Taming the Helwelder Beast

[shenion]

Ok, here is my vintage beast: http://shdesigns.org/Welding/airco.html

This is one of the 3 welders I got in my Ebay steal as mentioned in the "I wish I had 3 phase" thread. It is old and very low tech. So it should be easy to fix. Nothing burned inside. I have already replaced some leaking caps. Only other part likely to fail is a selenium rectifier. That can easily be replaced with modern diodes. Both fuses for the control circuits are still good, so looks like no shorted caps.

I will use this thread as I try to learn TIG welding and see if it still works. I think I have most of this beast figured out. There are a few switches I'm not sure about:

1. Start circuit in/out. The is already a HF start with start/off/continuous positions. I think the start circuit waits for a load then turns on the main contactor.

2. Metallic knife switch. I think this grounds the work side to the case for safety, open position is marked TIG.

3. Start adjustment: May be related to stick welding. I think it sets the initial current.

Came with a MIG wire feeder (feed motor is must weigh 5 pounds), a massive air-cooled stick electrode and a trashed spool gun. No TIG torch, hoses or gas/electrode plate.

I have a Weldcraft WP17 150A air-cooled torch with 25' lead on order. Should be fine for my uses, I did not want to mess with the water cooler. I need a 25' work lead and ground clamp. With the price of copper these days, it will probably be my biggest expense

I'll post pics as I get going. I think I can handle TIG as I have done some mild gas welding. But I bet I'll be baffled at some point.

This thing scares me. That 460A number on the dial is daunting. Amazingly, it goes down to 5 amps.

 

[MigTig]

Hmmm you wont be able to use 460A for Tig welding

I use 35a tops for sheet metal sometimes, and I only ever once tried it on 70a on a peice of steel, needles to say it makes a big molten mess. Mig for the big stuff, Arc for the biggest (untill I get that Portamig)

Looks like a good machine, you should consider sending it off for a full service prior to use, just so nothing blows..

 

[shenion]

This thing is 34 years old. Only company that services these things is 1900 miles away. It would probably cost me a grand in shipping.

I sent arc-products an email. They have no source for the leaky caps. I replaced them with a modern equivalent. They did send me an exploded view and parts list with an almost unreadable schematic.

I am an EE and spent years doing repair to pay for school. Nothing complicated here. Hard part will be finding parts. But I know how to substitute as needed. None of the fuses were blown and no visible burned parts. I should be able to get it going.

Yeah, I think I will hardly get close to the 150A limit on the torch I ordered. Will take a bit more on Al welding, but even then I will be doing small stuff.

I bet at the top setting it becomes more of a plasma cutter than a TIG welder.

 

[Drains]

Hmmm you wont be able to use 460A for Tig welding

I Don't think 460A would be a problem Migtig. Bear in mind a standard BOC transtig set is 375A. (with a watercooled torch obviously, which Shen doesn't have, so moot)

Have a play with this Tig Calculator

 

[shenion]

Si, thanks, the calculator is interesting. Shows I can do up to 3/16 with the 150A torch. Real nice how it gives the shroud and tungsten size.

I will be reading the TIG handbook and some of their other info while waiting for my torch to arrive.

 

[shenion]

The Beast Lives!

Looked it over all though. Nothing burned, no leaky caps. Checked diodes, ok.

Wired it up, flipped switch and nothing. No hum, no fan silence. Took a while but found there is a fuse in a dark corner of the beast. It was missing. Another one of those 6A, 600V 5" fuses they are impossible to find.

Hmm, why was it removed? The miller has the same fuse and it was blown. So, the Miller blew fuse and maybe they stole one from the Airco?

Still, did not want to risk things. I disconnected the main, wired in a temp fuse and hooked only the control transformer to an ammeter and my variac (this is what the missing fuse was for.). Slowly brought up voltage, current was about an amp at 80V, fan started turning and the gas and water solenoids buzzed. Good sign. Measured AC and DC voltages and looks like the old selenium rectifiers work.

So left fuse in (will still need to be replaced, but it meets the 220V specs.) Connected back to main. Flipped switch and it came alive. Fan will keep me real cool

Ok test 1: Set to A/C mode (eliminates shorted diode problems). Connect a stick electrode. I have never done stick BTW (well, played with a free 100A piece of crap once.) Check everything, set it to about 60A. Put in 3/32 6011 rod. Strike arc and rod sticks. Crank current up to about 100A and BZZZZZ bright stable ark Laid a long bead on 3/16 steel.

On to test 2: Set to DC Normal. Try to weld and get nothing but spatter. Hmm, wonder if "normal" means tig. Set to DC reversed, and BZZZ; cool beautiful arc and I instantly have good feel of arc welding. Weld pool very fluid and easy to control. Unit seemed to not even notice the current.

Flipped over and had more than 100% penetration on the DC reversed. AC bead showed HAZ on back, probably close.

Ok, main transformer, contactor, current control and rectifiers work. Next test will be seeing if it it will run the MIG feeder. I have no docs on how to have the feeder control the contactor. It was rewired to be used on the Miller. Sounds like I'll need to spend a bit of time with an ohmmeter and trace the wires.

One last thing. I reached up and flipped the HF start to continuous. The two spark gaps lit up bright blue with a ominous buzz. My caps work. Had sudden thought of Frankenstein movie, arcs buzzing all around and the Dr screaming "He's alive!"

Will have TIG torch next week. Will need to figure out gas plumbing. Probably spend a bunch at the hardware store on fittings and adapters.

Sooo close. I'm stoked.

 

[Drains]

Put in 3/32 6011 rod. Strike arc and rod sticks. Crank current up to about 100A and BZZZZZ bright stable ark Laid a long bead on 3/16 steel.

On to test 2: Set to DC Normal. Try to weld and get nothing but spatter.

Looking good Shenion.

The problems above probably relate more to the 6011 rod than anything else. It's probably ac, and dc something specific, hence it worked on ac and one dc setting.

Is "normal" electrode positive or electrode negative? If it were applied to tig welding it'd be -ve:- in US terms, "straight" polarity.

"reverse polarity" is elec +ve

6011's are not a readily available electrode here, except from specialist welding suppliers. Every corner shop seems to sell 6013's.

 

[snowcat]

Hmmm you wont be able to use 460A for Tig welding

Iv got 500 good english amps on the kemppi, some of the big ally requires the initial push to get it going, mind, just had to replace me big torch, £250 ouch.

 

[MigTig]

Well, my little Parweld Flexi torch certainly wont go to that kind of amperage

Onedayyyyy I shal get a workshop Tig set

 

[shenion]

Si,

The 6011 are basically the same as the 6013's. The 13's add all-position welding. These were cheap Chinese rods (heck, I bought them for the $0.99 welder.) I did not expect much.

Snowcat:

Ouch Yes, that is why I went with a 150A torch. Torch + collets, caps and a few tungstens: $140. If I do Al welding, will probably push limit on initial start, but well below on rest. My plans for Al is very small stuff (small engine repair.)

I figure the 150 will be small, light with just the gas and switch connectors. Don't want to always use a big water-cooled torch.

MigTig:

Don't know if I want a big TIG setup. I have a heavy-duty wire feed to do MIG (can take up to 1.6mm wire.)

This Airco should be nice. Has MIG, TIG and stick.

I do need a 40' 0-gauge ground lead. With the price of copper these days, THAT will probably be my biggest expense

 

[shenion]

Test 3: MIG

Here's the wire feed unit that came with it (was hooked to Miller.) Half the cover is missing, the whole right side of the front panel is busted off. Amazingly, this thing feeds great. Has 0.035 and 0.045 grooves in the roller. Has a Tweco #4 gun and a quick disconnect. That feed motor is bigger than many of my power tools have.

Hooked it up. I still need to get better connectors. Fired it up and it works. I did something I never did before. I blew holes in 3/16 (4.75mm) steel! I never did try 0.035 wire on the Clarke, would have probably come close. It works well even though the Airco is not a CV power source. It looks like it it comes close enough.

The wire feed has a 25' cord and the gun is 15'. Probably will put wire feed on cart so I can reach all the way out to in front of the garage.

Will probably make new front panel and cover for the feeder. I would like an 0.030 feed roller, no idea where to get one, may need to have one machined (have buddy that can do it.)

Now the agonizing wait for the TIG torch..................

 

[mishka]

The 6011 are basically the same as the 6013's. The 13's add all-position welding.

Erm, they are both all position (form xx1x), the differences being:

6011 = cellulosic flux, deep penetration, difficult slag removal, poor finish;
6013 = rutile flux, shallow penetration, easy slag removal, excellent finish.

So I would say quite different.

Here in the UK 6013s, being very easy to use, are everywhere, and produce nice looking welds, i.e. suitable for the average hobby welder. 6011s and 70xx you really need to go to a specialist welding supplier.

 

[shenion]

Ok, did not remember right.

Will definitely get some 6013 next time. Also the 6011's are AC or DC- and not for DC+. Explains my results.

 

[malcolm]

The Airco looks a lot like my 1979 Miller. Everything really big and heavy. Doesn't the idea of generating high frequency using a spark gap seem pragmatic. Sure it wouldn't be allowed these days.

Are you planning to use the machine for MIG with that wire feed? It'd be interesting to learn what difference the constant volts (MIG?) vs constant amps suppy (TIG, arc?) makes in real life.

 

[shenion]

The Miller Syncrowave TIGs have spark gaps. When looking for the HV caps (no longer made) and trying to figure out the spark gap, I found lots of other machines use gaps.

Yeah, probably kills AM radios for a block

The MIG works, I do plan on using it. Just received the TIG torch. Just need to do a bunch of plumbing.

The Airco uses a saturating inductor to adjust current. A true CC uses a variable inductance. The saturating inductor is used as a voltage drop (saturating current controlled by BIG rheostat ). So it is somewhere between CC and CV.

The MIG works well. I just laid some of the best welds ever using it. I also blew holes in 5mm steel. It has a hard time starting, wire hits and takes a full second before it starts arcing. Then works well. It just hit me that I might try turning on the HF start when using MIG. Would start the arc sooner.

There is a "start adjust" dial that I'm not sure about. Played with it and no real change, may need fixing. Also a start on/bypass switch.

If I crank up the current so it starts easily, then I have to move real fast or it blows holes. Should be easier with 0.030 wire instead of 0.035.

 

[malcolm]

I wonder if your start adjust alters the frequency of the HF. I have a knob on the Syncrowave that does that, though I've never used it - I leave it in the middle. Though it will probably say in the manual - a cracking read downloadable from the Miller website (under support/manuals/Syncrowave 300) and would probably help with any unexplained knobs on your welder.

 

[shenion]

The start circuit monitors the voltage and trips a relay. I think the start control sets the voltage trip point. Maybe I tis not working at all. Will ohm it out.

In the bottom is another big rheostat that adjusts the HF current/frequency.

Just tested TIG. The gas solenoid no longer cuts on. It comes on for the postf-low time on power-up but is no longer triggered by the contactor. Guess time to stare at that unreadable schematic.

Edit: oooh, the gas solenoid is only triggered when using the remote control input. Guess I'll have to rig a footswitch. I though the gun had a switch on it, but it didn't.

 

[shenion]

We HAVE TIG!

Rigged up small metal box with pushbutton as foot control (on/off).

Set everything up, hit pedal, arc started right up and tungsten disappeared into torch. Took a few tries before I realized the polarity was reversed.

This is my second attempt (first was just trying to lay a bead on flat steel.) Simple butt weld on 2.5mm steel:

And the back side (upper half of bracket):

Did stop in the middle to fiddle with wire (using MIG wire twisted together as welding supply is closed today.)

This is absolutely fantastic . I'm amazed how easy it was. Then again this is mild steel, not real thin or real thick.

Just how amazing how the weld pool works. I had a crappy MAPP/O2 setup, you had to run lots of gas to get it hot enough, then the weld pool blew all over the place. This is so simple and the weld pool just flows like solder.

Was using the 20-260 amp range, dial was set to about 2.5.

Thanks all here for for support, info and humor. Would not have even tried without you guys

 

[shenion]

Test 4: Al TIG

1/8" Aluminum, 5356 wire:

Looks good, sooo much easier than MIG.

Looks like about 75% penetration.

You will notice I started in middle and stopped before the end. Will need a foot control before I can do Al without blowing thru the end.

I could not be more pleased Will need to work on technique to do flat welds and proper start/stop.

 

[Drains]

I bet you're dead chuffed Shenion. Hat off to you. Good looking welds, and obviously a top line welder (after you'd sorted it!)

Well done!

Si