Re: [Paddlewise] Pumps

"Peter Treby" <ptreby_at_ozemail.com.au> wrote

>"Pumps have always been problematic. I have recently purchased 
>a pump that has the batteries inside. Although it bench-tests well, 
>the ocean environment will be the true test. It uses 3 D batteries 
>and pumps 200 gpm with a 4 foot head and may be purchased 
>from West Marine. "

200 GPM ?!  That thing will suck you right out the cockpit with all 
the water. ;)
More likely 200 GPH.  How long did the 2 D cells last in your 
bench test?  200 gph gives less than 3.5 gpm, not to impressive!

Last season I fed my Rule 500 gph pump with 8 AA cells (to get 
the 12V).  They lasted for several runs were the cockpit was full 
with water up to the coaming with nobody sitting in it ~5 minutes 
each time.  During weekly rescue drills on the lake for 3 month I 
burned 1 set of batteries.  In this situation, with me back in the 
rightened boat and the amount of water getting in during reentry 
and roll or similar situations, it took less than 2 minutes to get the 
water out. No problem to switch the pump on before getting back 
in, but shutting it down after spraydeck back on and water out was 
a pain in the neck with the switch under the rear coaming, espcl. 
when working and concentrating on preventing another capsize.  
Right now I am working on a sensor switch (bench tests work).  Its 
a little circuit with a relais, two transistors, and two sensor 
electrodes.  The switch I use has 3 positions, 1)OFF, 2) ON with 
sensor (pump only works if water is above a crtain level in the 
bottom of the boat), 3) ON pump runs as long as switch is in this 
position and batteries last.   Personally I see advantages compared 
with a common float switch. Time will tell.

Cheers

Ulli


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