A number of early C3's I've looked at have a series of small bumps or dimples on the fiberglass between the headlights and the leading edge of the hood. My understanding is that these are rivets which are corroding. Some sources I've read say this is a serious problem. Others (mostly sellers) say it is not so serious. What is the real story: is this a major problem, and if so, how is it best corrected? Any thoughts are appreciated.
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Re: C3 Front End Rivets - How Serious?
"...Some sources I've read say this is a serious problem. Others (mostly sellers) say it is not so serious..."
It depends on the meaning of the word "serious". There is no easy solution...fixing it means grinding, cleaning, glassing, filling, prepping and painting. If all that is your idea of a "good time", then it's not too serious. -
Re: C3 Front End Rivets - How Serious?
Dave------
I don't know how to define the term "serious". In the sense that the problem you describe is going to cause the car to fail to be functional, they are not serious, at all-----quite trivial, in fact.
The only repair for this problem is to grind out the fiberglass/filler over the rivets, remove the rivets, replace them, repair the surface, and re-paint. So, if that sounds like serious work, then the situation is serious. If it sounds easy-to-do and inconsequential, then it's quite minor.
By the way, years ago Ralph Eckler published in Vette Magazine an absolutely OUTSTANDING article on the complete repair methodology for this problem. I still have the magazine around here but I don't recall what the date was, so it makes it very difficult for me to find it. As I recall, though, to do this repair properly and in such a manner that it will be DURABLE is a fairly involved process.In Appreciation of John HinckleyComment
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Re: C3 Front End Rivets - How Serious?
The only correct solution is to replace the hood surround panel.
Attempting to repair in any other fashion is wasting time and money.
JohnComment
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Re: C3 Front End Rivets - How Serious?
Now that WOULD be serious, but such a drastic step is actually unnessary. One of the advantages of fiberglass is that it's, er, easy to repair. If you don't like what you have done, i.e. the repair contour doesn't look like the real deal or the resin doesn't set up properly, you can always just grind it off and try again...continue doing that until you're satisfied.
Just as any other minor panel damage like cracks, gouges, or small missing pieces doesn't require the replacement of the panel, neither does the dreaded "rivet corrosion bulges". Grinding open the area over the rivet, cleaning out the corrosion, replacing the rivet, and fiberglassing, filling the area over the rivet back to contour and painting is a perfectly acceptable solution, and unlike fender or other repairs, it is undetectable if you do good body work.
HOwever, a perfect question for sellers that claim such a repair is not SERIOUS is: "If this repair is so insignificant, how come you haven't done it already?"Comment
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Re: C3 Front End Rivets - How Serious?
I would agree, not too serious of a repair.
TerryComment
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Re: C3 Front End Rivets - How Serious?
Almost in 100% agreement with you Chuckdude. I wouldn't be so quick to replace the rivets except in extreme cases. If the Rivet head will clean up and maintain at least %75 of the original head thickness, I'd leave it in.
The only thing I would do in addition to the repair you describe is paint the head of any existing or replaced rivets with green Chromated Epoxy Polyamide Primer. This the same stuff used on aluminum aircraft parts and will prevent a recurrance of the corrosion of the aluminum rivet head.
tcComment
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Re: C3 Front End Rivets - How Serious?
John, I have to disagree with you. I have repaired several over the last 20 or so years with very good results. The repair methods suggested by the other posters will do a very good job. The only thing that I do different is that I use a self etching epoxy primer instead of the zinc chromate. The results will be the same.
One trick that a lot of people do is to do the repair and let the car sit in the sun for several days/weeks before they prime and block. Allows for shrinkage. The adheasive (I use Lord/Fusor) that is used to bond the panels together seems to shrink less than a "bondo" type filler.
Lotsa luckDick WhittingtonComment
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Re: C3 Front End Rivets - How Serious?
Thanks for your insight folks. My conclusions from this are to wait until a respray is in order and correct the rivets at that time.Comment
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Re: C3 Front End Rivets - How Serious?
Dave there is another way to repair this. It takes a bit of time but done right you wont have to repair the fiberglass. You remove the support bracket that is attached to the underside of the surround I have done this a few times already. You use a thin puddy knife to unbond the support you must be very careful not to punch through the surround this is a tight space if you take your time it can be done. Before you remove it mark it so you can install it in the same position. Once you have it out seperate the bonding strip from the support remove the rivets then you can reattach the bonding strip to the support without rivets use an panel bonding adhesive to reattach strip. Then after it sets you can reinstall the support assy back on the surround. If you let the car sit for a few days after you remove the support like in the warm sun the bumps will shrink to there normal position most time at least for me. PaulComment
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Re: C3 Front End Rivets - How Serious?
Hi Dave,
Before you blow off thinking about a repair to the rivets/support, you should take a hard look at the support it'self and make doubly sure that it's not already starting to pull away from the surround.
If your not noticing sagging of the surround down from the point of the hood, then the odds are that it's still bonded in good shape. If you detect the dreaded sag, however slight, then you may be looking at repairs sooner than you think.
My special "Bubba's" solution with my basket case was to jamb a broken handled garden hoe between the lower core support and the surround to keep the whole affair from imploding. The picture I took doesn't do it justice.
There's a ton of weight and stress on that support from the headlight buckets.
ChuckComment
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Re: C3 Front End Rivets - How Serious?
Sounds like someone (like Mikie #14) in your car's history liked to use the front end of the car as a "recreational playground" while parking with his or her significant other.
Headlights aren't THAT heavy..
tcComment
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Re: Now that you mention it Tracy *NM*
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Re: Now that you mention it Tracy
You could get rid of the rivets completely and bond the bar on like it was done in 73. Lord Fusor will do the job and if you want the new bar to appear original use the Lord Fusor to install the part of the original rivet you can see to the bottom of the new pannel before bonding it to the surrond.I doubt many judges would spot no rivets underneath in flight judging. The spots will never come back and most original reinforcement bars need replaced if the bumps are showing.
LyleLyle
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Re: Or better yet
Just throw the support on the bench, fire off the pop rivets through the support from the "bond" side and then re-bond the beam with the faked rivets attached.
But, I'm a little concerned that the beam was riveted for a reason, and that was to HELP the bonding material hold that heavy chunk of steel in place.
Even though I understand that the technology of the bonding materials is far superior to those used even as late as the eightys, I still wouldn't put all my eggs in one basket and trust that it will never separate again just because I used Fusor alone.
I'll grind out the rivets and replace them the way the General did along with the Fusor. Then I'll seal up the ends of the rivets where the moisture enters and move on thank you very much.
ChuckComment
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