The deeper I have gotten into this project, the more I've wanted to learn the skills required for building an Interclub 60 years ago So, even though I could get by without installing new planks in the interior of #48, I decided not only that I would, but that I'd mill them myself.
I used wood from a supply of 5-inch wide, 7/8s-inch thick, 8-foot mahogany boards I ordered awhile ago from Chesapeake Light Craft in Annapolis. CLC's mahogany now comes from sustainably-harvested sources in Fiji, where vast tracts were planted just after World War II using seeds from Honduras. It is genuine mahogany* but it isn't on the CITES protected list or illegally harvested in the rainforests of South or Central America.
I used a bandsaw to resaw the boards into thin strips just over 1/8th inch thick. This is not hard to do if you set the saw up correctly, taking extra care to make sure that the blade is parallel to the fence. After a few attempts that didn't turn out as well as I hoped, I realized it's more important to focus on applying even pressure to the bottom of the board (like I am doing in the photo below) as I pushed it through the saw. I could easily see the top of the board (and take corrective action if the saw blade began to drift), but the bottom where the blade exits is hidden. I also cut slowly, giving the saw time to clear out waste. Each board yielded five planks and a lot of sawdust. (Tool note: the blade on the saw was a Lenox 1/2 inch carbide tipped blade with 3 teeth per inch. It's specially made for resawing.)
Some readers who see the photo of the final step below may groan and throw up their hands because it's sort of cheating. Our shop is equipped with a powerful Timesaver sander. It is a great device that sports a three-foot wide sanding belt and automatic feeder. All I had to do was insert my rough-sawn planks into the machine; they'd emerge on the other end with one side sanded flat. I had to flip the board and make multiple passes to get the dimensions I'd set my calipers to, but it was a fairly quick and relatively foolproof (big plus for me) process. The Timesaver controls the tension the sanding belt applies to the wood with precise pneumatic pressure that is regulated by sensors. Check out the control knob wheel on the bottom left corner of the machine. Each full turn of that knob lowers the sanding belt to remove exactly 1/32-inch from a board. But a quarter turn is as far as you want to go for each new pass, removing 1/128-inch of thickness per pass. For the final pass, you put the board through twice without touching the knob. This achieves an effect similar to switching to a finer grit sandpaper.
The photo above shows a stack of finished and unfinished mahogany strakes, er, planks, on the cart. I marked each with chalk before feeding them into the machine. When all the chalk dust was removed I knew they were fair.
Even though Interclub was originally built with 1/16-inch thick planks, I made these a little fatter: sanding down the 1/8th rough board to 3/32s. This gives me an extra 1/32 of play when I sand them again after they are epoxied or glued** into place. If some are too stiff to bend into the right shape, I can always put them through the Timesaver again.
I don't know if the guys at Zephyr Boat Works had a contraption like this in the 1940s, but it's a good bet they would have used it if they did. It also would be possible to do this work with a set of jointer and smoothing planes or a hand-held sander, but that's obviously a lot more time consuming. (The fastest way would be to buy pre-cut 1/16th-inch veneer.)
The cart in the photo holds enough finished strakes to plank one side of the
boat.
*There are many types of woods classified as mahogany, but not all are "genuine" mahogany. The label refers to the type that has been historically preferred by shipwrights for its beautiful grain, stability, light-weight for its strength, resistance to rot, and because mahogany trees can yield enormous boards (the trees grow as high as 150 feet tall and six feet in diameter). The specific species is Swietenia macrohylla and, in addition to the genuine label, also can be called Honduras, Peruvian, Bolivian, American and bigleaf mahogany. Genuine mahogany can vary greatly in quality and care needs to be taken when selecting it. Until recently, there were both political and quality issues associated with mahogany from Fiji. Most of these seem to have been cleared up with the launch of something called the Fiji Pure Mahogany initiative. Gibson Guitar was one of the first companies to switch to using mahogany from Fiji.
***I am still deciding whether to use epoxy or glue to laminate the new planks to the hull. There are arguments for and against epoxy when it comes to joining wood. I'll be discussing these in a future post.
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