Tig welding 1/4" aluminum 1st attempt

[H80N]

Confuse the newb some more.Etching, buying helium mix... come on the guy's machine is underweight for doing it anyways.He don't have enough amps welding on a heatsink.

That's nice.... but not very constructive.... if the OP was looking to buy a larger machine ... am pretty sure he would have asked for purchase advice...
the idea is to help him accomplish the task with the welder he has... ... it can be done and is every day.... sure the welder is marginal... but with the advice from Shovelon...and the others.. he can do a decent job of it.... just part of the learning curve toward the skillset to get the job done with the equipment at hand....

[Goose14]

Wow, I really appreciate all your responses, ill try 1/8" tungsten, but does that mean changing cup and filler size? Ill definately try clean preheat clean as well. I did notice the welds looking better after the piece got super hot from previous passes. wish I could post pics to thread but they only upload to profile photos.
And yes im confused about what exactly etching means or how nackfilling is done
I also take it that my settings apart from the penetration cleaning balance were ok?
Once again thanks for the great advice

[H80N]

Wow, I really appreciate all your responses, ill try 1/8" tungsten, but does that mean changing cup and filler size? Ill definately try clean preheat clean as well. I did notice the welds looking better after the piece got super hot from previous passes. wish I could post pics to thread but they only upload to profile photos.
And yes im confused about what exactly etching means or how nackfilling is done
I also take it that my settings apart from the penetration cleaning balance were ok?
Once again thanks for the great advice

Goose

you might download and study the TIG Handbook... it is a wealth of basic info and a good general tig reference....it should answer the majority of your questions... and besides it is free...

http://www.millerwelds.com/resources/TIGhandbook/

[Goose14]

Thanks for the tip ill check it out

[Drf255]

Chem Etch the joints, preheat, and get yourself a bottle of Argon75%/Helium25%.

Backfeed into the corners if you have the talent.

Back off your balance as far as possible until your tungsten balls back too much. You are not allowing the puddle to form on the surface with your balance at full penetration. The puddle will just not glaze if you are at full pen on the balance knob.

Good luck.

Gotta a question on this one.

Not sure on Goose's Lincoln, but my Syncro 250 transformer topped out at 68% EN with the balance set on MAX. Wouldnt lowering it more put less heat into the part?

[shovelon]

Gotta a question on this one.

Not sure on Goose's Lincoln, but my Syncro 250 transformer topped out at 68% EN with the balance set on MAX. Wouldnt lowering it more put less heat into the part?

It would put less heat in the metal and more in the gap.
I see too often the balance set too much towards penetration and not get an adequate amount of cleaning. When you can clea the surface it helps with the glazing that forms the puddle.

YMMV

[Goose14]

What is chem etching and backfeeding, also I checked out Tig handbook it says to sharpen tungsten then flaten tip? Im using fine flap disc to sharpen all I have is 41/2" grinder

[shovelon]

[QUOTE=Goose14;287840]What is chem etching and backfeeding, also I checked out Tig handbook it says to sharpen tungsten then flaten tip? Im using fine flap disc to sharpen all I have is 41/2" grinder[/QUOTE

Chem-etching is essentially acid or alkaline etching for removing the oxide layer. Backfeeding is tig welding the opposite direction you would normally weld, or pulling.

Flatening a sharpened tip is counter-intuitive to me. If a flat gets on my tungsten, I sharpen it. The flat on the end of the tungsen changes the arc characteristic to a more columnar arc. I however do that with frequency.

[Goose14]

Got it

[Goose14]

Do I "mash" down on the pedal tp create an instant puddle or do I start off slowly

Also im sharpeningy tingsten withfine grit flap disc and it doesnt seem to be balling up evenly but it does have a controled arc, whats thebest way to sharpen 2% thoriated tungsten