Marine Forum

Hull Paint

SeaDog

03 July 2007 11:58:47

Joined: 14 November 2005 14:23:57 | Posts: 11

What hull paint is the best for the environment?

Hull Paint

MontereyMan

03 July 2007 12:11:13

Joined: 29 March 2006 09:55:00 | Posts: 4

Choose an environmentally friendly anti-fouling strategy (i.e., combining the use of less toxic paints and bottom coatings with mechanical means to control growth). Less toxic bottom coatings provide alternatives to soft sloughing paints that release heavy metals. Talk to your boat yard or marine supply shop about the less toxic alternatives on the market.

Re: Hull Paint

Anonymous user

03 July 2007 13:39:34

Joined: Unknown | Posts: Unknown

Algal skin – a tailor-made alternative to hull paint
To date, pleasure boat hulls have had to be painted to prevent fouling by algae, barnacles and other growths that create resistance when a boat is sailing. However, an algal skin, a tailor-made tarpaulin that covers the boat’s hull up to the waterline, can now replace the environmentally harmful hull paint. The algal skin was tested in Skærbæk harbour. The test showed that the algal skin sufficiently inhibits the growth of barnacles to prevent them from affecting the sailing properties a boat requires during pleasure boating, although barnacles may cause enough resistance to affect a boat used in competition. The algal skin is both cheap and durable, but being made of PVC, the skin must be studied to see if the phthalates it contains are harmful to the marine environment.
Background and objective
Hull paint to be phased out
Hull paint on pleasure boats must be phased out, because this type of paint is suspected of affecting snails’ reproductive capacity, for example, and because the active agents may accumulate in food chains. This creates a need for alternatives to hull paint, so that pleasure boats can continue sailing with reasonable fuel economy, maintain their good manoeuvrability and, thus, be a safe place to pursue one’s hobby.

The objective of the algal skin test was to study the yachtsmen’s time consumption and the efficacy of the concept. In addition, the study was to provide an idea of how to design the algal skin to ensure a usable and economical solution.

The study
Six months’ experience with algal skin
The boat was set afloat in Skærbæk harbour near Fredericia at the end of April 2000 and taken out of the water in November. During the test period, the boat was out of the water twice for ten minutes to be photographed and assessed. The first time was in June, at which time the boat was almost slimy and about 50 small barnacles had settled on the top part of the keel where it meets the hull and on the bottom of the boat behind the keel. The next time was at the end of August, at which time it appeared that the front of the ship was still free of growths, but that the barnacles on the bottom and on the top of the keel were now stuck, and that new barnacles had settled on the rudder. The boat was not cleaned in this season. However, the barnacles on the rudder were scraped off with a board because the boat was to participate at a club championship! A rope was used to attempt to scrub the barnacles off the bottom. This was practically futile – but undoubtedly boosted the contestants’ morale at the club championships.

The boat was used in boat races once or twice a week, on weekend trips and on a 14-day summer holiday trip in the Kattegat and the Bay of Aarhus. The duration of all the trips was entered into the log, and at the final review it appeared that the boat had been out of the skin 11% of its time in the water.

Main conclusions
Durable, cheap – and hopefully non-polluting
The algal skin makes it possible to sail without problems for a full season without hull paint. It takes no extra time to leave the algal skin when the boat sails out, and it only takes an extra 10 to 20 seconds to fasten the stern fasts when the boat returns to harbour.

All boat types can use the present concept, and the algal skin also functions as intended in fresh water areas where there are no barnacles. However, in seas with barnacles, barnacle growth poses a problem to yachtsmen at the end of the season, as the barnacles create some resistance and thus slow down the boat. On<