Birdcage Rust

[Roger G]

I have a 1970 Coupe, 454, 4 speed. Similar to yours. Bought it over 25 years ago, took the body off the frame in 1991, still working on it... Didn't go nearly as far with the body as you have. Cleaned it up well, underside , engine compartment, firewall, etc. Did a few spot repairs on the drive shaft tunnel, replaced some rusted parts here and there, mainly sheet metal pieces which were rivetted to the body around the rear body mounts. Replaced the tubes and metal covers for the drainage tubes which direct water from the rear vent into the wheel well.

I'm curious as to what drove your decision to remove the front clip and firewall to expose the lower portion of the pillars.

I looked at mine but can't see much below the fender. Appears there's some sort of caulk or filler between the fender and the top of the firewall. Most of the pillar is covered by the firewall. I see some surface rust on a few spots below the windshield, nothing major from the look of it. Wondering what I'd find if I took the windshield out? Wouldn't surprise me to find some rust on the windshield frame. Pulling the front clip off and firewall would be a huge set back. I'd need to see some evidence it was necessary.

Was there anything which suggested you may have rust behind the fiberglass?

[MaineVette]

took the body off the frame in 1991, still working on it...

And I thought my project was dragging on!!! I guess I don't feel so bad about being 5 years into it now...

I'm curious as to what drove your decision to remove the front clip and firewall to expose the lower portion of the pillars.

I looked at mine but can't see much below the fender. Appears there's some sort of caulk or filler between the fender and the top of the firewall. Most of the pillar is covered by the firewall. I see some surface rust on a few spots below the windshield, nothing major from the look of it. Wondering what I'd find if I took the windshield out? Wouldn't surprise me to find some rust on the windshield frame. Pulling the front clip off and firewall would be a huge set back. I'd need to see some evidence it was necessary.

Was there anything which suggested you may have rust behind the fiberglass?

There were a few indicators that led me to remove the front clip and firewall. Trust me when I say it's a massive undertaking that should be avoided if possible. I'll tell ya, if I knew what I know now, I would have found another car to restore....

On mine the first warning sign was a musty smell in the interior of the car. Also, when I pulled off the interior trim panels I could see rust stains on the frame indicating that water was getting into the interior and running down the frame.

However, it really became obvious when I pulled off the windshield trim pieces (and ultimately the windshield) and saw first hand all the corrrosion on the windshield frame. Some of these areas visibly extended beneath the firewall/front clip so it was fairly obvious that major surgery was required. With the trim pieces and windshield out of hte way I was also able to probe around a bit with a screwdriver and flashlight and could tell there was some corrosion below the front clip\firewall. You can see what I was dealing with first hand in this update:

http://www.corvette-restoration.com/res ... emoval.htm

If the frame around your windshield is intact, and you don't have any musty smell in the car you're probably ok. If the interior smells musty you likely have a leak from somewhere that you'll need to track down. If you want to post some photos I might be able to help give you a better opinion as to what might be required.

So what do you think? Is there something in paticular that's causing you to have concern?

[Roger G]

And I thought my project was dragging on!!! I guess I don't feel so bad about being 5 years into it now... ]

Two kids, a new house, and a few job changes slowed the project quite a bit. The Corvette is an older hobby for me, other interests compete for time.

Trust me when I say it's a massive undertaking that should be avoided if possible. I'll tell ya, if I knew what I know now, I would have found another car to restore....

I can see it's quite a job. Thanks for being so thorough with your postings, photos, etc. I find you project to quite interesting. Some portions I can relate to. In other areas you've gone deeper than I had ever thought to. I'm not
sure you'd necessarily find a better project car knowing what you know now. Some damage appeared to be hidden.
No sellers would let you pull trim parts off and start poking with a screw driver. I'd say you'll be rewared with a very nice Vette when you're done. Very well documented. You'll know every square inch of the car, no surprises waiting to surface later. Much better condition than many out there now.

On mine the first warning sign was a musty smell in the interior of the car. Also, when I pulled off the interior trim panels I could see rust stains on the frame indicating that water was getting into the interior and running down the frame.

I bought mine about 27 years ago. It has been in a garage for most of the last 19 years so I can't go by musty smells. There was water damage in the rear of mine. Carpet rotted away, steel vacuum line rusted. I found the tubes going from my rear vent to the wheel wells were rotted and split (rubber). They may have been at least part of the problem. I think I have photos of the inside of the firewall with the panels removed. I wasn't looking specifically for rust, took the photos for general interest. I'll see if I can find them.

However, it really became obvious when I pulled off the windshield trim pieces (and ultimately the windshield) and saw first hand all the corrrosion on the windshield frame. Some of these areas visibly extended beneath the firewall/front clip so it was fairly obvious that major surgery was required. With the trim pieces and windshield out of hte way I was also able to probe around a bit with a screwdriver and flashlight and could tell there was some corrosion below the front clip\firewall. You can see what I was dealing with first hand in this update:

http://www.corvette-restoration.com/res ... emoval.htm

Looked at that a while back.

If the frame around your windshield is intact, and you don't have any musty smell in the car you're probably ok. If the interior smells musty you likely have a leak from somewhere that you'll need to track down. If you want to post some photos I might be able to help give you a better opinion as to what might be required.

So what do you think? Is there something in paticular that's causing you to have concern?

Nothing in particular other than suspicion there may be damage around the windshield frame. Last owner put some sealant around the trim. Seemed he had a leak. Wouldn't surprise me since many GM products built in that era seemed to develop leaks after a relatively short time. I've been thinking about pulling the trim to have a look. If I do so I'll need a plan to deal with it. I may be opening Pandora's box. I wouldn't feel comfortable reassembling it with intent to fix later.

I recall noticing a water leak once, think it was after I disturbed the windshield wiper drive (don't know the correct term for the splined shafts which drive the wiper arm). I assumed it was probably a matter of having broken the seal.

The rust you found behind the fiberglass was something I hadn't seen before. Wonder how many Vettes are out there with rust in this area, owners unaware? It seems that any moisture, rain, getting behind the fiberglass could start this rust. Maybe a car from an arid climate, Southwest perhaps, would not develop rust in this spot though there's
no guarantee. From your photos it looked like the rust started between the fiberglass and birdcage, rusted in. Not from the inside out? Didn't appear to be directly related to the rust on the windshield frame. This is the area which concerns me. I would need an awful lot of justification to pull the front clip off. On mine, there is some surface rust right below the windshield I've been meaning to wirebrush off and treat. Doesn't appear to be anything deep.

I'll take some photos of areas I can see when I get a chance.

[Drews69]

The way I figured it out was the pieces of rust falling out of the frame onto my lap as I drove down the road. I understand about this being a huge undertaking...I'm very scared for when I actually go to start restoring this car. I think I'll end up sucking it up and paying someone to replace it. I don't feel confident enough in my abilities to get everything lined up and fiberglassed back together properly. Should be a nice thorn in my side for a while.

[Roger G]

The way I figured it out was the pieces of rust falling out of the frame onto my lap as I drove down the road.

Can't say I've seen anything like that in my car. Doesn't mean rust isn't there...

I did have a mouse come running out of the floor duct, heater, while I was driving once. Guess it got to warm for him..

RE: Large body work project. I found this source of info on the Zip Products web site. Looks like it may have answers to questions as to how to go about removing and replacing the front clip?

Home Restoration Guides Vol. 3: 68-82 Front to Cowl Body Repair Guide (CD)

Vol. 3: 68-82 Front to Cowl Body Repair Guide (CD)

Be it poor panel fit, seams showing, or even large-scale damage, the fact is most all Corvettes have some sort of body problem. Author Ray J. Shiro shares his 32-years' experience in the Corvette body repair business in this set of step-by-step guides for the do-it-yourself enthusiast. Written in "plain language", these easy-reading cds (with printable documents) cover location of body seams, seam repair, bonding adhesives, panel removal and replacement, complete front or rear assembly and more.
Volume 3 includes: 68-82 complete front end replacement, door skin replacement, T-top panels, body panel removal and replacement. Over 170 photos with explanation and illustrations to make it easy for you to restore your Corvette

[MaineVette]

I did have a mouse come running out of the floor duct, heater, while I was driving once. Guess it got to warm for him..

Now that must have been interesting. I bet you got pulled over pretty quick to give your extra passenger the old 'heave-ho'

Based on what you've written it doesn't sound like you've got a major issue going on. As you correctly surmised, what I found on my windshield lower corners is not uncommon. However, it would be uncommon to find that much rust concentrated in those two areas only. Generally if the car has been exposed to that degree you'll have areas of deterioration elsewhere. In my case I had major corrosion at the upper corners and down the side winshield pillars.

[Roger G]

Now that must have been interesting. I bet you got pulled over pretty quick to give your extra passenger the old 'heave-ho'

Nope, I was on the highway, difficult to stop. Just watched him for a moment while he scurried under the passenger seat. Fortunately no human passenger at the time...

Over the years I've had several mice decide to make a home in the Vette. Typically under the console or in
the heater. Had one die in the heater at the furthest end. Had to remove the entire dash and heater unit so I could dismantle it to remove the critter. I inserted double layers of fencing between each section when I reassembled to try to keep them out. Before this they chewed the blades off the heater fan and chopped the fiber optic bundle going to the rear lights in half. Replaced the entire rear wiring harness.

For this reason I've been leaving my console plate off. One less area for mice to hide.

RE: State of my birdcage... I may pop off some trim to have a look, see what damage there may be. Go from
there. I'd be reluctant to remove the front clip without thinking about it for a while. Based on what I see in photos it looks like the rust behind the fender begins when water gets down behind the fiberglass. Maybe a bead of RTV would
seal it off?

[Roger G]

Spoke too soon.

I popped off the trim around the windshield last night. Sure enough, found rust here and there.
A hole about the size of a nickel on the inside of the header, roughly where the visor screwed on.
An obvious spot on the right pillar where the corner piece and vertical are joined. Dug around a
bit, can't tell much more until the windshield is removed.

This repair is a bit beyond my skill set. No welder, don't think it would be a good idea to learn
on this car. Took it to a local shop. Owner probed around a bit between the glass and frame.
Said it doesn't look that bad but we need to pull the glass off to know the full extent. They
have original pieces available if needed. Assume from a donor. Other than the header, could
just need some patching. Best to deal with this now before sinking money into paint or other
items. TBD...

If I had a chance to go back in time, I'd look the birdcage over thoroughly as well as the
frame. Some problem areas can be seen without pulling trim off.

[MaineVette]

Ah man, that stinks! Trust me, I feel your pain! At least you found it before you spent a bunch of money on body work and paint. Hopefully it won't be too bad...

I bought a bunch of replacement pieces from a donor car, but you can also buy NOS or aftermarket replacements as well.

Good luck, and let us know what you find out...

[Roger G]

Good luck, and let us know what you find out...

Will do. Owner of the shop was optimistic. We'll see.

What concerns me most is the area which I'd need to pull the front clip to gain access.
I've heard of some cutting the fender. That doesn't sound attractive either, suspect there may still not be full access.

Got to go in reverse now, remove the interior I almost finished installing, at least the dash and carpets.

Wish I knew of this while the body was off. Better to deal with it now even if it means pulling the clip rather than
later after investment in paint, etc. If not for this web site and the Corvette forum I would never have known of
the problem area behind the firewall. Thanks ???

FYI: The shop recommended buying a windshield from OEM Glass. Went to their web site. They say they make the windshield from original prints. Also offer correct logo and date for another $60 if desired. Appears they make glass for many antique cars.

The Corvette shop I took the car to told me they've had trouble with cheaper glass, wrong contour, too narrow, thin, etc. Quote came in around $430 without logo and date code. This include shipping which as quite expensive. Phone is 800 - 283 - 2122