[Public-List] Automatic bilge pumps

[Gordon Laco]

I would agree.

The worst outcome of having an automatic pump is the situation where the
pump comes on without you knowing... And masks a problem that might not come
to your attention until the pump is overwhelmed or your battery goes flat!

The volume of water even apparently powerful ones can lift is quite small.
The outputs are rated with no head to push water up... Even a couple of feet
lowers the volume of water dramatically - the 4-5 feet of head needed for an
A30 will cut the amount of water being moved to a trickle.  To minimize the
vertical lift, the outlet gets put low on the hull...which can mean it is
put under water when the boat is under way due to the quarter or stern wave.
If that happens, you can experience the dreaded 'cycling' were the pump
empties the bilge...the hose syphons back the water, which is pumped out,
etc etc until the battery is flat; then the syphoning fills the boat until
you notice the floorboards are floating.

What I am getting at is; don't count on the submersible electric pump (Rule,
Attco, etc) being much help in an emergency. They will only move a fraction
of what the manual pump will shift, and as I said above, they can
seditiously hide a problem or leave you in a bad spot when suddenly you find
you can't start the engine because your battery is flat, there is water
rising in the bilge, and the source is already under water and difficult to
find... 

I considered putting an electric pump under the engine in #426; I thought
about having the outlet in the cockpit from which it would drain overboard
through the cockpit drains.  I figured that I could easily see when the pump
was going and also eliminate the possibility of syphoning while keeping the
vertical lift to a minimum.   While mulling that over I re-examined why I
thought I needed an electric pump and decided I didn't.

What I may fit to the boat some day is a Jabsco 'Water Puppy'.  This is an
high output non-submersible that is powerful enough that it will really move
water; enough to act as an emergency pump or even supply a fire hose.  The
high amp motor really draws power so if it were to run for any length of
time running the engine to keep the batteries up would be a good idea.  If I
put a hose to the bow it could also supply pressure water to clean the
anchor chain as it comes aboard.  I guess in that application it would be a
good idea to have a Y valve in the pump's intake so that one could choose
the suction being from over the side or the bilge...

Oh what fun to think about boat projects...

Gord 
#426 Surprise


On 1/5/09 11:51 AM, "C.B. Currier" <cbcurrier at spinrx.com> wrote:

> 
> 
> Don't waste your time. Caulk all of the holes in the deck instead ( which
> you should do anyway & don't forget the chain plates) then make sure
> your whale pump is operating properly. You should then have few problems
> with leaks and needing a pump.
> 
> Reasons why the electric pumps
> are junk:
> a. The electric connections eventually fail - 1-3 years
> timeframe
> b. Drain the battery
> c. don't rely on them maintaining
> or the switch working all the time, they don't ( the float switch
> sticks)
> d. you should visit your boat regularly anyway (if you don't
> you may have to deal with bird mess, vandals & other issues even if
> you have marina security etc)
> 
> I put one in & replaced it 2x
> so 3 in Infinity & it was such a headache that I went back to the
> whale with no problems what-so-ever.


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