Hey all

I'm getting ready to start a new project making a racing kart frame and cage for my son. I will be welding 1 1/4" .095 wall and 1" .065 wall 4130.

I am wondering is Tig the best way to go or is mig acceptable? Seems like depending on what you read one guys says this another guy says that.

ESAB had a link in the welding journal indicating that MIG was okay for NASCAR. Except they predominantly use mild steel tube since there cars are so heavy. The kart complete with the driver ways about 425 lbs. So I need to keep it light to be competitive.

The chassis flexes a lot to compensate for no suspension so I was thinking I would use ER70s wire / rod to keep the welds ductile.

These are open wheel karts and they go about 60 mph. Not uncommon to see them flip.

I currently have a millermatic 210, but I know I would have far better control with the TIG. I'm concerned with the small tubing about the cold starts associated with MIG most frames that I see built typically have about three starts around the tube.

Any thoughts appreciated.