[highstringer]

Hey Everyone,

I have a miller dynasty 200dx and have been having trouble when welding aluminum at a higher voltage like 150 to 180. The tungsten tip just deforms, kind of blows out, and gets nasty looking. The arc goes all over the place. I just have an air cooled wp17 torch, and use the red tungsten that I get a nice ball end on. It seems to do it quite often. It does it on high frequency or low. Not sure what I'm doing wrong. I'm just welding some aluminum square tube together. The funny thing is the welds don't look too bad. It almost seems like the voltage is blowing the end of the tungsten apart.

Any Ideas

Thanks

[pro mod steve]

2% lanth dark blue You don't need the ball with a dynasty. Do a search jody has a vid comparing tungsten. I only use the 2% lanth on my dynasty on al and never a problem. Tried the red it splits and spits. Sharpen it like you would for steel and put a land (flat spot) on the end and let it eat.

[NT Unique]

Sounds like your tungsten is too small, step up in diameter. On an air cooled torch your gonna find your tungsten really is a consumable item at 150-180 amps. I run a watercooled Wp20 and can run 140 amp for extended periods with a 3/32, but I'm also running 2% Zirconiated.

Cheers

[jakeru]

If it only happens on high amps, then quite possibly you are overheating the conductor inside your aircooled torch cable, and that's melting the hose it is inside of (the hose is probably made of PVC material). When the PVC hose material melts, PVC vapors will outgas and contaminate the shielding gas. The contaminated shielding gas causes the symptoms of the arc going funny (erratic), the tungsten degrading (not just down at the tip but up even possibly up higher around the collet) and also of course, contaminate your work.

You can verify if this is likely what is going on, by making it happen (weld with the conditions that make it happen) and then feel the temperature of the torch cable. If it's hot (such as, too hot to hold it next to your skin) it's almost certainly what's going on.

The fix is to get a heftier torch / cable setup than the WP-17 you are using currently. (Look for a torch with a higher rated current and duty cycle.)

[maniago]

Your pushing the WP17 aircool beyond its capabilities. I have the same and I've found that despite what the books say, this is too small an aircool torch for that kind of amps for any serious length of time. You might have better luck using 1" tungsten electrodes (just kidding). But in reality if you re using 1/8' its probably still not big enough to handle the heat, but might be doable with enough cool time for the torch. Water is pretty much what you are headed for, if you are doing any serious duty cycle, which I expect you are with AL square tubing...

My rough guide is that if I'd use stick on it if it was steel, the 17 isn't gonna cut it....