Q. What type of welding filler should I use to TIG weld 4130 tubing to 1020 tubing? I have heard references that use stainless steel filler. The tubing will be used in a car frame as well as the rear uprights. 4130 will be used where its characteristics are needed but other elements can be 1020. I will use a Miller Squarewave machine. (Submitted by: David Schriner from Unknown)

A. I would prefer to use an ER 80S-D2 filler for your work. It sounds like a drag or hot rod situation where it needs to be semi-rigid but not with stand massive impact like a stock car. You could also use an ER 70S-2 filler if you wish.