Aluminum Tig

Well I was doing pretty well with tig on steel so I thought I would try aluminum. From reading here I know I need it super clean say use denatured alcohol and a dedicated wire brush. So I picked up some srap 1/8" 6061 and started playing. I can push a little puddel along ok and add filler with some work but trying to to a t joint the aluminum doesn't flow well. The top part just desolve before the bottom get's fluid. Where should my heat be consintrated? I am on HF AC with 135amps with a 3/32" pure tungsten (I'm going to get a pack of lanthated tungstens next trip to the welding shop). Anyways what wave form should I use and how much electrode positive should it have? I have a thermal arc 185 and I'm pretty new to tig welding.

Thanks,

Justin

1/8" = 0.125" = 125 amps + 30% (fillet weld) = 166 amps.

Obviously you need a better tungsten or at least a bigger one.

An 1/8" pure will work, ick!!

The arc should be aimed a little more on the base metal than the vertical. The vertical has an exposed edge so it will heat faster.

The trick to get the bead started is to melt a small ball off the end of the filler rod, using very low amperage, so the ball is resting in contact with both pieces. Now directly heat the ball until it flows out to both pieces. This will start your bead.

Square wave is prefered.

A balanced arc should be about 30% from DCEP to DCEN, or at 3 out of 10.

You should try increasing the AC fequency of your arc to narrow the arc and reduce the amperage needed.