Welding Tips and Tricks

Hoping someone can help out with this. I haven’t struggled welding anything 1/4” or below, getting a nice shiny stack of dimes, but the job I currently have is whooping my ass. I haven’t tig welded too much thick aluminum and it seems like everything I knew has gone out the window.


Project consists of:
Two 6061 T6 kaiser 4027 plates measuring 3’x 1’ sandwiching three 1/4”x 6” tubes.

Powersource is a dynasty 350

I’m having the hardest time getting a bead larger than a 1/4”, and also getting a nice wetted out appearance. Most of the time the opposing parts want to reject each other, and when adding filler, it doesn’t want to accept it. When I can get things going, it never goes smoothly, and I’m typically left with a wide cleaning zone.

The plates were water jet cut and came back stained like a coffee table. The plates were acetoned, then da’d. The areas to be welded were, hit with 60g flapper, then 120 Roloc disc, then wire brushed, then acetoned.



Settings:
#7 cup tried anywhere from 10-20 cfh
1/8 lanthanated, both balled and pointed
Tried anything from 60hz to 200 hz
Tried 65-80% balance
Maxing the machine out on amps and running 300EN and somewhere around 230EP
Using 1/8 5356 filler

I can’t seem to grapple this weldment. I replaced a guy who passed and he was a wizard. I was told he never had anything to preheat and his stuff turned out amazing (a display of the unit is assembled for tours). The welds are perfect, with a small cleaning zone

I have no idea what I am missing to achieve the results the legend did, and it’s driving me insane.

Hopefully the pictures upload, I’d like share the difference in mine and his work.

I’m highly appreciative to any help!

looking at a weld calc i would say your machine and setup is under sized.
so more than likely preheat or helium mix was used (or both).

on your practise plate are you getting a good puddle quickly?
if the filler is not melting when feeding into the puddle it means the puddle is to cold (or not really a puddle).

15 cfh
60Hz to drive the heat into the material
72% AC Balance
300 Amps EN
250 EP
Advanced Square Wave would be my choice.

Be aware, once the part starts getting heat soaked, your weld bead will start to diminish in crisp dimes. You can jam more filler in to really chill the puddle, or you could pedal pulse just a bit to reduce the amps while you add filler.

Arc length and torch angle will control your HAZ a lot with that configuration. You have plenty of machine to weld that thickness and with adjustable amplitude, you can easily drive the heat into it.

Doesn't sound like a setting issue but possibly more of a technique thing to me.

When I'm welding heavier sections and want a bigger bead I find the only way to achieve it is either bigger cup or pull back the torch and ramp up the gasflow to compensate.

I do that once I've got the root of the weld to puddle and fuse while building the weld size out while pulling back till it's where I want it.

Oh and I run a #8 for heavier stuff, anything smaller just seems to get melted up or shatter