Couple of TIG questions

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Hi everyone,First post! here we go....  Been lurkin' , learning and searching for a while, but can't pinpoint my problem.I felt like it was time to move up to TIG.  I bought a Miller Diversion TIG unit, which I am pretty happy with (trying to dredge up some of the O/A skills from 20 years ago)TIGed some mild steel, that went well, but the project at hand is aluminum.  I've been practicing running beads on 1/8" aluminum with mixed results, here are the things I'm struggling with, hope someone has an idea;First issue, no matter how nice I get the beads, they always look "dirty" (pepper flakes), I can't get the nice smooth shiny welds I see others producing.  I have SS brushed the metal, tried wiping down with acetone, aluminum brightener (lemonade), scotch-brite wheels, etc.  I have wiped down the filler with cleaner as well.  I have experimented with the argon flow etc.  Any ideas what I'm missing.Second issue, perhaps related to the first, on a lap weld or corner weld, I have a very hard time getting the two puddles on each piece to come together, If I try to add filer to the 2 puddles, the rod balls up and wont flow with the other two puddles.  Running a bead on scrap I can bring the puddle along and add filler OK, (maybe not that pretty yet, but sound) but not when I have 2 pieces together.  Driving me crazy.Sorry this post went on so long, TIA for any advice.
Reply:Forgot to mention;1/8" aluminum, 20cfh 100% argon,1/16" 2% orange electrode, 1/16 filler, (also tried 1/16" green electrode and  3/32" orange with 3/32" filler)
Reply:I don't see any notes regarding amperage, nor any info regarding your selection of AC or DC current.  My guess is that you are running DCEN when you should be running AC current with a wave balance toward EN.  The rule of thumb suggests about 125 amps, though I might run a bit hotter than that on 1/8" aluminum.  Also, stick with the 3/32" tungsten, as 1/16" tungsten doesn't carry enough current in AC mode, and it will just quiver and melt.
Reply:Just noticed the first response beat me to the punch.  Its certainly sending you in the right direction.One more question though.  What alloy is the base metal and the filler?Black specks could be magnesium from either.But, I still agree that your problem sounds more like you're running DCEN.DCEN will not "clean" the surface, and certainly explains the wetting issue you're having with joining a corner.  You'll know you're on A/C from the loud buzzing noise.  Yes, it really is supposed to make that awful sound.  Again, on A/C. the tungsten runs MUCH hotter, and 1/16 is too small (I know you didn't list the current, but 1/16 on A/C is too small for anything but the thinnest of sheets).
Reply:Thanks for the quick responses,Sorry for missing the details,  Always set on A/C for aluminum.  6061 & 6063 base metal.  Filler rod is 4043.  The Diversion has no balance control, the percentage is fixed.I have the max amps set at 125, but generally am not stomping the pedal to the floor.I originally started with 3/32 rod, but thought it was too much.As a side note, if I run the puddle without filler, it looks decent, but seems that the crap floats in when I dip the filler rod.  The 1/16" rod is from a sealed tube, but the 3/32" is a 4 pound "handful" (literally) that the guy at the LWS puled out of an open box.  Is that normal?  Isn't this stuff supposed to be kept sealed?ThanksLast edited by Northwind; 02-27-2009 at 04:39 PM.
Reply:if youre only getting the "flakes of pepper" when you dip your filler, try to scotch brite your filler rod.only thing worse than an ugly woman is an ugly weld
Reply:Originally Posted by El_Lloydeoif youre only getting the "flakes of pepper" when you dip your filler, try to scotch brite your filler rod.
Reply:i dont seal mine ( won't rust)  just keep them in  pvc tubes  glued together  to make a rack next to welder contamination can be caused  if you pull the filler out of the gas flow.. all i use is 3/32 tung  2%red  for everything --alum,ss,ms,nibral
Reply:is your high freq set to continous?only thing worse than an ugly woman is an ugly weld
Reply:Originally Posted by El_Lloydeois your high freq set to continous?
Reply:i welded one time with a dynasty and those are nice for millers hahaonly thing worse than an ugly woman is an ugly weld
Reply:Last two nights in class, I 'lost' my oxide cleaning zone (the white strip along the toes of the weld) and got the black flecks. I fixed it by shortening my stick-out length, from about 5/16" to 3/16". And I was using a 5/8" (#10) cup, which will allow a longer stick-out than a smaller cup. I had been using that longer SO since class started in August, on mild steel, without problems. I'm guessing the Diversion came with a 3/8" (#6) cup. So you should try a SO of less than 1/8". I recommend bigger cups for learning, #8 or #10.I like 3/32" filler, it has enough mass that it won't melt before you get it to the puddle. The biggest improvement to my alum welding was the step up to 3/32". I still rarely use 1/16" and that's just to humble myself again.  Most of my welding is 1/8".Keeping alum filler sealed doesn't matter until you're welding for NASA. Don't use green tungsten in an inverter, there was a thread recently and this was the problem the guy figured out.Edit: sn0border88: I imagine the HF on the Diversion is linked to the AC/DC switch.Last edited by Craig in Denver; 02-27-2009 at 05:27 PM.9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:Ya, check your HF setting, you should be able to change it from start (steel/stainless) to cont. (alum)  If its not set right this will mess with the cleaning action.Also, what is on your filler hand?  Dirty, oily gloves will turn clean filler into junk at first touch.What are the joints like where your getting this problem?  Sheared edges with sharp corners can melt off and turn into contamination, if its cut with a cutoff wheel/chop saw then your in even worse shape as the grit from the wheel gets embedded in the cut and even if you clean the top and bottom there is plenty left in the thickness of the material.Last edited by sn0border88; 02-27-2009 at 05:19 PM.Have we all gone mad?
Reply:Craig,I have noticed that the cleaning zone (frosted area) is almost non existent.  Maybe a pitfall of buying a unit without AC balance control.The cup is #7.  I have been using about a 3/16" - 1/4" stick out.  I was thinking about picking up a different cup.  I also was thinking about getting an actual flowmeter.  The rig came with a pressure gauge type flow meter and, if I remember my physics correctly, this would only be accurate under one specific set of conditions.I'll try messing with the stickout and cup.Thanks.
Reply:A small cleaning zone is fine if the metal is clean to start with, it seems like the contamination is coming from the base metal/filler.  What about my question as to how it is cut and how the joints are fit?Also with a #7 cup you have a very small shielding area which means you will have to keep your filler really close to keep it from oxidizing.  maybe your pulling the filler to far away?Have we all gone mad?
Reply:in ms ( not sure about aloom) too long an arc length can deteriorate the arc intensity and cause the 2 puddles to fail to coalesce..thats why on plate its less of a  problem, you only make one puddle..in a fillet the arc wants to be tight into the corner and grow the puddle  right there with short arc length,,,as i say not sure bout aloom..u start balancing stickout versus arc length...
Reply:Originally Posted by sn0border88A small cleaning zone is fine if the metal is clean to start with, it seems like the contamination is coming from the base metal/filler.  What about my question as to how it is cut and how the joints are fit?Also with a #7 cup you have a very small shielding area which means you will have to keep your filler really close to keep it from oxidizing.  maybe your pulling the filler to far away?
Reply:Originally Posted by sn0border88Ya, check your HF setting, you should be able to change it from start (steel/stainless) to cont. (alum)  If its not set right this will mess with the cleaning action.
Reply:Have you figured out what happened when you weld 6061 Al ??Because I just bought a Diversion and happen to have the same problem, I need to fill some nuggets here and there and make a second pass in small circles very close to move the puddle to get rid of all the holes and fuse to both surfaces it leaves black flakes and a lot of dull gray crust.I'm not a very good weldor yet, I'm still on my first tank of Argon, but I was doing good on the shiny plate (no clue what it is).