How do birdcages rust

[Walter F.]

Since the birdcage is mostly away from road salt, how do they rust? Is there some kind of drain issue?

[Mark E.]

Re: How do birdcages rust

From what I've seen, water leaks through the windshield trim, which rusts the windshield frame. Also, water leaks through the cowl/plenum, which rusts the lower birdcage behind the kick panels.

[Richard P.]

Re: How do birdcages rust

Mark, thanks for already answering a question with which I was about to start a thread. Rusty birdcages were discussed several days ago and got me thinking about where the most likely places to look for rust would be. Now that that question is answered my other one is: Is my '63 coupe more vulnerable to this kind of damage than other years with similar construction? Thanks.

[Walter F.]

Re: How do birdcages rust

From what I've seen, water leaks through the windshield trim, which rusts the windshield frame. Also, water leaks through the cowl/plenum, which rusts the lower birdcage behind the kick panels.

So that means EVERY C2 and C3 left outside in the weather was susceptable to bird cage rust correct ? Which would mean evey Corvette of those generations must be carefully inspected no matter how the rest of the car looks. Is there a way to tell and where to look for damage?

[Carl N.]

Re: How do birdcages rust

Also depends on how many windshields it has had and quality of seal. Another factor is area of country car spent most of it's life - dry southwest vs coastal region.

[Keith B.]

Re: How do birdcages rust

There are a lot of factors and a little luck comes into play. Moisture and it's environment all has to come into play. A car sitting on pavement will most likely be rust free vs a car sat on grass or dirt. And any rodent making a nest in the car won't help either.

[Joe L.]

Re: How do birdcages rust

So that means EVERY C2 and C3 left outside in the weather was susceptable to bird cage rust correct ? Which would mean evey Corvette of those generations must be carefully inspected no matter how the rest of the car looks. Is there a way to tell and where to look for damage?

Walter------


I've been saying this for years. Every C2 and C3 Corvette is suspect for birdcage corrosion. Certain factors make them PRIME suspects. Having "lived" in areas of the country with salted roads for any part of their lives makes them HIGHLY suspect. Unfortunately, birdcage corrosion is difficult to detect in many cases. However, if a car suffers from significant frame corrosion, which is relatively easy to detect, that's a big clue.

As I've also said before, birdcage or frame corrosion MASSIVELY de-values the car, an amount most owners are unwilling to accept. But, that's how it is. For many later C3's the value may be reduced to nearly ZERO as the cost to repair exceeds the value of the repaired car.

[Walter F.]

Re: How do birdcages rust

Where I live on Long Island New York, C3s are a common sight. Especially mid to upper 70s cars. Many are left outside all year round under car covers. We have damp winters and hot summers. I have ssen these cars sit for a long as 6 months or longer. A felllow who moved in across the street has a mid 70s. The car has sat all winter under a car cover. Are car covers safe enough to keep birdcages from rust? Or do these cars rust from within, from dampness?

[Joe L.]

Re: How do birdcages rust

Where I live on Long Island New York, C3s are a common sight. Especially mid to upper 70s cars. Many are left outside all year round under car covers. We have damp winters and hot summers. I have ssen these cars sit for a long as 6 months or longer. A felllow who moved in across the street has a mid 70s. The car has sat all winter under a car cover. Are car covers safe enough to keep birdcages from rust? Or do these cars rust from within, from dampness?

Walter-------



A car cover is enough to prevent corrosion as long as the cars are ALWAYS under the car cover and NEVER driven. If they are driven, even modestly, that's another story.

Also, keep in mind that in areas where the roads are salted, it's not just winter driving that causes corrosion problems. Much of the salt applied to the roads in the winter stays around on the roads in the summer. Summer showers "re-mobilizes" the salt. Drive a car in summer showers and one gets pretty much the same salt effect as winter driving. Remember, once salt-induced corrosion begins, it proceeds inexorably. All C2's and C'3s have been around long enough now that the corrosion process has had plenty of time "to proceed".

I think you'd be surprised at how many of the cars you mention are suffering from substantial corrosion damage.

Personally, if I were in the market for a C2 or C3 (and, thankfully, I'm not), the most important purchase decision would be based upon two things:

1) Does the car suffer from ANY frame corrosion beyond mild surface rust, and,

2) Does the frame stamped VIN derivative match the car's VIN plate and registration.

If either above are problems, I wouldn't touch the car with a ten foot pole. You'd be surprised just how many cars out there would fail.

[Mark E.]

Re: How do birdcages rust

Is there a way to tell and where to look for damage?

If it's a car you don't own (e.g. you're an interested buyer) and your permission to remove stuff is limited-

- Look for evidence of current or past water intrusion into the interior. Clues include carpet dampness and stains, rusty components under the dash, a musty smell. If water got into the interior, the bird cage is vulnerable. If you suspect something, ask the owner to remove the kick panels for a first hand look.

- Look for rusty pillars through the windshield (e.g. on the left side, where the VIN tag is located on C3s). Nice black paint may indicate a recent repair or coverup. If you see something, ask the owner to remove the interior A-pillar trim for a closer look. This isn't fool proof since a lot of damage can be hidden behind the windshield.

- Is the sealant along the top of the windshield trim damaged, cracked or missing? This would allow water in. A thorough inspection of upper areas requires removing the w/s and t-top trim, which is an involved process.

[Mark E.]

Re: How do birdcages rust

Is my '63 coupe more vulnerable to this kind of damage than other years with similar construction? Thanks.

Good question; maybe someone more knowledgable with '63s and C2s will chime in. They may be more vulnerable from the perspective their birdcage is more elaborate because of the large (compared to early C3s) sloping rear window.

[Keith B.]

Re: How do birdcages rust

Is my '63 coupe more vulnerable to this kind of damage than other years with similar construction? Thanks.

nope. 63-67 bird cages are the same expect for the rocker channel in regards to the molding tabs, and later 65-67 N-14 notches

[Richard M.]

Re: How do birdcages rust

Even restored cars must be scrutinized......



Sadly, the owner of this car found out it had serious birdcage issues AFTER purchase....



Story HERE

[Keith B.]

Re: How do birdcages rust

Richard pictures like that will have just about everyone who bought a restored car out in there garage taring there car apart

[Mark E.]

Re: How do birdcages rust

It looks like the C2, C3 birdcages only go back to the rear door pillar area, and are not under the C2 rear window.

But the top is different for a C2 coupe, C3 coupe (t-top), and convertible.