The keel and rudder are shown, best, in the profile view. They are to be made from fairly thick wood or plywood and carved into an airfoil section.

The rudder should be about 3/16" thick on the 36" version and 1/4" on the 48" version. You can use plywood or solid wood to make it. If necessary laminate several layers of plywood with epoxy or waterproof glue. These layers of plywood can all be larger than the rudder then cut to shape or can be cut to approximate the airfoil then smoothed. Drill a hole for the rudderpost 1/3 of the way from the front to the rear of the top of the rudder. Use a 3/16 drill and brass rod for rudder post of the 48" version 5/16" for the 36"er. Sand the rudder smooth then glue in the rudder post and seal it with epoxy.

I usually file the top of the rudder post to a rectangular section so that I can make a fitting which will be able to turn the rudder with out slipping on the rudder post. Above that, I thread a short length to accept a nut to hold the tiller fitting onto the rudder post.

I waited until the deck was attached before installing the brass tube which holds the rudderpost.

Make the keel the same way as the rudder. It should be 3/8-1/2" thick for the 48" version and 1/4-3/8" for the 36"er. I made my keel removable by making it fit into a slot in the hull. I laminated the keel from two pieces of plywood and one piece of aluminum plate. It is not necessary to use metal, plywood reinforced with fiberglass is plenty strong enough. Coat the keel with fiberglass cloth and brush on unthickened epoxy. Sand and seal the keel with unthickened epoxy. Leave the part which sticks into the hull rectangular in section.

Make a box in the center of the hull to accept the keel. It should be made from two sheets of plywood separated by two strips of wood which are just thicker than the keel. It should just project through the deck when you install that. Cut an opening in the bottom of the hull and bond the box in place with thickened epoxy.

Make the weight, or ballast, part of the keel by making a mold and pouring molten lead into it. Design the ballast so that the center of mass is just forward of the rear of the keel fin. Note that the circular mark on the profile view is the center of buoyancy of the boat which should coincide with the center of gravity of the completed boat, at least lengthwise. The lower the center of gravity the better. The lighter the rest of the boat can be the more weight can be put into the ballast and the lower the center of gravity and the better the boat will sail.

You can estimate how much lead to use by floating the boat with the keel, rudder, deck, radio gear, mast, and sails on board and the added weight needed to bring the boat to its intended waterline. The intended waterline is shown on the profile view. The added weight is the amount of lead you will need.

Make the mold for the keel ballast in one of several ways.

I made a crude but effective mold by bending two pieces of 1/8"x1" aluminum into half airfoil shapes which when clamped together and to a base plate make an airfoil shaped pool.

Another way is to carve a mold from wood. Yes, it will burn a bit, but it does work. Make sure the wood is quite dry, water will turn to steam and make a mess of your ballast.

A third way is to carve a wooden pattern, make a plaster mold from that, and use the plaster to mold the lead. Again, make sure the plaster mold is very dry before molding your lead. Bake it in the oven for a while.

Melt the lead in a welded seam can such as a coffee can or large soup can. You can use your Barbecue or gas stove for heat. I concentrated the heat of my barbecue with firebricks. Be very careful pouring the lead into the mold.

Use leather work gloves and long handled pliers. Lead is heavy, do not drop the can of molten lead! Allow the lead to cool completely before removing it form the mold. Also wear leather shoes or boots and heavyweight long pants to protect yourself form possible accidents.

The rough casting can be smoothed using a block plane, wood file and sand paper. Be careful to keep cleaning the file so it does not clog. Only push the file or plane, lift it on the return stroke.

Bolt the ballast to the keel fin and fair it (if necessary) with thickened epoxy.