Does running mig/shielding gas penetrate deeper than running flux core?

super55 · Feb 8, 2012

Been thinking about upgrading my welder. I have a century 90 amp mig that is run off of 20a/120v that I've had for 15 years. Thing is convenient being small compact and able to do small repairs. Works great on small gauge steel and stock up to about 1/8". After that it seems I can still get good penetration if I crank the amps up to max and take it slow but it seems the welds aren't as strong as they should be. Will doing conventional Mig w/ a shielding gas get me better results or is looking at getting a new mig with more amps the answer? Would like to be able to be able to weld up to 1/4" stock.

The welder is capable of running a shielding gas but all I have ever ran through it is core flux.

k0ua · Feb 8, 2012

Now this is just an opinion, but why not get a 220 volt stick welder (Inverter) for about $300 or a used Transformer based (DC prefered) for maybe less. and save your wire welder for the small stuff. The stick will be good for much larger pieces, and it is not all that hard to learn stick, and good clean results can be had with a nice inverter DC stick welder running some 7018 or 7014. Or pop for a really nice 220 volt mig, but open your wallet here. I don't think your penetration will be any better at all with Gas on your Mig, in fact I think it will be less. The welds will look prettier with gas. Again this is just my opinion. Lets see what some of the welding professionals have to say. ( I am not one)

James K0UA

Shield Arc · Feb 8, 2012

I'm all for flux core, spent a life time running it. You should get more penetration with flux core than with Mig. Have you done any destructive testing to see your weld results? I should add here I've only run one 120-volt wire feed in my life, and I couldn't get away from it fast enough!
If you have your heart set on running gas, I suggest 100% CO2 for the best penetration.

cowski · Feb 8, 2012

all things being equal fluxcore penetrates deeper than mig.a 220 would better than a 110. i have used a lincoln 135 it would be better than your 90 amp.90 amp machines just is not enough for a 1/4.

namesray · Feb 9, 2012

k0ua said:
Now this is just an opinion, but why not get a 220 volt stick welder (Inverter) for about $300 or a used Transformer based (DC prefered) for maybe less. and save your wire welder for the small stuff. The stick will be good for much larger pieces, and it is not all that hard to learn stick, and good clean results can be had with a nice inverter DC stick welder running some 7018 or 7014. Or pop for a really nice 220 volt mig, but open your wallet here. I don't think your penetration will be any better at all with Gas on your Mig, in fact I think it will be less. The welds will look prettier with gas. Again this is just my opinion. Lets see what some of the welding professionals have to say. ( I am not one)

James K0UA

if it were me, i would keep your small welder for the small stuff and get a stick welder for the larger. i have used both (not an expert with them but have been able to keep my stuff going) and i like the ease of my 110v flux core for the small detail stuff, but to me it is almost as easy to weld the bigger/thicker stuff with a stick. i welded a hitch on my small wood trailer with my flux core (85amp) and the metal was about 1/4" thick. i "V"'d out the connect areas and made mutiple passes when welding, and it must have penetrated good because i can put a whole face cord in that trailer and it's green wood, pretty heavy and it shows no sign of being weak where i welded.

super55 · Feb 9, 2012

how many amps does a 220v Arc or Mig generally draw from the panel? Right now my service to the panel to the garage is only 50 amp. I still have plenty of breaker space and the garage has flourescent lights so as long as I am not running any other heavy draw items i would think I could get away with a maximum of a 220 v 40 amp draw. Is this enough to run an old lincoln "grandfather clock" arc or a 125 amp mig?

Thanks for clearing up the mig/flux issue for me. I always had mixed feelings towards flux but it sounds like I was asking more from my welder than it was capable of doing hence the weak welds and lack of penetration.

k0ua · Feb 9, 2012

Lincoln 225/125 AC/DC rig also know as a Tombstone..says

AC:50A
DC: 36A

so maybe not full 225 amp output on AC but yes full 125 amp DC output which is about all you would need for a 1/8 inch stick of 7018.

Inverter rigs are a little more effiecient so you would get more bang for you 40 amps input current. so in general I think you would be OK even with the tombstone. and most likely better off with a newer design inverter rig like an everlast PA200 or longevity 250 and to be honest with you I would buy one of them anyway instead of the tombstone, unless I found the tombstone cheap used. I would not buy a new one.

James K0UA

Shield Arc · Feb 9, 2012

super55 said:
I always had mixed feelings towards flux but it sounds like I was asking more from my welder than it was capable of doing hence the weak welds and lack of penetration.

You really need to do some simple destructive testing to get a feel for your abilities, and the process / settings you're using.

Here is a thread I did on Mig welding. I have done several different test if you're interested.
http://www.tractorbynet.com/forums/welding/212146-mig-break-test.html

super55 · Feb 9, 2012

Just checked on that longevity 250 specs :thumbsup: 30amp at 220v Sounds like this welder will fill my niche. I went and checked on a hobart 235 just to compare and it draws 47.5 amps. I will keep my old 115v welder for the small stuff (it's awesome for welding exhaust and sheet metal). Are these the only two brands of invertor welders on the market? I would like to do a little price shopping before I purchase.