I would use a larger nozzle and use about 1/2-5/8" tip to work distance. I generally run 1/2" tip to work and haven't had any issues. It's possible that air is being sucked in where the mig gun enters the power point, just after the drive rolls. Generally porosity occurs easily on an outside corner or edge weld. Fillet welds, lap welds and butt welds are less of an issue as the joint configuration helps trap the gas coverage.
I'm thinking at lower flow there is risk of too little gas, at higher flow there is risk of eddy currents swirling air into the cloud. Finding a mid range where neither happens is the magic.
I tend to get too close. The process needs more stick out to get the flux heated before it melts off. It is a spray process so contact tip to work is critical. In my experience 3/4" is about right.
An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Have you mentioned your wire & your gas. I think last two digits in the wire are the argon percentage required. 85% wire HAS to have 85% argon.......
An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
In his first post he said he was running Outershield elite 71 https://www.lincolnelectric.com/asse...lite/c3103.pdf
I would be trying to match the specs in the manufacturer's PDF above as closely as possible: Gas 100% CO2 or 75 - 82% Argon / CO2, Flow Rate: 40 - 50 CFH, 3/4 inch CTWD, 350 ipm, 25-28 volts. If you are doing all of that, there has to be a gas leak somewhere, as this stuff normally runs like a dream.
Last edited by Louie1961; 08-10-2022 at 08:42 AM.
Miller Multimatic 255
That's the same stuff I was running, I had an issue with the oring leaking, once resolved, it did run like a dream
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I don't have a Euro style torch.
Ok, I'll find a bigger nozzle, thank you.
You mean 1/2" TIP to work and not 1/2" NOZZLE to work right?
I'm trying to understand why air would get sucked in at that point, shouldn't gas just be blowing out instead?
I had a project this winter I used a lot of this wire on, open corners on 1/2" metal, didn't have any issues there, but seemed like any time I had a fillet or lap, all bets are off. The open corners were vertical up however, and until this current project, I hadn't had any issues w/ that, just other positions.
Those are the specs I'm trying to match. Some welds run like a dream, some are a nightmare when I knock the slag off. That's part of what's frustrating here, I can't tell it's not welding well until I knock the slag off. The sound doesn't change (not that I've perceived anyhow), the wire isn't pushing back on me, I can't see the holes because of the slag, I make an entire weld and then am nervous the knock off the slag every time. It seems about twice as hard to grind out as a MIG weld too. If this were hardwire, it would let me know real quick that something was wrong.
How sensitive is this wire to gun angle do you think? I clearly haven't ruled out an equipment issue, but keep wondering if it's just me that's the problem.
Millermatic 252
1965 SA-200 (burns oil)
1975 Miller 55g (leaks oil)
In my experience it's not that sensitive, but for you who knows as we can't tell what gun angle you are using. You really want to be straight in on a vertical up weld, or pretty close to it. Maybe a 5 degree push tops. Next step would be to swap a gun from another machine and see if it makes a difference.
BTW does it do this in the flat position? In the flat position be sure to drag it and not push it.
Miller Multimatic 255
Photo shows no gas on the wire.
Most try weld fluxcore like mig with short stick out .
Next is they want to see the contact tip like mig. With fluxcore you need gas around wire or you see what photo shows.
It could be a leak in gas line , cup to short, regulator error.
When shop I had order long cups so welders could not push cup down.
Dave
1/2-5/8" at the tip which apparently is somewhat recessed. If the gun isn't sealing properly where it plugs in , it will suck in outside air. The higher the scfh the more air it will try to pull in, like a venturi effect. Too much gas flow will also create a turbulence at the nozzle as well . I doubt it unless your regulator or flowmeter is creating too much pressure. It's typical to have a high pressure burst when you hit the trigger but it should stabilize quickly.
Fair enough on the gun angle, but I know what I can get away with using hardwire, just wondering if I need to be a lot more careful w/ dual shield. I try to be 90 degrees on vertical up.
I can't remember having it happen in flat position. I don't try to push w/ this wire.
Ok, I understand the venturi effect, I guess I was thinking about the setup differently, but makes sense, thanks.
Millermatic 252
1965 SA-200 (burns oil)
1975 Miller 55g (leaks oil)
I don’t know if there’s any value in this, but I just laid a lap joint on some scrap. Set as close to your parameters as I could….0.045 Esab dual shield 70 ultra plus. 25.0v. 350ipm. 35cfh of c25 gas. It’s feels a little ‘low and slow’ for me in a horizontal, I think I’d be happier up around 27v and mid 400’s wire speed. Likely with a bit more stick out to make it work nice. But I don’t see turbulence or voltage as issues with my setup.
FWIW when I walked up to that machine, I had been doing a lot of small out of position beads and it was set at 24.5/375 from the last time I ran it a few days ago.
I know it’s not the prettiest pass, could use a little more wet out on the bottom, but you get the point. This was stringer, no weave.
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Looks better than the first photo.
I keeping the cup closer to metal so shield gas does not blow away. Not the stick out but cup needs to be closer.
When I was doing a lot of welding with E71T-1 and had have cup with out I would turn up the cfh and block for drafts.
You think the flux would help more but needs the shielding gas.
Fluxcore with gas wire for fast welding close speed of submerg welding.
Dave
Thanks for taking the time to do that. I think I probably do weld 'low and slow' compared to a lot of guys on here, I dunno if that's good or bad. I'll try some sometime at 27 and 450 just to see. I'm waiting on the gas flow tester and a larger nozzle and then I'll play around. I just finished out this project with hardwire to get it done so I'll have to just try some scrap when they get here. I really didn't expect this much help on this problem, you guys are awesome, thanks again.
Millermatic 252
1965 SA-200 (burns oil)
1975 Miller 55g (leaks oil)
Try seeing what the flow is "at the torch" by using one that attaches to the end of the torch. I use about 20 to 25 cfh without a problem. CO2 requires a narrower heat window so you need to be within maybe 10 amps of the sweet spot, usually close to what the wire spec says and adjust up/down. I've used 71M on a 230 amp mig and it worked ok but I had to use every bit of power that box would throw at it to get it looking good.
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South Carolina Native w/:
Everlast 255EXT
Millermatic 210 & Gun
Maxstar 150STH
Lincoln AC Buzzbox
Two large 12v batteries
I hope you don’t mind if I ask on your thread?
I’m getting ready to do some 1” with the er 71 dual shield pre heated to about 300 degrees. What should I be doing pushing or dragging? Also to slow puts more heat into the metal with 1” wouldn’t slow be a good thing?
Thank you and sorry if I stepped on your thread.
Boyd
Slight drag angle unless it’s a vertical joint. What type of joint and prep? You’ll likely need multiple passes…run slow steady stringers and fill it up. Watch your interpass temp, I use esab wire and it likes to be below 400 degrees interpass.
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I prefer a drag also and think it puts a lot more heat into the metal. Drag the hard wire too and get a lot of berrys when I push and feel like not much penetration is happening
Last edited by motolife313; 08-19-2022 at 02:13 AM.
I've always pushed when possible. Haven't noticed much difference as far as penatration goes.