MIG welding thin steel

[WilliamTO-35]

I've been using my MIG welder as a flux core welder, with no shielding gas, for several years. I do ok with steel thicker than 14 gauge, up to about 1/8 inch thickness. My problem has been burn through with anything thinner than 14 gauge. I've tried different thickness wire, and different wire speeds and currents . This summer, I'm going to buy a bottle of gas, and try using the machine as a true MIG welder. I have some concerns, though. One is that the visibility of the welding process is great with flux cored wire, but poor using a gas nozzle. I'm also concerned that using the gas may not solve the burn through problem as much as I expect, and that I'm doing something else wrong . Any suggestions ? Thanks.

 

[Shield Arc]

It really gets down to how well you can set the Mig welder. Far as volts, and wire speed / amps.
Here is a calculator by Miller that should help you get close.
Weld Setting Calculators - MillerWelds

 

[yomax4]

What size flux core were you using? you can get it in 030. I hate it though. You will love 023 hard wire with gas on thin metal. Hopefully you have variable amperage control.

 

[ctrider]

I'm not sure what you have for a welder or helmet. I have used the flux core very little on my Miller 211. There's just a huge difference using C25 for me anyway. I'd also suggest an auto darkening helmet. You can adjust the sensitivity and shade on most of them. I can see the puddle and arc quite well even with very thin metal. The thinnest I have tried and welded successfully is this grille on my JD MC dozer I'm trying to restore. It's probably 22ga and very small pieces. I actually cut out some of the grid from another grille and welded it in where there were gaps and breaks in this one. It was obviously a low setting, I just used the auto set feature on the 211.

 

[flingwing1969]

I'm afraid you'll simply have to go to MIG and get away from FCAW for thin stuff it is simply too difficult to do with .030 wire. As YomaX4 said, you will love MIG and .023 for your project, turn down your heat and reduce your feed, keep your stickout short, and move quickly to minimize heat deformation. I like to move my spot to keep the Heat Affected Area to a minimum on thin stuff - like a 16" piece, tack quickly on one end, move to the other, tack in the middle then go back halfway between the middle and the top weld, etc. You might also want to keep an air gun nearby to air cool welds before moving one to minimize movement - you will get some for sure, just try to minimize. Play with some sample pieces and you will really get so you love MIG. Now TIG, you would really warm up to for the tough welding jobs.

 

[dragoneggs]

What size flux core were you using? you can get it in 030. I hate it though. You will love 023 hard wire with gas on thin metal. Hopefully you have variable amperage control.

Been running .030 exclusively with my 211MVP. I don't do so good with 14g or less, either. I guess I have to go through the hassle of swapping out wire to .023... or get a new welder!

 

[tomplum]

Been running .030 exclusively with my 211MVP. I don't do so good with 14g or less, either. I guess I have to go through the hassle of swapping out wire to .023... or get a new welder!

I hear you. It's so dang bothersome having to change wire when you could just have one set up ready to squeeze the trigger. Let's see, a little blue one for .023, a red one for .030, a green one for 045, maybe a maroon one for .035. Just like grinders....

 

[dragoneggs]

I hear you. It's so dang bothersome having to change wire when you could just have one set up ready to squeeze the trigger. Let's see, a little blue one for .023, a red one for .030, a green one for 045, maybe a maroon one for .035. Just like grinders....

Except it is much easier to build a fleet of grinders! :drink:

I like your color coding idea, though!

 

[BotaTrac]

You're a better welder than me!

 

[MickeyDBC]

I used to have an old Century mig welder and no matter what I tried the thing made me feel like an idiot. Nasty looking booger welds on thicker material and burn through on thinner stuff. Eventually moved up to a Miller 175 and a good auto-darkening helmet and all of the sudden I was a decent welder. Good equipment and being able to see what you are doing works wonders.