Tig welding aluminum question

[regal2800]

When Tig welding steel or mild steel in a T joint i get the puddle going and with the torch i can drag this puddle as long as i want and fusion weld the joint. Obviously i add filler at appropriate intervals but never the less i get this puddle and it makes for seamless addition of filler. Now for some reason when welding aluminum i can only get this puddle going 50% of the time. The other 50% of the time i can get a puddle going but it never fills in at the root of the weld and kind of keyholes (without burning through the other side). I have to add filler to close in the root. The final product looks good but i know something is wrong.

I have tried everything from higher amperage, torch angle and tungsten distance from the work piece. Can anyone give me advice on what i am doing wrong?

My coupon samples are 1/8" 6061 clean. (Cleaned with acetone and stainless steel brush.)

Machine is dyn 350. 70% balance, 110 hz freq and 150 amps.

I have added 2 pics

IMG_2071.jpgIMG_2073.jpg

[Country Metals]

That is a secret that no one has ever figured out for 100% of the time. Aluminum is a very fussy material. I have never been able to fuse a plate to a fitting before, it just doesn't want to.

[shovelon]

What tungsten are you using, and how are you grinding it?

Are you breaking the oxide layer with a clean wire brush and solvent?

[welding insp.48]

When Tig welding steel or mild steel in a T joint i get the puddle going and with the torch i can drag this puddle as long as i want and fusion weld the joint. Obviously i add filler at appropriate intervals but never the less i get this puddle and it makes for seamless addition of filler. Now for some reason when welding aluminum i can only get this puddle going 50% of the time. The other 50% of the time i can get a puddle going but it never fills in at the root of the weld and kind of keyholes (without burning through the other side). I have to add filler to close in the root. The final product looks good but i know something is wrong.

I have tried everything from higher amperage, torch angle and tungsten distance from the work piece. Can anyone give me advice on what i am doing wrong?

My coupon samples are 1/8" 6061 clean. (Cleaned with acetone and stainless steel brush.)

Machine is dyn 350. 70% balance, 110 hz freq and 150 amps.

I have added 2 pics

IMG_2071.jpgIMG_2073.jpg

tig welding as with any type of welding ,when you have problems ,go back to the start. your powersupply.are you useing 100% pure tungsten?
start from the right and go right to left,if your right handed.
ac high frez.
your weld looks good ,but i know a few little changes and you will be perfect.
most times it's only a little change ,not a big one and you got it perfect.
one little hint about aluminum,pre heat(a little) it will flow better.

[regal2800]

I am using 2% lanthanated tapered with a flat spot at the tip.

yes all alum has been cleaned with alcohol. Experimenting with what affects wire brushing has on welding alum.

[shovelon]

I am using 2% lanthanated tapered with a flat spot at the tip.

yes all alum has been cleaned with alcohol. Experimenting with what affects wire brushing has on welding alum.

Ok, 2% lanthanated is what I like, but it needs a while to "break in", or slightly season the tip. I grind my lanthanated to a near point with a pencil like taper. Or just grind it to a point and let it melt back a tad. That point gets tight into that corner.

You might try the default program, as I find it works very well on sheet alum. As far as cleaning, it the oxide layer is thick, the arc will dance around until the layer lifts off.

Sometimes you just have to lay into the pedal and move the filler rod in fast or the joint will open up. I have found that 5356 gets a puddle started a little better.

Keep trying.

[go2building]

I would go to at least 175 HZ and 75 on the balance