Frame rust

[Willie B]

Sometimes you have to suspend the feeder and have the gun hanging down. Hard to do with an all in one machine. Same reason aluminum is major problem to feed with a standard gun. A short gun with the smallest liner is about all you can try.

What I haven't tried is the spool gun. Bought the spool gun 12 years ago. I then immediately bought the Miller Dynasty 280 DX. I fell in love with the TIG machine & haven't found a situation where I felt the spool gun might be better.
I did consider spool gun for aluminum recently. We have a satelite firehouse, one bay has a low doorway and a low ceiling. The 1976 mini tanker is getting crusty. Bought a newer truck low enough, but off the shelf tanks are tall. There was discussion of building a tank, but the decision makers chose someone else to build it.

 

[Welder Dave]

Tig on aluminum is better once you get the hang of it. Dynasty 280 DX is a great Tig welder!

 

[Willie B]

Tig on aluminum is better once you get the hang of it. Dynasty 280 DX is a great Tig welder!

The change to square wave was amazing for aluminum. Cathodic etching is how the surface oxide is removed for a clean, fused weld. Sine wave power loses ionization 120 times a second. Ionization of the gas must refresh to get the EP half cycle. A 60 HZ, sine wave machine is stuck at 50/50 balance, sending too much heat to melt the tungsten. Square wave is as effective in cathodic etching at 75% Electrode Negative, sending more of the heat to the pieces being welded, less to distort the tungsten.

Welded a bunch of cracks on an aluminum dump body that had once hauled asphalt. Each had been welded with a spool gun. By cutting out the crack leaving something to fill I got full penetration repairs. It held up very well. I was amazed how effective the cathodic cleaning action was at 60% EN.

 

[Truck Shop]

Cloverdale Paints.
#71007
#83040

 

[Welder Dave]

It's nice when you can adjust the AC balance for dirtier or different thicknesses of aluminum..