Welding Tips and Tricks

I have one tube that I just can't quite get with the angles of tubes that I have, and I the connecting piece on the opposite side has about .004 gap (2/3 the thickness of a nickel, even if it looks bigger in the pic). I know with stainless you really need tight fitup. But I also know that if I get the other end tacked good the weld will draw it in some. If I run some pretty high CFH argon backside purging, do you think I can get away with filling this side on my header build?

the tube is 1.625 stainless, .065 wall thickness. Appreciate your counsel. Of course I wouldn't need this if the 120 deg bend I'm using were 122 deg...but close is no cigar.

Purged, it will be fine. Tack the “widest” section first, else tacking where the fit is best worsens the wider section. You might need to run a bit “cold” until you get it healed, then you can go back over it to wash the weld in a bit cleaner. If you’re too hot at the start, the weld may droop internally, even with a purge.

Can you touch it up with a belt sander or file?

77cruiser wrote:Can you touch it up with a belt sander or file?

It’s a gap... filing will only increase the gap.

cj737 wrote:

77cruiser wrote:Can you touch it up with a belt sander or file?

It’s a gap... filing will only increase the gap.

my take is you'd sand/file the side that touches so as to bring them together...

Did you mean .040"? .004" is about the thickness of 2 sheets of paper.
You were well advised to tack the gap first, then the tight side then maybe a couple more tacks near the first. give it time to cool in between the tacks. Then do the finish weld from tack to tack. That will help maintain the fit/angle better. Remember all welds (and tacks) shrink and pull.

metalman21 wrote:Did you mean .040"? .004" is about the thickness of 2 sheets of paper.
You were well advised to tack the gap first, then the tight side then maybe a couple more tacks near the first. give it time to cool in between the tacks. Then do the finish weld from tack to tack. That will help maintain the fit/angle better. Remember all welds (and tacks) shrink and pull.

You're right...meant .040 roughly. Decimals and I sometimes don't get along!

Well I cranked up the CFH and put tube #4 in; think it will do just fine. Thanks for your encouragement.

Hold your postflow over that tack longer. You want that thing to be shiny silver. You can also brush those welds immediately afterwards with a stainless toothbrush to remove the color.

LtBadd wrote:

cj737 wrote:

77cruiser wrote:Can you touch it up with a belt sander or file?

It’s a gap... filing will only increase the gap.

my take is you'd sand/file the side that touches so as to bring them together...

That was the thought, thanks.

LtBadd wrote:

cj737 wrote:

77cruiser wrote:Can you touch it up with a belt sander or file?

It’s a gap... filing will only increase the gap.

my take is you'd sand/file the side that touches so as to bring them together...

That was the thought, thanks.