Looking for good undercoating for steel hull

[downtown7486]

I recently bought a steel hulled houseboat. I am working on cleaning and scraping outside and inside of hull. I am new to steel hulls so I was wondering if anyone can recommend a very good undercoating or sealer (as opposed to paint) for exterior and interior seal stop or prevent rust. Thank you in advance.

[S/V Alchemy]

You generally want a two-part epoxy barrier coat, but you may also benefit from some sort of galvanzing layer/zinc primer. You may wish to ask your surveyor about this, but essentially, the treatment is quite similar to restoration of car body panels: remove rust to bare metal, top immediately with zinc-rich primer, coat in a waterproof barrier coat, and then antifouling that won't react with metal.

Devoe makes something called "Rust Bar" and Pettit makes something called "Metal Prep". I've had luck with both, but you should get someone local to you to clap eyeballs on your particular boat and make some recommedations.

I have found this boat very helpful:



It's important to understand why boats rust in order to properly stop it. Possess this understanding and do the work, and your metal boat will likely last as long as any plastic boat. It's more than just about paint.

[mrohr]

Hi: Do a search on hot zinc galvanizing;must be done after a proper sandblast and no cutting corners!!!From there do your homework on the best (and proper) coatings for steel. Having stated all this,it is a truism that steel boats rust from the inside out, so be warned.
If it were not for coatings and paint systems,steel would be totally unsuitable for any salt water environment.

[Honey Ryder]

simple. sandblast inside and outside and then paint with a high quality epoxy like ameron (two coats). then paint over the epoxy with a topcoat (the epoxy degrades with exposure to uv). if you do this then the boat will last longer than you will live.

anything else is a false economy. rust is like cancer. even a speck of rust will grow with time and oxygen. add water and salt and it speeds things up. eventually it will all turn to rust.