Leeboards
View GIF alone for better quality.
The drawing shows the starboard leeboard - the port one is assembled the other way round (eg, the leeboard handles are outside the leeboards on the boat).
The leeboards are made from two thicknesses of 9 ply bonded together.
The leading edge of the board should be rounded, say over a distance of 50mm from the edge, and the trailing edges tapered to a thickness of about 6mm, starting about 100mm from the edge.
The leeboard handles are made from 73x22 (3"x1") wood - softwood is probably OK, though I made mine from mahogany. The leeboards can be lowered with a thump, putting quite a load on the handles, so make sure you get good straight-grained wood - I didn't and broke one leeboard handle through the stop pin hole. It did serve to show what tough stuff the epoxy resin coating the wood was - the wood broke, but the parts were still held together by the epoxy skin on one side.
The front top edge of the 'windward leeboard' (ie, the one not in use) will project into the water up to 100mm when raised, so the top edge of the handle (top right in the drawing above) should be chamfered over this distance - otherwise you tend to get a jet of water hitting the top of the leeboard handle and spraying into the boat!
The free end of the leeboard handle should be rounded over on all sides, so that it is comfortable to use.
When making the leeboards, it is much easier to coat the pieces in epoxy before assembly. If you do this, make sure that the epoxy coating is sufficiently abraded where the parts will join, to remove the amines that come to the surface of the epoxy during curing.
The leeboards and handles can be fixed together either by epoxy bonding (eg, epoxy/microfibre 'glue') with a couple of screws to hold the parts while the 'glue' sets, or just by screwing them together. I bonded mine, but screwing them together does allow just a leeboard or handle to be replaced on its own - once bonded, they cannot be separated.
There are four holes that need to be drilled in the assembled leeboard in the positions shown:
- two 6mm (1/4") diameter holes at the end of the handle for the leeboard downhaul string and the leeboard shock cord;
- a 12mm (1/2") diameter hole in the middle of the handle for the leeboard stop pin;
- a 12mm (1/2") diameter hole through the handle and the leeboard for the leeboard pivot pin.
Leeboard Fittings
View GIF alone for better quality.
Each leeboard pivots on a 12mm (1/2") diameter pin - these can be most easily made from long stainless bolts (ie, only part-threaded) with the threaded portion cut off.
Fit a washer under the head of the bolt, but do not fit washers between the leeboard and the gunwhale as they would enable to leeboard to 'rattle'.
At the inboard end, a hole is drilled through the pin to take a spring-loaded locking pin, which can be obtained from specialist boat rigging suppliers. Between the locking pin and the boat, place a 'pack' of washers (three in my case) glued together, to get the clearance right and allow for future wear.
To avoid anything being lost overboard, drill the head of each pivot pin and tie the pivot pin, the locking pin and the washer pack to the arm of the leeboard.
To stop the leeboard being pulled down too far, a stop pin is fitted to each leeboard arm as shown. This pin is made from the same bolt as the pivot pin, but with the head cut off. It is fitted to the leeboard arm by two nuts and washers. It may be necessary to recess the inner nut into the leeboard arm, as the length of thread may be insufficient to go through the whole thickness of the arm.
Photos of the leeboard can be seen here.