Finding hidden rust
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Pro
Joined: Jun 2014
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From: New Jersey
Finding hidden rust
It has been quite a few decades since I have had a 70's car, but was amazed at the amount of rust that can be on a fiberglass car.
Looking at this photo, I see bubbles around the headlight area that should not be there.
It would appear to me, that there are some steel attachment points there that have corroded away.
Is this correct, or is there another explanation?
Looking at this photo, I see bubbles around the headlight area that should not be there.
It would appear to me, that there are some steel attachment points there that have corroded away.
Is this correct, or is there another explanation?
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
There is a reinforcement bar under there and the rivets on it have corroded, there is a recent post where a member is repairing that problem.
You want to see rust, check out this link.
http://forums.corvetteforum.com/c3-g...-corvette.html
You want to see rust, check out this link.
http://forums.corvetteforum.com/c3-g...-corvette.html
Team Owner
Joined: Sep 2006
Posts: 31,237
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From: Westminster Maryland
Hi F,
PB is right the reinforcement bar under there is steel and can rust.
The neatly spaced bumps are the rivets as he also points out.
What's interesting is that the rivets are aluminum so they oxidized enough to make the bumps. Not rust as we usually think of it.
The RUST was saved for more devilish locations on the car.
Regards,
Alan
PB is right the reinforcement bar under there is steel and can rust.
The neatly spaced bumps are the rivets as he also points out.
What's interesting is that the rivets are aluminum so they oxidized enough to make the bumps. Not rust as we usually think of it.
The RUST was saved for more devilish locations on the car.
Regards,
Alan
Team Owner
Joined: Jan 2006
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From: Crossville TN
Those rivets are aluminum, I believe. And, they will eventually oxidize just from being in contact with the air. About the only place in the U.S. you will find any C3's [unrestored] that don't have "lumps" on the front end is the Arizona/Nevada area or the "inland" areas of southern CA. Until those lumpy areas above the rivets actually break open or the paint begins to crack, consider them a 'badge of honor' for an intact, original car.
(You beat me to it again, Alan...
)
(You beat me to it again, Alan...
)
Last edited by 7T1vette; Jun 13, 2014 at 05:54 PM.
Le Mans Master
Joined: Aug 2006
Posts: 7,425
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Is that only on chrome bumper cars?
Did GM stop using that bar or stop using rivets after a certain year?
Team Owner
Joined: Sep 2006
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From: Westminster Maryland
Hi Pb,
The bar continued through 82 but I think you're right about the rivets…. the way the bar was bonded to the surround must have changed because I don't think the rivets continued to be a problem as the cars aged.
Regards,
Alan
The bar continued through 82 but I think you're right about the rivets…. the way the bar was bonded to the surround must have changed because I don't think the rivets continued to be a problem as the cars aged.
Regards,
Alan
2026 Loser of the Year
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From: New Or-leens Loo-z-anna
But seriously...as a rookie I am still amazed how the simplest things that were done to increase profit are not supposed to be improved by car owners nearly 50 years after the fact (poor Rvzio is learning the art of Overspray as we speak).....but I'll get over it.
EDIT: OOOOOOOOOOOPS......back to the rust................
Last edited by doorgunner; Jun 13, 2014 at 07:10 PM.
Team Owner
Joined: Sep 2006
Posts: 31,237
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From: Westminster Maryland
Hi dg,
I wouldn't think any change in the headlight reinforcement bar, or it's method of bonding to the hood surround, would have had anything to do with increasing profits.
Regards,
Alan
I wouldn't think any change in the headlight reinforcement bar, or it's method of bonding to the hood surround, would have had anything to do with increasing profits.
Regards,
Alan
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From: New Or-leens Loo-z-anna
I was just picking Alan.....while I have your attention---thanks again for all the great advice on this Forum!
Team Owner
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From: Southbound
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As adhesive technology advanced, the aluminum rivets were no longer needed and were discontinued. Later cars have no rivets.
Le Mans Master
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
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Bar, no. All C3s have it. Rivets, yes. Early cars have a fiberglass bonding strip riveted to the headlight reinforcement bar which was then bonded to the hood surround. With age, the aluminum rivets undergo a galvanic reaction which makes them pull away from the steel reinforcement. Hence the bumps in the hood surround in the pic.
As adhesive technology advanced, the aluminum rivets were no longer needed and were discontinued. Later cars have no rivets.
As adhesive technology advanced, the aluminum rivets were no longer needed and were discontinued. Later cars have no rivets.
