Let's talk bilge pumps....

Discussion in 'Boat Yard Basics' started by TomFL, Nov 15, 2009.

  1. TomFL

    TomFL Well-Known Member

    Somewhere on here I thought there was a post discussing what brand bilge pump forum members liked, and I can't find it.

    I have a unique need with the tunnel hull; I need two bilge pumps, one for each side. I'm thinking about getting the ones with the built-in float switch so each side can turn on independently in case of a water intrusion problem.

    Can I rig them both to the same through-hull fitting without the flow from one side back-flowing through the other pump that's not on? Or would it be best to run each to a through-hull?

  2. mark_gardner

    mark_gardner I Love microskiff.com!

    not sure about the backflow question but one thing comes to mind that if both turned on ( lets say you get swamped by some old geezer driving is pleasure cruiser too fast  :eek: :mad: ) would the size of the pipe and thru hull fitting be large enough to handle the volume of water created by 2 pumps clicking on? i have 2 thru hull fittings on the f &f . one for the bilge pump and the other was for a live well drain which is no longer being used so i might add an additional bilge pump just in case. definitely like the peace of mind of a float switch  :cool:

  3. TomFL

    TomFL Well-Known Member

    Yes, that would have to be thought out as well, good point.


  4. Brett

    Brett > PRO STAFF <

  5. The_Skiff_Shop

    The_Skiff_Shop Well-Known Member

    If I remember correctly those hulls are self bailing and the bilge does not take on much water.  If that's the case I would go with a couple of rule 500's, one each side with independent systems including the discharges.  Shorter runs allow the pump to work with less effort. ;)  If she is not self bailing, I would go with 1100 rule's.

    You only need automatics if you are ever going to leave the boat in the water unattended, even for one night.  One storm can sink a boat.  We replace the built in auto's on a regular basis so I suggest float switches if you have the room to mount them.  I'm putting an 1100 built in auto in my SUV because my well is not large enough for an 1100 and a float switch.  I can also swap and warranty the auto just by running to the shop 24/7 but I will probably be inclined to carry a on spare on extended trips where we do not return to the ramp for several days.  I have another option of mounting a redundant pump about an 1" higher and may elect to go that route. Just be aware the auto's are prone to failure.
  6. firecat1981

    firecat1981 BBA Counselor

    you can't use one thu-hull for 2 pumps, the pipe size will be way to resrictive and the friction loss will only allow enough water flow equal to one of the pumps. you's be better off going with 2 totally separate systems.
    as said above the ones with build in float switches seem to fail more oftem then the ones that are seperate. I've been using the Attwood Tsunami pumps from walmart for a few years now in my old gheenoe with no issues, I now have 3 of them on my new boat (1 for the bilge with a float switch and 2 for the livewell). The bueaty of them is they are cartrige based so when a pump fails you just replace the cartrige instead of the whole housing. As an added bonus the cartrige is cheap, I think $12 for a 500gph.
  7. Un-shore

    Un-shore Well-Known Member

    Johnson pumps come with a check valve option for this use. It does restrict the the flow slightly but not that much. the size of the hose is a restriction but that only increases the velocity of the water more and slightly decreases the gpm. so for your intended use go with a little bigger pump, check valves, and one through hull fitting IMO.