mig and flux core tips and techniques, equipment, filler metal
SkyZero
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    Wed Jun 03, 2020 10:00 pm

Hey folks,

I've been wanting to learn how to weld for awhile now and I've decided to pick it up and try to teach myself a new skill. This is a hobby for me and at the most I'd use it to do jeep repairs/upgrades and maybe odd jobs and projects around the house. Till then I'd just like to learn as much as I can.

Right now I have a Hobart 210 MVP I got at a steal. I actually wired a 240v outlet/50 amp breaker in the garage for it. Just been running beads so far.

Running solid .030 wire with c25 gas, dragging with a slight back and forth motion on 1/8 steel. Gas was about mid-20's. Machine was set at 4 voltage and 40 wire speed. Trying to work on getting a consistent speed and stick-out.

I'd appreciate any feedback, especially on how to avoid the huge craters at the end. I'm unsure of the technique needed to end the welds nicely. I tried a few things like backtracking but get inconsistent results.

Thanks for any help! :D

https://imgur.com/a/wm0OP3A
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Forget about the craters. You have a shielding gas issue. I can see porosity hiding its ugly head. Means oxygen is making its way into the weld puddle in large amounts. Go back to square 1 all the way back to the tank, and do leak tests with soapy water to see where the leak is. Check the machine and it's fittings/O-rings. ~25CFH should be plenty so long as you are holding a consistent 3/8" CTWD. Also check your polarity. You should be on DC positive on the mig gun.
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cj737
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    Thu Sep 29, 2016 8:59 am

Oscar wrote:Forget about the craters. You have a shielding gas issue. I can see porosity hiding its ugly head.
Amen to that!
SkyZero
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Oscar wrote:Forget about the craters. You have a shielding gas issue. I can see porosity hiding its ugly head. Means oxygen is making its way into the weld puddle in large amounts. Go back to square 1 all the way back to the tank, and do leak tests with soapy water to see where the leak is. Check the machine and it's fittings/O-rings. ~25CFH should be plenty so long as you are holding a consistent 3/8" CTWD. Also check your polarity. You should be on DC positive on the mig gun.
Thanks for the feedback! I'll take a look and see if I can find a leak and double check the polarity. The 3/8" distance is something I need to practice more of I think.
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Turn up the gas, check to be sure the torch is fully seated in the machine and you haven't pinched an O-ring, clean your metal first...no sense in learning on dirty metal, it just handicaps you. Also I would go up to #5 on the voltage once you get your gas sorted. You aren't welding outdoors are you?
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SkyZero
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    Wed Jun 03, 2020 10:00 pm

Thanks for the help guys. I checked all my connections to the gas tank and made sure my polarity is correct. Turns out the mig gun wasn't seated completely in the machine, so completely my fault. I checked after to make sure gas is coming through the nozzle and it is. The "bacon sound" is much clearer now and it feels like its more consistent.

Here is a picture of how the welds look now. These are just straight stringers, no alternating motion on 1/8", machine still set at 4/40. Welding in the garage with it open.

https://imgur.com/a/6IeK0C2
cj737
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    Thu Sep 29, 2016 8:59 am

Bingo!
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There it is. Just need more wfs and V. They look ropey, so try running a little hotter.
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SkyZero
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    Wed Jun 03, 2020 10:00 pm

Thanks! I'll give those a shot and see if I can improve the bead profile.
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