Welding Steel Tubing to Sheetmetal
 

I've seen it done before and curious about the correct method behind it. For instance some of these full frame cars will have a 4x2 .120 wall tubing welded the to rocker to accept the sheet metal floor, which all gets welded together. I have a project I'm working on that I would like to incorporate a tube frame into the rockers for additional strength.

Could anyone enlighten me as to the correct method behind this?

concentrate on the thicker/larger metal and let it flow to the thinner stuff.
practice practice practice also its good not to have a large gap between the two.

Yep -- What Vince said..... heat on the thicker piece and it will "incorporate" the thinner metal with just the slightest movement of your hands... this is were skills come in.

Ok, I figured as much, and thats the method I've used previously, but wasnt sure if there were any specific trick I should practice to make sure everything was penetrated properly. Thanks!