A hinged main mast

I saw an article in Woodenboat magazine (WB #237, March-April 2014) about a year ago describing a simple but elegant mast hinge. I figured that a hinged mast would be easier to manage and set up than standing on a boat on a trailer and manhandling a free-footed 15' spar with all the lines and rigging doodads. So I copied the article and put it on my desk for future reference. This past weekend, I made the mast and hinge. 

For two reasons, I decided to forgo JW's hollow mast design and try out the birds-mouth method. First, I thought having a lighter mast would be good for boat-handling (less weight aloft), and for  ease of rigging-from-the-trailer. Second, I wanted to gain woodworking experience by using the birds mouth technique. 

I bought a nice piece of 16' sitka spruce, and managed to completely destroy it. I had purchased a birds mouth router bit from one of the woodworking mags, but I don't have a router table. So I improvised one. The bit sort of worked...but my table didn't help, and I managed to mangle all my staves beyond usefulness. Not wanting to shell out another $200 for a plank of sitka, I figured I could use prime clear pine. I bought some 8' lengths from Home Depot, and used a rented contractor table saw to make the 45-degree angle cuts after scarfing them together to make 16' lengths. The table saw did a much better job. 

(Note: I keep thinking that a router has the potential to be such an amazing tool. But that thing scares the be-jeezus out of me. The bits are wicked sharp—I sliced my hand wide open and deep just grazing one of them while reaching for another tool! And much as I try, I find that the router has an amazing ability to instantly destroy a perfectly good piece of wood if you're not extremely careful. So for the moment, I use it only when absolutely necessary. 

Anyway. If you want to try making a birds mouth mast, there are some great calculators from Duckworks that can give you all the dimensions you'll possibly need. Here are some pix from my efforts:

Upper mast all glued up. I used cheap hose clamps about 1 per foot of mast length to hold it all together.  The very top and very bottom of the mast have an octagonal solid ash plug. The lower one to hold the hinge parts, the upper one for a solid place to attach the peak halyard block. There's also a solid plug about 18" down from the top where the hounds will be. 

End view of the birds mouth mast. I'm pleased that my math and geometry (never my best subjects!) worked out right and that my cuts were sufficiently accurate to give a nice fit. My dad was kind enough to let me know that a good carpenter would never leave his plane edge down on his bench. Point taken.

Gluing up the stub-mast. This I'm starting square. I'll shape it to an octagon at the deck-level, and then round it where the hinge parts meet.

Here's the bottom of the stub-mast. The square bit will fit into the mast-step installed in the boat a few months ago. 

Making the mast round. Not the plane on it's side ;P    Nothing more gratifying or better smelling than a nice pile of wood-shavings. I took somebody's advice and made sure all the staves grain was going in the same direction, which made the planing a joy. No tear-outs. In this photo, you can see the two stainless hinge "cheeks" with a hardwood spacer between them.

Here's a dry-fit of the hinge assembly. The entire hinge is 18" long.  The bolts are 1/2" stainless, counter sunk into the mast, except for the "lock" pin for ease of access. The stub-mast has not been shaped yet. 

different view of the hinge