Buiding my own Tig welder.....

[anwar]

Ok so, I wanted to learn to Tig weld but I cant afford a good tig welder. But I had an idea, what if I converted a stick welder into a tig welder by switching the handle? It should work, right? I was gona try and use my old lincoln buzz box and attach a tig torch on it. I believe it would be perfect because it has a min of 40amp and a max of 225 amps.

I already know the pros but could anyone elaborate on some of my cons?

- its ac (I will be mainly welding mild steel)
- it will be 60 hertz (no high freq start) (may contaminate the tungsten)

Those are the only problems I can think of but anyothers would be helpful. I only wish to learn tig and do basic shop welds so the beautiful artistic welds of the pro machines are not expected or required.

So, has anyone tig welded on lo 60 hertz freq? How does it work? What will happen to my weld if I dirty the tungsten rod from scratch start?

[greywynd]

Converting a stick welder to Tig isn't difficult, adaptors for the tig torch for the gas connection are usually availbel off the shelf or next day delivery at most local welding suppliers. Usually though, it's done with a DC capable arc welding unit. Most tig is done using DC, the only exceptions being aluminum and some other 'exotic' metals.

Since you only have AC on your welder, what would happen is approxiamately half of the heat would go into the tungsten, and half into the work. This will cause your tig torch to run hot (and fast), whereas on DC the heat is concentrated on the workpiece. Now if you have a cheap tig torch, it might be do-able....go to a large collet and tungsten (3/32" or 1/8") and stay with thinner materials. It's not ideal, but may work to an extent. Personally I'd only try it if the costs were low.....wouldn't be running out and buying a new tig torch or anything in case it doesn't work.

Hopefully someone here has tried what you want to do and can shed some light on how well it did or didn't work.

Mark

[Mike W]

You need a high freq box in order to use AC. Check ebay for one.

[frank]

with a Lincoln tombstone, high freq box, tig torch, and 100% argon. The welds were ok for using a machine that was NOT designed for that application.....BUT the transformer did not like it. The trans noise was teribble........I have since been using my resereckted Miller AC/DC unit and there is the normal noise with the high freq on AC, With out the high freq you cannot control the arc to get consistent welds.....the arc will wonder all over the place.


Frank

[pgsmith]

If you are only going to do mild steel I would advise you to sell your ac buzzbox for whatever you can get for it. buy a hobart stickmate ac/dc for about 350.00 and a weldcraft
17 torch set with valve and 2piece cable 80.00 at arczone.com. pickup a flowmeter and an argon bottle, some consumables and away you go. just remember only goes down to 30 amps so real thin stuff is out. I have a miller thunderbolt setup like this and it works ok

[bpickell]

I don't know if this will actually work or not, it is complete speculation.

To convert your AC welder into an AC/DC welder I would think all you need to do is get a high amperage 2 position switch.

position one has straight ac current coming out of the switch.

position two has a high current diode on that pole turning the welder into a DC welder.

I have no idea if that would even work or not, but I do know that is how an alternator on a car works, by turning an AC current into DC current with diodes.

[84ZMike]

An auto alt. uses a diode trio.....will this convert his ac only to ac/dc...yes,but he will still need an arc stabilizer......alot of work for (from what I have been told) not so great results.
Mike

[Mike W]

You need 4 diodes to make up a full wave bridge rectifier. That is what I did to mine as well as add a high freq box. It works fine.

[c25]

If you are only going to do mild steel I would advise you to sell your ac buzzbox for whatever you can get for it. buy a hobart stickmate ac/dc for about 350.00 and a weldcraft
17 torch set with valve and 2piece cable 80.00 at arczone.com. pickup a flowmeter and an argon bottle, some consumables and away you go. just remember only goes down to 30 amps so real thin stuff is out. I have a miller thunderbolt setup like this and it works ok


That's exactly what I'm using, a Thunderbolt 225 ac/dc and a Weldcraft 17 from arczone.com (arczone is good people).

I'd rather buy a stickmate or find a used ac/dc welder than mess with building bridge rectifiers and other stuff. Also, you only need the HF box if you're going to do a/c tig welding, usually that's only done for aluminum and some other fancy metals that I don't mess with.