Adding high frequency to the Harbor Freight TIG

I finally went and looked at the $200 unit after the various discussions on this group. It really looks pretty good for what it is. The torch looks just like my name brand units, nice fingertip gas control. I really like the fully adjustable current knob, and it looks like adding a foot controlled 10K pot will be do-able. I found some companies that sell then for well under $100, although I haven't researched such things as sewing machine pedals, guitar pedals, etc, to see how many ohms they have or if they have a pot that can be swapped out. You can find these on eBay for a couple of bucks.

Right now I have an AC welder with a Sears high frequency TIG adapter on it. It works well, but is AC only and I want to get into thin steel sheet metal with a DC welder. Would it be possible to add the hi-freq to the Harbor Freight TIG? It would have to run off a remote switch, I guess, to operate only at the start. I asked the people at Hobart if my converter was ok to use on the Stickmate AC/DC welder I was considering, and they said it would work. But the Stickmate would not be possible to convert to foot control.

Maybe it isn't worth the effort if the HF does indeed use a lift arc start? I also have a water cooled torch on my existing home-made TIG, but I was using it for aluminum and I doubt that the HF would benefit from water cooling for the low amp applications I have for it.

Dennis

Reply to
Dennis Thompson
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Dennis, After playing with the Harbor Freight TIG for a few days now I don't think it would take long to get by without the HF start. At the extreme low end of the amp scale it is a bit tricky to get a fire lit but with the ceriated tungstens it was not too bad. One hitch in the "lift arc". If you go to restrike an arc you should let the thing cool down till the gas shuts off before you touch off again. It tends to stick otherwise. This only happens at the really low power range. I have not built a foot control for it yet and am considering a thumb control on the torch. Having never used either I am not sure which way to fly. I was able to make a nice bead on a coffee can using .035" filler and

1/16" ceriated tungsten. I made lots more holes than weld but I am sure the thing will do it once I get my hand tuned into it better :) If you are near Medford, OR you are welcome to come by and try one out.
Reply to
Glenn

Thanks, Glenn, but I'm in Ohio. Does the unit have a automatic gas solenoid or just the valve on the torch? I was just looking on eBay, and sellers are having a field day with these things. They are selling well above $300, one seller claims they have gone for more than $500. Another guy is even selling *just the box* for $200 starting bids, and he removes the torch, hoses, etc and is selling them on a separate auction. Jeeez...

How are you using the start, do you just touch the electrode and lift? I'm used to high frequency and have never tried that method, in fact we were taught to never let the electrode touch.

Dennis

Reply to
Dennis Thompson

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