Getting a smaller bead on aluminum?

[Mike W]

When doing a fillet weld on 1/16" thick aluminum I get a much larger bead then I would like. It seems the main problem is getting the fillet started. I get the two pieces molten and use the filler to get them to flow together.

It always seems that I am using too much filler to accomplish this and the molten pool is spreading out too far. The trick seems to be in getting the two pieces to flow together. On a butt weld I do not have this problem. Any tips? Thanks.

[Customwelds]

Hmm...a 16th inch is not very thick, maybe try to use as little filler as you can, make a tiny tack weld at the start to hold it and another where you'd like and see if that would be enough to get a good puddle going, then when you proceed to go, see what it looks like w/ little to no filler added. I've never welded a lap joint on that thin of aluminum before, so this is just what sounds like it would work to me. Hope it helps!

[Mike W]

Thanks, where can I get one of those neat welding avatars?

[Customwelds]

I "borrowed" mine from www.cyberweld.com on the Esab TIG welding page, hehe. Just go to different welding sites, find a tiny picture and "borrow" it.

Hey Mike. a couple of questions.
What size tungsten are you using?
What size filler are you using?
do you know what the material is your welding?
I have an SD180. I use 1/16" pure tungsten. and .030" 5356 mig wire. welding on 6061 aluminum.
It takes a lot of pratice, and a deft foot on the pedal. as soon as the puddle is established back off on the heat. Using .030" filler really helps.
good luck.

[Mike W]

I am using 1/16 pure tungsten. I use 1/16 4043 and also some smaller mig wire. I would probably be better off with the mig wire but it doesn't go a long way.

I think my main problem is getting a good start. On a butt weld, once I get started I can keep moving pretty good. The fillet is just harder for me. Steel is no problem just the aluminum.

[Customwelds]

This is an aluminum lap i did at school today on 1/8" plate.



To get it that way, i just upped the heat til i got a puddle to start on both plates, dipped a TINY bit of filler on them to get them to flow, then backed off the heat just enough to keep it hot enough to melt off the top plates edge and flow the puddle with the filler and plates. I was using 1/8" tungsten and 3/32 4043 filler. Maybe these tecniques will work for you.

PS, the flash caused a lot of discoloration, aluminum sux to photograph, it almost looks like stainless!