Purple tip Tungsten ?

[WaterH]

So I finally went and bought a new tig torch and hose. (My old one was in bad shape) Anyways, inside the box was a free sample Tungsten. It's got a purple tip. The pamphlet with it says it can weld AC or DC. I know there's all kinds of color codes for differnt stuff, but I've only ever used red for steel or green for aluminum. Has anybody used the purple? Im not sure if this is right, but I've only used AC for aluminum. So when they say AC or DC, does that mean you can weld aluminum or steel with the same tungsten? That would be nice.

 

[bdkw1]

Yup, gold and purple can weld both. It's nice not having to swap out all the time. Purple will also hold a point on AC making for some finer welds.

 

[Scott Cee aka 2drx4]

Yeah, purple is a very universal tungsten. Is it the best? Probably not, but I don't think you'd notice unless you're doing it all the damn time.

 

[WaterH]

That sounds great. I guess I'll be buying a set of them.

 

[tracyb]

i use blue, 2% lanth, for everything.

when i used a syncro 250 transformer machine i used green/ red. but when i got the dynasty i went to blue only

 

[gt1guy]

i use blue, 2% lanth, for everything.

when i used a syncro 250 transformer machine i used green/ red. but when i got the dynasty i went to blue only

This post on the Miller site explains why the green isn't a good choice on inverter machines.

TIG arc depends on ionized gas to carry an arc. Sine wave 60 HZ AC the tapering to a zero current, then reestablishing a new one gives sufficient time to lose ionization. HF overrunning current maintains ionization, but still the return "stroke" is hampered by the oxides, and contamination on the larger surface of the workpiece. This work negative stroke brings with it lots of heat. Sine wave machines, even at 50% balance don't heat the tungsten as much.

Square wave machines are more effective at establishing the return stroke. They bring lots of heat with it. Pure tungsten won't resist heat well enough, it melts into too large a ball. I like nearly any tungsten for AC except pure. I use as large a tungsten as possible, and grind very blunt, let it round nose a bit. Set balance as high as you can make work. Most sharp tungsten work for DC