Thanks for all the replies guys. I don't see/hear much about it peeling off just a personal fear. Suppose I got to break down and try it at some point and see for myself. I like the oil drain prospects but also sealing the casting pores. Like concrete cast iron seems to dust eternally.

Eastwood is where I bought the can I have. Used a gift certificate I got to there on it. Wonder if its still good? Been years on the shelf but don't think its frozen ever. Anyway thanks again.