Bottom Paint: Earth Day, 2012

Happy Earth Day.

With spring here, many people are working upon their boats, getting everything ready for the summer boating season. Part of this often involves hauling out the boat and applying bottom paint to keep the growth off the bottom of the boat. While I and my family want to keep the growth off the bottom of our own boat, we are also concerned about the environment - God's creation. Is there a way to do both?

It was about a year ago that we hauled out and painted the bottom. Part of the process involved trying to figure out what the bottom had been painted with before, so that we added something compatible. No sense in putting a hard bottom paint on an ablative, we'd just go sailing to have the hard (new) paint ablative off with what was used before. The other alternative would be to strip off all the old paint and then but something new on (in which case we could use what we wanted). We (us and the boat yard) were fairly certain that what had been used before was an ablative paint, so that's what we used again. (An ablative paint slowly comes off as one moves the boat through the water exposing fresh paint and allowing the fouled paint to fall off.)

Once any item is left in a salt water environment it quickly becomes covered in "scum." "Scum" is my "scientific" word for all the tiny miro-organisms that quickly attach themselves to the smooth surface. But it is not long before muscles and barnacles and various forms of weed are growing upon the item. One winter, we forgot to take the milk-jug bailer out of the dinghy when we turned her over on the dock, with the result that the bailer was hanging by it's string into the water all winter long. The next spring, there was an entire colony of sea life growing on, in and around the bailer. We ended up leaving it there (attaching the string to the dock rather than the dinghy) for the kids to look at all summer - their own underwater aquarium.

The problem is when all of this is attached to the boat, the boat struggles to go anywhere. On large supertankers, the fuel bills go up (not to mention the green house gases) and on a sailboat it can mean one has a hard time sailing.

Hence, painting the bottom of the boat with something to keep the critters at bay. What kind of paint/bottom does one use to keep the fouling at bay? I'm not sure there is a perfect paint mixture, in terms of being safe for the environment, effective, and user friendly.

Over concern about copper levels in the Puget Sound, Washington State passed a bill prohibiting the sale of any new boats treated with copper-based bottom paint effective January, 2018. Effective 2020, no paints containing more than 0.5 percent copper can be used on old or new boats. (The law applies only to recreational vessels up to 65 feet in length.)

The problem, as I see it, is that many of the non-copper paints tend to use biocides which I'm not convinced are better for the environment.

In the mix of this personal conundrum, I ran across the following 3 web-page article by Jill Dickin Schinas "The Search for an Effective and Environmentally-Safe Antifouling" (12 April 2012). (Links to the articles here:)

The Search for an Effective and Environmentally-Safe Antifouling (page 1)
The Search for an Effective and Environmentally-Safe Antifouling (page 2)
The Search for an Effective and Environmentally-Safe Antifouling (page 3)

What I appreciate from the Mollymawk site is that they speak not only from a theoretical perspective, but from their own experience, too.

I'm still not sure what the answer is, perhaps you have some insights to share?


Blessed Be


Joel