Author Topic: tig high frequency  (Read 831 times)

Carpenter84

tig high frequency
« on: March 24, 2020, 09:58:26 PM »
quick question...

for tig welding i have my beastly giant Airco transformer multi-process machine. its mediocre in all process, but its not going anywhere, im kind of attached to it... (until the day i use a modern machine, im sure...)
 
a while back i found a high frequency unit designed for this very machine. an Airco HF 15-1.
ive been tig welding stainless lately. its scratch start. no fancy electronics. it welds decent (my skill is sub-par at best...) i have yet to hook up the high frequency machine. i bought it for the ability to weld aluminum - which i have yet to do... however, what would the high frequency unit do for regular DC tig welding? is there any benefit in hooking it up for this stainless, or any other mild steel tig welding?
i know AC welding of aluminum requires the high frequency to even start, but, what does it do for DC? it has the option to run DC. theres a toggle switch on the front for AC/DC. what would change in DC if i hooked it up?
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

Terrywerm

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Re: tig high frequency
« Reply #1 on: March 24, 2020, 10:57:51 PM »

I used a then-new Hobart about 20 years back, and it was a very nice machine. Did a lot of 316 stainless work. It had HF for aluminum and it also had HF start on DC. If I recall correctly the HF kicked out once the arc was started. BUT, that HF start would sure make you sit up and take notice if you hit the pedal but didn't have the torch right up to the work. With the HF behind it, the starting current would manage to find all kinds of paths to ground, and most of them hurt!


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Terry

Making chips with old machines!

Carpenter84

Re: tig high frequency
« Reply #2 on: March 24, 2020, 11:08:49 PM »
This unit does not have a pedal, unfortunately. The high frequency electrodes are arcing constantly as soon as you turn the unit on. So, not sure about them shutting off once the arc is lit, but, I haven't tried yet.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

Terrywerm

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Re: tig high frequency
« Reply #3 on: March 24, 2020, 11:19:19 PM »

Oh wow, I didn't realize that it didn't have relays for weld current and gas supply. As far as using HF on DC, I don't know how it would work, as HF is always using AC current - as far as I know. I don't understand how you could use HF on DC.  DC is direct current, although I guess you could have HF pulsed DC, but I've never seen it.



Even though I did quite a bit of TIG work back then, I am no expert by any means and I have a hunch that there are others here that could probably provide a better answer than I.


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Terry

Making chips with old machines!

PJB

Re: tig high frequency
« Reply #4 on: March 24, 2020, 11:23:51 PM »
My .02 If you have HF unit I would absolutely use it.   Makes starting way easier.  I donít weld much but at work we have bunch of Miller 200A Inverter machines w HF and foot pedals and starting arcs is super easy.  At home I have a little 150A Miller STL Inverter for doing occasional TIG work but it doesnít have the HF just a lift arc function.  Its better than scratch start but not near as nice as the HF.   I didnít want to spend the extra cash to buy the next model up w HF but now whenever I weld I wish I did.   
1991 Bridgeport Series I 2J-VS  9"x48"
1979 Clausing Colchester Bantam Mk2 11"x30"
1972 Harig Super 612
2015 Tormach PCNC-1100 Mill

"I wants what you gots!"

Carpenter84

Re: tig high frequency
« Reply #5 on: March 25, 2020, 12:37:59 AM »
So it seems the consensus is it helps with starts... well, thatís enough for me.. I really donít like scratch start. I keep a nice sharp electrode for about, one strike... especially if Iím welding some inside corner horse crap... like everything Iíve been doing last two nights.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

f350ca

Re: tig high frequency
« Reply #6 on: March 25, 2020, 09:56:30 AM »
I learned to tig weld aluminum on a Miller version of what sounds like the same attachment Shawn. You powered it with AC from a welder and it produces HF AC. Works well for aluminum but not what you want for steel.

Greg

PJB

Re: tig high frequency
« Reply #7 on: March 25, 2020, 12:20:38 PM »
Hereís a couple pages from a handbook I have might be of interest


1991 Bridgeport Series I 2J-VS  9"x48"
1979 Clausing Colchester Bantam Mk2 11"x30"
1972 Harig Super 612
2015 Tormach PCNC-1100 Mill

"I wants what you gots!"

Carpenter84

Re: tig high frequency
« Reply #8 on: March 25, 2020, 01:19:45 PM »
Thanks Paul, I'll read them at home on the computer. Too hard to read on my phone.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

PJB

Re: tig high frequency
« Reply #9 on: March 25, 2020, 03:49:25 PM »
1991 Bridgeport Series I 2J-VS  9"x48"
1979 Clausing Colchester Bantam Mk2 11"x30"
1972 Harig Super 612
2015 Tormach PCNC-1100 Mill

"I wants what you gots!"

PJB

Re: tig high frequency
« Reply #10 on: March 26, 2020, 11:19:09 AM »
Shawn funny you bring this topic up as Im currently working on a project at work to convert an old junker Haas VF mill to a CNC Tig welder.   One of the issues Iíve got to work around is shielding the contols from going Loco due to the HF arc starts.    I would love post pics but donít want to run afoul with my employer posting our stuff on the net
1991 Bridgeport Series I 2J-VS  9"x48"
1979 Clausing Colchester Bantam Mk2 11"x30"
1972 Harig Super 612
2015 Tormach PCNC-1100 Mill

"I wants what you gots!"

Carpenter84

Re: tig high frequency
« Reply #11 on: March 26, 2020, 12:21:10 PM »
Could ask permission? I'd very much find that interesting.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.