I finally got my hands on a 220V stick welder free of charge (yeah I'm a cheapskate). The welder says Airco, has high (to 250) and low(to 150) settings. The high or low settings are selected by plugging the electrode wire into either the high or low port. It has a hand crank of the top to adjust the Amperage. The unit ID plate is scratched and I can't read the model number.
The question I have is why does it have two settings high/low?
Could one be DC and the other AC?
Another buddie also gave me some 7010 A1 rods. It appears that these rods are for DC use.
Hence the question.

The way I see it is your highest high setting is 250 and your highest low setting is 150 ,and 150 is still high for some thin metal welding. Hopefully you can crank it lower to about 50 on the low setting. This is just a guess without seeing the machine.

high will be from 150 to 250, low will be from probably about 50 to 150. most of your stick welding will be done in the 110 to 120 range unless you are welding plate over 1/4". This seems like a very old machine, and is probably a dc only unit. These are easy to use. just do some practice runs . keep a short arc and don't travel too fast. 7010 may be a bit hard to use for a first timmer, since the flux is heavy, and can roll in front of the molten puddle, and cause flux entrapment in the weld bead. I would start with a 6010 or 6013. the weld bead is not as smooth as that from the 70 series rod, but they are good to learn with, strenght 60 thousand lbs /squ " vs 70,000. Tom

You are plugging into a different tap on the transformer, some did it with the plugs some with switches, there were a lot of those airco welders made, I still see a lot of them around.

Thanks for the reply's guys.
Just ran out and looked at it again. The high scale goes from 50-250 and the low from 40-125. It's definately an old one, it's about 2'wide x 16" deep x 3' tall and weighs alot more than it appears it should.
What's the difference in a DC vs AC as far as electode selection/limitation is concerned?

I'm pretty sure those old aircos were ac only, if it is ac you can get a tig setup and tig weld with it also.

How do I find out if it is AC or DC?

I would expect it to have seperate AC and DC output connectors if you had a choice, without these it could be either AC or DC. Open up the case and look for 4 power diodes mounted on some type of a big heat sink, they will look sort of like 3/4 inch bolts and have heavy wires connected to them, these convert AC to DC, if not there then you have an AC welder.

If you have an adjustable current setting on the top of the unit you may also have a plunger knob there too, if so, you pull the plunger up to allow you to move the amps setting knob, you then need to push the plunger full down to clamp the internal sliding contact firmly in place, not clamping it will cause arcing at the slider, this will likely burn up the transformer's slider windings in the first couple seconds of use.

Thanks for all the good input guys. I'll see if I can take some pics tomorrow. I'm kind of baffled as to why there are high and low settings and seperate plugins if the high one covers the same range as the low setting. Any thoughts?

i could be way off the mark being from downunder but here goes .
to weld with tig it will need to be dc output with the hand peice gauge bottle argon it will only do ferrous metals with reverse polarity to do non ferrous it will need to be ac with high freqency doubt that oldie would have it.I reckon straight forward transformer ac welder if it is dc it would most likely be constant current in which case opens up a whole range of options air arc, tig mmaw. You will know when you strike an arc ac will sound crackly harsher and will require more amps for same size rod dc will be smoother arc like a hiss no crackle will require lees amps same rod size. Oh those rods will fizz and crackle they are cellulose root run electrodes get youself some gp 12 or 13 they will be easier to use cheers andy

This is a pic of the same welder I found on a different site.

It appears it was made by Miller for Airco long. long ago. That's as far as I've gotten. Anyone?

Heres a larger pic.
Thanks.

DoubleD
-your welder has only 3 plug ins for the cable so it is an AC machine. one is common one is high, one is low. Be sure when you purchase rods, that they are for an ac machine. although all electrodes will work, some dc electrodes will be sticky and hard to strike an arc. Tom

Thanks Tom,
That's what I was wondering. I guess now I need to dig a trench to put a panel in the shed to power this baby. Great, more work. I have a good feeling about this one though from what I've been reading these oldies seem to be pretty simple and long lasting.

Tim,
I don't see any kind of heat sink inside. Just 2 coils of wire, a smaller one centered above a larger one, two heavy cables going from the center coil to the switch, and what may be a big magnet(?) going up and over the coils of wire. Sound correct?

I have not seen one of these welders myself but it sounds like a simple AC transformer type welder, the second smaller coil may be what is called a stabilizer coil, these are simply heavy wire wound around an iron core to create an electromagnet. The stabilizer coil helps make the arc run smoother, it compensates the current a bit as you make the arc shorter or longer when running the weld bead.

I found THIS short discussion, sounds like the same welder, not a lot of info but it sounds like it is a good basic AC buzzbox welder.

That looks similar to my AC buzz box welder. I also have the high and low taps.

quote:

I don't see any kind of heat sink inside. Just 2 coils of wire, a smaller one centered above a larger one, two heavy cables going from the center coil to the switch, and what may be a big magnet(?) going up and over the coils of wire. Sound correct?

The smaller coil is likely moved in and out of the larger coil by your current adjustment knob. The deeper the smaller coil goes into the larger coil the greater the current thats available. This can also be achieved by a shield that can be lowered around the inner coil.
Mine seems to work great but I have nothing to compare it too

quote:

I guess now I need to dig a trench to put a panel in the shed to power this baby.

Its amazing how much money I guy can save making his own fuel eh? LOL
cheers,
Jon

Thanks for all the help on this one guys,

I sent an email to the tech dept. at a company called arc products (http://www.arc-products.com/) and after some back and forth emailing, they were able to I.D. the welder and can even provide an owners manual.
They have been a great resource.


It is a Model M C M 1353
230V
A.C. only
transformer arc welder.

Nice score!
Jon