6061 aluminum tig

[stack o dime]

hello,
I am joining pieces of 6061 aluminum channel about .16-.2 inches thick in the verticle position and seem to be getting some black soot resedue in places along the weld. i highly doubt that it is coming from dipping the tungsten. my machine is a dynasty 200dx and im running about 180 amps, 75 balance, and 110 herts frequency pure argon about 15lbs, 3/32 cerated tungsten with regular cup, and 3/32 4043 filler. do my settings seem correct or am i doing something wrong.

[Tanner]

how are you cleaning your metal? I think thats the culprit

[Andy249]

My personal preference for TIG welding aluminium is using Zirconated Tungsten. I have welded 6000 series aluminium extrusion using both 4000 and 5000 series filler rod and have never really noticed any soot. I would like at ensuring that your preparation surfaces are nice and clean and that there isn't any contamination coming from that. Is your cup nice and clean and free of bits of molten ally? Make sure the seals on the cap aren't perished either as sometimes they can draw in a bit of air meaning you can get a bit of oxidisation in your weld pool. I had a problem getting a TIG to weld ally properly once and in the end I stripped the torch and replaced all the consumable parts and hey presto the problem disappeared. Have fun, it can be frustrating!

[Mike W]

I sometimes have a problem when I don't pay attention to keeping the end of the filler rod protected by the gas.