Thursday, June 5, 2014

A Dry Bilge (Tuggers Vol. 60)

By John Niccolls, Knock Off #66
j.niccolls@blakelandscapes.com


Removing all, or almost all, water from Knock Off's bilge was hampered by the inherent inability of submersible pumps to reach the deepest area of the LNVT bilge just below the shaft log. Our solution was to add a self-priming diaphram type pump and to locate the strum box (Whale 3/4" side entry from GO2Marine) under the shaft log. In less than 30 seconds of operation, the new pump discharged about a half inch of water that was in the bilge following a long and hard rain storm which occurred while we were anchored on La Trapp Creek in Maryland in June.


Flojet's run-dry bilge pump mounted under the galley 

The pump, a FloJet Quad II by Jabsco (Model 04125114), comes with an in-line strainer. Connections to the pump and strainer fit 3/4 inch hose. The strainer caught an accumulation of bilge debris during a vigorous wash down of Knock Off's bilge.

The pump was mounted on a bridge located above the shaft just aft of the transmission. The six inch wide bridge, made of half-inch Starboard, is about 15 inches port to starboard and has legs about eight inches tall. It's secured to the boat's floorboard support system.

The Jabsco pump--less than $150--is available at serveral on-line marine outlets. About 15 feet of 3/4 inch bilge pump hose was required. The pump discharges to a tee in the galley sink drain system. An anti-siphon loop was run up to the underside of the galley countertop.

The pump's electrical requirement, 10 amps at 12 VDC, is supplied via 12 gauge marine wire. About 30 feet was needed to run from the house battery bank to the instrument console and back to the pump. The ground lead run is less than six feet so 14 gauge wire was used. The system is controlled by a Blue Sea marine breaker equipped with an indicator light which glows when the switch is closed.





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