I am having trouble getting my flat fillet joints to run acceptably. I am hoping you guys have some tips. Here is the story. I am practicing for the aerospace aluminum (6061 t-6) cert.. The plate is .050". 1 G comes out great tons of penetration, the rod flows like butter. Not so for me with the fillet. Here are the particulars: I am using a Dynasty 200, set at 100 amps with 75% balance and 150 Hz. I've tried experimenting with the hertz as low as 120. This helps a lot for flow but, doesn't seem to work as well as the higher frequencies ( 135 - 150). I usually use 3/32 rod (4043). I can also run it with 1/8 but it is much harder to keep the weld small. The plates are setup in a jig with purge gas. My main problem seems to be heat, as in not hot enough. When I run what I think is an acceptable plate, the weld is flat across but, the top has little "dots" where the rod cooled the puddle. Also lately I can get the first inch to run perfect but, then it is like the plate sucks all the heat out of the puddle. I've been increasing the amps slowly but, still the middle often looks cold. Also, The back side can have 0 burn through and preferably no heat marks. This is starting to make me crazy because I still have a 1" tube to move on to in a 6 position. Help!
without pics, just going by settings and your description, it sounds like you're welding way too damn hot. that 'cold' look in the middle is likely caused by overheating. if you're getting the first inch perfect, thats a clear indicator that you've got plenty of heat at the outset and afterwards you're too hot. you're welding small (right?) thin aluminum coupons, those are going to heat up to 350+ degrees SUPER fast. try setting the dial for say 65-70a, run the first inch flat out, then back off. it should look nice, no spots, no burn through, no sagging.