I recently got around 35 plaster molds for free the other day of various sizes. I tried to pick only the ones that were in good condition, but I couldn't resist getting a few in rough shape. I have one very large mold that looks like a old milk can. The bottom of one half of the mold has been chipped away and needs to be made flat again. A few others have some dings and scratches on the outside of the mold.

any suggestion on this?

Thanks,
josh