Aluminum boats are wonderful. The only problem area is with painting. It is not an easy material to get paint to stay on without problems. On the other hand, it is the only material which can be left bare, and that is a huge plus. We like the look, and the lack of maintenance. And if someone messes up a docking maneuver, we ignore the scratches – or if we’re feeling ambitious, polish them out with ScotchBrite pads.

Of course you still have to do something with the part of the boat that is in the water. What is done below the waterline is quite different than above. The system used needs to tie to the bottom paint being used. In the past we’ve always used TBTF bottom paint, but this is no longer available.When the time came to start thinking about a bottom painting system for Wind Horse, the first person we turned to was Dale Morris at Ventura Harbor Boat Yard ( www.VHBY.com ). Dale has more experience maintaining the paint on aluminum boat than anyone else we know – he takes care of crew boats working in the Santa Barbara channel. Dale said he had been using an Ameron barrier system, tied to a special copper-based bottom paint, with excellent results.

When we asked about problems associated with bare areas, perhaps due to collision with flotsam, he indicated this was not a issue.

In New Zealand we found the same system from Altex Chemicals. We had Kelly Archer prepare a sample panel of aluminum, with some parts painted per the spec, and other areas bare. This panel was then tested in salt water for six months. The antifouling seemed to work well, and the bare part of the aluminum panels did not show corrosion from the bottom paint. So far, so good.

We went ahead and put the Altex Coating system on the boat and the results have been excellent. The bottom paint is the best we have ever used. With the exception of sitting in Marina del Rey (reputed to have the worst fouling anywhere in the world), the bottom has self-polished when underway. With the boat sitting last winter, we found it necessary to have the bottom cleaned three time between November and April. But for the period from May through October – encompassing New Zealand through the tropics to California – the bottom was not touched.

For the cruising season in 2006 the paint has worked well except for a three-week period in Poulsbo, Washington, when we grew quite a beard around the waterline. This was easily removed with a light water blast when we hauled to change props. That was in mid-June. Since then, the bottom has not been touched, and was clean when we left the boat in Ventura late September.

Here is the material that was used, supplied by Altex Coatings in New Zealand. Date is presented in the order the coats were applied.

• ZECA Primer
• Altra-Build 540
• Altra-Build 540
• Epoxy Primer #1
• Epoxy Primer #1
• Three coats #5 Anti-Foul except for #10 Anti-Foul (harder material) on the bottom of the keel, stabilizers, around props and completely covering the rudders.

It looks like we do not need to repaint for at least another season. Given that there are now over 16,000 miles on this bottom, we are very pleased with the results.

One word of warning on paint systems. It is best not to mix suppliers. Our preference is to always stay with a complete system from a single vendor. That way, if something does go wrong, it is easy to know where to look. For new jobs we always specify that a paint company tech rep check each stage of the job to make sure it is done to their satisfaction. These lessons have been learned at high expense! There is lots more on this subject in Offshore Cruising Encyclopedia.