... which was somewhat effective on the blades but not so effective on the hub/shaft. This year I'm planning to try ZRC Cold Galvanizing Compound spray, which claims to be 95% zinc by weight in dry film. I have not verified that this will hold up in an underwater application in saltwater on spinning props, but they do use it for cold galvanizing docks and bridges and this seems to be the best stuff for that. Here's a case study illustrating an underwater application. http://www.zrcworldwide.com/case-studies/us-dept-of-interior/

It's an experiment.