by DanaDCole on Fri Jan 23, 2015 9:50 am
I propose a change to Pete McCrary's excellent design for installation of an electric bilge pump. In his third picture I noticed the exhaust line sags in three places (between floor joists). Water will collect in those areas and conceivably grow algae, which could clog the line. The chances of this happening are admittedly pretty small, but still I would rather not have to remove the floorboards in order to replace or clean out the line.
My proposal is to run the exhaust line through Floor 4 only, and immediately up through the floorboard, then back to the footwell. The line could lie flat across the floor until it reaches BH7 and curves up to the footwell, but best practice would have it always slanting slightly upward fore-to-aft. Plumbing code calls for a minimum of 1/4" slant for per foot, so the line would only have to rise about 1 to 1 1/2 inches. The code calls for the slope (1/4" minimum and 3" maximum per foot) mainly to facilitate removal of solids (poop), but the algae problem I mentioned has been known to occur in things like air-conditioner drains that drain water only. I plan to slant mine up 3 or 4 inches fore-to-aft because the floor won't always be sitting level on a trailer. A long, narrow wooden trough will be glued to the CB trunk to facilitate the slant and eliminate sags.
This modification will not look as pretty as Mr. McCrary's design, but I believe it should be more practical. After the pump stops running, a small amount of water will flow back down and out through the pump, but I think this will be negligible and will eventually evaporate in the well-ventilated cuddy.