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Why do birdcages rust so easily?

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Old Dec 26, 2018 | 02:34 PM
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Default Why do birdcages rust so easily?

Subject says it all.

Reading through older posts here I have noticed that everyone invariably worries about birdcage rust.

Was in an oversight that allows that or just natural wear?

Just curious.... No problems there that I know of in my '74 but I'll take another look tonight.
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Old Dec 26, 2018 | 02:57 PM
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In a nutshell, birdcage rust comes for fifty years of water leakage. It's easier to repair/replace a rusty frame than it is to rehab a rusty birdcage.
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Old Dec 26, 2018 | 03:23 PM
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to add these cars leak water when water leaks it goes and lays on the birdcage. the water has no where to go. so rust starts
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Old Dec 26, 2018 | 03:34 PM
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Originally Posted by Nowhere Man
to add these cars leak water when water leaks it goes and lays on the birdcage. the water has no where to go. so rust starts
in fact, the body being made of fiberglass made this more insidious. If you remember cars of the late 60s and 70s, they used to rust out horribly. The corrosion perfection was ineffective. Although the birdcage is thicker than body panels, the metal was hidden from view and so surface rust was never dealt with.
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Old Dec 26, 2018 | 03:43 PM
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Originally Posted by CA-Legal-Vette


in fact, the body being made of fiberglass made this more insidious. If you remember cars of the late 60s and 70s, they used to rust out horribly. The corrosion perfection was ineffective. Although the birdcage is thicker than body panels, the metal was hidden from view and so surface rust was never dealt with.
metal cars where the same, they leak water then the water gets trapped with no where to go until it rust a hole though it.
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Old Dec 26, 2018 | 06:18 PM
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Along with the above answers, you have to consider that the automakers never intended their cars to last 40+ years. Back in the "old days", just long enough to make it through the warranty period, was considered "good enough".....
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Old Dec 26, 2018 | 07:00 PM
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YEP...drive the car in salty conditions and the fact that the sealant GM used...in time would get hard and crack and allow water to get into areas it originally was beign stopped by the sealant....and WHAM...you have rust.

So much of it obviously depends on how expose the car was to certain substances.

DUB
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Old Dec 26, 2018 | 07:50 PM
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Good answers all. Do you all think garaging a C3 with little birdcage frame is sufficient? Never take her out in the rain (much less snow) but I do worry about moisture in the air such as found on
a rainy/foggy day.
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Old Dec 26, 2018 | 08:37 PM
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I got rather fortunate with my car....it was an old show car, so customized a good bit, and then cut back some and repainted and put on street......NICE paint job.....that was done all over the window frame, and far as I could tell the entire bird cage......even the chassis was redone with GOOD welding all over up front in the usual spots .....so when redoing the car some 24-5? years ago, I pulled off ALL the stainless trim, and interior trim, it's a convertible......and while that was off, I filled ALL the hollow spots with the good black RTV, and then reseated the stainless trim on it, then sealed/packed solid the fenders to the steel cage....in this function I also wrapped the top stainless with black vinyl starts under the top trim and wraps around over top of the stainless and is glued down and goes under the interior trim....stone waterproof into a hurry-caine at 80 mph.....still is NOW!!!

the little 'bucket' square clips that are just under the top hatch hinges, that also attach to the frame were rusted out though, when I redid them, I painted the hell outta them with some poly can't pronounce it paint from a marine supply house......no rust......
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Old Dec 27, 2018 | 08:08 AM
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Originally Posted by jpatrick62
Good answers all. Do you all think garaging a C3 with little birdcage frame is sufficient? Never take her out in the rain (much less snow) but I do worry about moisture in the air such as found on
a rainy/foggy day.
Certainly, anything that you can do, that will keep moisture out of the car, will be of great benefit. The major problem, however, is unless you're the original owner, and know the car's history, you're most likely fighting an uphill battle. You didn't mention what year car you're speaking of, but an early C-3 is now 50 years old. That's a LOT of time, for moisture to have been doing it's thing....
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Old Dec 27, 2018 | 10:47 AM
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I was extremely lucky with mine. Bird cage is in great shape for a car that lived it's life in the Northeast. It was obviously a garaged, fair weather driver. Now that it's located in the dry Southwest, rust will not be an issue.
I believe the steel GM was using back in the day was prone to rusting out pretty quickly. I remember my Dad purchasing a brand new Chevy pickup in 1974. The body was rusting out within the first year.
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Old Dec 27, 2018 | 12:33 PM
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Originally Posted by fastimes
I believe the steel GM was using back in the day was prone to rusting out pretty quickly. I remember my Dad purchasing a brand new Chevy pickup in 1974. The body was rusting out within the first year.
i think that has more to do with paint materials, prep and body design.
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Old Dec 27, 2018 | 01:09 PM
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Originally Posted by Nowhere Man


i think that has more to do with paint materials, prep and body design.

I'm sure that's true. I had heard, years ago, GM had sourced recycled, low quality steel in the 70's, but that is probably urban myth.

Last edited by fastimes; Dec 27, 2018 at 01:10 PM.
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Old Dec 27, 2018 | 01:15 PM
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Originally Posted by fastimes
I'm sure that's true. I had heard, years ago, GM had sourced recycled, low quality steel in the 70's, but that is probably urban myth.
that may just speed the procces up. Cars and trucks rust from the inside out. Manly from leaky windows(poor body design) then water gets on the floor the paint is thin or none at all water lays with no where to go and rust forms.
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Old Dec 27, 2018 | 01:52 PM
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Age period...these are maybe 50 yrs old even in Ca, AZ eventually youll get rust.
Mines been garaged for many yrs and some hardware is starting to get some minor corrosion. Drive em, nothing lasts forever
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Old Dec 27, 2018 | 02:11 PM
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Originally Posted by cuisinartvette
Age period...these are maybe 50 yrs old even in Ca, AZ eventually youll get rust.
Mines been garaged for many yrs and some hardware is starting to get some minor corrosion. Drive em, nothing lasts forever
So true. Drive em while you can.
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Old Dec 27, 2018 | 02:30 PM
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Not so much the moisture as it being trapped......for years. And once it starts it is impossible to stop if in an inaccessible area.
My 72 was garage kept its whole life.......the birdcage is a 9.8 out of 10 with just a hint of surface rust in the pocket behind the kick panels.......and the frame is beautiful for never being restored........
I am a lucky man as I bought the car here, on CF from a member in SC.
As a rule of thumb.......most times, BUT NOT ALL, one can gauge the overall condition of things like the headlight pop-up assemblies and vacuum can.....things that corrode easy and determine whether or not the rest is worth investigating. There are some pretty chrome bumper cars out there that are rotted out in their bones.......but the visual inspection of ancillary components is usually a tell.....

On a side note.......it appears my 72' was coated around the windshield frame with an epoxy black, semi gloss.........it looks great and there is no repairs in it but I do not remember my 69' 427/400 having a black finish on the windshield frame. Can anyone verify what was correct? My windshield is not original so a smart man could have painted this while everything was off. Anyhoo.....if GM didn't do this they should have.....

Jebby
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Old Dec 27, 2018 | 03:00 PM
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Originally Posted by Jebbysan
Not so much the moisture as it being trapped......for years. And once it starts it is impossible to stop if in an inaccessible area.
My 72 was garage kept its whole life.......the birdcage is a 9.8 out of 10 with just a hint of surface rust in the pocket behind the kick panels.......and the frame is beautiful for never being restored........
I am a lucky man as I bought the car here, on CF from a member in SC.
As a rule of thumb.......most times, BUT NOT ALL, one can gauge the overall condition of things like the headlight pop-up assemblies and vacuum can.....things that corrode easy and determine whether or not the rest is worth investigating. There are some pretty chrome bumper cars out there that are rotted out in their bones.......but the visual inspection of ancillary components is usually a tell.....

On a side note.......it appears my 72' was coated around the windshield frame with an epoxy black, semi gloss.........it looks great and there is no repairs in it but I do not remember my 69' 427/400 having a black finish on the windshield frame. Can anyone verify what was correct? My windshield is not original so a smart man could have painted this while everything was off. Anyhoo.....if GM didn't do this they should have.....

Jebby
My windshield frame is also a semi-gloss black color. Windshield is original.
My car was also garaged it's whole life, and I too have some surface rust down in the frame pockets. Still very luck given the 47+ years the car has been around.



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Old Dec 27, 2018 | 03:03 PM
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You have to remember that GM rushed the C-3 into production. They had to invent the first T-top when the 68 coupe's original one piece roof did not work out.
Just look at all of the roof and door glass B pillar weatherstripping changes made in the first five years to stop leaks.
Oh, and in the early seventies it was a sad joke, but true, that to check your back tires on a Ford, you just opened the trunk because the floor back there rusted
out so bad so fast! Lou.
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Old Dec 27, 2018 | 03:26 PM
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Originally Posted by fastimes
My windshield frame is also a semi-gloss black color. Windshield is original.
My car was also garaged it's whole life, and I too have some surface rust down in the frame pockets. Still very luck given the 47+ years the car has been around.


Cool...good to know.....and those pics could be of my own car

Jebby

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