I'm getting a start on fabbing a new exhaust for my truck (currently down for an engine rebuild/hopup) . This morning I set my Lincoln Weldpak 100 up to run a couple of beads on the header collector adapters , and it wasn't at all pretty . The wire is .023 ER309L , shield gas is argon at varying flow rates , electrode negative . First thing I noticed is that this wire sure seems to burn a lot faster than ER70S6 , so I bumped the feed speed up . Still ain't right , so I drop the amps a notch (this machine has 4 settings for current) and it's a bit better but still too hot . Drop it another notch and the wire isn't burning back so fast but there's zero penetration and the bead is very narrow and tall . Drop the wire feed and it's still too cold . I'm totally lost here , I was hoping MIG welding the joints would be fast and easy but ... I ended up using the TIG to flow the welds and got things looking less like pigeons crapped on my weld seam , but that has problems too . I have no means (yet) to purge the back side of welds in tube . I did get the inside cleaned up with die grinders and flap wheels , but that ain't going to work on a 6 or 7 foot long piece of exhaust tube ! I sure could use some tips on MIG welding SS ! I hesitate to use ER70S6 or flux core since the tubing is stainless , but it may come down to that to get a decent weld .
2 years ago