Frosty looking aluminum weld beads?

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Hello fellow weldingweb'ers,Can you please critique my weld and offer some advice?  I've been practicing A/C Tig welding on a 1/4" 6061 aluminum plate and my welds keep having this frosty quality.  I turned the A/C Balance (cleaning) down to ~37% (almost all the way to the left) and it looks like marginally better penetration, but I want a shinier/cleaner stack-of-dimes look with better penetration.  The arc starts consistently, but it doesn't seem to focus on one spot very well (frequency in the 100-120Hz range) and dances around until I start adding filler.Machine: PowerTig 225LXTorch: air cooled hand-held with switch, control in 4T positionGas: 100% pure argoncup: everlast #7 cupFlow: 7L / minTungsten: 3/32 2% lanthanated (sharpened to point)Filler Rod: 3/32 4043Amps: (I forgot :P)PreFlow: ~1-2sPostFlow: ~8 secondsPulse: OffMetal Prep:  80 grit belt sander on surface, followed by rigorous brushing with a steel brush (only used on aluminum). Then, it's cleansed with 100% cotton cloth dipped in acetone.The bead on the left half-way pictured was done with balance higher in the ~10 o'clock position.
Reply:On clean metal you can crank the balance to 10. I usually don't run below 8 unless it's cast.To properly weld 1/4" Alum your machine should be set to 250Amps (minimum) with a 1/8" tungsten (minimum)  with straight Ar.  A bit less with a He mix.Buy American, or don't whine when you end up on the bread line.
Reply:You don't list how many amps you are using. My guess is that you have the machine set too low and have to take a while to get the bead going. That will work with steel, but not with alum. You are most likely overheating the material because you have the amps set too low. Alum being a good heat sink pulls heat away from the bead, heating up the whole plate rather than getting a puddle started. You need the amps set high so you can stomp on the pedal and quickly get the puddle going and then back down and go fast. Overheated material will often give you that "frosted" look to the bead itself rather than the nice shinny bead.1/4" alum is too thick to start learning on. Get some 1/8" instead. It's thick enough so that you don't burn thru and thin enough that you can get a feel for the material and don't need a machine capable of 300 amps. Set the machine to at least 150 amps and stomp on the pedal to get the puddle up and running fast.If you are just starting out learning tig however, get some 1/8" steel instead and learn the basics of heat control 1st on a material thats easier to see the results on. Then once you have heat control down well move on to alum..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Thanks guys,    do you know where I can get some cheap 6061 1/8th inches thick aluminum plate to practice on?  I saw some on Amazon, but wasn't sure how good it was.  Also, any place I can get a cheaper copper plate to use as a base for welding?  Thanks.
Reply:Originally Posted by TheMeatHeadThanks guys,    do you know where I can get some cheap 6061 1/8th inches thick aluminum plate to practice on?  I saw some on Amazon, but wasn't sure how good it was.  Also, any place I can get a cheaper copper plate to use as a base for welding?  Thanks.
Reply:Originally Posted by TheMeatHeadThanks guys,    do you know where I can get some cheap 6061 1/8th inches thick aluminum plate to practice on?  I saw some on Amazon, but wasn't sure how good it was.  Also, any place I can get a cheaper copper plate to use as a base for welding?  Thanks.
Reply:as a side note, it looks like you need to add more filler. This isn't like steel where you just add a drop of filler, you really have to feed it in. Otherwise you are going to have cracking isssues when you start welding 2 pieces together. watch at 1:25 his filler hand. He over exaggerates it a bit, but he's consistent and his stack of dimes is asthetically pleasing.Of course it doesn't make a difference, but sometimes that's just the look people want
Reply:Turn your balance fully left.  This will improve the frosting, but speed up or use more heat.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Geeeezzzzzzzzzzzzzzzz...You mean to tell me nobody caught this??He is prepping the surface with a 80 grit BELT!!!!Red flag right there.DO NOT use a belt sander for prep!!!You know where all that sand gets imbedded correct???That's why the frosting.The acetone with the stainless brush is more than enough!!!You all need to go back to class for another entry level exam.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Thanks guys, your suggestions helped .  Regarding cleaning the frosty outer edeges of the weld to look more shiny, do you just use a scotch-brite pad on a drill?
Reply:Originally Posted by zapsterGeeeezzzzzzzzzzzzzzzz...You mean to tell me nobody caught this??He is prepping the surface with a 80 grit BELT!!!!Red flag right there.DO NOT use a belt sander for prep!!!You know where all that sand gets imbedded correct???That's why the frosting.The acetone with the stainless brush is more than enough!!!You all need to go back to class for another entry level exam.....zap!