Six months after doing. Colour no longer pink happy to say.
My boat does not live in the water but rather on its trailer under the carport. Saves me quite a lot of money in annual maintenance and mooring fees that way. Since this was always my plan when I built it I didn’t bother with antifouling the hull bottoms. This wasn’t a major problem provided I didn’t leave her in the water for more than a fortnight at a time. Even after this time she was starting to grow ‘hair’. I left her in for three weeks once and little hard lumps (barnacles I think) appeared as well.
After 16 years when below waterline repaint time came round I decided to anti foul this time as nearing retirement, I anticipated using her more. (Hasn’t happened yet but ...)
Some research as to the different types (and COST!) had me worried. Some dry out and fall off if left out of the water, some need annual replacement and the long lasting ones are horribly expensive.
Some basic research on copper epoxy antifouls which seem to be the way to go for trailer sailers came up with the figure of 2kg of copper powder per litre of epoxy.
Now I happened to have a 1 litre tin of Aquacote sand coloured paint I’d bought by accident on line (got the product number wrong didn’t I). I know it’s usually epoxy used for antifouling but the price! And I had the Aquacote on hand. I did some searching and found a company in Sydney that sold powdered metal and rang them. A very obliging lady said yes they often sold one of their products for the use in DIY antifoul. I promptly ordered 2kg of the recommended grade.
I repainted the hull sides a couple of years ago (with Aquacote) but hadn’t done below the waterline at the time. Some minor repairs needed especially up in the bows.
To gain access for this I raised the boat up off the trailer on chocks one side at a time. The other side was securely tied down to the trailer to prevent it sliding either sideways or back and forward. I fixed up the dings and scratches and added a little more glass cloth where wear had become evident.
I then wet sanded the hull with 180 wet and dry making sure I covered the area to be painted completely. A note here Aquacote does not like any oily contamination of the surface – even fingerprints can be a problem if your hands are oily.
304 stainless shoe – should have used an etch primer first, rest of it looking good after 12 months.
When ready I cross linked a quarter of the paint and added half a kilo of copper. Heavy! The copper really wanted to sit on the bottom of the container so had to be almost continuously stirred.
My plan (which worked well) was to use a 4” long Little Ripper High Density foam roller. This has one end rounded so with care you don’t get roller end lines appearing. (I used these when repainting the rest of the boat and didn’t need to tip off with a brush. Got a lovely even finish (but did have an issue when the sun hastened the drying on the last little bit)
A further idea I got from an article in Australasian Amateur Boatbuilder & Kitboats etc was to use a piece of Masonite about 40cm square, pour a little paint onto it and load up the roller from this. Each time I reloaded the Masonite I stirred up the paint.
One of the beauties of Aquacote is the way the crosslinker dies after about 40 minutes, unlike conventional 2 pack where after 20 minutes you throw the unused paint and the tools away. With Aquacote you can literally pour it back into the tin for another day. And the tools clean up with water. (For a good result though you do need to strain the paint each time as little lumps of hardened paint get into it.– pantihose feet work well)
How well has it worked? Three weeks in sea water on a mooring and no ‘hair’ let alone shellfish. I washed down with a hose instead of elbow grease, a scraper and high pressure washer like before.
Only downside to doing this was the hull bottoms went pink! Fortunately as the boat has been in and out of the water, been rained on, washed etc the pinkness has gone and it now looks like a conventional greenish anti-foul.
The only thing I’d do differently is to use an etch primer on the stainless shoes on the bottom of the keels, the paint has not stuck to them well.