# shopping for MIG welder



## dtbaker (Jan 5, 2008)

slightly off direct build topics, but I trust you guys... I am shopping for a 'real' welder as I have been getting by for years with a crummy 120v stick welder. I'd really like to be able to weld thin and weld aluminum.

I found a local millermatic 250x MIG on craigslist for $1000, and wonder if this is a good deal, or not. I looked at Miller and current model is the '252' which retails for like $2600. I don't know why this old one is for sale, or how to check to make sure it is working correctly....

Are there things I can check to make sure that it is ok? voltage? wire feed rates? Do these things wear out?


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## etischer (Jun 16, 2008)

The hardest thing about doing aluminum with a mig is getting the wire to feed without jamming. If you plan to do aluminum, Id buy one of the newer welders that has the small wire spool in the gun instead of pushing the wire though the long hose. I spend 10 minutes clearing a jam to get 20 seconds of uninterupted welding, even with a new liner in the hose, and keeping the hose perfectly straight. 

I bought a lincon from home depot and have been using it for about 7 years. Im into it for about $700. For steel I use flux core, seems to give better penetration. 



dtbaker said:


> slightly off direct build topics, but I trust you guys... I am shopping for a 'real' welder as I have been getting by for years with a crummy 120v stick welder. I'd really like to be able to weld thin and weld aluminum.
> 
> I found a local millermatic 250x MIG on craigslist for $1000, and wonder if this is a good deal, or not. I looked at Miller and current model is the '252' which retails for like $2600. I don't know why this old one is for sale, or how to check to make sure it is working correctly....
> 
> Are there things I can check to make sure that it is ok? voltage? wire feed rates? Do these things wear out?


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## Woodsmith (Jun 5, 2008)

I have heard flux core gives of poisonous gasses.

I have also had recommendation that it is better to buy an old industrial mig rather then the same money on a new one. They are much more robust and have better wire control which reduces jamming. Best thing to do is to try it and see if it does everything and everythign on it is working.

Etischer is right about the aluminium wire, a spool on the gun is best.


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## azdeltawye (Dec 30, 2008)

I picked up a Millermatic 251 off eBay several years ago which I am very happy with. Welding 20 gauge body panels are a breeze as long as you use the thin wire (0.023"). I use 0.035" solid wire for everything else including 1/2" plate. Haven't tried aluminum yet, still need to get the spool-gun attachment for that.

I haven't touched the stick welder since I bought the MIG...


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## Thaniel (May 25, 2008)

dtbaker said:


> slightly off direct build topics, but I trust you guys... I am shopping for a 'real' welder as I have been getting by for years with a crummy 120v stick welder. I'd really like to be able to weld thin and weld aluminum.
> 
> I found a local millermatic 250x MIG on craigslist for $1000, and wonder if this is a good deal, or not. I looked at Miller and current model is the '252' which retails for like $2600. I don't know why this old one is for sale, or how to check to make sure it is working correctly....
> 
> Are there things I can check to make sure that it is ok? voltage? wire feed rates? Do these things wear out?


Didn't mention thickness? or rather How thick? Thicker material requires a welder with more umph. Thin stuff seems to require low heat settings. The right welder depends on what you plan to do with it.

I have a Lincoln Pro core 100. Not expecially fancy or expensive. Does what I need but I do not weld things that are very thick.

Things that could wear out are the feed rollers (and motors) and gas solenoids and valves. i wouldn't expect the electrical parts to wear out but who knows.

Thaniel


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## evlowrider (Jul 23, 2009)

etischer said:


> The hardest thing about doing aluminum with a mig is getting the wire to feed without jamming. If you plan to do aluminum, Id buy one of the newer welders that has the small wire spool in the gun instead of pushing the wire though the long hose. I spend 10 minutes clearing a jam to get 20 seconds of uninterupted welding, even with a new liner in the hose, and keeping the hose perfectly straight.


Thats one of the reasons why I chose to get a TIG welder. Don't have to worry about the wire feed. I'm a complete noobie when it comes to welding but that what I chose, cost me $1500NZD which would be about 1000-1200 USD i guess, it was 2nd hand but in very good condition with a auto-darkening helmet (must have imo). Also has arc and plasma cutting function built in.

My requirement for the welder was to be able to weld aluminium for my battery trays.


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## dataman19 (Oct 7, 2009)

Whoa here - did I miss something?
..
Is not the purpose of Mig and TIG the shielding gas? Wire feed aside (which I find both a necessity and sometimes total curse). The main purpose of MIG or TIG is to get the oxygen shielding effects of the gas to keep the welds from getting too brittle.
..
Yes - when doing aluminum, you always want a wire spool fed from the gun and not down that snake hole tube in the feed line from the welder. Aluminum rod is always too soft and mallable to push that far and everyone knows it. Unless you have a really bid TIG welder with a 4" dia feed tube and feeding 3" DIA wire to weld 6" thick aluminum plate. Then maybe I would suggest you go with the longer feed line (and a 6000 lb gorilla to help you hold it!!).
..
Seriously, I agree use a gun mouted spool and feed assembly to do aluminum. But the whole point of MIG and TIG over a stick welder is the arc shielding gas.
..
Or am I too retro here?
..
Dataman19


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## Voltswagen (Nov 13, 2008)

I have a German Einhell MIG that has performed faithfully for over 20 years. It's a small 130 amp machine and I have welded up to 1/4 inch (4 gauge) steel with it. I only use shielded gas (Argone & CO2) I don't really care for Flux Core Wire. Smokes a lot, stinks and blocks your view of the piece.

Don't go by amp rating alone tho. I've seen 100 amp machines that perform just fine on metals up to 1/4 inch. A lot has to do with the operator. And for the majority of automotive welding a 250 amp machine is over kill not to mention expensive. How often are you going to weld 1/2 inch steel?

Most good machines have an internal - "thermal trip" circuit. If I were buying a used machine.......I would set it on HIGH-MAX, draw a long continous bead on a piece of angle iron and see if it would "trip" prematurely. You should be able to weld for 30 seconds or more without "tripping" it. You don't want to have to stop every 15 seconds and wait for it to cool down.

BTW.....I live in awe of those of you who have mastered TIG. I have a little 90 amp stick/TIG machine. I just can't get a decent weld with it.

Roy


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## dtbaker (Jan 5, 2008)

I am thinking the Millermatic 250 is overkill.... I mostly want the MIG to do thin stuff, not industrial; mostly 1/8" angle with the occasional sheet metal for body work and such.


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## david85 (Nov 12, 2007)

Ideally, for aluminum mig wielders you want to use a "push-pull" setup that has a large spool in the machine and a puller motor in the gun. That system is the most reliable for aluminum wire feed.

Our old Hobart AC/DC wielder has a steel main spool in the box, and a 1 pound spool gun for aluminum. (AC for aluminum, DC for steel)

A little tip to prevent jambing with a pound gun is to use an oversize contacter tip. Longer wields puts a lot of heat right where the wire comes out and that gets the tip and the aluminum sticky. Aluminum is normally a sticky metal but when you heat it up it gets really bad.

Shielding gas is also different when it comes to aluminum mig verses steel mig. Mig and tig BOTH require shielding gas, or the material would simply burn. You would be lucky to even get a bead down let alone worry about embrittlement.


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