If you can manage to clean the silver paint and pitch from the hull the Interlux Bilge Coat does work well.
The bilge coat wont adhere to any of the pitch residue. The goo will soften and bleed through.
Also need to etch the Aluminum if you choose to paint. That Interlux etch will make you sterile so make sure you have plenty of fans and doors/windows open.
I used all kinds of thinner and gas to clean that damn tar/pitch. Scraping and filling grocery bags with that crap. Ruined my back for few days but with that Bilge Coat the surface is like an epoxy gloss which, is very easy to keep clean.
Or just leave it bare AL.
If I had my way I'd pull the engines and fuel tanks and blast the engineroom clean, etch everything and spray a few layers of that Bilge Coat. And then drop in a set of Diesels with IPS drives.....There I go, daydreaming again.
-K
1986, 32' Sedan, twin 360ci, 275hp Chrysler's w/ K&N flame arrestors