Faced with extensive panel replacement on a rust bucket decided to try the copper alloy mig wire. Worked great and would recommend to cut way back on warping. It's pricey, $600 for a 12" spool, but cheap when shrinking and picking is figured in. We ended up buying a new gun and lead assembly so the liner would have no contamination and had to tweak the feed roller tension but no bad problems. We broke a 90* on the edges of both panels and joined them with a 3/16 wide puddle to fill the "V". End result took nearly zero hammer work or sanding since copper is self leveling. Messed around and didn't take pics but will on next one. Stored remaining wire in an argon purged bag.

Evan