Cleaning American Flyer sintered trucks

First off wash them well with a degreaser. Dawn dish liquid should work well. As long as you plan on painting them anyway I would brush them with a brass bristle brush first to remove heavy deposits, then if the white stuff is still present soak them in white vinegar over night. Be sure to deactivate the vinegar when you remove them by brushing with a baking soda solution, rinse and let dry well before painting. You might want to primer coat them first before using a finish coat. Hope this helps you out.

Thanks for the excellent advice!  I’ll give it a try.  

I usually bead blast them to bare metal, then reblacken using gun blue. Looks perfect factory.

What equipment do you use to bead blast them?

Basic blasting cabinet from Harbor Freight. Get 50 lbs of 80 grit glass beads, and a medium compressor.