Hard Antifouling Paints and Haulouts

6

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.

Darrell Nicholson
Practical Sailor has been independently testing and reporting on sailboats and sailing gear for more than 50 years. Its independent tests are carried out by experienced sailors and marine industry professionals dedicated to providing objective evaluation and reporting about boats, gear, and the skills required to cross oceans. Practical Sailor is edited by Darrell Nicholson, a long-time liveaboard sailor and trans-Pacific cruiser who has been director of Belvoir Media Group's marine division since 2005. He holds a U.S. Coast Guard 100-ton Master license, has logged tens of thousands of miles in three oceans, and has skippered everything from pilot boats to day charter cats. His weekly blog Inside Practical Sailor offers an inside look at current research and gear tests at Practical Sailor, while his award-winning column,"Rhumb Lines," tracks boating trends and reflects upon the sailing life. He sails a Sparkman & Stephens-designed Yankee 30 out of St. Petersburg, Florida. You can reach him at darrellnicholson.com.

6 COMMENTS

  1. A popular paint in the Cleveland area for sailboats, particularly for boats that do some racing, is Interlux VC 17m. We have been using it for seven seasons and many of my sailing friends use it as well. It is a thin film paint that produces a smooth finish with little build-up. It dries quickly. We use 3M Scotch-Brite Red pads to lightly wet scuff sand the bottom each spring. My boatyard says that is enough to reactivate the copper. To save money and time, we only repaint the area a couple feet below the water line, the leading edges of the bow/keel/rudder. Those areas wear faster. Three of us did the work on my Beneteau 321 in less than six hours yesterday. This included the time to put on and take off the masking tape. We used less than two quarts. We paid $90/quart from West Marine. Once every three seasons, we repaint the whole bottom.

    We sail the boat about three days a week in the season May to October. Marine growth on the bottom is minimal.

    Interlus says that VC 17m is suitable for freshwater or low fouling cold salt water. We have very pleased with VC 17m and the ease of use.

  2. A popular paint in the Cleveland area for sailboats, particularly for boats that do some racing, is Interlux VC 17m. We have been using it for seven seasons and many of my sailing friends use it as well. It is a thin film paint that produces a smooth finish with little build-up. It dries quickly. We use 3M Scotch-Brite Red pads to lightly wet scuff sand the bottom each spring. My boatyard says that is enough to reactivate the copper. To save money and time, we only repaint the area a couple feet below the water line, the leading edges of the bow/keel/rudder. Those areas wear faster. Three of us did the work on my Beneteau 321 in less than six hours yesterday. This included the time to put on and take off the masking tape. We used less than two quarts. We paid $90/quart from West Marine. Once every three seasons, we repaint the whole bottom.

    We sail the boat about three days a week in the season May to October. Marine growth on the bottom is minimal.

    Interlux says that VC 17m is suitable for freshwater or low fouling cold salt water. We have been very pleased with VC 17m and its ease of use.

  3. I am surprised there is not mention of Coppercoat. I asked a couple of sailors who painted their boats and said that they just clean some growth (basically seaweed) once a year. One of them painted 6 years ago and another 9 years and both strongly recommended it. I read somwhere that there are more than 70.000 boats painted with this epoxy/copper hard paint.

    Silicone as bottom paint.- I am suprised as well that there is no mention on Practical Sailor about silicone as one of the most efficient antifouling paints. I just met the owner of a 30′ sailboat who was thrilled with the silicon paint after 5 years and not a barnacle or algae attached. I would much appreciate any further info since I intend to paint my 85′ steel motorsailer with silicone and would like to know the negative aspects.

    Cheers and friendly winds

    Juan