Unless you’re prepared for more prep work than a light sanding, the first step to selecting a bottom paint is finding one that’s compatible with what’s on your hull now. All of the manufacturers in Practical Sailor’s most recent antifouling paint test will provide guidance on this, either over the phone or on the company website. If you’re planning an extended cruise abroad, choosing a maker with worldwide distribution can help simplify making a match. Interlux (under the brand name International) has the widest distribution of the paints we test, but most makers in our test have a very strong presence throughout the most common cruising areas for North American sailors.
Generally, you can repaint a hard paint with either a hard or soft paint, while a soft ablative paint will need more sanding or a “tie-coat” primer when being coated with a hard paint. Some “thin-film” racing paints don’t like to be recoated with ordinary paints without extensive prep. Bare fiberglass or metal will require a primer, and aluminum components like saildrives need a special paint that won’t induce potentially disastrous galvanic corrosion.
Before plunking down nearly $100 or more a gallon, consider where your priorities lie.
- Simple application: With no unpleasant solvents, water-based paints are easy and safe to apply.
- The environment: We’re seeing many more paints in our tests that do not contain copper.
- No paint buildup: Over time, ablative paints wear away; hard paints form thick layer cakes.
- Quick recoating: Hard paints can take a second coat sooner than ablatives, although some of the newer co-polymer ablatives can be recoated after four hours or less. Many “thin-film” racing paints dry very quickly.
- Haulout schedules: Some paints (typically hard paints) lose their effectiveness if not launched after painting within a certain time frame, or if the boat is later hauled out for an extended period. (You can sand some hard paints to “reactivate” them after a long haulout.)
- Color: Nearly all the major makers offer lines of paints with broad palette choices.
To help narrow the selection to the paints that best fit your priorities our test results are supplemented with tables that indicate the best paints in various categories. If you have any comments or questions on choosing a bottom paint, feel free to post them below or contact me here.
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