Lift Arc-Start TIG - Tungsten Sticking to Mild Steel

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John 21 years ago

I started a TIG welding class last evening. We are using lift arc-start on Miller welders (sorry, didn't note the model number). We are practicing on 16 gauge mild steel with 1/16" 2% thoriated tungsten, and 15-18 cfh argon gas. The amperage on the welder is at 60 amps, DCEN.

We were taught to touch the electrode to the practice coupon, depress the foot control, then lift the electrode to start the primary arc.

However, the initial contact between the electrode and coupon is welding the tip of the electrode to the steel. There is a noticeable spark. I have to twist and bend the electrode to break it free to start the primary arc. A small piece of electrode is breaking off the tip most times, eventually reducing my sharpened electrode to a blunt, jagged tip. It still welds, but I am wondering if I should change something on the machine or my technique.

I will ask the instructor next class, but he was pretty busy last evening and I didn't get a chance. TIA

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Ernie Leimkuhler 21 years ago

That is weird. You normally don't use the foot pedal with lift arc. The point of lift arc is to be able to start without a foot pedal or high frequency.

I thnk that the machine is set wrong.

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Footy 21 years ago

Is the machine you are using designed for lift-arc?

Is the appropriate switch in the lift-arc position?

Is the lift-arc circuitry working properly?

The lift-arc circuitry is designed to provide a power level low enough to preheat the tungsten some but low enough to not melt the work.

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Doobie 21 years ago

Someone is teaching you wrong...the footpedal eliminates the need to touch the tungsten to the work....(provided the machine has high freq. start capabilities) I have never seen a machine that has a pedal with no high freq.

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acrobat-ants 21 years ago

sure there is when I first was looking into the maxstar 150STL wich is lift arc only, the local welding shop let me try one which was in their "pool" of rentals (for big companies)

maxstars package can be oredered with hand or foot remote.

the idea is: if you don't press the pedal first you can touch the tungsten to the metal all day long it will not fire /arc. = cold , just like a mig gun.

the correct procedure is: ( at least I was told) get ready , pess the pedal to get the machine "HOT" or ON, at this point the gas starts to flow, touch the tungsten to the metal , do not scrach or tap , jus light pressure hold for 1/2 second and slowly lift up, after that your pedal is your remote control.

check this out: lift arc video

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my TA 185 has a foot control and has a lift arc the manual does not say a word about the operation, I guess I should try it one day in lift arc mode....... but that HF is so nice and easy ! why mess with lift arc ?

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enl_public 21 years ago

tungsten,

depress

noticeable

No.. there are a lot of variations. My Maxstar has at least five start options, between HF and liftarc. Virtually all TIG machines (HF or not) will have remote capability.

I like the 2T setting with fixed current at the panel, when using a hand controller (tap buton, touch and hold 1/2 sec, lift. tap to stop arc) and when I use the foot pedal with pedal control of current, the sequence is touch-press-lift to strike, release pedal to stop. It does vary from machine to machine, but generally, the touch must be about

1/2 sec to 1 sec, not jammed in, just a firm touch, and lift smothly and slowly STRAIGH UP. If you jiggle and the tungsten retouches after you start to lift, it is the same as dipping the tungsten when welding.

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Lift Arc-Start TIG - Tungsten Sticking to Mild Steel

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