With all the fiberglass sheathing work on the hull completed it was time to install the keelsons. Keelsons are the strips of wood on the bottom of the boat that protect the hull and improve steering. The keelsons are 1" wide by 1/2" thick and were cut from the Mahogany lumber. There are three keelsons, a center or bilge keel, and two outside ones.
The locations and lengths of the keelsons were obtained from the blueprints. The ends of the keelsons were beveled at 45 degrees to prevent them from snagging underwater objects. The first keelson installed was the bilge keelson. The surface of the keelson that was to lie against the hull was wet out with pure epoxy. A mixture of wood flour and epoxy was then mixed to the consistency of peanut butter. With a stirrer the peanut butter was spread on the center keelson and it was set into place. Placing the long strip of mahogany that had epoxy on one side was a two man job. In order to hold the keelson against the hull while the epoxy cured bungee cords were strapped around the hull over the keelson. This was only necessary in the front of the boat where most of the curvature exists. The keelson was cut a little longer than needed. A hole was drilled in the keelson at very end at the bow. A bungee cord was hooked at this point to achieve the necessary force to pull the keelson in place at the very front of the boat. The epoxy that squeezed out from the keelson was wiped away. Another small batch of epoxy peanut butter was mixed. This was used to form a small fillet at the joint between the keelson and the hull. The round end of a stirrer (tongue depressor) was used to fillet this joint.
The next step was to install the outside keelsons. These were to be 18" from the center keelson. To make certain that all keelsons were parallel I cut three 18" pieces from some 1/2" x 1" scrap fir. Working with one keelson at a time I laid the 18" scrap strips on the hull butting them up against the center keelson. I used a square to check that they were at 90 degrees with the center keelson. Next the outside keelson was epoxied into place just as the center keelson had been. The process was repeated with the other outside keelson. These two keelsons were held in place with bungee cords. Blocks of wood were placed under the bungee cords at the ends of each outside keelson to apply enough force to keep them flush with the hull. Once the epoxy had cured the bungee cords were removed the fillet joints were sanded smooth. The keelsons received three coats epoxy.
To protect the keelsons from abrasion it is recommended that they be covered with a metal strip. Devlin suggests brass half ovals. I found aluminum strips at my local hardware store to be more affordable and just as effective. I purchased five eight foot pieces of 1/8" thick by 1" wide. With the sander/polisher I sanded one side of each strip so that paint would adhere. I drilled counter sink holes in each strip every six inches. The strips were fastened into place with 3M 5200 bedding compound and #6 1/2" stainless steel screws. The leading edges and trailing edges were beveled to prevent them from hanging.
The locations and lengths of the keelsons were obtained from the blueprints. The ends of the keelsons were beveled at 45 degrees to prevent them from snagging underwater objects. The first keelson installed was the bilge keelson. The surface of the keelson that was to lie against the hull was wet out with pure epoxy. A mixture of wood flour and epoxy was then mixed to the consistency of peanut butter. With a stirrer the peanut butter was spread on the center keelson and it was set into place. Placing the long strip of mahogany that had epoxy on one side was a two man job. In order to hold the keelson against the hull while the epoxy cured bungee cords were strapped around the hull over the keelson. This was only necessary in the front of the boat where most of the curvature exists. The keelson was cut a little longer than needed. A hole was drilled in the keelson at very end at the bow. A bungee cord was hooked at this point to achieve the necessary force to pull the keelson in place at the very front of the boat. The epoxy that squeezed out from the keelson was wiped away. Another small batch of epoxy peanut butter was mixed. This was used to form a small fillet at the joint between the keelson and the hull. The round end of a stirrer (tongue depressor) was used to fillet this joint.
The next step was to install the outside keelsons. These were to be 18" from the center keelson. To make certain that all keelsons were parallel I cut three 18" pieces from some 1/2" x 1" scrap fir. Working with one keelson at a time I laid the 18" scrap strips on the hull butting them up against the center keelson. I used a square to check that they were at 90 degrees with the center keelson. Next the outside keelson was epoxied into place just as the center keelson had been. The process was repeated with the other outside keelson. These two keelsons were held in place with bungee cords. Blocks of wood were placed under the bungee cords at the ends of each outside keelson to apply enough force to keep them flush with the hull. Once the epoxy had cured the bungee cords were removed the fillet joints were sanded smooth. The keelsons received three coats epoxy.
To protect the keelsons from abrasion it is recommended that they be covered with a metal strip. Devlin suggests brass half ovals. I found aluminum strips at my local hardware store to be more affordable and just as effective. I purchased five eight foot pieces of 1/8" thick by 1" wide. With the sander/polisher I sanded one side of each strip so that paint would adhere. I drilled counter sink holes in each strip every six inches. The strips were fastened into place with 3M 5200 bedding compound and #6 1/2" stainless steel screws. The leading edges and trailing edges were beveled to prevent them from hanging.
