one badly rusted 69 Roadster frame...

[Tommy Boy McCabe]

I'm just shooting this message out there to all my fellow Corvette enthusiasts hoping to gather all info I can before I make a decision on what I do with my car. I have a really nice C3 ragtop with an outstanding body, interior, & drivetrain. When you put her up on a lift, she gets ugly. There's lots of scaley type rust on the frame and rear end. If you bang it with a box wrench flakes will fall off, some of them the size of a quarter. It's like I just found out a loved one has cancer. Can anyone tell me what my options are with regard to repairing this problem? I don't have an unlimited bank account so I'm probably looking at all options short of pulling the body off the frame. Thanx for your time in reading my message!

Tommy Boy

[Joe L.]

Re: one badly rusted 69 Roadster frame...

Tommy-----

It's really hard to say what your options are without knowing the full extent of the corrosion damage. If the corrosion is widepsread and extensive, there's probably no solution other than replacing the frame. If the really bad corrosion is limited to to certain areas, it may be possible to replace those frame sections with the frame still attached to the body.

One of the things that you can do is to raise the car on a lift and "poke around" with an ice pick or similar tool. Any area that you can push the tool through the frame by hand is totally shot and must be replaced. Unfortunately, the area of the frames that's most often "fully involved" with the corrosion is the "kick-up" area, just forward of the rear wheels. This area cannot be repaired with practicality with the body on the frame.

If your ice pick inspection reveals many areas of severe corrosion, then frame replacement is the only option.

To make matters worse, a car that suffers from extensive frame corrosion may also suffer from extensive "birdcage" corrosion (the steel understructure around the passenger compartment which includes the windshield frame). This can be hard to assess as it's mostly hidden. It's even harder and more expensive to repair than it is to assess.

[Jack H.]

EXCELLENT advice from Joe!

He's covered all the primary issues in good capsule summary. A solid used/original frame will run $1500-3500 depending on source and transportation cost. Then, you're looking at the labor content to execute the transfer of body, power train and suspension components onto the donor frame.

If the bird cage is badly rusted around the windshield (can't tell until you strip the windshield molding components and visually inspect), a windshield upper frame from a scrap yard donor car will run $125-300 depending on source and transport cost. Figure there's a SOLID 1-2 days of labor involved with executing a windshield frame swap/repair.

These are both places where you'll want more than one opinion before you swing into action. If it's JUST minor surface scale and NOT bona fide major rust through, it may be possible to salvage what you have using rust arresting chemical applications. This would be an EXCELLENT time to join and get active in your local NCRS chapter to get the second opinion assistance from those who've been there, done that, gotten the T-shirt who are geographically close enough to look over your shoulder and help!

[Dave F.]

Re: one badly rusted 69 Roadster frame...

Along with the birdcage rust damage that can occur from severe frame rust, you could also be looking at other rusted components such as seat belt mounting plates, radiator core support, miscellaneous brackets, gas tank & straps, exhaust, and a lot of bolts. My personal experience is if you see rust damage, double your estimate for what you don't see - at a minimum!! There is a lot of fibreglas work involved with replacing the bottom of the birdcage that I didn't anticipate when I discovered the damage on mine. If you shop this repair out, definitely get someone with verifiable experience in this area!

[Mark H.]

Re: Source?

Good sources for upper birdcage? The patient is a '72 coupe, bad rust visible with the door open above the beltline. Thanks!

[Dave F.]

Re: Source?

Try America's Finest in Ramona, CA.

[Dave F.]

America's Finest Corvettes: afc@corvettesusa.com *NM*

[Tom M.]

2 T.M.'s here? *NM*

[Chuck R.]

Re: Next to impossible Tom

I hope that the frame isn't punky or rusted through as it will be next to impossible to perform quality frame repairs with the body setting on the frame. There's just too many flamables as well as there being almost zero room to manuever around the frame/body.

Other than esthetics Tom are you experiencing body fit/sagging issues?

Are the doors closing nice and square, or are the door gaps wide/narrow?

If you can't put Joe's reccomended ice pick through the frame rails, then I would look at wire brushing/rough sanding the frame and shooting it with a quality self etching primer and paint to help slow down the corrosion process and call it a day.

IF the frame seems sound, one other thing to possibly consider is removing the end plate from the frame rail so that you can flush out any loose scale that's setting in the botttom of the frame rails.

Then get a small flue wire brush with a couple of extensions and brush the H _ ll out of the interior and then flush it out again.

Then when it's good and dry, treat the inside of the frame rail with a self etching primer shot through an undercoating gun and then top coat it with a rust proofing material of your choise.

You'll probably be looking at about $300.00 to $400.00 after purchasing the materials and the best is that you can do this yourself......IF the frame is still solid, that's key.

Unfortunately there are other pet areas for blowing out that you should be taking a peek at such as the lower differential crossmember (where the snubber mounts), front crossmember and where the kickups are welded to the lower crossmember. Those kickup/trailing arm pockets collect a ton of dirt that's the prime ingredient for attracting and holding moisture.

You want to see scary Tom, I got pictures of my 68 frame in all it's ugly glory you can use for reference if you want.

Chuck

[Michael W.]

That's what I thought too! *NM*