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View Full Version : OT: airco 300 Heliwelder



zukIzzy
12-12-2007, 11:22 AM
I picked up one of these welders for a price I could not pass up yesterday. I played around a bit last night but had trouble striking a consitent arc. Anybody familiar with it or have an owners manual I could beg, borrow, buy?

Thanks
Wayne

Optics Curmudgeon
12-12-2007, 11:45 AM
Don't know about that one specifically, but when I worked for Airco back in the late '70s their welders were made by Miller and painted orange with the Airco logo.

Joe

Ries
12-12-2007, 12:18 PM
Many Airco welders are complete orphans, with no parts, service, or info available. Thats why they are so cheap.

Hopefully, Macona, who is a welder service tech, will chime in here- but first, in what mode were you trying to weld?
Stick or Tig?
AC or DC?
HF on, off,or start?
Polarity?

Many of these older tig welders have a spark gap on the HF, that needs to be gapped like an old spark plug. Thats one of the first things I would check.

lazlo
12-12-2007, 12:19 PM
Wayne, I don't know the Airco brand, but assuming you're welding steel on DC EN, do you have the high-frequency set for arc start, and not continuous?

lazlo
12-12-2007, 12:22 PM
Ries, the Heliwelder is an old AC/DC TIG unit.

zukIzzy
12-12-2007, 05:16 PM
Many Airco welders are complete orphans, with no parts, service, or info available. Thats why they are so cheap.

Hopefully, Macona, who is a welder service tech, will chime in here- but first, in what mode were you trying to weld?
Stick or Tig?
AC or DC?
HF on, off,or start?
Polarity?

Many of these older tig welders have a spark gap on the HF, that needs to be gapped like an old spark plug. Thats one of the first things I would check.


I tried all of the above and with different results. I did not know what to set the air gaps to so I did not touch it but one was really small almost touching. Do you know the gap specs?

Wayne

zukIzzy
12-12-2007, 05:25 PM
Wayne, I don't know the Airco brand, but assuming you're welding steel on DC EN, do you have the high-frequency set for arc start, and not continuous?

I tried both but on DC it worked best with the HF start in the off position. It would not strike an arc with a stick electrode unless the pre and post flow were off and the controls were on Local. which make sence.

I did not have a water cooled tig torch on hand but with an air cooled one Jimmied on there it had a weird wandering arc and worked best in DC with the HF in the off position and AC with it in the start position. Remote pedal seemed to work fine in TIG.

We are talking about 15 minutes tops of playing so I may get some more info tonight.

It cost an hour and 3 gallons @ $3.30 per gallon so even if it is a bust I am not too unhappy. I found Arc products in San Diego who carries parts and has a manual they will sell me.

I will updates as things happen.

Wayne

Renegade
12-12-2007, 05:32 PM
Gap for the HF is .008 on the older Millers.

macona
12-12-2007, 06:03 PM
The Heliwelders were actually made by airco in conjunction with Esab. Pretty simple machine. Probably about .008 to .010 for the gap.

Not a whole lot to go wrong with them.

Wandering arc is caused by wrong tungsten size for the current range you are running. Usually too big.

lazlo
12-12-2007, 06:59 PM
it had a weird wandering arc and worked best in DC with the HF in the off position and AC with it in the start position.

Are you sure the gas solenoid is working (the argon was coming out)?

zukIzzy
12-12-2007, 07:00 PM
The Heliwelders were actually made by airco in conjunction with Esab. Pretty simple machine. Probably about .008 to .010 for the gap.

Not a whole lot to go wrong with them.

Wandering arc is caused by wrong tungsten size for the current range you are running. Usually too big.


Thank you

Anything else I should check?

Thanks
Wayne

rollin45
12-12-2007, 08:29 PM
A wandering arc can also be caused by grinding the tungsten point radially rather than longitudinally. Been there and wondered about the wandering myself.

rollin'

The easiest way to grind the points is to use a drill motor, insert the tungsten and keep the thing turning as you grind.

JoeFin
12-12-2007, 09:38 PM
Best to take a look inside the machine.

I have an old Airco Heliwelder 500 amp. When I pulled off the side panel every thing said "Miller" on it. Harris Gases here in Sacramento has an older service tech that knows these machines.

macona
12-13-2007, 02:08 AM
If he didn't have gas he wouldn't have a tungsten more than a few seconds.

Cant think of anything to check. Times like this is best to take the machine down to a weld shop and have them load test it. It difficult to work on a machine without putting it on a stable load.

zukIzzy
12-13-2007, 12:49 PM
Update, after a couple hours last night I decided to take it to Arc Products in San Diego. They are a service provider for Airco machines. It would pop the 50 amp breaker just to turn it on last night until I disconected all the leads and remote.Once I got it turned on it would not strike any arc except for in TIG mode with the HF on all the time and that arc was so weak it would not melt metal. Seems like a transformer problem or a power delivery thing. I checked all I could with a multi meter but my expertise ended when the last cover screw was removed.

Thanks for the help
Wayne