Painting the Hull
TL;DR: Lots of text explaining finishing the boat. Read on for hopefully a little education and entertainment, otherwise just look at the few pics.
The original idea was to leave the hull unpainted, showing the wood strip construction. The cheap fiberglass I bought left bubbles that showed the weave of the fabric. No amount of poking at the fabric with an epoxy-soaked chipping brush would make the bubbles go away. But fiberglass is an expensive part of the whole project, so I stuck with the "bad" stuff. The only way to hide the bubbles was to paint the hull.
I really did still want to show the hull construction, so I sanded off all the fiberglass in the fantail stern, bought small piece of (expensive!) "good" fiberglass and re-glassed that area. It was SO much easier and faster using the better fiberglass. Lesson learned. The wedge shape shown in the pick below is an attempt to have something other than a boring straight line joint between the wood and painted sections.
The non-painted area is coated with oil-based polyurethane. Also shown in this picture is the rudder post bedded in place, and the faring on the end of the keel also bedded and screwed. "Bedding" is the term used to attach a piece of hardware to a boat hull or deck. It is more than just gluing because the bedding compound coats all the surfaces of both parts of the joint so water cannot get into the wood. Even the screws are "bedded" to prevent water seeping around the threads. Bedding compound remains flexible to move with the wood and not crack.
The bedding compound I used was Rust-Oleum Loctite PL Marine, a polyurethane caulk. It is white and so shows itself quite obviously, but I kinda like that the bedding compound is visible.
The Rest of The Hull.
There is a bewildering variety of boat finishes and methods: two part epoxy-based paint, two- part polyurethane-based paint, acrylic latex paint, water-based polyurethane, oil-based polyurethane, and traditional varnish. I've done a lot of reading about this subject over the years and have made many attempts at getting a smooth and shiny surface, none of them very successful.
SIDE BAR: when we went to the wooden boat show in 2023, we saw a large fantail launch that the owner claimed had 14 coats of varnish. The surface was like a mirror! He frowned when I touched it. I won't be putting that many coats of anything on Unicorn.
I resolved to take the time and effort to figure out how to do it "right" and went down a rabbit hole that ended with me quite confused about what and how to paint the hull. When I was about to throw up my hands in frustration, I came across an old article about painting wooden boats with good ole' (actually new) acrylic latex house paint. After reading it and reading some of its reference articles, that's the path I chose. Unicorn is finished with Sherwin-Williams Everlast Satin Base 4 Enamel, Jazzy Blue color; covered with crystal clear Rust-Oleum Varathane Ultimate Spar Urethane Water Based Gloss.
I first tried applying two coats of paint and two coats of polyurethane ("poly") using the roll-on then tip with a brush method. Tipping is when you drag a good quality paint brush across the paint with the handle almost 90 degrees to the surface and with very light pressure. It smooths the bumpy surface caused by the roller and is supposed to leave a smooth surface. This method works with expensive epoxy or two-part polyurethane paint, but apparently does not work with latex paint. The finish showed all the brush strokes of the paint, making the whole hull look cheap and crude, so I decided to repaint it, which meant sanding off the poly and some of the paint.
I then tried several methods in small patches to figure out how to get a smooth surface from the paint. None worked very well. The last and best method was a heavy coat of paint applied with a roller that was supposed to make the paint smooth (it doesn't), but it also did not show brush strokes, just an even surface of small bumps. Coating it with the gloss polyurethane made the surface smooth.
I rolled on a single thick coat of paint over the old paint, waited for it to dry just to the point where it wasn't tacky, then applied the poly over the paint. After waiting for that to dry I sanded it lightly and applied another coat. The goal was to sand off the bumps in the poly caused by the paint, but not sand down to the paint. A coat of poly, a little sanding, a coat of poly, a little sanding. It took five coats of poly to fill in the paint and get the finish smooth-ish, -not a mirror finish like the boat with 14 coats of varnish, but shiny enough for Unicorn. I may end up applying more poly when Unicorn is right side up and outside where the paint job will show its flaws.
The Stem.
For some reason I didn't take any pictures of the stem construction. Or at least if I did I can't find them. The picture below shows the keel curving around and up the bow stem. If you look closely you can see the joints between the 5 pieces of wood that make up the keel and stem.
Coming in from the left is the main keel. It is made from a piece of mahogany that I have absolutely no idea how I got it or where it came from. The next piece, a sort of two-tone color, is what could be called the bow grounding strip, or the outer lower stem. It is made of Brazilian Ebony, "Coracao de negro", (no relation to Ebony). Caracao de negro is one of the hardest commercially available woods. When freshly cut it is yellowish, but it quickly turns black when exposed to oxygen. Not really on purpose, I planed and shaped this board and then coated it with epoxy before it had a chance to completely turn black. I have no idea how long it will remain two-tone.
The next three pieces, making up the bow stem, are Angelique. This is also a very hard wood. These pieces are scrap wood from when Mystic Seaport was making a copy of the famous slave ship, Amistad. You have to look very closely to make out where the three separate pieces are pieced together.
That's all for now. The next step is making the cradle that will support the boat when it is turned upright.
p.s.
I stumbled across a company making an electric fantail launch. $35,000 !!!
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