Has anyone on here used one of the arc to tig conversion boxes that has the gas control, high frequency start and amperage control built in? Are they common and how much do they cost?
We have one at school thats just sitting in the corner, but I can't get ahold of it, they just don't sell equipment.

I'm going through TIG withdrawel after using a 5,000 dollar lincoln TIG machine for the last 4 years while I was in college. I'm now shoping for a really cheap TIG since I'm a broke graduate.

Here's what I honed my TIG skills on. It's a mini-baja buggy that we built to compete in SAE's annual min-baja east competition. The big side pods are there for floatation, yeah this thing had to cross a lake as well as handle moto-x style jumps and tight woods sections. Tons of fun and lots of fab work. The frame is 4130 steel, we didnt' get to heat treat, we ran out of time, but we did do some testing that showed that my welds weren't the weak point.

 

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Ahhh, mini baja, i remeber that, i did that at Washington State a while back.

I think you would be better off saving your pennies for a good tig welder. I dont even know if theres an easy way to convert an arc over.

 

kinda what I figured, the box at school is kinda expensive looking.

 

Get a tig torch with a body mounted gas valve and separate lines and hook one side right up to the bottle and one up to the welder. You’ll have to open the gas valve with your fingers and scratch start as well as learning what power setting you need to start with and to control heat with travel speed and gun attitude, but it does work quite well. I know at least one person that tigged some headers like this.

Supposedly the arc starter boxes work quite well but I’ve never used one in person.

 

i have/do what 83 said. plug the torch into one lead from my machine and another to the argon. torch has a manual valve. it's all you need for everything but white metals.

 

and this gives the strength of a real TIG weld?

 

They had a setup like this at school before I got the big machine working again. I had problems with breaking off the tungsten when I lit the arc. My arc went all funky half the time and made it a pain to weld.

Are their any tricks to avoid this? I had one guy suggest a brass "strike plate" to start the arc on and then move over to the real material, but I never tried it since I got the good machine working.

 

It is a real tig weld

I do something similar using an alternator as a power supply and a pedal rigged to control the power to the field coil, giving me everything but a HF arc starter/stablizer.

At some point I'm going to add a small circuit to controll a gas valve (N2O solinoid), but for now it's all manual

 

awesome! about how much does this cost? the tig torchs aren't very much on ebay, right?

 

Well (all prices shipped or with tax):
Alternator: free (was supposed to be $18 at crazy ray’s jy, but they were closing and were like “I don’t care, just get out”)
5hp/20a/240V motor: HF closout at $29
Pullies: free, used an eaton blower pulley on one end and modified a fox mustang PS pulley to work on the other end
Belt : $4 autozone (shortest 6 rib belt, v belts don’t like transferring that much power)
Base/frame: free, carved out of assorted scrap wood, will eventually make a new one out of bits and pieces of cutup roll cage that I have sitting in the basement.
Mounting/adjusting hardware: free, took it with Romex/switch/switch box….: free again, left over frome assorted wiring projects around the house
Inert gas fitting: $2 at Roberts Oxygen
12V power supply: free again, I use whatever is sitting around, usually an extra car battery or my battery charger
10A wire wound rheostat (rough power output setting): $.25 at a ham fest
Pedal assembly: free, dumpster dive behind a sewing machine store, had to be modified quite a bit to work like I wanted.
AR regulator/gauge assembly: $13 ebay, cool old lab instrument style with brass bodied gauges, fittings and fastners and mineral glass lenses. Polished up really nice, looks almost like marine brass
Hose: $.29/foot, about 4’
Weldcraft SR17V-25-2 Tig torch (nice, 150A , separate 25’ lead, gas valve on body): $23 shipped, ebay with an assortment of collets, cups…
Assortement of tungstens: $8 on ebay

 

NICE!! Thanks for the grocery list of parts!

 

Looking at the list, I forgot to list the 80cu bottle of argon from the local “bottled gas” store, but that would be something that you’d have to buy even with a “real” tig. If you wanted to do aluminum with it you’d either have to figure out to do AC and build an arc stabilizer or get a bottle of He and mix it with the argon to weld it with DC, like steel, stainless, titanium, copper….

Like I already mentioned at some point I’m going to build a gas valve into the welder so that I don’t have to control it at the torch anymore. I intend to use an N2O solenoid or a solenoid gas valve that I have sitting around, a microswitch as a trigger in the foot pedal (but a friend of mine keeps insisting that I let him build a circuit that just detects when I start “giving it gas” on the pedal), a relay (probably just use one of the generic bosch relays with the N2O solenoid or a P&B relay for the other solenoid valve) and add a small capacitor into the trigger circuit to flow the shielding gas for a little while after I release the foot pedal

 

whoops wrong thread..