TIG - types of HF start

I"m considering watching for a TIG welder and note that there are
different types of high frequency starting.
It looks like the lift to start method is on less expensive machines.
I assume that you tap the tungsten on the work and then lift to get it
started. Does that contaminate the tungsten?
Can lift to start machines use remote amperage foot pedal or thumb
What's the disadvantage of a lift start machine compared to whatever
the better machines have?
Is there high frequency at all on the scratch start machines?
On the better machines, I see that there's HF on start only and
continuous HF - I guess the latter is only on older machines, right?.
If you're down in the cellar or out in the garage is HF likely to
interfere with electronics say 50 ft away?
Ignoring interference, is there any disadvantage to a machine that has
continuous HF?
What's the purpose of a pulser?
Reply to
GeoLane at PTD dot NET
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Tip to start does not involve high frequency. It is called lift arc and involves the power supply starting off with low current, to increase as it senses that the tungsten is being lifted.
No idea. I like HF, which is what I have.
No, it is the worst of all worlds, where you have to have super dexterity to start the arc, without contaminating material with your touch.
Continuous HF is needed on sinewave AC machines due to arc extinguishing itself during zero crossing.
Not too much.
To agitate the molten pool.
Reply to
If it doesn't COME with that attachment, don't assume you can get one for an old machine, or that even the specs on the components and pin connections will be available. (Miller and Lincoln have manuals back to their earliest TIGs, but don't assume that is true for others.)
Shield gas pre-flow. I usually set 5 seconds of pre-flow on mine. When the HF turns on, then I know the area is purged of air.
Most likely, not.
No, continuous HF is for aluminum and other materials that tend to contaminate the electrode, HF-start is for steels, mostly.
Yes, it may contaminate the electrode or the weld, or just affect the weld appearance.
Now you're getting into the deep stuff. It can be handy when welding thin materials, or welding thin to thick. You definitely need to be in the "expert" class before starting to use such features. I'm definitely NOT there, yet.
Reply to
Jon Elson

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