What is the correct way to adjust your gas while MIG welding

JD Seller

Well-known Member
I am largely self taught at MIG welding. I have just been using one for a few years. I have a lot of rod welding time but not MIG.

I am using 75% Argon and 25% CO2 GAS. Usually the welding thickness is 1/4 to 3/8 steel. Running 100-125 amp on Miller welders, 252 and 35.

I am currently running the gas at 25 CFH. It seems to work alright but is this close to right?? How do you really know where to set the gas at? I see some of you guys talking about too much or not enough gas effecting the weld. SO how do you know what is correct???
 
I've always adjusted them by pulling the trigger letting some wire out and setting my gas at or around 30psi. So you should be close enough. Go weld !!!!!
 
I run 12 CFH inside a shop. If there is a breeze or I'm outside, I'll bump up to 20 CFH. If I get porosity, I'll add more CFH. But 12 is what mine regulator is set on 95% of the time.
 
It really depends on the conditions. Inside with no wind on clean metal I'll run 15-20 cfh. If the metal has some rust or paint or I'm working in some wind I'll turn it up to 30 cfh or a bit more. Working on farm machinery is not the same as certified welding on a presure tank and is much more forgiving. Also there is some veriation in regulators and gages so any fine recomendations have to be adjusted for those differences. It sounds like you are close but if your concerned about how much you are spending on gas just start cutting back til you get porosity or trouble with the weld the go back up til it works again. Here is a link to help out a bit.
Untitled URL Link
 
I turn it down until I can tell I'm not getting enough then bump it back up. I'm cheap and I hate running out of gas mid project.
 
My Hobart BetaMig 250, bought in the 90"s, uses a flowmeter, and I also run 20-25 CFH.

My neighbor just bought a new Miller 225 from the same welding supplier, and is does NOT have a flowmeter, just a low pressure gauge. I haven"t had a chance to look at the operator"s manual to see how the correlate the PSI readings to flow.
 
I set shielding gas (usually C-25 or Moongone) at 35 and forget it. My philosophy is if you get porosity, change the conditions, not the gas. With gas set at 35, I have never gotten "worm tracks", indicating too much gas, either.
 
20-25 cfh is about right, but because I'm cheap I try to run around 15. No sense wasting it, it's pretty obvious if there's not enough.
 
Jon: My concern is quality of weld not cost of gas. A tank lasts me 1-2 months now. So it is not a big cost compared to the benefits of the wire welder.

An example of my concerns. Today I had to do some welding on a bale trailer. Just some flat irons I added to keep the bales form sliding off sideways. They are light flat iron deliberately. They are always getting hit accidental. This way they give rather than some thing major. Half way through the repair I had to switch wire when I ran out. When I started to weld after that I got worm holes in the beads. Same steel, ground clean, inside so zero wind. The wire brand was different but the same size and rating. So what changed??? Even more puzzling to me is that after a few welds it quit doing it.
 
Took a welding course at our local college a while back to learn about mig"s & tigs. Inside we ran the gas at 30. Outside was even higher. Everyone I know is too cheap to run the gas that high but it does a better job. Most people run 15 & let it spit and sputter. Not my style to go cheap.
 
Miller 252? You have a flow gauge instead of a flow meter. The gauge will still read in CFH the same as a flow meter. 30 CFH is about the norm for MIG. A lot of times the parameters for the wire will list the recommended gas flow as well.
 
The first part of the wire could have been contaminated and/or dirty, maybe from your hands? Sometimes spatter will build up inside the nozzle and block the gas flow. That's why a lot of welders don't like the spatter spray. It doesn't let spatter stick but can cause dirt and stuff to stick in the nozzle. Nozzle gel is applied when the nozzle is hot, drips off and doesn't leave a sticky surface to catch anything.
 
I use the regular nozzle anti splatter paste in the small can. I dip the wand/nozzle in while hot. When I replace the small copper wire guide I usually clean up the outer copper shield on the inside too.

I am a real novice on this MIG welding. I have been thinking of taking a welding coarse this winter at the local community college to learn more.
 
There are many reasons that could have happened. A bad stretch of wire is quite common. Wire varies a lot and I've had to toss more than one roll because it didn't work, some for feed problems because they had bad shape and wouldn't feed even. Some for content problems that caused what you have. If it only lasted for a bit it could be gas contamination in the gun from something you did while changing the roll. I've also seen bad spots or contamination in the iron give problems. Without seeing it while you are welding, anything I say is just a guess tho. That is the problem with giving advice here, diagnosing a welding problem, especially with mig, is as much about sight and sound as the technical settings and we don't have that here.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top