Monday, February 2, 2015
A Bigger Bumpkin
Anyway, they are the spars that project from the stern of a yawl to provide a mounting point for the mizzen sheet block. Ideally, it should look something like the one in the Blue Moons plans, a portion of which is reproduced below:
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| Bumpkin on Blue Moons Plans |
The BMs builder built them out of laminated douglas fir, instead, making up for DFs reduced strength by keeping the bumpkin 2 1/2" in diameter for its whole length. The result was functional, but not particularly attractive, at least to my eyes.
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| Original Bumpkin |
Even worse, the bumpkin curves in so sharply that it passes over the back of the outboard, so it is impossible to raise the outboard out of the water. This problem was made worse when I replaced the bracket in the photo above with a heavy duty bracket big enough to support my lovely Yamaha 9.9.
It was so bad, in fact, that I couldnt even get the cover off to check the oil. Since I was doing more motoring than sailing on the ICW, this was a major pain. I liked to check the oil every few days, and I changed the oil every 500 miles or so. So I eventually removed the bumpkin.
Last summer, I never did reinstall the bumpkin, since I needed to raise the motor when moored, and because I did a lot more sailing, and lifting the outboard out of the water adds at least 1/2 knot while sailing.
In short, I need a new bumpkin that meets 3 requirements, in this order:
- shaped so I can raise the outboard, or remove the cover
- strong enough to climb out on, when necessary (at anchor, only!)
- good looking enough to improve the BMs look, rather than detract from it
To meet the first requirement, the bumpkin needs to curve around the space needed for the raised outboard. The current boomkin curves sharply in. I want the new one to curve out, and then in.
To achieve this, I first laid out the desired shape using a batten.
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| Bumpkin curve laid out on lofting board |
The vertical 4 steel ruler shows the centerline of the boat. The horizontal piece of oak shows the transom line. The short steel ruler indicates the line of the current boomkin. The batten shows the proposed shape of the new boomkin, which provides over 4" of extra space around the outboard, which should make it possible to raise it out of the water, without removing the boomkin.
For wood, I am going to try to use hickory, as specified by Tom Gilmer. Last weekend, I bought two live-edge, air dried planks, about 2" thick from a local sawmill... actually, a landscaper with a small portable sawmill. My boat building friend Roger was kind enough to help me mill them up into 2 1/2" boards, about 1/2" thick.
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| Milled Hickory Boards ready for laminating. Most of the dark areas are burn marks from the circular saw. This is hard wood! |
Unfortunately, the wood isnt of the highest quality. A couple of the boards have large knots that will probably make them unusable for this project, but I should have enough wood even without them.
However, I am not sure these particular boards will bend into shape without cracking. Rather than spending a lot of time theorizing over this question, Im just going to build a steam box and give it a try. If they crack, they crack. I didnt pay much for them, so no great loss. Ill then have to decide whether to try a better grade of hickory, or perhaps some other wood, like white oak.
But thats getting ahead of myself. Over the next week or so, Im going to build a bending form on the table above, and build a nice steam box, which Ive been wanting to build, anyway. It should be rather interesting.
Ill probably be posting fairly frequently, and dont want to send out too many emails to my subscribers, so just check back every 2-3 days if you are interested in following this project. Ill send out one more email when the project is done, if you want to wait until then to catch up.
Spring is coming fast!
>>> Next Episode: Steam Box 1
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