A Glimpse of SSTIKS
Bow Seat

Centerboard Trunk

StemtreatmentI've made a little progress on my Joel White Pooduck Skiff.  Before I go into that I'd like to mention a few things about finding wood for boat building.  I like to go to my local lumberyard or big box home improvement store for wood most of the time just because it's convenient.  I can usually find clear western red cedar in long lengths, mahogany, red oak, and clear vertical grain douglas fir there.  I buy wood a little at a time as I need it because I'm too lazy to sit down with the plans and calculate all the wood I need and buy it all at once.  It's not the most efficient way and sometimes I end up using scraps of what I already have instead of what's recommended, like when I laminated the stem and frame from the yellow cedar I already had instead of fir or mahogany.  Sometimes though you really want to get the right wood and can't find a source.  Well I finally found the ultimate specialty supplier of boat wood.  I had ordered wood from Edensaw before but only recently did they open up a Seattle location (actually Kent) which makes it much easier to shop for wood.  Although the main Edensaw location and mill is in Port Townsend, the Seattle warehouse is a wood worker's dream -- rows and rows of exotic wood planks, plywood, woodworking tools, and even some epoxy products.  I stopped by for the first time the other day and picked up a big board of Honduran mahogany, a sheet of Meranti Hydrotek marine plywood, and some spar-grade Sitka spruce rough cut 2x4s.   Whatever wood you need they have it, and if they don't have it they'll get it for you.  Be sure to take advantage of their free delivery for big orders.

Cbt1Cbt2Cbt3Building the centerboard trunk presents a challenge because is has a moving part (the centerboard), fits through a hole in the bottom of the boat, is subject to a lot of stress from the centerboard, and is prone to rot and leaks.  One alternative to using a centerboard is to use a daggerboard, which does not slide up if it hits bottom.  Since I wanted to be able to use the skiff in very shallow water I decided to go with the centerboard.  I also like the convenience of having the board stored within the trunk.

I actually built the trunk twice.  The first time I used red oak for the bed logs and cut them a little too low.  The conventional wisdom is that red oak is "totally unsuitable" for wooden boat building.  It is very porus and has poor rot resistance.  By the way, I think it is that porosity which makes red oak the gold standard for steam bending, and it makes great ribs for skin-on-frame kayaks.  But it would probably have been a poor choice for the bed logs which hold the trunk to the hull and are always wet.  It could rot from the inside of the trunk, and the rot would be difficult to detect and repair.  So I trashed the first trunk and built it again with Honduran mahogany.  I had thought about keeping the first trunk and encapsulating the whole thing with epoxy and fiberglass which might have been OK but in the end didn't want to bother with all that.   My understanding is that if wood is encapsulated well then it doesn't matter how poor it's rot resistance is because the wood never gets wet.  For instance, Pygmy kayaks are made with Okume plywood which has poor rot resistance but they do fine.  I was also afraid of cracks developing in the epoxy and fiberglass from all the stresses on the trunk from the centerboard.   The trunk is expected to move a little.  For instance, it is  attached to the hull with screws and 3M 5200 marine adhesive, which provides a permanent, yet flexible, bond. 

Well, it's starting to look like furniture.  Now to get to work on the seats.


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