[concrete guy]

Did some test pieces today on some 1.25" x .120 wall DOM. I have welded quite a bit of it before but I am trying to dial in my technique as tube structures are always in odd positions. You can see that I don't have 100% penatration on either tube. In the past I have found out that when I do complete penatration that the vertical tube will actually have an undercut on the inside of the tube so I try to reach that fine line where that doesn't occur. I would like opinions from tube welders in the know.

Thanks,
Scott

Not the best pic of all four joints but they all look like the two joints you can see clearly




I know my weld is not perfect but was more concerned with my penatration

[Otto Nobedder]

My first thought is, why not two passes? A tight, close pass with 1/16 filler to establish a full-pen root, then a cap pass to achieve the fill required. It'd take a little more time, unless you consider the rework time. (Never time to do it right--Always time to do it over )

Steve

[concrete guy]

My first thought is, why not two passes? A tight, close pass with 1/16 filler to establish a full-pen root, then a cap pass to achieve the fill required. It'd take a little more time, unless you consider the rework time. (Never time to do it right--Always time to do it over )

Steve

Do you think doing two passes will effect the HAZ? As in the steel integrity?

That pass above was done with a 1/16" rod. I have tight chamfered joints. Could a person do a root pass with no rod?

Scott

[weldin mike 27]

Hi there,

Better to do 2 quicker passes than 1 big slow one. Looks better too. Depending on the type of material you are using (mild steel, cro mo (4130?)....) Heat may not be a problem. After all we're not talking a 50mm fillet weld.

You can do a root run with no filler, depending on your joint design, how it turns out will be largely about your skill(?)

That'll do, getting out of my depth here, as a great man once said, "Don't teach what you don't know"

Mick