MIG welding - gas or flux core?

I'm new to welding and have recieved alot of helpfull advice from you guys. I got my welder yesterday. It is a Hobart 140 Mig welder. It can be used with gas or without, using flux core wire. A guy around the corner from me swears you don't need gas for sheetmetal work on the body. A local welding shop guy told me the gas keeps the welds cool enough to prevent warping thin sheet metal, like metal on a car body. First of all how do you know the guage of your car or trucks sheet metal? Is there a tool or guage for this? Second of all when filling little pin holes from small rusted areas is it necessary for the gas setup? I know from past postings that gas is needed for cleaner weld and less spatter, but the heat thing is new to me. My welder's spec sheet say flux core is ok for certain guages of metal, so I'm putting it out there to the welders amongst us, what do you guys think? Steve.:HMMM:

Yes it is highly recommended to use gas on thin metal, but you will still need to be carefull! they do sell guages for sheetmetal, but i have no idea where. most newer car bodies use 22-24 guage, most older cars are 18-20 guage. That mig should do great on sheetmetal! just use the .025 wire and it will work better for you.

Thanks! What are your thoughts about using 75% Argon/25%co2?:D

GAS!!! (purple..........just like Pop's '27 T) :LOL:

"Stargon" aka 75/25 works just fine for steel. You want straight argon for aluminum.

Stargon for steel, argon for aluminum. Just like Uncle Bob sez..... I don't like the flux stuff at all, for me it just never would put down a consistent bead and is a booger to due sheet metal with..... But hey, I'm half blind and weld by Braille!!!!

Im with dave on the flux, its just plain horrible! Straight argon will make for bad steel welds!

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Originally Posted by hotroddaddy

Im with dave on the flux, its just plain horrible! Straight argon will make for bad steel welds!

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Phew!!! Thought it was just me!!!!!!:LOL: :LOL: :LOL:

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Originally Posted by Dave Severson

Stargon for steel, argon for aluminum. Just like Uncle Bob sez..... I don't like the flux stuff at all, for me it just never would put down a consistent bead and is a booger to due sheet metal with..... But hey, I'm half blind and weld by Braille!!!!

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the flux stuff to me is just a spool of arc rod so you just buy a buzz box and some sticks :3dSMILE: mig is cleaner job with 75/25 gas and there a 3 mix gas and strait co2 but i have not ever seen a need for it the strait co2 is messy there is not to many times you would use argon gas for steel less you are useing a tig or welding alum. i had to do a small bit of welding with the mig ran out of mix gas hook up a argon bottle it welds very hot with a mig not some thing you want to use:3dSMILE:

Thats pretty much the scoop I'm getting. I think the neighbor doesn't weld too much and maybe is just a little shy about it. But come to think of it, he was welding his frame when I was talking to him, not the body, but he did say he redid the window frame that way. Anyway, with my entry level skill, gas combo sounds the way to go! Whats more money for a gas cylinder anyway at this point, my engine money is dwiddling!:3dSMILE: :CRY: :eek:

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Originally Posted by Bob Parmenter

GAS!!! (purple..........just like Pop's '27 T) :LOL:

"Stargon" aka 75/25 works just fine for steel. You want straight argon for aluminum.

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Wow Bob, love that shade of Purple. I may have to paint my next car that color. :p :LOL:

Oh, yep, use gas, you will be way ahead in all respects.:)


Don

My local welding shop rents tanks for 6 bucks a month+ gas refills. Its a good way to go if you do not have the upfront cash to buy a bottle and gas. Once i had the cash i bought the tanks, i think it was 140 a tank filled, not a bad price! but you are in the land of spending, so your price might be higher.

You know that might be just the ticket for now. Rent gas for the body jobs, save money for engine, and get a tank down the line when it is more affordable!

.....this is the sheet metal gauge that you were referring to. Most welding supply stores have them..... Bill

Gas is the way to go by far,but also remember that if you are welding outside a lot gas won't cut in any type of breeze.

Thanks Bill. I think I may have seen one of those in an add, and thought it was a saw blade!
Thanks Blow by. We live in a breezy area. Fortunately it's calm in the a.m. and then windy in the afternoon. Although the wind chimes are ringing right now. I guess I'll have to weld in the garage. Any dangers to breathing Argon/co2? Would the shop doors being open be good enough or do I need to take additional precautions!:eek:

.....LOL, a saw blade!!! ;) good one.... ;)

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Originally Posted by stovens

Thanks Bill. I think I may have seen one of those in an add, and thought it was a saw blade!
Thanks Blow by. We live in a breezy area. Fortunately it's calm in the a.m. and then windy in the afternoon. Although the wind chimes are ringing right now. I guess I'll have to weld in the garage. Any dangers to breathing Argon/co2? Would the shop doors being open be good enough or do I need to take additional precautions!:eek:

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you should be fine in a shop with the doors open, just dont huff it out of the bottle! im not sure about co2, but argon displaces oxygen, and it can build up in your lungs. if you get the feeling like your lungs are getting kinda heavy, then stand up and bend over to get the excess argon out, kinda breath out real hard to push it out of your lungs. This is what they told us in welding school. i wear a special welding resperator when i am welding, it helps with the burning metal fumes too!

Thanks Hotroddaddy! One great thing about this place is all the help for people like me, new to welding, etc.
It's funny, because a few months ago I was fretting about how to get the truck to an exhaust place, running it with straight headers, and not getting a noise ticket! Now I can do it myself, and with the savings, put it right back into the engine! Some bodytold me, once you get one you'll find all sorts of things to use it on. Now I see why!:D

You can use a 2 % oxygen 98 % argon for a spray arc. Works great on steel as the spatter is almost nonexistant. It's a very quiet arc when done correctly. We use it at work all the time on up to 1 inch thick. Also lots of heavy TIG wielding 200-300 amps.