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Coho Re-model: Bilge Pump

By Dennis Andrew

The design intent when I built my Pygmy Coho sea kayak was to have ample room in the cockpit for storage of oft-needed items like an insulated lunch box, an extra shirt or paddle jacket and some fishing equipment. The plan was to pack "day hatch" type items in the cockpit, past my feet with a tether attached. When I wanted an item, a simple tug on the tether cord would produce one of several bags into my lap.

Practice sessions in early October on Cd'A Lake and Lake Pend Oreille drove home safety issues about large volume cockpits and the requirement to pump out a cockpit with the spray skirt attached while using both hands on the paddle to brace. The conditions that caused a capsize and wet-exit would still be there after I got myself back into the boat. Only now that the cockpit was flooded, the boat's stability and maneuverability were greatly reduced. This greatly increases the risk for more capsizes.

A hard decision was made to move the forward bulkhead back 7 inches. This would create a mounting platform for a foot-operated bilge pump and reduce the total cockpit volume. Even after I knew that this would make a safer and better boat for my uses, I spent two weeks reviewing methods and tooling requirements to accomplish the task. Really they were just stalling tactics because I was afraid of cutting into my pretty boat.

I was nervous right up to the point of placing the 2" hole saw up against the bulkhead to create four access holes, one each at top center, bottom center and left and right shears. After the first hole was cut, the rest of the demolition was easy. I used an 1/8" ceramic tile cutting bit in a Dremel rotary tool to trace through the epoxy fillets along the inside of the hull. The bulkhead was gone in 30 minutes. The left-over material was sanded smooth with 80 grit sand paper in an electric palm sander and the surface was leveled with a wood flour/epoxy mix. The wood flour was used mostly to hide the blemishes on the bright finish. The last step of the removal process was to lay a two-inch wide strip of fiberglass cloth and epoxy resin where the bulkhead had been to completely hide evidence of its removal.

A cardboard pattern for the new bulkhead was created by the time-consuming 'trial cut and fit' process. The bulkhead is cut from 3mm plywood; commonly sold as doorskin to you home re-modelers. The plywood was seal-coated with epoxy and fiberglass cloth was placed on both sides. Four stainless steel T-nuts were sunk into two pieces of poplar, 1/2" x 1" x 5-1/2" ; the wood blocks were seal-coated with epoxy, and glued to the bow side of the bulkhead to accept the pump mounting screws from the cockpit. The blocks were relieved between the mounting holes for a strap or small rope. Now the blocks may be used for anchor points for bags stored in the bow. The bulkhead was epoxied to the hull and deck using 1-1/2" fiberglass tape which was backed up with a 1/2" fillet of thickened epoxy.

A water-proof vent was created in the forward hatch by drilling a hole, filling the hole with epoxy, then drilling an 1/8" hole through the epoxy. The two-step drilling process maintains the waterproof integrity of the bulkhead. A patch of gore-tex was glued over the hole.

The pump I chose is the "Guzzler 400s-lws" built by Bosworth of Rhode Island. It is capable of pumping 10-12 gpm, has a center button for foot operation and comes with a lightweight spring (lws) for kayak installations. West Marine can order the pump ($59.30 + tax) or it can be purchased directly from Bosworth ($60.95 + S&H). The pump is mounted on the vertical panel with the inlet and outlet horizontally opposed. This arrangement allowed the pump to sit a bit higher on the bulkhead than if the outlet was at the top. The higher location places the foot button at the ball of my foot. A 1" O.D. PVC fitting was placed through the deck just above the shear and epoxied in place. The little bit of white plastic showing through the deck is acceptable to me, but some of the more particular folks might object. Later, when it spouts water, I think it will look very cool. The inlet and outlet lines are 1 inch vinyl tubing. I will still carry the hand operated bilge pump common to most sea kayakers as a backup or to help another paddler.