[Goldhawg]

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.

[cj737]

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.

[77cruiser]

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

[cj737]

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

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

[LtBadd]

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...

[metalman21]

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.

[Goldhawg]

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!

[Goldhawg]

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

[cj737]

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.

[77cruiser]

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.

[77cruiser]

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.