Monty

I removed the entire front clip of the 72 Convertible I bought a few weeks ago and have stripped the interior, removed the doors, removed all the body mount bolts,etc in preparation for pulling the body off the car in a couple of weeks. While the frame and the rest of the birdcage are in excellent shape, I discovered that the windshield frame has some rusted areas due to the windshield seal failing some time ago and allowing water to get in. I'm going to replace the windshield frame with new side, corner, and top pieces I got from Paragon, however I had to cut out some sections of the lower corners in the cowl area that were rusted through. I'm going to weld in new metal in it's place after I apply POR15 to the insides of the lower windshield frame/cowl. Also I'm going to fully weld all the seams and add additional gusseting to the frame, as opposed to the spot and stitch welds used by Chevy, to provide a little more rigidity to the car since it's a convertible and the twin turbo LS7 will probably make around 1200-1400hp.

The right side wasn't as bad as the left side. The inside of the frame barely has any surface rust on it. The left side is a little worse and I will have to cut out a little more rusted metal and form it out out of multiple pieces. Here are some pics:






Anyone who has replaced the windshield frame, got any tips? Do's/Don'ts, etc especially related to ensuring that the replacement frame is perfectly located to ensure the convertible top and side windows seal and align with it correctly? I've welded up a brace and bolted it to the upper hinge area and the door striker to support the body when I remove it from the frame/chassis. I was thinking I could weld a support to the brace that would locate the top corners of the existing winshield frame, and then use that as a guide and support for locating the new frame as I TIG it together.

Philvet

Mine was is a T top, so the center brace held it some what together.
The side pieces are made up of two parts, inside and out side, spot welded together.
Drill out the spot welds one section at a time
My inside part was in good shape so I left it intact, then lined up the outside to the inside
and welded them together.
Hope this helps

Vette Gator

Excellent idea! I am going to do this job very soon and never thought about being able to replace the inside or outside separately. Thanks for a great suggestion.

Mark G

I haven't done it, but if I've done a bunch of other fabricating. I think I would do like you are thinking and weld up a metal brace that was attached to the body somewhere (securely) and have it align to some point on the old frame. Make a drawing, take measurements at a number of different spots and record on the drawing where they were taken and pictures as well.

Mark

Twin_Turbo

How is the rest, especially the lower sections and the parts where the firewall is bonded to? i would pull the firewall so you have full access to the sections that need to be repaired. Since it's a convertible I would check and repair or replace the entire birdcage and have it powdercoated like 69myway did. Why tig it together? I would use mig, reasier to add material, you won't see the welds anyway and it's not as big a problem if there's a little bit of rust or contamination left.

Monty

The rest of the birdcage is spotless, there's no reason to replace it or remove the firewall on this car as the areas that need to be repaired are easily accessible now that I've remove the front end etc. The rest of the birdcage still has the original paint, overspray, carpet adhesive, etc. If it weren't for a poorly installed window/seal I doubt the area shown would be rusted.

I use a TIG because that's what I have and that's the process I prefer.

Twin_Turbo

oh, from the pics it looks like you cut away all the way to the firewall, how are you going to weld it there without setting the firewall on fire?

Monty

It's close but I'm sure I can weld in the replacement without getting the fiberglass too hot. That's one reason I prefer TIG, I can cotnrol the heat alot better than with a MIG. In any event, if I do have to repair an area where the top of the firewall meets the cowl frame of the birdcage, I was thinking I could just cut out the fiberglass flange area an inch or two down, make the metal repair, and then rebond and rivet the cut out piece of fiberglass since it's just a flat flange of 'glass.

Twin_Turbo

Yes, that is a major advantage of tig..the controllability and the concentrated heat input. That flat area of fiberglass is the only sealed and bonded (& rivited part) but yes I agree, you could remove small sections or larger ones for that matter and repair it later on, I repaired that entire strip on my firewall when I had it off because removing the firewall cracked and weakened a lot of those areas and some were torn and peices were missing, the glass had lost all it's strength and fel mushy. I'm sure you will do an awesome job and make it like new or better.

Monty

Did you remove or replace the whole firewall on your car? If so, why?

Twin_Turbo

I repaired it, there were about 20 cracks in it and it was split in 3 major pieces..I repaired it, glassed up some holes, removed the heater box and removed some stuff here and there like the bonding strips for the front end because of my flip front. I had to remove it to fix the birdcage damage on the passenger side.

I couldn't find a suitable replacement here so there was no other choice than repairing.

cardo0

Never repaired the windshield frame but i do have a question 'bout separating the front clip - how'd it go? Did u use any heat to soften bond or need to cut and cheisel it off? Too much work to do for just a paint job?
I'm curious how to R & R the front clip as i consider doing my own painting and would like to separate clip from the body. Also have bonding repairs to do.

cardo0

Monty

That was the first time I've ever removed a front clip off a Vette. My '82 had a solid body and frame so it wasn't required. Anyway, I used a combination of heat from a heat gun and chisels to remove it. After removing all of the bumpers, brackets, grills, radiator, radiator support, etc the only thing holding the front clip on was the bond at the door pillar and cowl area. After removing the doors, I started applying a little heat and chisel at the bottom of the fender where it bonds to the rocker panel. After getting that removed, I moved my way up along the inside of the fender where it bonds to the piller filler panel. For alot of it, I was able to seperate the bond by applying heat and steady pulling without having to use the chisel.

I wasn't planning on reusing the front clip anyway so I wasn't as concerned with removing it without damaging it. I'm going to replace it with a new PM, jig-mounted, one piece. I was more concerned with not damaging all the filler panels in the pillar and cowl area. As a result, I did have some seperation of the fender from the top surround at the bonding strip due to being a little over agressive with pulling the front clip off at the end.

cardo0

Thx Monty, great write up. Put it on file for that stage if decide on painting my own or trying at least.

When u say replace with 1 piece jig mounted do mean a tilt? PM means?
A 1 piece fron tilt would b nice but not many go there and i can't figure it with the bonded skirts and bottom skirt covers all need support then somehow clear frame the covers are bolted to - don't want that stuff flapping around. Core support needs something to bolt to also. Just alot of added fabrication along with added weight up front where its not needed.

cardo0

RPOZ4Z

he is replacing it with a "Press Molded" (PM) jig assembled front end.
it's the same thing that the factory did.

Twin_Turbo

??? added weight? It's lighter than the whole stock deal, no need for inner fenders, you can chop half of the side off the firewall (bonding panels)..and so on. The only thing you have to do is cut the panels behind the wheel, on the body line and the lower panels w/ the gills have to be secrued to the car, the lower stock screws can be used, all it needs is a little bracket that hold them to the firewall. It's very simple and the way in which you can work on the engine is awesome.

Monty

Almost done repairing the windshield frame. I bought a used windshield frame off of eBay for $200. After cutting out the rusted panels at the factory seams/spot welds from my car, I cut out the replacement panels along the same seams/spot welds from the donor frame. I'm waiting on some POR15 to be delivered. After applying that to the inside of the frame, I'm going to tig the patch panels back in place, patch up the firewall a little where I had to cut it back to get access to the spot welds/seams, and it should be as good as new. Luckily the rest of the birdcage is pristine, so a full birdcage removal won't be necessary.

Right Side...








Left Side...