I welded a batch of two cracked cast aluminum wheels. The first one was a Volvo OEM wheel. I was actually quite impressed by its light weight!
The second one was an Axxis aftermarket wheel.
The volvo wheel had a "y shaped" crack.
The Axxis had a straight crack.
The process for preparation is the same... remove all paint from the surface around the crack, and vee out the crack with a carbide burr.
I used a dental scaler to scrape a bunch of crap out of a crack that relatively wide:
Before I weld them, I like to do some more cleaning (or rather to "test the cleaning") by running a low-amp arc over the area to be welded until the area is completely etched and is arcing without producing lots of smut (black or other colored, soot like powder) where the metal needs to flow. This is actually one of the more dirty wheels, but this shows how it looked before I began to final, high-power welding.
(continued next post)