View Full Version : airco welder info and question

06-22-2005, 06:38 PM
Picked up an Airco mcm heliwelder 200amp. I paid bit less than a dollar an amp..also got about 300lbs of steel stock thrown in, some rod, etc. I have not done much welding in a few years, mostly just tacking with my lincon 155 mig. Any opinions on machine...was holding off for a tig but older gentleman was moving..and had a bad deal fall through on welder so I bought it for even money to help him out. While waiting for a tig to fall into my lap..this machine i did note has a "high frequency start button" and an area to plug something into..(i know nothing about tig other than avoid letting a body part complete a circuit!) does this make it a tig power supply also? anyway it is a bit of a beast, is on casters, and whole name is "airco mcm heliwelder, mcm-h" anyway any info is appreciated..should be fun


3 Phase Lightbulb
06-22-2005, 09:11 PM
Can you post pictures of the front panel controls, and pictures of the connections?


06-22-2005, 10:31 PM
airco made many a fine welder and some are 20+ years old and working today.

I would like pictures also.

the combine factor I worked at had an old airco tig for welding up stainless bulk tanks for grape havesters, it was a good welder but we also had this crazy biker who was a welding wizzard who welded like a machine did it, every bead was perfect.

some times its the guy running the welder and not so much the welding machine.

anyway airco is a good brand.

06-23-2005, 05:28 AM
will be pickin it up this weekend..will post a pic, thanks for the info...the older gentlemen that i am buying it from also swears by the machine...appreciate info...btw..will try to snap a pic of the harborfreight 200$ liftgate earnin it's keep..lifting into truck


12-02-2005, 06:53 PM
well here is the welder, i know it has been awhile. it has 3 settings, high/med/low controled by putting the plug on the left into one of 3 places, then you dial the amps wanted in one of those settings. the HF control is the dial on right, goes to 100 ?amps, also has a toggle switch for hf start and a 2 prong outlet..for something..dunno torch i guess? or foot switch? dont know a lot about tig...or nothing..the welder welds like a dream, but i dont even know if it ac or dc? doesnt say anywhere..it is a 2mcm-h model..heliwelder 200amp but goes up to 250 amp, 50%duty at 200 amp, 100% at 140 amp or so. appreciate any info you can give

12-02-2005, 07:31 PM
It looks like the 2 prong plug is the hi-freq start. I've used a welder with an add on hi-freq box and it had a switch on the tig torch which was used to start the arc. For the gas you had to turn it off/on at the bottle.

Looks like you did pretty well! I've seen serious bidding wars on just the hi-freq boxes on ebay.

You're just an air cooled torch, a switch, regulator and tank away from having a tig welder.

Gotta love old iron http://bbs.homeshopmachinist.net//biggrin.gif

Does it have any place to hook up gas lines to it?

[This message has been edited by hoffman (edited 12-02-2005).]

12-02-2005, 08:20 PM
Heliarc was used mainly for alum. and is usually AC.The two prong outlet could be for your foot control. If it has HF built in you'll know when you go to strike an arc.

12-02-2005, 08:26 PM
yea figured must be an ac unit...wonder if the dial is 0-100 amps or a percent number? dunno. no connections for gas or water..guess that was the old days...was gonna add a modern hifeq box to machine with water/gas connections. It is a great welder....for arc thusfar..All i remember about arc in my college days...was a lot of shortin out..tho a lot was my technique..this one it is almost too easy to maintain a gap.
thanks for the info..

12-02-2005, 08:40 PM
The 0-100 knob is probably your HF intensity control which adjusts the arc stability. (Lincoln calls it "spark"). It's not related to your amp setting.

You also may have something like a "start" and "continuous" switch which determines if the HF just initiates the arc or stays on while welding.

From the looks of your machine you probably don't have remote current control.

I'm no expert but I went through a similar learning process not too long ago.

12-02-2005, 08:46 PM
Thinking of aluminum welding, have any of you guys ever tried aluminum electrodes for stick welders? I thought i'd try 'em just for kicks and they weld really well on DC reverse polarity. Never had one of the welds x-rayed so i don't really know how good of bead they form metalurigcally speaking, but i did some destructive tests in a press and they all held up. Admitedly, i dont know the proper procedure for destructive testing of an aluminum coupon, so i just did the same as what you'd do for steel, so that could have something to do with it http://bbs.homeshopmachinist.net//smile.gif