MIG welding cast iron works sometimes but it is a crap shoot!
On Wed May 14 22:06:58 2008, the following results were submitted from the "mig welding question" on weldingtipsandtricks.com:
CAN I MIG WELD CAST IRON? IF SO, WHAT IS THE BEST WIRE AND PROCESS TO USE for mig welding cast iron? (I DON'T HAVE A STICK-WELDER MACHINE)
I have done it and a friend of mine says he welded his daughters cracked exhaust manifold with his battery powered solar mig using flux core Lincoln nr211 wire.the thing is it is a crap shoot. if you can get to everything, groove the crack out with a grinder or carbide burr, and you can preheat using a torch (or old grill) you have a good shot. I would recommend having a ball peen hammer handy and only weld about an inch at a time before stopping to peen the weld with the ball end. that keeps the weld shrinkage stresses down. Sometimes it even works.
like i said, Crap shoot! good luck
THANKS A LOT, I'M GOING TO TRY THAT, I CAN'T AFFORD TO BUY A NEW WELDER MACHINE RIGHT NOW( I'M MOSTLY A MACHINIST PLAYING A LITTLE BIT WITH SPARKS)P.S. I APOLOGIZE FOR MY BAD ENGLISH, I'M TRYING HARD.
mig welding cast iron is a crap shoot