Hard Antifouling Paints and Haulouts

Some of our best performing antifouling paints in our past tests have been hard, modified epoxy paints. These paints generally carry a higher percentage of copper biocide, which makes them very potent in heavy fouling areas. One of the drawbacks of these paints is that they can lose their effectiveness after being hauled out and stored ashore for more than 30 days.

This means that if you hauled your boat out last winter and are relaunching this spring, you’ll have to take a few extra steps before your boat splashes to get maximum protection. Even newly painted hulls can lose their effectiveness if the launch is delayed too long. Fortunately, there are ways to reactivate a hard paint on a newly painted boat that has been stored ashore for less than a year.

The following instructions apply to Pettit Marine’s popular Trinidad line of hard paints. Similar advice applies to hard, modified epoxy antifouling paints made by Interlux, Blue Water, and Sea Hawk Paints. Always check with your manufacturer for the most up-to-date information.

1. Launching of newly painted boats may be delayed up to 60 days after painting without sacrificing antifouling performance.
2. Boats painted between two and 12 months prior to launch date must be scuff-sanded with 220-grit production paper or abrasive pad before launching.
3. Boats painted more than 12 months prior to launch date must be lightly sanded with 100-grit production paper and recoated before launching.
4. Boats in the water for less than 24 hours (e.g. for in-the-water water testing) should be pressure washed lightly to remove dirt, salt or other contaminants and allowed to dry. These boats should still be considered newly painted and may be launched up to 60 days after the date of painting.
5. Boats in the water for more than 24 hours, but less than 30 days, should be pressure washed when hauled, then lightly sanded with 220-grit production paper immediately before re-launching. If necessary, launching may be delayed up to 60 days after the bottom has been sanded. Note: Boats re-launched within 72 hours of haulout do not need to be sanded before launching.
6. Boats in water for more than 30 days should be pressure washed when hauled, lightly sanded with 100-grit production paper and recoated with antifouling paint, even when re-launching will take place within 72 hours.

If you are still undecided as to whether you want a hard paint or an ablative paint, or are carrying out your first DIY bottom paint job, my previous blog post “Practical Sailor Bottom Paint Survey” includes several links to past tests, and links to articles dealing with application (and removal) and care of bottom paint.

Painting your bottom doesn’t require any special skills, but you do want to protect yourself from boatyard hazards, avoid contact with bottom paint and avoid inhaling potentially hazardous fumes (from solvents in the solvent-based paints). Over the years, we’ve noticed boaters making three common errors that can inhibit the effectiveness of their paint.

1. Choosing a paint that is incompatibile with the previous paint.
2. Ignoring the maker’s recommendations for surface prep work.
3. Hiring a bottom scrubber who doesn’t follow the  best bottom paint scrubbing protocol for ensuring maximum life.

If you are contemplating a complete cosmetic overhaul, our new ebook “Painting Your Boat from Bottom to Top,” covers everything you need to know about the selection, use, and application of bottom paint, topside paint, and non-skid paint.