Tim's Melonseed Build: Odds 'n Ends

I'm chomping at the bit to to glass the hull, but the weather is just not cooperating. In the meantime, I've made some progress with the centerboard and trunk. My first experience with fiberglass and epoxy was, thankfully, uneventful. I'm using the MAS product and so far it works as advertised. I followed the instructions using 6 oz. glass with 3 coats of epoxy on the trunk parts. For the first time I can see what the mahogany will look like when finished.

My next task is to drill for the pivot hardware. I'm using two flanged bronze bearings and a 1/2" bronze rod for the pivot mechanism. I like the idea of bronze on bronze and the bearings are inexpensive, less than 3 bucks a piece at Amazon. I'll add an O-ring behind the flange and use a bronze pipe cap to seal the end and hold the bearing in place. I had to machine the NPT threads myself, not difficult as bronze is relatively soft. The bronze caps cost $5.30 a piece at Hamilton Marine Supply.

I plan to install the pivot hardware before trunk assembly to make sure everything lines up properly.

The centerboard is almost ready to shape. I added a couple pieces of mahogany to the pivot area, reducing the clearance a bit and adding some strength.

The lead cavity is covered with a wooden lid and a hole is drilled for the lanyard.

Epoxy is poured to create a waterproof seal around the pivot and the hole where the lanyard attaches.

To do; shape the foil and glass.

Birdsmouth Test Case

I originally planned on using Sitka spruce for the mast and spars. I knew it was a favored material for this purpose and I have lots of experience using Sitka for guitar tops. The problem began when I tried to source locally. No dice! I called folks on the west coast who quoted $10 a board foot for spar grade material. The price didn't faze me but the shipping charges did, more than doubling the cost. Time to rethink. Doug fir is the other preferred material and after some searching I found a local source for fine grade 12/4 fir in 18' lengths. The source was a wholesale supplier, but kind enough to let me take a look before I committed. I drove down and followed the fork lift driver to a warehouse in the very back of the complex. The warehouse was filled with Doug fir, most of it unfit for my purposes. After a bit of searching we found the good stuff and I was able to procure a near perfectly quartered 18 footer, about 8 1/2" wide and 1 7/8" thick, for $7.23 a board foot.

After staring at the board for a week or so, I broke out the power plane and circular saw to do the initial resawing. The board contained several obvious defects and some hidden ones. I did my best to work around the obvious and the rest is luck. Thankfully, the board yielded just enough material for the boom and mast. The waste included a 3' x 8" piece that I will use to test the birdsmouth technique.

From a woodworking perspective, the hollow birdsmouth style mast is an amazing thing. The procedures for building a birdsmouth mast are well documented and there are many how to tutorials available online for reference. Having no personal experience with mast building, I thought it best to do a mock up first. The mock up will be built just like the bottom three feet of the real mast, tapering from 3 to 2 1/2 inches in diameter.

The fir I'm using is very fine grained and dense, so I'm going with a wall thickness of 16%. I started with 8 pieces, like those pictured below, using the online calculator at http://www.clintchaseboatbuilder.com/resources/calculator-4.htm to obtain the correct dimensions.