Adventures in maintaining a concrete hull.

Simon and I painted the Polar Bear white after several hard days' graft of sanding in Wales. It was originally blue. It was only after several days with a palm sander that we discovered that an angle grinder fitted with sanding disks was literally 100 times faster in removing the old paint.

Then, after we brought Polar Bear down to Portsmouth and hauled her out again, we discovered that the paint was already falling off in parts. That is when we learned that it is uncommonly difficult to keep paint on a concrete hull. Our new plan of attack was to sand it down all the way to the concrete on the lower half and down pretty far on the upper half and try again.

We have heard from other concrete boat owners that epoxy-based tar is a better way to go than marine paint. We've already bought the paint, though, so we are going to give it one more try. Also, tar is black, so we would have to rename her "Black Bear." Also, we need to rule out the possibility that the paint didn't set well due to the cold temperature in Wales, rather than just because the hull is concrete. We'll see how it turns out.

In the meantime, we owe a debt of gratitude to the Dearn family, all of whom spent several weekends in August to help us strip this hull down. We now know the hull intimately, though, and are happy to report that it is in great shape. Where we had rust, we ground it out, cleaned the fresh metal with acid and filled the holes with an epoxy-concrete goo. This worked astonishingly well and was easy to do. Simon was like a dentist, filling holes at the bottom of the keel. After the goo was placed in there, we used duct tape to hold it in while it hardened. Then we removed the duct tape and viola! But the epoxy mix turned his hands black for about two weeks.

We have similarly gone down to the hull on the inside (only the front half is done), and have rooted out any rust there, and painted over bear metal with an epoxy paint. There was very little, though.

The most important lesson that we learned: epoxy can fix anything (we also used it to help build some of our carpentry, but that is another post). It is our favorite substance. We should buy stock.




So it isn't much to look at right now, but it is beautiful to us since we know that the hull has it where it counts. We know that concrete can look rough, but it is unique. It doesn't look glassy like a fiberglass hull. Most people think that it is steel when it is painted, and it does look similar to that. Anyway, thanks to the great properties of a concrete hull, the marine paint is more for looks than for protection or functionality (unlike most other boats).

We couldn't paint the hull this last summer because it was too cold and wet. When we painted the decks -- see pictures below -- it rained right afterwards, creating a mottled, goopiness to the paint. The decks now require another coat -- which is OK, since we still need to put down the non-slip, but we don't want to make the same mistake with the hull.

Here are the topsides with our dinghy lashed on top (our dinghy was a salvage, and we haven't refurbished it yet... but it is awesome to get free dinghies, in my opinion).