Boat paint - opinions?

[TomLS]

My work premises is in a wharf, where there are a lot of boat restoration companies that deal with huge ships.

As the steel on ships has just about the hardest life there is, so it must follow that their paints are excellent at corrosion and impact prevention, so with my cheapskate hat on, I was wondering other people's opinion on trying to source some surplus paint (and given the size of some of the ships, that could be a lot!), to paint the underside of my moggy before waxoyling? Or is it just best to stick to tried and tested car paints?

[MarkyB]

Any idea what sort of paint it is?
I would guess some kind of epoxy concoction with stuff to keep the barnacles and seaweed off

[Dean]

According to FROST they paint boats with POR. Perhaps the frost website could give more info on whats in it?

http://www.frost.co.uk/automotive-rust- ... 473ml.html

[MarkyB]

Millionaires might use POR 15 I guess.

A chat with my mate who had a boat for a while suggests the stuff they use on the bottoms is quite nasty poisonous stuff.

I'd go for the stuff they use higher up, barnacles and seaweed are never going to be an issue on a car anyway.

[simmitc]

Below the waterline will be a form of anti-fouling. Some is hard, but much is soft - "self-eroding" to keep the toxins near the surface. Both types are applied over a sound base coat, and would be wholly inappropriate for car paint. Topsides paint might be more suitable, but I'd go with car paint. I did once paint an entire Traveller with International's boat paint. It looked great for a year or so, but would never take a polish like cellulose or two pack, although on a boat it was perfect for many years.

[Quendil]

As posted on the LR Series 2 forum on the question of POR 15

I used to use POR paint on various restorations but would not use it again on anything. You may think your chassis is clean but give it a couple of years and it starts peeling off. I discovered this on my Morris Minor van last week and I hand sand blasted the chassis before painting it. I do however like the marine cleaner and metal ready stuff.

Cheers
Dave

[chickenjohn]

The problem I can see with using boat paint is that boat paint is designed for boats and the marine environment and not for cars and the road environment.

Whatever undercoat you put on a car would be subject to more varied conditions than the paint on a ship- including more abrasive action from stone chipping, grit, mud and well as rain and sometimes hot temperatures and in the winter rock salt and snow on the road. It seems to me that the sea is a more constant environment for paint. Plus, a ship is made of thicker metal than a car, so flexing and movement/vibration is less likely to be a problem on a ship than on a car body.

Foe these reasons, I think car underbody treatments such as anti stone chip paint, seam sealers, and a top coat such as chassis black, then finally topped with an underbody wax is more suitable than a marine paint on the underbody of a car. Also where surface rust has wire brushed off the underbody then a zinc primer is going to be better for rust inhibition.