A friend emailed me the other day asking "how to get the gray off his engine". He had boiled it in a pan on the stove with Dawn Power Dissolver.

He says he is going to bead blast it now.

But just a warning on bead blasting. Make sure your bead blaster media is new and clean. I cleaned a muffler once in a bead blaster and it rusted. I was trying to figure out why aluminum rusted. Well, it had little steel particles stuck into the aluminum by the blaster. The steel was in the beads from a previous job.