Mig welders - gasless or CO2 ?
Answers:
Gasless mig? No such thing. Mig as a rule uses an inert gas cloud to protect the forming weld from oxidation cause by oxygen in the air.
The welders that use wire feed without gas are flux core welders. They have a flux that 'floats' to the outside of the weld when melted, again protecting the forming bead from oxidation.
If you're doing any welding that requires penetration a stick welder is the way to go. Mig isnt as strong without many passes and with flux core you have to chip flux off before making another pass. With light sheet metal in body work a cheap flux core welder will work just fine. My craftsman unit will go through up to 1/4 inch steel with good strong welds in one pass. The other trade off is the wire is a little more expensive, but its still cheaper than leasing a C02 + Argon tank. Nothing wrong with the flux core setup.
It also managed to help me make this happen:
http://www.cardomain.com/ride/2049971/3.
I prefer a conventional with the gas. It is a cleaner weld when done, and is easier to work with, I would say to get a Lincoln 135-T, this is the 110 volt welder. I bought the 135-Plus on the net for 489, and I think the 135-T was like 419. Shop around and you can find good deals. They arent the cheapest, but you get what you pay for also.
I bought one to do body work and it worked quite well. You don't have to get a bottle of gas or a contract for the gas and you dont have to worry about the strength,it's just as strong. There's a bit of slag on the weld but it comes off very easily with a brush. I have used it to build a steel work bench, repair my boat trailer and repair some steel chairs for a service club and made a few bucks at it. I found it works better with .035 tips rather then the .040 that came with it. I'm happy with mine.
If you know what you're doing flux-core is as good as bottle gas welding. My personal preference is spend the money and get bottle. If you aren't welding a bunch, you can get a smaller bottle fairly cheap. If money is an issue, use flux-core wire until you can step-up. For bodywork, there should not be any problems with weld strength. The only negative with flux-core is a lack of visibility and a little extra clean up - not a real big deal.
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