Well here is what I got. I decided against using the alumiweld rods. I had some aluminum wire lying around from a picture hanging project. I decided to try to TIG it with my DC welder. This was a longshot. DC and aluminum is a no go. I saw some videos on YouTube that showed you can kind of cheat and TIG weld aluminum with DC, argon and reverse polarity. This over heats the tungsten electrode so I welded in very short bursts. I decided it didn't have to be pretty. I just wanted to cover the cracks.
It was a cumbersome technique. I had to stop and sharpen up my tungsten several times. I also was limited to single tack welds. The arc also just wandered all over and didn't really behave. It needs a really short arc for things to happen...so I dipped a lot.
But, hey, it's welded! I ground things down and the cracks are definitely fused. Fun experiment. I think this casting is almost all aluminum. It welded pretty cleanly and didn't pop much like pot metal.
Enjoy the photos.
Cracked aluminum plate. Cast.
Cracked all the way through.
Poor man's DC TIG welds on aluminum. It's ugly but the cracks are fused shut.
Found more cracks and welded them. Ugly...it was really hard to control the arc.
Probably my best weld.
Ground down, cracks gone. Fused back together. Yes!
Nothing to be proud of, but the cracks are repaired. Nobody will see them in the door. Definitely AC is the way to weld aluminum but I had to try this hack. I don't weld enough aluminum to pay up for an AC welder.
The point of this experiment is that the castings are very weldable. They aren't really pot metal. At least the aluminum casting in the window regulator is not pot metal. And they can be welded using this awful reverse polarity hack in a pinch on a DC TIG with Argon. It looks like a robust fix.