Bought a mig, now which gas?

Archdukeferdinand

Well-Known Member
Joined
Dec 27, 2006
Location
Vilas, NC
So of course I ended up with something bigger than first intended, got a lincoln 175 mig- should be here by the weekend.

Anyways, what gas would folks recommend? I'm thinking CO2 as its cheaper and I guess a little hotter. I've been told that C25 makes the nicest looking welds...
 
Everyone I know that welds uses a mixture of 75% Co2 and 25% of Argon. Common mix found at any supply place.
For stainless you will need straight Argon.
 
I perfer 85-15
 
upnover said:
Everyone I know that welds uses a mixture of 75% Co2 and 25% of Argon. Common mix found at any supply place.
For stainless you will need straight Argon.
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Cool, I think I'll go with the unimix, thanks for the help.

As I understand it, I need argon for welding aluminum, too?


Edit: Also have an extension cord question.

I've got hundreds of feet of 10/4 SOOW 600v cable at work, I can use that to make a 50' extension cord, right?
 
For best performance stay away from using a drop cord. Get a circuit pulled with a 30 amp service.
 
FWIW, unimix is 75% argon and 25% co2 rather than the other way around, and is just a brand name for c25. I've never heard anyone call it unimix, only c25. For al use 100% argon. They make a tri mix for welding stainless, but c25 works fine.
Also fwiw, I've mig welded with straight co2, straight argon, and c25. The mix is definitely the best.
 
braxton357 said:
FWIW, unimix is 75% argon and 25% co2 rather than the other way around, and is just a brand name for c25. I've never heard anyone call it unimix, only c25. For al use 100% argon. They make a tri mix for welding stainless, but c25 works fine.
Also fwiw, I've mig welded with straight co2, straight argon, and c25. The mix is definitely the best.
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Thanks, that clears it up. I'd never heard of unimix either, just c25.

That's what I'll get then.
 
Archdukeferdinand said:
Thanks, that clears it up. I'd never heard of unimix either, just c25.
That's what I'll get then.
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ha, thats funny. I've never heard anyone refer to the mix as c25, only unimix...

if you really want to try to fine tune your welding, you can go to a 93-7. It works good on dirty metals and well with flux core wire. It may work differen with others, but thats what I have used it on in the past. Too much work for me to have 4 or 5 different bottles hanging around and changine them all the time, so I quite using it
 
gas

Most of the bottles that we get at CWIS here in Sanford say unimix on the green label. 75/25 is the only way to go.
 
C25, unimix, or #7 gas. Could be any number of other names, too. There's no industry standard, and it can get quite confusing. You're best to just call is 75% Ar, 25% CO2. The 93-7 or 92-8 is typically used in pulse welding applications, as it keeps the tip cooler. Aluminum wants straight argon, and stainless wants tri-mix, which is a mixture of CO2, Ar, and helium. I've tried unimix and straight argon on stainless, and messing with the mix can seriously affect the appearance of the bead. Either way, you're probably only going to be doing mild steel, so stick with the unimix. If you need some aluminum or stainless welded, I'm sure there's some guys on here willing to help you out.

The next thing I would recommend to make sure your welds are as good as they can be is this...take a class! Go down to the local community college and sign up for their night MIG class. It's the best thing you can do for yourself. Somebody there to teach you proper techniques, and you use up their consumables and steel. It's well worth the money. Good luck!
 
If you're really cheap get a CO2 bottle for your tires and use it for welding but its not use pure I think. I use the CO2 when unimix runs out and its not much different except remember to adjust settings for the CO2 vs. unimix
 
National has almost bought all the medium size businesses out. The cost of gas has risen pretty fast over the last 5 years IMO
 
The next thing I would recommend to make sure your welds are as good as they can be is this...take a class! Go down to the local community college and sign up for their night MIG class. It's the best thing you can do for yourself. Somebody there to teach you proper techniques said:
the single smartest thing anybody I've seen sugest on the subject so far, I'll add take a basic welding course that covers several aspects. You'd be amazed at how TIG becomes second nature after taking Oxy-fuel welding or how SMAW makes all other forms of welding seem inadequate when performed correctly on heavier stock. Besides you'll get to weld cut and build shop projects with materials that would cost ten times what your tuition would amount too, it's like a super low rental on a shop full of tools you'll likely never afford.:huggy:
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Yeah, at Forsyth Tech a MIG class costs $83 for 8 weeks of evening classes, I think Arc was like $63. I'm sure i used more than that in rods alone, with all the ones I firmly stuck to the target work metal...
 
Hmmm Unimix, where I used to buy it was called Stargon!
Sorry got the Co2 and Argon backwards.

And yes, 100% argon for aluminum, but doubt you will have much success pushing aluminum thru your liner. You will need a spool gun or I happen to know a guy who sell a very versatile welder/spool gun that will take care of your aluminum needs, and trail needs.

If that is 4 guage cable you have, it would make an awesome drop cord. On the heavy side, but no success like excess
 
WARRIORWELDING said:
the single smartest thing anybody I've seen sugest on the subject so far, I'll add take a basic welding course that covers several aspects. You'd be amazed at how TIG becomes second nature after taking Oxy-fuel welding or how SMAW makes all other forms of welding seem inadequate when performed correctly on heavier stock. Besides you'll get to weld cut and build shop projects with materials that would cost ten times what your tuition would amount too, it's like a super low rental on a shop full of tools you'll likely never afford.:huggy:
Click to expand...


I wish I could! Caldwell doesn't offer their technical classes at the watauga campus. ASU is kind of a pain, but I think I'll have no choice.

As it is now though, I do have a shopful of tools that I'll someday (hopefully) afford. I'm a mechanic for a ski resort, I've taught myself stick over the past couple of years on our miller AEAD-200LE (gas powered) using various shop manuals and the vise/sawzall/hammer. I've put teeth on a backhoe bucket,fixed tractor steering, made little shop tools and a tow bumper/steering box bracket for my XJ so I hope I'll pick up mig quickly.


I'd really like to get some proper training, but in the meantime I work 3rd shift babysitting compressors & pumps for the snowmaking system. Plenty of time to practice & work on personal projects. I've got the 2x4 steel to replace my rockers, fedex says welder'll be here friday :wheel:

I'm thinking the rockers will be a perfect first mig project, LOTS of weld on 'em and they don't move or see recovery forces. No danger of failure like a cage either.

Thanks for the info everybody, I'm excited to put down the slag hammer!
 
upnover said:
If that is 4 guage cable you have, it would make an awesome drop cord. On the heavy side, but no success like excess
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Is there any worry about voltage drop?

I dug a bit further into the boneyard last night and came up with some 8/4 600V SOOW, I'm gonna use it.

Should I go for mad overkill? I've got a couple spools of 2 guage...
 
Unimix....I've been using National for convenience, but I don't use nearly as much as some of the perfessionals on here.
I made a 50' drop cord out of 4 guage. I needed it so I could unplug the wifes dryer. Now that I have an outlet in the garage, I still use it, just changed the plug. With 2 guage you could go longer, or if you just like the exercise its much heavier.
Yes, you will get some current drop, but so what. Its easliy overcome by that thing called a rheostat on your welder. Once you compensate for that drop your good to go. The current capacity of the conductor is set by IR=V (or I=V/R) so the smaller the wire (larger guage) the more resistance per foot (ohms), voltage is 240. Here is a handy, first one I saw, chart. http://www.powerstream.com/Wire_Size.htm
 
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