Sunday, May 10, 2009

Making a Sailboat Mast (Update)

The Boat ... An original Barnegat Bay Sneakbox, built in New Jersey in 1922 ..... It's 87 YEARS OLD ! Older than me... Looks better too ...

In the previous post, A Walk in the Yard, I talked about Pete's, (of Pete's Pizza Oven's) boat, a Barnegat Bay Sneakbox. The original mast is shown below and while it's in perfectly fine and original condition, it's not that handy a set up if you want to trailer the boat to the next small lake or out to the ocean from southwestern Vermont. So, as I mentioned, Sam's building a tabernacle for the new mast which will requare that the mast be shorter by the amount that the original mast goes through the deck to the mortise below (I'm sure there's a nautical term for that place but I don't know what it is ... step hole maybe?) Anyway, we air dried some spruce 2 x 6 's for a couple of weeks, milled them down to 1.35" and glued them up with West System epoxy ... Sometime soon, we'll joint the 15 foot long piece and square it up to begin the layout and tapering of the finished product.

The original mast

Gluing it up with the epoxy

Long view showing support and set up

Jointing and planing it straight ... long thing

5/10/09 Making a Mast update ..

Well, I learned something new yesterday. I made my first 15' long 3.5" diameter, curved and tapered chair spindle. Remarkably, now that I look at my pictures and review the process, it is EXACTLY the same as the process I used to make windsor chair spindles from scratch, back in the 80's when I was making Windsor chair spindles from scratch. Made a lot of them. Hundreds of em. Pick some wood with nice straight grain; make a long, straight square; taper it; make it into an octagon; whittle it round and fit it to the chair. Same exact process, except this spindle weighs about 40 pounds, more than a whole set of windsor chairs. It's not rocket science, but there is a logic to the steps and we have to honor the process. Pete had a book, 'How to Build a Shellback Dinghy', by Eric Dow that had some good pictures and tips on mastmaking and we read that part and had at it. Great book ... if you're not a boater though there are some amazingly obscure words they use to describe different parts of the vessel and sailing processes and some of the paragraphs and descriptions we're stunning when ripped from their context and read aloud to amuse my wife.

After transfering the diameters of the existing mast to our blank, we bandsawed the curved tapers at 90 degrees and planed the cuts to our line, first roughly with a power planer and then with a Stanley #4 handplane

Once it was tapered and square we had to make an 'octagon' jig which was detailed in Eric's book and is essentially made from a drawing like the one above. I started with a square about a half inch larger than the largest section of the mast and then to use the jig, you angle it and drag it along. Once you get the hang of it, it makes proportional lines that are appropriate to the curve as you move it along. Pete's using it below to layout the octagoning lines .. (octagoning ... made that one up)

Click to enlarge the picture and you can see the jig pretty good.

The top curved parts we roughed to the line with a 45 degree bit in the router, the bottom untapered part of the mast we cut the bevels on the table saw.

After we fared the octagon, we sketched on lines with a magic marker to make a sixteen sided object,

Planed to those lines mostly by hand, and then switched to a number 3 Stanley for the final rough smoothing and then to a spokeshave until beer time. The photos above cover about 3 hours work for me and about 2 for Pete, just to give you some perspective on what's involved. Later today, we'll cut the "Lamb's Tongues" (great short video at that link) at the points where the mast goes from round to octagon and then to square .. more on that later.

There is something extremely satisfying about a spokeshaved 15' spruce mast. ...

1 comment:

J said...

Wow, cannot believe it took all that to create a sailboat mast. Hope the boat does not need boat repair! Good Luck to ya!