[Artie F. Emm]

I want to join a flat bar, 2” wide by 3/8” thick, to a 1” x 2” x 1/8” rectangular tube. The two inch surfaces will face each other squarely; the weld occurs along the edge. All hot roll steel; TIG because I need the seat time. Am I right in thinking the technique to set amps for the 1/8” wall tube, puddle on the flat bar first because it is thicker, and then include the tube?

Just trying to visualize before I start- thanks for any help.


>>Edit: worked up a drawing, but couldn't figure out how to attach a jpg.

[MinnesotaDave]

If you only set the amps for the 1/8" material, it won't puddle the heavy side.

As a result, set amps for the heavy material and start the arc there.
Keep more of the heat on the heavy material but be sure to have a nice puddle on both.
Once they are joined, it goes pretty nicely.

The largest thickness difference I've worked with is 1/16" to 1/4" aluminum.
As you can imagine, the amps needed for 1/16" wouldn't have done anything on the 1/4" side.

[Artie F. Emm]

Got it- thanks for setting me straight!

[AndersK]

>>Edit: worked up a drawing, but couldn't figure out how to attach a jpg.

Good help for that in this post:
http://forum.weldingtipsandtricks.com/v ... =25&t=2466