Spars, masts and appendages



Now it's time for the spars, specifically the gaffs & booms. Originally I'd wanted to make the spars from carbon fiber, but I'm in a hurry to get the boat onto the water so for now they'll be glassed wood. I will make carbon fiber spars later and use the wooden ones as spares. The masts, however, are carbon fiber.



Click on any image below for a larger view


Spar Blanks

The spars start out as clear, straight-grain 2x2 radiata pine. The edges are rounded and the blanks cut to length. After a cleaning with denatured alcohol they are ready for glassing.

The foreboom is on the left and the gaffs are on the right. The mainboom is not shown because it will be laminated from 2x1 pieces of wood. This is because the 2x2 wood is only available in 8-foot lengths.


Glass Sleeving

Rather than trying to wrap glass around the spars, I used biaxial glass sleeving. It looks like glass firehose.


Pulling Up the Socks

The sleeving is pulled up along the blank the same way you'd put your sock on. The biaxial weave, besides being very strong, works like those novelty finger traps. When the ends of the sock are pushed together, the diameter increases and it's easy to move things through the sock. When the sock is stretched, the diameter shrinks and the sock grabs whatever is inside it.

Be sure to cut the glass only after it has been fitted to the blank. Otherwise the piece cut for the blank will be too long and the remainder will be too short.


Ready for Epoxy

All 3 spars are glassed and ready for the epoxy. Note how smoothly the sleeving covers the blanks. It's continuous and seamless, with no overlapping or bumps.


All Glassed and Epoxied

The glass has turned transparent with the application of the epoxy, allowing the color of the wood and the grain to show through. The weave is also easily visible. This is the sign of a proper layup. These spars are ready to finish their cure and have their jaws attached.


Masts

The mainmast is on the left, the foremast on the right The mainmast has had its 2 layers of carbon fiber applied and is waiting to be epoxied. The foremast's CF has been epoxied and allowed to cure. It has received its outer layer of glass and is also waiting to be epoxied.

The CF is also in the form of socks, but it's uniaxial, not biaxial. It's made of CF threads that run the length of the mast. None go sideways. The strength of the CF is in the same direction as the stress on the mast. The threads are held together in bundles by spandex threads. The stretchiness allows the sock to be opened and slipped over the mast blank. Again, the assembly is seamless.

The outer layer of glass protects the CF from impact and abrasion.


First Step

This is the first time the masts are stepped. Obviously, the boat is on the trailer backwards. Since there are no mast partners yet, the masts are held vertical with nylon ratchet straps.

The traditional (obligatory) coins are under the masts - a Canadian dime under the foremast (since it has a gaff-rigged schooner on the reverse side) and a Hungarian 1-forint piece (since my name is László).


Rudder

Here's the rudder blank after several hours of quality time with Mr. Beltsander. The layers of the plywood act as a contour map and show the final shape of the foil.


Rudder Airfoil Section

This shot shows how the 2.25-inch thick woooden rudder blank has been transformed into a symmetrical NACA airfoil.





Copyright © 2012 László I. Mórocz. All Rights Reserved.

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