I've updated my Super Skipjack build blog.
tomsskipjack.blogspot.com
It's hard to believe my posts span three years but honest, I've only been working on it for about a year and a half.
Looks great! I love the spar rounding jig/lathe you made. Any plans available for that or is it your own design?
Thanks. I got the plan out of Router Magic by Bill Hylton. He has a bunch of jigs and good ideas in it. I highly recommend it to anyone with a router.Â
Yeah, that was a good discussion on stick building Dave, thanks for bringing it back. There's a lot of information about birdsmouth spar building on line. A lot of it has errors and short cut's (in some of the online stuff) I wouldn't employ, but the basics are there. I build about 6 - 8 birdsmouth masts a year professionally. This is down from over a dozen or so before the economy took a dump. I even have a 32' lathe (yes, 32 feet) to spin them for rounding, so I have some experience with them.
It can't be over emphasized about the weight of a mast. Hoisting it once is something, but having to do it regularly is another, than there's the RM issue. A light mast lets you sail longer in the same wind strength as someone that's thinking about a reef. You heel less and the boat is more responsive.
The Weekender mast is way oversize for it's sail area and RM. 3/4" thick staves are also way oversize. I've done birdsmouth masts with the same sail area, nearly half the physical dimensions of the Weekender, with no troubles, so consider making the mast as light as you can. Your back will love for it and the boat will sail better too.
Are there any plans out there for building a hollow box mast. What would be the steps for it.
A hollow birdseye mast is beyond my current ability.
I can manage my stock weekender mast but I'd like a lighter one for my vacationer to be.
i'm planning a hollow box style mast, taking pauls advice i'll plane the wood down to 1/2" thick, with my mast being 2 1/4 " square finished size, then i'll round the corners on a router table. i'm also planning to switch from the hinge system to a tabernacle. i'm currently looking for wood , and searching out pics of tabernacles on this board as well as online. i'll post pictures as i go, but i agree with paul, the lighter the better.
i've found the superskipjack a bit tippy as it is, i don't want a heavy mast making it worse.
I'm thinking about building a coopers mast for my new sailing canoe. I just read a report on the Duckworks site from Andrew Linn about the method, and it looked interesting. According to the article, I could make the spar as thin as a quarter inch and still have it be strong enough for my fifty pound boat. Look it up, it might be worth a try.
Al
A cooper's mast is built like a wooden barrel and not as strong as a birdsmouth, nor as easy. One of the best things about a birdsmouth mast is the self aligning nature of the strips, which you don't have in a cooper's method. Those afraid of a birdsmouth should just make a 24" section, to try out the technique. You'll find it much easier then you thought. The masts I've seen on Andrew Linn's site are ridiculously thin walled and would collapse on anything other then a canoe or kayak. What he fails to understand is, mast dimensions are governed by the boat's weight, RM, rigging choices and several other variables that he doesn't include in his piece, such as moment of inertia, mast bend, etc.
Bob, your mast should be 2 3/4" at the base (heel), tapering to 2" or 2 1/8" at the head with a 20% wall thickness (9/16" at the base, 7/16" at the head). This is the lightest you should go. Most folks like to have a slower taper on a gaffer, so 2 3/4" at the base, tapering to 2 1/2" or 2 3/8" at the hounds, then tapering to 2" at the head, with similar wall thicknesses. These dimensions have a reasonable safety margin, but would be at the low end of the spectrum. More diameter is the fastest way to gain strength, though you also pick up weight.
A 16' long mast made from the first dimensions of white spruce, will weigh less then 9 pounds and if Douglas fir, less then 12 pounds. Sitka spruce will be about the same as white spruce. A solid white spruce or Sitka mast would be about 13 pounds, while a solid Douglas fir mast about 18 pounds, so a pretty big savings.
I agree with you Paul,
I assembled a half dozen birds mouth masts at scamp camp. They are a marvel of engineering with respect to wise use of wood. The reason I am thinking of the coopers mast is exactly that it looks frustrating to assemble. Well, that and I want to see how light I can get the rig on the new boat.Â
Dave, I like your jig for tapering the staves. Why wouldn't you just run the whole works through the table saw? That seems to be simpler than the multi step method you describe.Â
Al