Frame Rust: What's the Big Deal?
Thread Starter
Instructor
Joined: Aug 2004
Posts: 142
Likes: 1
From: Minnesota
Frame Rust: What's the Big Deal?
After reading all the warnings about frame and birdcage rust, I did crawl around under my 72 before I bought it, and checked body gaps, and I think I'm okay. (It would have been hard to turn around and drive home 1000 miles if I'd decided otherwise, I'll admit- didn't realize how friendly and willing forum members are to check stuff out at the time...) The question I can't seem to find a simple answer to browsing other threads is, "What's the big deal?" What happens if your frame has rust- will the car fall apart, or will handling be poor, or what? 
-Owner of a former NY car
-=Boston!=-
-Owner of a former NY car
-=Boston!=-
Pro
Joined: Sep 2002
Posts: 653
Likes: 0
From: Dickinson (Houston) Texas
The frame is the backbone of the Vette. If it loses it's strength, the fiberglass alone will not hold the car together. Suspension parts could break away, like the front A-Arms and could become very dangerous.
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Originally Posted by gtr1999
Extreme cases the frame will collapse and crack the body. The doors won't open. Windshield and glass tops will crack.
seen it happen, and it ain't pretty nor cheap
Less extreme cases can cause doors to bind when jacking one corner. Some guys will tell you this is normal, but I can jack any corner of my '76, and the doors don't twitch a millimeter. In fact, I think this might be a quick and easy test for frame integrity. ...jack up a corner, if either door binds, walk away
Le Mans Master
Joined: Jun 2002
Posts: 8,339
Likes: 24
From: I can walk to MA
**** Ah Paul, You beat me to it with your picture. 
****
Yes - all of the above if left unchecked.
Here is an example of rust that weakened the frame in an already weak area:
http://temp.corvetteforum.net/c3/paul79//rust.jpg
This is the same picture above.
****Yes - all of the above if left unchecked.
Here is an example of rust that weakened the frame in an already weak area:
http://temp.corvetteforum.net/c3/paul79//rust.jpg
This is the same picture above.
Safety Car
Joined: Oct 1999
Posts: 4,101
Likes: 10
From: NorCal
Look at a picture of the frame (in the manual or AIM). The critical area is the "kickups" that are welded to the frame rails and have the trailing arms bolted on to the back. It's a natural "pocket" that holds moisture, salt, dirt, etc... and that's the area that falls apart. Looking at the picture, it becomes clear that you could loose the trailing arm or rear part of the frame if it was full of cancer...
Hans
Hans
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
It's true it is very dangerous, have been pondering this for some time, people buy these cars because the body usuallly looks great and never even take close look at points that can rust.
They jump in and go for a ride up to highway speeds on the way home after buying the car without ever even knowing if the car is structurally safe. I encourage everyone to take a close look at thier frame and look even closer before putting the 500HP crate motor in
They jump in and go for a ride up to highway speeds on the way home after buying the car without ever even knowing if the car is structurally safe. I encourage everyone to take a close look at thier frame and look even closer before putting the 500HP crate motor in
Team Owner
Joined: Dec 1999
Posts: 26,555
Likes: 257
From: Florida
2021 C2 of the Year Finalist - Modified
C2 of the Year Finalist - Modified 2020
C2 of Year Finalist (performance mods) 2019
St. Jude Donor '03 thru '26
Rust is to Corvettes like Cancer is to the human body. 
Melting Slicks
Joined: Dec 2000
Posts: 2,635
Likes: 0
From: Union Ontario
I'm in the progress of repairing frame and birdcage rust and when I got down to where I couuld see the damage, I just about crapped myself.... if I had of been in any kind of accident I would not have been protected.... the birdcage would have collapsed.... my frame was bad but not as bad as the birdcage was.
Safety Car
Joined: Jun 2002
Posts: 4,135
Likes: 1
its the whole design of the windshield frame posts- made to channel water under the trim down the post to the wiper well and down to the ground. like a gutter...i sealed the trim with the caulk they use to hold the windshiel in place so the water goes up and over------poor design on g.m's part
Advanced
Joined: Apr 2004
Posts: 69
Likes: 0
From: Lafayette LA
Originally Posted by paul67
These cars can be pretty until you look underneath. Buyer beware!
Le Mans Master
Joined: Jan 2001
Posts: 6,938
Likes: 1
From: San Diego CA
Originally Posted by wcsinx
Less extreme cases can cause doors to bind when jacking one corner. Some guys will tell you this is normal, but I can jack any corner of my '76, and the doors don't twitch a millimeter. In fact, I think this might be a quick and easy test for frame integrity. ...jack up a corner, if either door binds, walk away
True with the exceptions of convertibles. Mine has zero rust, never has never will but try opening the door with one jack stand up.
Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
i've never seen a 25+ year old car that didn't have some rust on the frame. how can you tell if its surface rust or something more serious? what's the best way to remove surface rust on a frame?
