Welding Tips and Tricks

I have been practicing running beads on aluminum around 26 gauge. I have no problem running beads, but when I try to do but welds the edges blow out on me. I am using an HTP Invertig 221, .040 2% lanth tungsten, with number 5 gas lense. Running about 15 scfh argon. Tried to go lower but tungsten always got contaminated almost immediately. I have tried multiple amps, and pulse modes. Please give any advise.

Try striking your arc on the filler and then move it to the base metal. You'll get a little ball of filler ready to wet out and you'll quickly have more metal there to help control the heat. Keep the puddle satisfied and frequent dips will also help with your heat control.

What diameter rod are you using? If it's too large, you may need too much heat to melt it while keeping that very thin sheet intact.

26 gauge - holy cow that is thin!

What are you trying to make? Maybe need a redesign for lap welds?

Jsfl welcome to the forum.

One thing that may help to to turn yout gas down. When your running low amps like that you don't want as much gas flow. When I do .030 aluminum at work, usually outside corner joints and butt welds, I run about 10 cfh number 4 defuser set up.

You could also try welding it on dc ep instead of ac.

ajlskater1 wrote:You could also try welding it on dc ep instead of ac.

Good idea - remember to use a larger tungsten though.

I've experimented with this and too small of tungsten will eventually blow up

DCEP amps
1/16" tungsten 10-20 amps
3/32" tungsten 15-30
1/8" tungsten 25-40

We did it with a DC only ThermalArc 95 and it worked great

Thanks for the feedback. I will try dc and see how that works.
I can usually get a bead going then after 1/2" to 1" in have problems. As for cup size 5 is the smallest I have now in gas lense. I have a 4 regular cup. As I said. I tried less gas flow around 6-10 cfh but the tungsten turned black and would not keep a point . Not sure why. I will try again and see what happens.

Also I am using .035 mig wire as filler.

Wow - I don't think I'd even try 26gauge in ali !
Is it possible to use a copper backing strip to help with heat soak & blow through ?

If you try the dc ep I would guess a 1/16 will work best but mayb 3/32 depending how fast you weld. The gas just help with arc stability at lo ower amps so it can allow yoy to weld at slightly lower and be in more control. Ma yb try a new defuser, it miggt be slightly plugged and at low gas everything little matters more. Copper would also greatly help if possible.

O and not how long of a weld you are trying to f2f o but unless you have a awesome I wouldn't weld much more than lije 3 or 4 inches, just to help with distortion and heat satyration and back step your weld if it is a long weld.

try backing it up with some copper! i save all the pieces of copper just like jody does! its handy for stainless as well

Got better results last night. I used a regular #4 alum cup and was able to turn gas down. I also adjusted my freq. to 50, bal 50. Had the pulse freq. at 10 pps, 25% duty cycle, and. ran around 35 amps.Played with that and never got around to switching to dc. Still will try that later and see how it works.