Bottom painting

[TOPTON]

I put that title on just to draw attention to this thread.

I bought an old GRP 17ft Fletcher speedboat as a project. Things are coming along nicely on the dry side but now my attention is on the wet side of things.

Someone has painted the hull really badly. The white paint is peeling off like peeling skin off a sunburnt back, a pressure washer took most of it off. Obviously it wasn't rubbed down and prepped properly and the hull is now almost all red, none of which is peeling or flaking. After I give it a good sanding with 80-100 grade, what would be the best (read cheap) paint covering for primer/topcoat below the water line??

I've resprayed grp cars in the past so spraying or painting is not a problem

I'm not looking for showroom shine, just a good durable finish. I've baffled myself with googling, there are so many different options.

[Moulder]

It sounds like what you have taken off is antifoul.

If the boat lives in the water you could look to put some back on again.

[Steve_D]

If you are now down to the gel coat of the glass fibre then remember you will need to use an etch primer before paint. I don't know but will assume you would also need to do this even if you were using anti-foul.

Steve

[Candellara]

Moulder said:

It sounds like what you have taken off is antifoul.

If the boat lives in the water you could look to put some back on again.

Correct. It sounds as though you have removed the anti-foul coating. It's pretty toxic stuff so make sure you wear gloves and a mask.

Anti-foul is a biocide? that ensures no weed growth etc and should be coated to about an inch or so above the water line of the boat. As another post states, makes sure you etch prime if you're now down to the gel coat. All of this is assuming you want anti fould and you're keeping the boat in the water on a mooring

[TOPTON]

I'm 99% certain it's not anti-foul coating. The boat lives on a trailer and judging by the amount of botch ups I found, I think anti-foul coating would be the last thing they would spend money on.

Its been too wet to do anything today but etch primer is a good shout when I get back on to it

[paintman]

Decide what boat paint & colour you want to use then follow the manufacturer's instruction re prep, undercoat etc.
Did the inside of mine last year using Hempel top coat - what it was painted in by a previous owner - & followed the instructions which were basically clean old coat (which was sound) degrease, wet sand to key, dry, degrease & paint.
Used roller & tipped off with good quality brush. If I was going to do it again I'd thin the paint a bit more but it's fine as is.

[gazzarose]

Just to clarify, are you talking above or below the water line? If below your best bet would be to antifoul it, it'll cover a multitude of sins and after a coat of etch primer should last well. If above the water line what about a vinyl wrap? Are you going to be keeping the boat on a trailer or in a marina? If in a marina then paint jobs can look chap quite quickly from rubbish from.rubbing on fenders.

[TOPTON]

Late reply but I'm here.

It is not down to the gell coat. The hull is showing red after I've peeled most of the flaky stuff off. If I sand that away a bit then it starts to show blue, so the hull has been painted before. The red is not peeling at all but is not what I want. I need a hard wearing white coat.
It will live on a trailer while not being used so anti foul is not required, a nice glossy coat is though.

So i think my choices are>>>> Acrylic, Enamel or 2 Pack Polyurethane. ??????

On a different note, some of the botch ups I've found

> the gear selector clamp on the motor was held together with a tie wrap
> fuel pump was hanging loose
> thermostat housing had so much gunk on it when fitted that the bypass holes were blocked
> wrong water pump impeller fitted, so it worked when it wanted too, or not at all
> a domestic house switch was wired up for the starter switch

Some pics after a strip out. You can see the house switch just above the remote box



Starting to get there




It's an old barge but I like it as it has a large deck area and deep sides, as it will be used for fun and fishing. So standing up when a massive fish is caught feels a bit safer . The motor is an Evinrude 115 v4.

[SeeFive]

Looking smart inside. No idea what paint to use I am afraid, but well done for the restoration so far.

It's nice to see someone taking care of a boat that had fallen into a bit of disrepair. There is a sunken '80s Bayliner close to my gaff which has been there for about a year and is down to the main hull and top sides - Windows gone, padded seats etc, all gone and covered in algae / seaweed at low tide, fully submersed at high tide. It is so sad to walk by and believe that one day, someone purchased that new and probably cosseted it like a baby for quite some time.

Again... Well done. Great to see the difference you are making. Enjoy it and keep safe when you get out on it.

[Huntsman]

You don't need boat paint. Results will be entirely dependant on how much effort you put into the preparation.

Oil based undercoat and oil based top coat, such as Dulux stormshield would be fine.

Unless keeping it afloat, then no need to antifoul.

If you wanted to spray it, two pack can be bought off ebay at reasonable cost. Do use a decent mask.