Well folks - good news! I'm FINALLY back working on the Corvette! After a bit of a reluctant break from my restoration project I'm picking things up where I left off.
After my last update I was left with the chore of dealing with some pretty severe corrosion and rust on the lower windshield corners. Rather than trying to custom fabricate replacement corners from scratch I instead decided to hunt down some replacements from a parts car (no Corvette vendors carry replacement corners for C3's). Granted it cost more to buy replacement lower corners, but it was well worth it to save myself the hours of labor needed to fabricate replacement corners.
I ended up searching for new lower corners for quite a while. Ideally, I was looking for corners from a model year 68-72 Corvette since those would be direct replacements. There was a bit of uncertainty as to whether the lower corners would be the same for all C3's based on the limited documentation that was available. After quite a bit of searching I gave up on finding lower corners from a 68-71 and settled on some corners from a mid-70's Corvette.
Once the lower corners arrived it was evident that the corners from a mid 70's Corvette are slightly different than the original equipment on my 71 Corvette. Luckily, modifying them to match will be relatively easy. I'm not positive of when the change to the lower corners occurred, but I suspect it was in 73 when the steel bumpers were eliminated and front clip underwent some significant changes.
Anyway, enough with the narrative - it's time for some pictures! Below are some shots of what was left of the lower corners, these need to go!
Below are a few shots of the drivers side replacement corner I'll be using before and after cleaning with a wire wheel.
These assemblies are held together with a number of spot welds located around the perimeter of each piece of the assembly. In the case of this project, only the top section of the lower corner is needed so the spot welds were drilled out and the steel plies separated using a putty knife and hammer. Care needs to be used to avoid bending or warping the sheet metal, but they come apart relatively easily with an hour or two of careful work.
Below is a comparison of the lower corners on my 1971 (above), and the replacement corner I have from a mid-70's Vette. The only difference is the shape of the triangular 'bump' out in the replacement. The simple fix will be to weld on some filler panels to match my 71. Luckily for me this is possible, corners for a 68-72 would not fit on a 73-82 C3.
Next I continued by drilling out the spot welds holding the corroded lower corner section in place on the birdcage. The various plies of metal were separated only as needed with a putty knife and hammer. Even if a small portion of a spot weld remains, you can typically get the pieces to separate with a bit of persuasion. This allows the spot welds to be released without having to drill completely through the steel.
With all of the spot welds released (including a few on the lower horizontal member to help loosen things up) I separated the ends of the lower corners and slid the old corners out of place.
A bit of corrosion was found within the lower corner that will need to be addressed, but its nothing too serious.
With the old corner off an out of the way, I did a quick dry fit of the replacement corner and was happy to find that it fit into place very well.
The photo below very clearly shows exactly how corroded the old lower corner was and also highlights the differences between the lower corner on a early model C3 (right) and a late model C3 (left).
Next the same process was repeated for the passengers side. Luckily, no significant corrosion was found below the lower corner once disassembly was complete.
And finally, below is a comparison of the replacement lower corner to what was removed from the car...
That's it for this update. In the next installment several repairs to the birdcage will be tackled prior to installing the replacement lower corners.
Check back soon. Unlike this one, the next update won't take 4 months!