My sunday project - update, finished this joker

My little brother and I are about to spend the day giving this old yard ornament a little attention. We plan on sanding it, flex-sealing the leaks, and repainting. Whats the best way, after sanding, to prep the surface for the new coat of paint?

I was thinking acetone but I'm open to suggestion. We'll be outside going to town with wire brushes but I'll check back in a few, TIA.


Update, took it out last Sunday and it didn't sink.



Thanks to everyone who helped, paint seems to be holding up really well after finding the right primer.