I am helping a friend build a racecar out of an eighties Mustang. He wants the front end sheetmetal seam-welded for strength. Also the mounts put in for a BBC, etc., etc. The problem I'm having is welding the galvanised sheetmetal. It appears to have been dipped, so any area that has lapped sheet is doubly tough as it outg***es, ruining the arc, or blowing hot metal on me. I've ground to bare metal, but often thats not enough. I know that accident repair would often involve welding on this, so how is it done?? I'm using a TIG, so please orient answers to that process, thanks. Next, is there any reason that I cannot use auto-body lead to join two pieces of sheet metal together?? For the life of me, I cannot come up with a reason this would not work, but I've also not heard of it being done, either. Thanks, Cosmo
Carefull. Seam welding things together isnt really a good idea on one of these. It will move flex points and may eventually cause stress cracking in some areas . If you want to tighten up things for racing , I had a friend of mine that was racing a Hemi Cuda who had a great contact at FoMoCo's collision research dept. A couple of years ago he got a case or 3 of the structural epoxy foam that is used to increase the torsional rigidity of some of todays unibodies and filled all the box channels , rockers and pillars. It also is used when replacing the door apertures on the Expeditions . The stuff is expensive ( around $75.00 per kit , probably 4 or 5 to a rocker ) and they say its as stiff as concrete and super light. One other warning, once its in you'll never take it apart again. As far as lead goes . Its use is as a filler material . Its not meant to replace a properly welded seam. Why lead in a race car ?
I think the lead question is about soldering together body panels, where they are overlapped. If you did this, to get needed strength you'd want a good solder alloy, not just body lead. Good surface prep would be vital. And it would be reasonably strong, although probably subject to cracking? Lead and solder have low tensile strength compared to steel, but since it's measured in psi, and you can get a lot of surface area with an overlapped joint, the overall joint strength could be pretty high. Interesting idea...but I doubt I'll be trying it out.
There are enough 8 second pro 5.0 cars out there, surely someone has let slip the secret to a race prepped fox body. If a cage and motor plate won't do it, what will?
Thanks. The lead question was for a different, non-automotive use (birdhouse). As to the race car ideas, thank you very much. Cosmo
Something that is not addressed here is that the "g***ing off" of the galvanized metal is hazardous to your health. I have heard of alot of things that remove galv from metal, but have never tried them. One suggestion was soaking the metal in a vinegar solution, not sure what strength or if that even works, but welding the galv is very bad for you.
Be vewry, vewry careful welding galvanized metal it puts cyanide in the air, that green smoke that it generates is VERY, VERY toxic. Only do it with strong ventilation, which is counter intuitive to tig welding. Big Jim
I have worked on a couple of Marillo's mustangs...no additional welding has been done to those aside from Your basic tube work...bracing along the sub rails, and a pair across the top of the engine bay (paralell to the fenders- they tie into the knee bar.) I also built a tie to the k-member, but nowadays, they sell aftermarket k-members that are nicer and easier to install than what I had done. Some flexibilty is Your friend. Too much rigity and they doo weird ****...like pull the a pillars away from the rest of the body!
The soldering of two overlapping panels will work if done properly. We used to solder pads to panels and use a 4 ton portapower to spread out the damage never had one come off.
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