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Old 05-31-2018, 08:14 PM
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Shade Tree Welder Shade Tree Welder is offline
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Join Date: Jun 2004
Location: Kankakee County, IL
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Quote:
Originally Posted by Razorhunter View Post
I'm going to try a little scratch start TIG with an old Lincoln buzzbox. I have the adaptor that the stinger clamps to, and I also have a 150 amp torch with gas valve on it.
So given there is no foot pedal, I've read you just have to "snap out" of the arc. My question is regarding the gas flow. -Do I need to quickly snap out of the arc, and then quickly point the torch back at the cooling puddle to attempt to give it some postflow, or is it just bound to get some oxidation that cannot be prevented?

Secondly, and someone correct me if I'm wrong here, but I think that for a TIG machine to weld aluminum, it must be AC capable, right? So why cant my AC/DC buzzbox also do scratch start TIG on aluminum?
Is it because there is no high frequency? Can someone clear this up for me? Thanks so much.
So if a guys decides he is overweight and wants to get a little exercise in,
so he starts climbing Mt. Everest. That is kinda what you are doing here.

At least you know you are starting in a hole.

Went you are starting a stick welding (SMAW) electrode you are effectively
scratch starting the arc. you need to do a similar start on your tungsten.
But unlike SMAW you will be contaminating your tungsten every time.
But hey you are not doing shit for a nuclear reactor or NASA.

Generally you are correct you DC- weld steel and steel alloys, and AC weld
aluminum. But there is more to it than that a AC stick machine has a
balanced waveform at 60 Hz. Generally AC TIG (GTAW) is an unbalanced
wave to the negative side. This allow better penetration and still adequate
cleaning. The HF is only active during starting of the arc to allow the arc to
start with out touching the base metal.

Best of luck.

You'll need it.
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