StevoWelds
- StevoWelds
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New Member
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Joined:Fri May 25, 2018 12:19 am
I have an everlast power mts 221. About half the mild steel I tig weld is getting porosity. My current issue is welding 2" caps on2" square tube. If I weld s.s. it's nice and clean. So I figure it's got to be the steel. I'm cleaning the mill scale with a grinding wheel and wire wheel. It looks clean. But I'm having trouble on the corners I even tried acetone to help clean. When I start the arc on the corner of the cap i get porosity, as i continue the weld and blend the steel from the cap with the tube it starts to go away until i get to the next corner porosity starts to come back. I did grind the corners down a little to match the tubing. How do i fix this? Why is this happening to me? Help.
Depending on the thickness of the tubing, you could easily be pulling contamination from inside. Or, you could be suffering from a gas “shear”. When you weld along a fine edge, the gas shielding is sort of cut, diminishing the shielded area. This promotes contamination, makes welds rougher looking, and is generally a pain in the asK.
Some solutions are to also wipe the internal of the tubing (contamination), the underside and edges of everything you’re welding, and point your arc a bit differently can help.
For the gas shielding issue (if that’s the cause) you can make an Argon dam with a scrap block of material clamped along the seam, laying on top of the cap, just back from the edge. That will help the gas to be captured. You can use ally to avoid welding the block to your carbon steel, or vice-versa.
Maybe a picture or two in case these notions aren’t the solution.
Some solutions are to also wipe the internal of the tubing (contamination), the underside and edges of everything you’re welding, and point your arc a bit differently can help.
For the gas shielding issue (if that’s the cause) you can make an Argon dam with a scrap block of material clamped along the seam, laying on top of the cap, just back from the edge. That will help the gas to be captured. You can use ally to avoid welding the block to your carbon steel, or vice-versa.
Maybe a picture or two in case these notions aren’t the solution.
StevoWelds
- StevoWelds
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New Member
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Posts:
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Joined:Fri May 25, 2018 12:19 am
Thank you that's helpful I'll give it a try. I'll see if I can post some pictures. All I know is to clean mill scale and get gas shielding. So any extra info is helpful. I am using a gas lense btw with a #8 cup. Maybe a bigger cup or new lense could help? With these caps I'm doing pretty welds are important and its pissing me off.
An 8 with a gas lens should be fine. With TIG, you can stop and start endlessly without an appearance problem. Worst case scenario, fill it, then pass back over in the other direction without filler and “wash it”. This will make it look very pretty and consistent.
A final word to the wise: when you weld something “closed” like tubing, the trapped air, heat and gas will force their way out. So you’ll get a blow out at the end of the weld unless there’s a vent hole somewhere. When I weld up tube frames and such, I lay everything in place, mark my X-sections, then remove the tubes and drill a small hole in the adjoining piece. Ultimately, the entire frame vents into itself. This allows me to work on the entire thing, and the heat from one end is insufficient to fill the entire frame so I can weld it up closed without a blow out. Takes a bit of time, some pre-thought, but works out well.
Welding those caps on, you could drill a small pilot hole in the cap, weld the seams, do another piece, then dab the hole shut quickly. Grind it flat. No one is the wiser
A final word to the wise: when you weld something “closed” like tubing, the trapped air, heat and gas will force their way out. So you’ll get a blow out at the end of the weld unless there’s a vent hole somewhere. When I weld up tube frames and such, I lay everything in place, mark my X-sections, then remove the tubes and drill a small hole in the adjoining piece. Ultimately, the entire frame vents into itself. This allows me to work on the entire thing, and the heat from one end is insufficient to fill the entire frame so I can weld it up closed without a blow out. Takes a bit of time, some pre-thought, but works out well.
Welding those caps on, you could drill a small pilot hole in the cap, weld the seams, do another piece, then dab the hole shut quickly. Grind it flat. No one is the wiser