I previously posted some basic questions and pics, as I am learning to tig alum. (I should say "TIG weld period" for that matter, as I have never done it before). In any event, I took everyones advice from before and tried my best to follow. The most significant thing I noticed was how the bead shape changes as the part gets hot. I can see now why preheating is suggested for larger parts. It seams as the part gets hotter the bead gets a little wider and not as tall, (I'm guessing better penetration at this point). You can see this in one of the photos. I'm guessing letting off the heat a little to keep the bead even is the solution there?? Another thing I noticed was the affect of the aluminum melting under the oxide layer, forming what looks like a bubble. I only had this happen when tacking the parts together. This makes it basically impossible to fuse the two parts, (stop and reclean). It would also apear that the two puddles would repel eachother as I would try to add filler?? Let me know what you think. Thanks in advance. This is what I used this time.
.08" 5052 Material
1/16 2% Thoriated
Gas Lense #8 cup (pure Argon 13 - 15 cfh)
.06" 5356 Filler
80 - 100 Amps / 100 - 120Hz / 20% (more than 20% really seems to take a toll on the tungsten)
Stainless Brush and then wipe with acetone (parts and filler)