Gasless MIG

[mylesdw]

Has anyone experience with gasless MIG welders. More specifically, can you use the special shielded wire in ANY mig welder?

I have a small MIG kicking about at home and would very much like to use it from time to time without the continual expense of renting bottles, or buying the very expensive disposable bottles.

[Tim Brewer]

You can use shielded wire in any mig machine, but you must reverse the polarity first. The polarity works opposite than when using gas. But in my experience, the welds are always better when using gas. But when welding outside, shielded gassless wire seems to work best because if there is any wind at all, it will dissapate your argon and give you a bad weld. Not an expert or anything, but hope this help a bit.
Tim

[mylesdw]

Hey thats great info Tim, do you need to have it switchable then? Ie one polarity for gas and one without? How do the 'proper' gasless machines do it?

[grumpy]

mylesdw,
With flux core you will only get a slight bit more spatter than with gas, but with a 4" heavy wire brush on a 4 1/4" small grinder the majority of spatter can be knocked off easily.
Will require a very good ground preferably at the plug point if you are distance of 50' plus from your entrance ground. If the issue of pulsing or sticking like an old stick machine comes up it's your ground causing it, THE MOST COMMON problem of MIG units.
Also buy the wire cleaning/lubricating adapter that attaches before the feed head to make your feed smoother.
Tip Dip will be needed and extra tips will also be used great due to the additional spatter
grumpy

[cobrashoch]

Flux core wire welds will also rust out faster and are weaker than gas welds, or so I've heard. Not to say that a flux core weld is totally bad though. Most of the high end body restore shops and rod shops I've dealt with will talk bad about a flux core wire weld. Sometimes I think some of those attitudes are total crap though, as they are trying to just justify the equipment/methods that they just happen to use. A flux core weld is easier to use and easier to learn when you are just starting out. Not that mig welding is all that hard in the first place.
cobrashock

[mylesdw]

I don't think there is too much doubt that mig is better than gasless and for any major project I would get a bottle of gas in but for just occasional use I wondered about using the flux cored wire. I'm sure one of the reasons the body shops don't use it is because the wire is about three time the price.

I suppose the question is, how does a gasless mig compare with a traditional stick welder?

[Tim Brewer]

Myles, sorry so long to get back to you, I've been out of town. All gas mig machines are switchable. Usually there are directions under the lid telling you how to reverse it. I've never heard of a gassless only mig machine, but I guess there could be. A stick welding machine can do as good a job, but is more difficult to do for most people. Hope this helps,( kinda cool talking to you from New Zealand, some day when i've saved up a whole bunch of cash, i'd love to vacation there someday)
Tim

[mylesdw]

Tim: I'll take a look inside to see if has stuff about reversing the polarity. Do you know why, techinically, the reversal is needed? Another alternative that has been suggested is to use carbon dioxide for general purpose steel welding, I will have to investigate whether I can buy a small bottle rather than renting.

Perhaps we will see you down here in the south pacific sometime, I guess it is the travel that works out dear, for most visitors the exchange rate makes things seem pretty cheap one they arrive.

[Tim Brewer]

Myles, I'm not really sure why reversing is necessery, just know it has to be. The welding just won't work when the polarity is wrong. The gas I use is 75% argon and 25% carbon dioxide. The welding supply shop will sell you what works best for your needs.
Tim