[Tigosaurus]

Experimenting with my newly owned used Lincoln Precision TIG 185 using thin wall aluminum. I tried a lap joint and went well. However, when I tried to use that piece to do a filet weld , had problem creating a joining puddle between the horizontal piece and the vertical piece. Using 1/32 Aluminum "flats"; 15 cfh argon with a 17 size torch; a number 7 cup, 1/16" 4043 Al feeder rod, also 3/32 tungsten. The weld "cleaning" action from the welder started a nice puddle on the horizontal piece, then the vertical piece, but both puddles got "dirty" and wihdrew from the joint creating a gap.Not quite as slick as Jody's videos. Any suggestions?

[MosquitoMoto]

Hey there.

How much cleaning action do you have dialled in? And how clean is the material you're welding?

Can't imagine why the puddles would go 'dirty' on you. On these joints I start with a fairly sharp electrode and move in as tight as I can - keep your arc length short or it will wander from one piece to the other.


Kym

[motox]

maybe you dipped the tungsten or touched it with the rod.
check you gas fittings as well.
craig

[Tigosaurus]

The material was clean and I think percentage was right, but I believe there was some splatter on the electrode. The sharper tungsten helped a lot on the start. I tried again with much better results. Thanks!

[LtBadd]

If the vertical piece is rolling up, creating a hole then you may be drawing in air (into the molten puddle) from the backside. Also for that thin of material I wonder if you could get away with a 1/16" tungsten, this would allow you to get closer to the joint. I know the Dynasty could do this, not sure about the Lincoln

[Tigosaurus]

There was an improvement, but I'm pretty sure in other situations that could be the problem. I will try getting some 1/16 tungsten electrodes. Anything else can be done in a vertical or near vertical otherwise open air situation to prevent air being "back drafted" into the weld? Some of the boat repairs with thin aluminum will be a similar situation.

[big gear head]

Use some aluminum foil and build a dam on the back side to catch argon that flows around the end of the part being welded. This can greatly improve coverage. You can also use a block of some other type of metal and sit it on the back of the part so that it traps argon and prevents air from getting to the weld.

[LtBadd]

There was an improvement, but I'm pretty sure in other situations that could be the problem. I will try getting some 1/16 tungsten electrodes. Anything else can be done in a vertical or near vertical otherwise open air situation to prevent air being "back drafted" into the weld? Some of the boat repairs with thin aluminum will be a similar situation.

You can use the filler to take the brunt of the arc, as a puddle begins to form move the filler into the arc zone, in contact with the weld joint (not in mid air), continue to add amperage and form a puddle as the arc consumes the filler.

Hope that makes sense

[Tigosaurus]

Tried the 1/16 tungsten and feeder rod, definitely helped with control on thin material, especially when welding some small conduit on another one of my projects. Also, using the feeder rod gap-fill technique has helped with the aluminum and conduit. But the big solution in this situation was the aluminum foil. That was the ticket, trapping the argon behind the aluminum. All helped though, THANKS! to each for your response. All that is left is a lot of practice, but the positive results is very encouraging.