^Brazing not a bad idea either. Noticed my bottom cab corner seams are brazed. Or looked like it after sanding. Factory I presume. First attempt at lead didn’t stick. Tried a big ding in the top of the tailgate. Not enough tin in flux I think? Used normal tinning flux. It’s like 4% tin powder. Tinning butter is 50% tin powder.
I have no experience actually working with lead, only removing some. I'm sure there are some benefits but I have to believe it is an antiquated and outdated process as no one seems to work with it even on high dollar restorations. Personally, I'd cut it out and weld in a small patch panel and apply POR or comparable to areas not seen/ hard to reach. I don't know when GM went away from lead in substantial amounts but I assume early 60's as I had both a '62 Nova and a '63 Nova. The '62 had lead in a bunch of joints such as where the roof merged with the sail panel and the '63 used some sort of filler at the same joints. Could have been a difference in Fisher body plants. And while the '62 and '63 looked the same, the '62 had a lot of older tech parts like door latches, hood hinges and such that were upgraded in '63 so I think Detroit was adopting new methods and technology across the board.
Only using a mapp gas torch. Buddy got the real tinning butter and we tried it again. Got a good tin layer on but the lead still didn’t really take. Better then before but could still pop the patch piece off with a hammer and screwdriver with mild effort. Tried some lead free solder. It stuck better than the 50-50 but still able to break it loose. How well “should” it stick? Don’t have a frame of reference but seems it would have to hold better than it is.
I've only used map gas on copper pipe, and I don't believe it is a clean flame, with brown tip solder it does not run as easy. Maybe oxidation. map burns hot too.
Interesting theory. Maybe burning dirty. It wasn't heat, I tried hot, too hot, barely enough to melt the solder, you name it. Cleaned the heck out of the tin layer, tried it melting solder into the tinflux puddle. Idk
You're probably going to have to use some type of acid to clean that metal with. Probably the type used in batteries. Try acid core solder as well.
Interesting and valid idea. I got it tinned well with the high Sn content flux and the tin bonded well. I haven't had time to paly with it much though. Been too good of snow on the weekends! (If I'm home)
Anything you put over that rust without fully removing the rust will come back and the lead will pop eventually. Late 60s mopar muscle cars had lead on every one of there seams and they always popped if rust started forming underneath. Without sandblasting or cutting out and removing the rust, it's gonna come back in a few years. Just hate to see you do all this work to have to redo it in a few years. This is just my 2 cents on this.