Please help - aluminum fillets

[MrMega]

Ok so I can weld beads like a pro now, but I cannot weld fillets to save my life. I am trying to weld fillets on 2- 1/4" plates. I have tried different nozzles, different size tungsten, different tungsten exposed length, gas flow, etc. but I have the same result every time. I cannot get a puddle to form at the joint. I can get a puddle on one piece or the other. If I get puddles on both sides I'm at 200 amps and it puts out so much heat that my filler rod just drops off before I can get it close enough. But it still won't form at the joint. I can sometimes get it going but I have to put so much power into it is just a mess and melts off the edges of the material. I am typically using a 3/32 2% thoriated tungsten and #6 cup with about 20-25 cfh flow rate and 3/32 4043 filler. What am I doing wrong? Like I said I can weld beads perfectly on this material with the same setting.

[Rambozo]

If you are using a pedal, it often helps to give it an extra blast to get the two pieces to fuse, then back down on the amperage to continue the weld. Also practice directing the puddle with torch position and angle. You can create a puddle on one piece then wash it up to the other. Many ways to skin that cat, it just takes practice.

[sportbike]

You will likely need at least 200 amps to weld a fillet in two 1/4" plates.
A #6 cup is pretty small for using a 3/32 tungsten and welding 1/4".
The regulator you have may be calibrated in liters per minute, in which case you will likely be better off with about 15lpm.
If you have a variable frequency machine, try increasing the frequency. This will focus the arc more and allow you to get into the corner better.
If you are melting the filler rod, you dont have the base plate hot enough to be dipping the rod. Need to have a puddle before trying to dip.

[Poptm]

Maybe your torch angle is too far forward (common cause of rod just melting away). Maybe your tungsten isn't close enough to the root (common cause of not get a single puddle to form). Try a tungsten to root spacing of no more than the diameter of the filler rod. See how that works. Are you cleaning the metal to remove the oxide? Doesn't help if you are not, especially while learning. Are you using AC (I assume so from you other statement about being able to weld other joints with the material)? Keep at it, it will come.

[MrMega]

Thanks for the advice. I tried again using 1/8" plate with a #4 cup, increased the cleaning and frequency and got the tungsten very close to the joint. After getting a small puddle I tilted the torch pushing it slightly forward to get the filler rod in it. I was fairly successful doing this for about 2" at a time.

[Poptm]

try moving faster now, once you get every thing started.