Have an alum. Myco trailer and the aluminum mag wheels have become pitted from dipping in salt water.

I've tried Speedy metal polish, but it doesn't remove the pitting.

What is the best process to bring the wheels back to new?

I took my wheels and had them powder coated silver came out bad a$$. You can powder coat them any color including clear, if you get them cleaned up agin. The clear protects them very well , lots of boaters hove done this.

I bought Weld's for my Excursion. Within 2 months, they looked like $hit. Pulled them off and had them sandblasted. Then I had them powdercoated in chrome wit a clear overcoat. Came out a very unique silver- not pimp-chrome but attractive. Nothing sticks to them either. Cost me $200.

If your wheels are pitted, they need to be sandblasted VERY THOROUGHLY or the PC will react and mottle. Ask me how I know this

I was hoping someone would have a sanding remedy for me....

Many years ago I redid some trailer wheels. I took an old dryer motor and screwed it to a board. Found a long v-belt and mounted the rims to the trailer without tires. Started the motor. Then I worked them down with sandpaper. I used a couple of cut-down allen head capscrews in place of lug nuts. It bevelled the leading edges of the mag slots but it looked OK. The problem came back though- it's bare aluminum after all.