I'm a beginner with Tig and am using a Miller Syncrowave 250 DX. I'm looking for opinions and tips from the experts here on welding 19 gauge sheet. My problem is that the weld line shrinks below the surface of the sheet along its edges in spots. When I grind the weld I'm left with low spots that need to be raised before grinding again. The problem is that most of the time I can't get behind the weld to bring it up. I'm using an .040" 2% Lanthanated tungsten and .035 ER 70 S2 filler rod. I set the machine to 50 amps and use a foot pedal. Any suggestions on settings or technique to keep the entire weld bead above the sheet surface while still getting a good weld?...Thanks
- Braehill
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Weldmonger
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Posts:
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Joined:Sat Jul 06, 2013 11:16 am
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Location:Near Pittsburgh,Pennsylvania. Steel Buckle of the Rust Belt
Ispoto,
Tying to explain to somebody in print how to keep sheet metal from warping is almost as hard as mailing someone a haircut. There's actually more art to this than science. While you're welding you are putting heat into the metal at a very fast rate which causes the metal to expand and then it cools at a much slower rate causing it to contract at a different rate. This all distorts the metal and leaves you with high and low spots, the nature of the beast.
Some things that I've tried with limited success are to put a slight flare outward about a 1/4" from the edge of the sheet to act as a stiffener and to also leave a little room for contraction of the weld.You don't want to leave a crease here so just roll it out softly. Sometimes it will pull flat without out leaving low areas. Other times I have heated it up after welding and quenched it with water to shrink out the low spots, but this is dependant on what kind of metal it is.
Len
Tying to explain to somebody in print how to keep sheet metal from warping is almost as hard as mailing someone a haircut. There's actually more art to this than science. While you're welding you are putting heat into the metal at a very fast rate which causes the metal to expand and then it cools at a much slower rate causing it to contract at a different rate. This all distorts the metal and leaves you with high and low spots, the nature of the beast.
Some things that I've tried with limited success are to put a slight flare outward about a 1/4" from the edge of the sheet to act as a stiffener and to also leave a little room for contraction of the weld.You don't want to leave a crease here so just roll it out softly. Sometimes it will pull flat without out leaving low areas. Other times I have heated it up after welding and quenched it with water to shrink out the low spots, but this is dependant on what kind of metal it is.
Len
Now go melt something.
Instagram @lenny_gforce
Len
Instagram @lenny_gforce
Len