120v MIG 3/8" coupon test results

[mikehaugen]

Well I'll say this... I agree that it has been established that you cannot make a book passable weld on 3/8" with a 120v mig. I will also say that even if it didn't work out, we all should have learned an awful lot along the way about joint prep, parameters, and a couple other tricks to get the most out of these welders to make the best possible weld we can. The tests may have been failures, but the threads have certainly not been. I will walk away from this with a lot more knowledge than before, so it was not a waste of my time to follow this. I have a 220 stick, but I still learned a lot and will be able to apply it if/when I buy a 120 mig.

Sodo, I for one appreciate your persistence through all of this to draw as much knowledge as possible from these pros. And yes, I think many of the welds made would be acceptable for many practical purposes, especially if something is overbuilt to begin with. I think the times are rare when some piece of equipment is relying on every weld to be absolutely 100%.

Finally, thank you very much to all of the guys who stepped in and gave it an honest attempt. Your sharing of knowledge was very useful, even if it seemed like failure.

 

[brain55]

A guy with the time/ability/tools then needs the knowledge. Withholding the knowledge is a strange thing. But in any case I can't find it anywhere else, so it kinda appears to me that Mark and Mike are the only ones doing it.

Brain, FYI in case you were unaware, there exists a thread called "120v MIG 3/8" coupon test results" where your premise is being tested.

How about you start a thread called "Using a '55 Chev within its parameters" instead?

:laughing: :laughing: :laughing:

Sorry Brain, couldn't resist, you kinda left yourself hangin out there.. Hope the previous fussing doesn't deter our 2 pros from showing how they'd tackle this problem..

I was reading that thread and the results seemed pretty unanimous that even in perfect circumstances 120v welders weren't the answer to 3/8" plate.

I'm not sure about starting a thread about '55 Chevy parameters, but here's a pic of what happens outside those parameters. Lol

 

[IslandTractor]

Would those who are adamantly opposed to using a 120v welder on 3/8" plate also be negative on using a 240V welder on 3/4" plate? Is the energy delivered (and required) not directly proportional? Seems to me it is more about proper weld design, preparation, beveling and number of passes than voltage.

 

[Blade Breaker]

Would those who are adamantly opposed to using a 120v welder on 3/8" plate also be negative on using a 240V welder on 3/4" plate? Is the energy delivered (and required) not directly proportional? Seems to me it is more about proper weld design, preparation, beveling and number of passes than voltage.

Once you can get a machine to spray arc transfer even with .035 wire you can weld some heavy plate using proper technique and multiple passes. Its the short arc transfer that limits the thickness you can penetrate into the base metal. Some 240V machines could easily run more than .035 wire and even get into dual shield wire. All you mentioned are important but the ability to run high voltage and current is what allows you to spray arc.

 

[IslandTractor]

Once you can get a machine to spray arc transfer even with .035 wire you can weld some heavy plate using proper technique and multiple passes. Its the short arc transfer that limits the thickness you can penetrate into the base metal. Some 240V machines could easily run more than .035 wire and even get into dual shield wire. All you mentioned are important but the ability to run high voltage and current is what allows you to spray arc.

That certainly makes sense. Does the same hold true for stick welders? Are 240v stick welders somehow able to deliver more than twice the energy of a 120V or is it simply the lack of more than 15 or 20amp circuits that limits the 120v machines? As I recall, welding voltage is actually in the mid twenty range coming out of the gun/electrode so it is really more the available amperage rather than 120/240 that makes the difference. No?

Would an autosensing dual voltage mig machine like a Miller Passport or Multimatic be able to utilize more than 20amps at 120v if it could be delivered? I thought some generators produce up to about 30amps on 120, wouldn't that get enough energy to weld more than the traditional limit of 3/16ths or 1/4"?

 

[Blade Breaker]

That certainly makes sense. Does the same hold true for stick welders? Are 240v stick welders somehow able to deliver more than twice the energy of a 120V or is it simply the lack of more than 15 or 20amp circuits that limits the 120v machines? As I recall, welding voltage is actually in the mid twenty range coming out of the gun/electrode so it is really more the available amperage rather than 120/240 that makes the difference. No?

Would an autosensing dual voltage mig machine like a Miller Passport or Multimatic be able to utilize more than 20amps at 120v if it could be delivered? I thought some generators produce up to about 30amps on 120, wouldn't that get enough energy to weld more than the traditional limit of 3/16ths or 1/4"?

120v x 20 amps = 2400 watts
240v x 100 amps = 24000 watts

Your correct in saying that if you could get a machine made to run on higher amperage at 120v you may be able to get better results but I would not expect much improvement. .035 wire running short arc is only recommended for around 1/4" plate and under if I remember correctly no matter what machine you are running it on. Short arc process just doesnt dig deep for heavy plates but that is why it runs nice on sheet metal.
The 120V stick/tig welders are still running at the same wattage as the migs but the stick welding process using 6010 takes less current/amperage to get the deeper penetration needed for heavier materials. That is why it has been recommended as a 120v option.

 

[zing]

Thank you Mark for the tests and the info in your posts. The coupon tests are very instructional about the limitations of a 120V welder.

For all of those criticising the point of this conversation, I do not have 220 in either of my sheds and do not expect to be in a position to put it in anytime soon, but I will still continue to use my 120V welder and try to learn to use it better.

I think the point has been made clearly about the lack of penetration of a 120v weld, so I will not be doing anyting with my welder that would put me or someone else in danger. I will not be welding the frame of a trailer that does 75 on the highway, or bucket hooks that will be suspending heavy loads. Without the comments and coupon tests I don't know what I would have done, because I had no knowledge of the issue. If anything that is a positive that has come from all of the debate. I think that policy would apply equally to an inexperienced person with a 220V welder as well, but that is a different argument.

Not every weld is a life or death weld though. My current issue is a yard trailer with a broken axle that I am thinking of turning into a walking beam. It would be one of my first real things to build. I am not sure how thick the metal will be but it won't be sheet metel, so the info here about prepping the edges, using multiple passes, and clearing out the soot between passes will help. I would prefer if my welds don't break as it does 5-10 mph over my fields, but if they do the only casualies will be some spilled manure or apples on the way to a be spread around a field. The only consequence will be that i have to weld it again and chalk it up to more practice.

Thanks to all that contributed. I look forward to more tips and tricks over time from those experienced welders that are willing to share their knowledge. :thumbsup:

 

[muddstopper]

The only thing in this thread that has me thinking is the statement about using a bigger breaker to supply the welder with more amps, and would it allow more output at the business end of the welder. I dont know, so am asking if its possible.

With that said, I was trying to tig some 3/8 aluminum with my 220v 250 amp machine the other day. I have a 60amp fuse (yep, I said fuse), in my panel, actually 2 big fuses, about 1in dia and 6inches long, at $17 each. While trying to tig the aluminum, with machine set on 250amps, I blew one of the fuses. Installed another fuse and blew it too. Pretty sure the machine is supposed to be fused at 60amp and darn sure the machine was at max capacity. Recommended amp for 3/8 aluminum tig weld is 230-260 amps, so I was at the limits for my machine, kind of like the 120migs on 3/8 steel. Not sure I would want to use a bigger fuse to power the welder, in fact, I plan on a whole new breaker panel installation next wkend. Still, I wonder if using a bigger breaker than 60amp would or would not damage my machine, and I plan on dragging the welder out from the wall and checking the panel on the back to see if the machine is indeed supposed to be wired to a 60amp breaker or fuse, or if maybe it might suppose to have a even bigger power supply. Machine is a idealarc 250/250 stick tig with high fre start.

I should probably also note that I am a beginner tig welder and just happen to have a aluminum spindle housing off a lawn mower that was really beyond repair, and I just wanted to know if I could weld it using tig, just for practice. I realize my welder, even tho it is a 220v machine would be pushing the limits for tig welding 3/8 aluminum and I aint beyond paying someone with the right equipment to weld a job I am not equipped to do myself. I think thats something some of the guys that want to keep pushing the limits of their 110v migs should take into consideration.

 

[CNC Dan]

Use helium for shielding gas and you should be able to do it.

 

[MinnesotaDaveChalmers]

The only thing in this thread that has me thinking is the statement about using a bigger breaker to supply the welder with more amps, and would it allow more output at the business end of the welder. I dont know, so am asking if its possible.

With that said, I was trying to tig some 3/8 aluminum with my 220v 250 amp machine the other day. I have a 60amp fuse (yep, I said fuse), in my panel, actually 2 big fuses, about 1in dia and 6inches long, at $17 each. While trying to tig the aluminum, with machine set on 250amps, I blew one of the fuses. Installed another fuse and blew it too. Pretty sure the machine is supposed to be fused at 60amp and darn sure the machine was at max capacity. Recommended amp for 3/8 aluminum tig weld is 230-260 amps, so I was at the limits for my machine, kind of like the 120migs on 3/8 steel. Not sure I would want to use a bigger fuse to power the welder, in fact, I plan on a whole new breaker panel installation next wkend. Still, I wonder if using a bigger breaker than 60amp would or would not damage my machine, and I plan on dragging the welder out from the wall and checking the panel on the back to see if the machine is indeed supposed to be wired to a 60amp breaker or fuse, or if maybe it might suppose to have a even bigger power supply. Machine is a idealarc 250/250 stick tig with high fre start.

I should probably also note that I am a beginner tig welder and just happen to have a aluminum spindle housing off a lawn mower that was really beyond repair, and I just wanted to know if I could weld it using tig, just for practice. I realize my welder, even tho it is a 220v machine would be pushing the limits for tig welding 3/8 aluminum and I aint beyond paying someone with the right equipment to weld a job I am not equipped to do myself. I think thats something some of the guys that want to keep pushing the limits of their 110v migs should take into consideration.

60 likely won't do - check this manual (if yours looks like this) page 6

http://www.lincolnelectric.com/assets/servicenavigator-public/lincoln3/im315.pdf