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Neilukd
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    Sat May 31, 2014 4:28 pm

Toady what should have been a simple job turned into a pain in the ass. My wife found a curtain tie back finial had broken off it's mounting collet. I take a look and say simple job to weld it back on. So I grind the components back to clean bright metal as the parts have been painted. The grind tells me this is steel, be all that it may a poor quality steel. I jig them together set up my welder on pulse 50 base and 80 max 2.4 mm sharp electrode 7L pure argon shield gas. This is a machine I have had for 6 years and am very comfortable with. So I strike up the arc and start, the weld pool starts foaming like there is no shield gas. So I check the flow and I have gas. So back to the grinder clean up ready to start again. It's at this point I notice that there was no penetration into the collet in the original manufacture and the welds were just small tacks. Odd. So I try again and the same thing happens. So I ran a bead on a piece of clean scrap to check the welding set up. The bead is satis so no equipment problem. So I cleaned up the job and turned up the gas and amps and did the weld which is holding but looks very rough and given the piece is acceptable. I filed back some of the welds and they had all foamed though are holding. I have not had this happen before and I am thinking the steel was contaminated in some way which despite preping the work was not removed. Thus after a long shaggy dog story how do you deal with contaminated steel that can not be cleaned to get a best quality weld possible when you can not scrap the work and start again.
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That's likely "pot metal". Largely steel, but many random melt recyclables in it.

Braze it, or solder it. Welding it will forever be a challenge. You'll have to "butter", grind, and re-"butter" each half to weld it.

Steve S
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Neilukd,
I've found that using a 309 rod can overcome some of this. I'm finding more and more steel that comes from China with all manner of crap within the steel itself. I try to avoid it if I can for anything remotely critical. If if happening in the weld, it's probably happening in the heat affected zone at a lesser rate that in my mind will make the metal brittle and crack in the HAZ. I don't think it would be be a problem in your case, unless you end up on the wife's bad list. :)

Len
Now go melt something.
Instagram @lenny_gforce

Len
Neilukd
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    Sat May 31, 2014 4:28 pm

Steve, I am sure you are probably right and given the nature of the piece it could have been done in a Mom and Pop shop where they were dropping whatever scrap they could find into the pot. With hind sight brazing would have been the route to go down, my mistake of course was thinking 'simple job' :D. It's kind of worrying given the amount of products coming out of china that the QC/QA is not better.

Len I'll try the 309 on the other one which also looks looks suspect and see how that goes. As to my wife now it's filed and painted she is happy with the result.
Drifta-X
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As long as the mrs is happy that's what matters

Happy wife, happy life
I have a soldering iron!
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