New Welder and aluminum TIG welding

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I'm new to this forum but have a few questions about the welder and they weld sample.  I was at an auction and purchased this welder (Hobart TR-250-HF) which included everything I needed except the bottle of gas.  I have been doing a little practice on sample aluminum but now I think I'm ready to go for the gusto.  Here is my question, I have 1/8" zirconinated rods and aluminum filler rod but am having a problem on welding the "T" joint.  When the walls start to puddle and I try to get the filler rod in the puddle to join the  two it just seems to melt the filler and blow it away.  All I end up with is a big glob of aluminum.  The butt / flat joint seems to weld OK and I'm getting pretty good penetration.Also it seems that the electrode erodes away quicker than I would think it should.  It is possible that I’m using too much power.  I have it set to about 90% and the pedal to the metal.Any help would be greatly appreciated.Thanks,JeffHere is a picture of the welder and the picture of the weld will be next. Attached Images
Reply:I did not clean the weld after I welded it.  I did brush the aluminum before I welded. Attached Images
Reply:I am not familiar with the controls on the machine.  Looks like you need to clean the material better and/or run your balance more on the cleaning side.  However, that would heat your tungsten up faster.  If that is a 250 amp unit x 90% = 225 amps - would not think you would need that much power to weld 1/8".  What diameter tungsten are you running?BTW, what did you pick the machine up for?
Reply:with 1/8 corner joint you should be using 3/32 tungsten and no more than about 160 amps if that machine has a balanced wave ac (square wave) you should be a little lower if you are at 200 or above you are way too high on power. You may be able to get away with the 1/8 zirconiated. Make sure your flow rate is about 20 cfm...
Reply:The dirty area I think is caused by using the HF arc to preheat the area.  I will run the arc around the area of the weld to get it warmer than room temp.  The wall thickness on the above picture is 1/4" but I will be welding 1/4 wall to 1/8 wall shortly and 1/8 wall to 1/8 wall also.I paid a little less than $500 for the unit and all I needed was a tank and some torch cups/tungsten.  I'm using 5356 aluminum 1/8 filler rod since the material I'm welding is 6061.  I always wanted to build an all aluminum trailer so this winter project is that.
Reply:do you tig that up outside, if you get a small breeze it will blow away your argon sheild and you will have something that looks like that also.
Reply:clean clean clean when doing aluminum !b-
Reply:Are using pure argon?, should use about the same amps as material thickness 1/8"= 125 amps. .250"= 250 amps. When you start, keep your arc in same spot, except for small circular motion to keep heat even on both mating peices, untill puddle forms, then just foward motion.  On your .250" & thicker stuff, I pre heat to 300 degrees before welding.  Good luck & have fun!