120v MIG 3/8" coupon test results

[firemanmike69]

Settings? I assume you had it cranked all the way up? Thank you for sharing. Great pics and to the point!!! :thumbsup:

Wire speed at 70/100 and voltage 7/10. Ran each pass nonstop and back to back to back the machine never so much as hiccuped

Thanks again Fireman. Experienced welders have been "imagining" the limits of 120v MIGs for so long, it's time! The opposition to this "project" has been either amazing, humorous, or pitiful. Everybody should know that a 120v MIG pushin' it at 3/8" but also they should know it "can do it" with weld prep and knowhow, in a pinch. It's pretty much the same methods that any experienced welder knows when welding thick stuff just that nobody will show 120v MIG owners how to do it. It depends on the weldment size, and the application too. The notion that 120v MIG can only weld 12ga, is out the window. Or ought to be, I guess we'll see how long that takes! :laughing:

I have welded me a big thing or two and we have the big welder to run the heavy amp stuff but you don't always need 600+ Amps to weld tin or a bracket

 

[dragoneggs]

Wire speed at 70/100 and voltage 7/10. Ran each pass nonstop and back to back to back the machine never so much as hiccuped

Great! I think the guts/ability of the 140 are probably the same as my 211 on 120v.

 

[Arc weld]

Thanks again Fireman. Experienced welders have been "imagining" the limits of 120v MIGs for so long, it's time! The opposition to this "project" has been either amazing, humorous, or pitiful.

Everybody should know that a 120v MIG pushin' it at 3/8" but also they should know it "can do it" with weld prep and knowhow, in a pinch. It's pretty much the same methods that any experienced welder knows when welding thick stuff just that nobody will show 120v MIG owners how to do it. It depends on the weldment size, and the application too.

The notion that 120v MIG can only weld 12ga, is out the window. Or ought to be, I guess we'll see how long that takes! :laughing:

I don't want to create a big argument but the bend tests are a fail no matter how you look at it. Maybe from not enough heat or lack of fusion but never the less a fail. Normally a properly done MIG root pass with no fill will pass a bend test, same as TIG or 7018. A weld doesn't have to crack/break in the weld metal to be considered a fail. In an actual bend test you are allowed a 1/8" maximum combined flaw in all your bends. If you do a 6" pipe with 8 bends, there's very little room for error. This has nothing to do with firemanmike69. It was great that he took the time to do this test. What it clearly shows is why the manufacturers put a capacity rating on their machines.

 

[firemanmike69]

I don't want to create a big argument but the bend tests are a fail no matter how you look at it. Maybe from not enough heat or lack of fusion but never the less a fail. Normally a properly done MIG root pass with no fill will pass a bend test, same as TIG or 7018. A weld doesn't have to crack/break in the weld metal to be considered a fail. In an actual bend test you are allowed a 1/8" maximum combined flaw in all your bends. If you do a 6" pipe with 8 bends, there's very little room for error. This has nothing to do with firemanmike69. It was great that he took the time to do this test. What it clearly shows is why the manufacturers put a capacity rating on their machines.

I totally agree that the root bend is a fail but how is the face bend a failure?

 

[Arc weld]

There's a chunk of metal missing from the end and the tears above the weld could be caused by the welding technique. I don't know how the piece was cut or prepared prior to bending so just going by the picture. There's also insufficient fill. I don't know if the weld was a little low to begin with or if it opened up a little when bending? I think it is an excellent example of why 120 volt MIG's aren't recommended for 3/8" steel. Look at all the work done in attempt to make it work and it still split open. That should be a big red flag shouldn't it? A good bend test looks like a piece that was never welded except you can see a slight discoloration where the weld is. I don't think MIG will do it but 6010 bent at 650 deg's will break in the weld so you can see if there's any internal flaws.

 

[dragoneggs]

And look how much it bent to 'fail'! Obviously not perfect but that join is pretty dang strong. Good enough for a nuclear plant? No! But is that weld quality going to be a problem for the 99.9% of us? No... as well. Thanks again, Firemanmike!

 

[Sodo]

One attempt, after work, just for TBN, is a lot to ask ------ for total success welding double the recommended thickness of 3/16". I bet, that if Firemanmike had the time to do a few of these, he could figure out how to make it successful.

Arc maybe you have suggestions how to make it successful?

 

[firemanmike69]

There's a chunk of metal missing from the end and the tears above the weld could be caused by the welding technique. I don't know how the piece was cut or prepared prior to bending so just going by the picture. There's also insufficient fill. I don't know if the weld was a little low to begin with or if it opened up a little when bending? I think it is an excellent example of why 120 volt MIG's aren't recommended for 3/8" steel. Look at all the work done in attempt to make it work and it still split open. That should be a big red flag shouldn't it? A good bend test looks like a piece that was never welded except you can see a slight discoloration where the weld is. I don't think MIG will do it but 6010 bent at 650 deg's will break in the weld so you can see if there's any internal flaws.

The chunk missing from the end is where I flipped it over to cut it I didn't have it lined up perfect in the saw. The under re enforcement is within the 1/32" allowed and was there from the start. The coupon was about 10" long to start and I literally just cut it in half and bent each piece. I know for an actual test I would have been bending thinner strips that would have come from closer to the center of my plate so as not to include as many starts and stops. Is over reinforcement preferable to under and then just grind it flush? Also you refer to a 6010 weld being bent hot, should I have bent these hot?

 

[firemanmike69]

One attempt, after work, just for TBN, is a lot to ask ------ for total success welding double the recommended thickness of 3/16". I bet, that if Firemanmike had the time to do a few of these, he could figure out how to make it successful. Arc maybe you have suggestions how to make it successful?

I'm not trying to start a big peeing match by doing this, just trying to bring some civil discussion back to the welding forum. Maybe I'll fire up the big girl and do one with a 1/4" 7018 and do the whole coupon in 1pass with 1/2 a rod lol

 

[JimRB]

I was curious to see if Mike welded the same materials with a big setup if things would look different. That could take away the variable of different welder technique. It is possible/probable that if I submitted a sample done with my Hobart Handler 140 on a 120v 20 amp 12 wire gauge circuit might look just as bad as me trying to weld with a bigger Miller running off 208 or 240. I have done some darned ugly welds using the bigger Miller but they have worked ok. But I sure would not want to post here as I am embarrassed. Obvious to me that I did not have the machine set up correctly but not obvious to me what the correct settings are as I am a weekend warrior who might only fight the welder a few times a year.

By the way I bought the Handler 120v rig from a recommendation from a friend who was trained in the trade in England. He did some oil rig work. I do not know if he did nuclear construction welding. He did work for a number of years for a company that made samples for non destructive testing customers. You know the samples you buy at great expensive that have defects you are supposed to find the defect without destroying the material. I gather you use magnetic testing, ultrasonic, dies and xray to find the defects. I do know I have never stumped him when I bring a piece of steel or aluminum in for repairs. Anyway he has a few of the small Hobarts on the trucks and likes them for what they can do. Obviously the Handler cannot do as much as the big welding rigs but they are handy and light.

Here is a short article that discusses some of the NDT techniques that can be used. The ABC's of Nondestructive Weld Examination