2013 6:08:45 PM (AZT)|/UPDATED|

OFF TOPIC....... You still owe me a Ride in The Black Widow!ebo

I have the rivet bumps. When you say reseal....what exactly are you talking about? Filling the drilled out holes with glass/resin or pull the metal support off from underneath, stripping and sealing it or?

Thanks,
Dave

I have one also.  I was going to have  Corvette restorer shop fix mine because I only have one that is showing.

Once the corroded rivets have been drilled out, they problem should not resurface(no pun intended) again.The real problem is filling the holes to where THEY won't show thru eventually. Bondo won't fix it, as it will shrink over time, as do other body fillers. Fiberglass is the only way to make sure the holes will not return, but even then, it has to be properly done.
Not real sure about what kind a "sealer" was mentioned, but I assume they were talking about sealing the metal support from future rust issues.