180 Amp Mig

[Shammy]

I have a friend who has been using a 120v mig and wants to upgrade to a 220v machine. He's looking at a Lincoln K8421-1 that's 180 amps but says it will only weld up to 3/16" with gas in a single pass. He says it claims to be able to weld ½" with fluxcore in a single pass. Does this sound right? I only have a stick so I don't know much about migs.

Wouldn't he be better off with a Hobart or a Miller in this duty range? He's got some ½" plate he wants to weld and he doesn't want to go back to a stick only (can't afford both he says) and he doesn't want to use fluxcore, so that's why he's so concerned about welding half inch in one pass with gas. Any ideas?

[cope]

It will not weld 1/2" in a single pass. My MM210 won't do that. He needs the HH187 or HH210.

[G Austin]

1/2" Single Pass vertical is possible but not something I suggest. But it can be done.

Single pass 1/2" flat takes some VERY serious current density. If you try to just slow down and fill it up you get results similar to this

There is a pic of a subarc weld i/p that I stopped at http://weldingdata.com/WorkPictures.htm that shows some lack of fusion being produced. This is a subarc, tractor gun at about 350 amps.

[bluesparks]

He should easily be able to afford both stick and MIG. Old stick machines can be had on Craigslist for $50-$75 almost daily.

[Dan]

Set up with the correct .045 self shielded fluxcore, is the only way I 'd use a 180 amp wire unit on 1/2". This would definitely not be a single pass application either.

I wouldn't even attempt to weld 1/2" in a single pass with my 250+ amp Migmaster 250.

[cope]

Set up with the correct .045 self shielded fluxcore, is the only way I 'd use a 180 amp wire unit on 1/2". This would definitely not be a single pass application either.

I wouldn't even attempt to weld 1/2" in a single pass with my 250+ amp Migmaster 250.

Dan,

What was the setting you said you used on your MM210 for 3/8" short arc?

[Dan]

Dan,

What was the setting you said you used on your MM210 for 3/8" short arc?

Alan,

Tap #7 on the MM 210 isn't short arc with an .030 solid wire and C-25.

Due to the number of units that I have around here it has actually been a while since I last ran the MM 210. My HH 187 and a HH 210 have seen the most usage. Not all of it though, because there were a few task where the Migmaster 250 was the best option- spray transfer.

Anyway, for a flat or horz T or lap joint constructed from 3/8", I'd go with tap #7 and a wire speed setting more then likely somewhere between 75 -80. Input voltage and the brand of wire influence this wire speed setting. When ever possible I push the weld puddle. Pulling the puddle may require a different wire speed setting then pushing to keep the weld bead from piling up in the middle.

[cope]

Alan,

Tap #7 on the MM 210 isn't short arc with an .030 solid wire and C-25.



Anyway, for a flat or horz T or lap joint constructed from 3/8", I'd go with tap #7 and a wire speed setting more then likely somewhere between 75 -80. Input voltage and the brand of wire influence this wire speed setting. When ever possible I push the weld puddle. Pulling the puddle may require a different wire speed setting then pushing to keep the weld bead from piling up in the middle.

Dan, thanks for the reply. I usually run .030, would .035 be better for this. I assume from your answer that I will be in globular transfer? I guess this calls for a recessed tip!

[Dan]

Dan, thanks for the reply. I usually run .030, would .035 be better for this. I assume from your answer that I will be in globular transfer? I guess this calls for a recessed tip!

Alan,

With the above mention machine settings the unit will be outputting 200+ amps. At 200 amps, the .030 wire is going to have a higher current density (more intense arc) then the .035. Which translates into meaning, at this amperage level, the .030 can potentially produce a deeper penetrating weld then .035.

.035 would produce the weld puddle slightly quicker. In the end, @ 200 amps either wire size will work.

Yeah with C-25, you'll be in the globular transfer range ( 24 -25 load volts @ 200+ amps), so if you don't want a decent amount of spatter all over your basemetal, I suggest applying a light coating of anti-spatter.

Alan, I don't remember which gas mixes you have available. If you have 98/2, I'd go with spray arc over globular.

[cope]

Alan,

With the above mention machine settings the unit will be outputting 200+ amps. At 200 amps, the .030 wire is going to have a higher current density (more intense arc) then the .035. Which translates into meaning, at this amperage level, the .030 can potentially produce a deeper penetrating weld then .035.

.035 would produce the weld puddle slightly quicker. In the end, @ 200 amps either wire size will work.

Yeah with C-25, you'll be in the globular transfer range ( 24 -25 load volts @ 200+ amps), so if you don't want a decent amount of spatter all over your basemetal, I suggest applying a light coating of anti-spatter.

Alan, I don't remember which gas mixes you have available. If you have 98/2, I'd go with spray arc over globular.

Thanks for the response. I don't plan to do much over 1/4", and in a pinch, I have my old 250 amp AC Miller Arc welder. I'm down to C-25. I had some C15, but after I sold the PowCon, I had it re-filled w/C-25. I have the HH140, HH187 and MM210, and can't justify another cylinder that just sits around.

[Dan]

Thanks for the response. I don't plan to do much over 1/4", and in a pinch, I have my old 250 amp AC Miller Arc welder. I'm down to C-25. I had some C15, but after I sold the PowCon, I had it re-filled w/C-25. I have the HH140, HH187 and MM210, and can't justify another cylinder that just sits around.

Alan,

The reality is with the top end power level that the MM 210 offers you, C-25 is perfectly fine for 1/4", 3/8", or even 1/2" applications.