Brian and Ian will be glad to hear that their contributions to the
thread on the design of the extended range bilge pumping system were
not if vain.

I have experimented with both the siphon and checkvalve versions of
the cofferdam idea and it has been very instructive. Both seem like
simple ideas that just have to work. If fact, both will if you are
dealing with rapid water level changes such as would happen with a
broken stuffing box hose. Most of the time though, the bilge system
will be experiencing very slow accumulations and level changes. Things
happen very differently at this time scale.

Check valves that work reliably at very low heads and slow level
changes are not a trivial engineering proposition. The very slow rise
does not put any pressure in the flap so water seeps in. This
equalizes the pressure on each side and the cofferdam fills up. If you
pre-load the check valve, it will prevent the cofferdam filling but
then there won't be enough difference in pressure to allow it to
empty. It can be done but would be so delicate an adjustment that it
would never work reliably in the real word.

--

Roger Long

"Roger Long" wrote in
:

Most of the time though, the bilge system
will be experiencing very slow accumulations and level changes. Things
happen very differently at this time scale.



"Lionheart", an Amel Sharki ketch, dumps everything into a very deep bilge
in her keel...sinks, shower, seepage, everything except the cockpit
scuppers. When Geoffrey first got this boat, I was concerned the Rule 4000
gph pump down in there with its little Rule float switch was going to seize
if anything went down the drain. I mean, we wash dirty dishes into the
bilge, not just shower soap! You may have suggested why this arrangement
works so good.....

Every time someone washes anything out, there are no "very slow
accumulations" into this deep, but narrow bilge. No sooner than you pull
the plug on the dishwater, it all goes flooding into the keel and cycles
the pump...HARD...to dump it overboard above the waterline. There IS a
Rule checkvalve in the large hose going overboard, about 4' from the pump
outlet, to keep it from backflushing into the pump, especially when we're
heeled over to port, submerging the outlet if we're lucky...(c; Maybe
flushing all that detergent, abrasive coffee grounds, sanitizing booze? and
SoftScrub through there is what keeps it from clogging up! Whenever we
fill the 200 gallon keel watertank from the plughole under the center
cockpit helmsman's footrest, we dump the hose running wide open down into
the 8x6 hatch right above this sump for a while to stir up any solids that
may be down there while we have the chance.

What I find really odd is this chemical/food/booze/soap soup DOESN'T smell
anywhere near as bad as the old Endeavour 35's leaky bilgewater that never
had anything but "very slow accumulations" of rainwater from the mast and
seepage around some through-hull fittings and the packing gland. It stunk
like a dead swamp whenever you lifted the Endeavour's floorboards in there.
The Amel's bilge is damned near refreshing in comparison....

I never clogs....and amazing stuff has made its way down in there.....

Unfortunately, the original bilge pump, a big diaphram, self-priming beast
with big hoses, was worn out when we got it. That thing LOOKED like a
sewage pump!

Another report of a checkvalve installation that works.

Maybe you would answer the question that I didn't get an answer to
from the other checkvalve user.

Do you pump or strip out your bilge by any other method?

I also have a hand pump plumbed in on a separate line which I plan to
take a few strokes on to remove the residual water in the bilge and
keep it as dry as possible. Since it is positive displacement and a
suction pump, it will clear its own line. This will bring the water
level below the inlets of the two Rule pumps. If these pumps can
become airbound as I see numerous references to, it seems that water
draining back from the pump and line up to the check valve would
certainly disable them as well. It's pretty hard to get an airbound
pump going again because you have to get down in the bilge and break
the line.

I'm sure check valves work fine as long as you don't let the water
level drop below the pump inlets.

Interesting about the "dump everything in there" method. I'd like to
know what Peggie thinks. I can see how it could work. Odor could be
from one type of bacteria thriving. By dumping so much stuff, the
ecology is constantly changing so that no one bug ever finds favorable
conditions long enough to grow to the critical numbers that cause
odor.

--

Roger Long



"Larry W4CSC" wrote in message
...
"Roger Long" wrote in
:

Most of the time though, the bilge system
will be experiencing very slow accumulations and level changes.
Things
happen very differently at this time scale.



"Lionheart", an Amel Sharki ketch, dumps everything into a very deep
bilge
in her keel...sinks, shower, seepage, everything except the cockpit
scuppers. When Geoffrey first got this boat, I was concerned the
Rule 4000
gph pump down in there with its little Rule float switch was going
to seize
if anything went down the drain. I mean, we wash dirty dishes into
the
bilge, not just shower soap! You may have suggested why this
arrangement
works so good.....

Every time someone washes anything out, there are no "very slow
accumulations" into this deep, but narrow bilge. No sooner than you
pull
the plug on the dishwater, it all goes flooding into the keel and
cycles
the pump...HARD...to dump it overboard above the waterline. There
IS a
Rule checkvalve in the large hose going overboard, about 4' from the
pump
outlet, to keep it from backflushing into the pump, especially when
we're
heeled over to port, submerging the outlet if we're lucky...(c;
Maybe
flushing all that detergent, abrasive coffee grounds, sanitizing
booze? and
SoftScrub through there is what keeps it from clogging up! Whenever
we
fill the 200 gallon keel watertank from the plughole under the
center
cockpit helmsman's footrest, we dump the hose running wide open down
into
the 8x6 hatch right above this sump for a while to stir up any
solids that
may be down there while we have the chance.

What I find really odd is this chemical/food/booze/soap soup DOESN'T
smell
anywhere near as bad as the old Endeavour 35's leaky bilgewater that
never
had anything but "very slow accumulations" of rainwater from the
mast and
seepage around some through-hull fittings and the packing gland. It
stunk
like a dead swamp whenever you lifted the Endeavour's floorboards in
there.
The Amel's bilge is damned near refreshing in comparison....

I never clogs....and amazing stuff has made its way down in
there.....

Unfortunately, the original bilge pump, a big diaphram, self-priming
beast
with big hoses, was worn out when we got it. That thing LOOKED like
a
sewage pump!

"Roger Long" wrote in
:

Do you pump or strip out your bilge by any other method?


I guess the answer would be "sometimes". Amel installed a big hand pump
under the main hatch steps with a hole in them so you can fill the pump
with dirt every time someone climbs down into the boat with dirty shoes.
This big diaphram pump has a "shoe" that really sucks from the bottom of
the bilge sort of like a vacuum cleaner attachment for bare floors and does
a very nice job scavenging anything the electric pump misses. So, when we
clean the bilges..not as often as we should...I always pump out the bilge
for a while with this nice pump, cleaning the inside of it and its hoses
with the commercial bilge cleaner soap, too. As it sucks from a little
different place than the electric, from much lower down where you can't
even see, it gets a lot of the solids from the very bottom.

Geez, don't pump that handle in front of some greenies on the dock...(c;
Late at night when they're all drunk is the best time....

Here's the final bilge system installed.

http://home.maine.rr.com/rlma/Bilge.htm#Final


--

Roger Long

"Roger Long" wrote in
:

http://home.maine.rr.com/rlma/Bilge.htm#Final



Wow...so CLEAN! Has this boat ever been in the water??...(c;

Where's the oil and exotic marine life aboard??

On a more serious note, move those wires away from the floats on the Rule
switches....thanks.



Geez, guys, look at all that SPACE! I bet we can get 20 more hoses up into
the engine compartment! Where's the intake for the Whale manual pump,
anyways?

Just doesn't seem natural with nothin' leakin'....just a l'il....(c;

"Larry W4CSC" wrote in message

Wow...so CLEAN! Has this boat ever been in the water??...(c;

The boat is incredibly clean. Fresh water helps but the former owners
spent full time on it during the sailing season and I think they did a
lot of cleaning as well as keeping it open and ventilated.

The engine looks in better shape then many five year old boats I've
seen.

On a more serious note, move those wires away from the floats on the
Rule
switches....thanks.

The wires are below and not as close as they look. I'm looking for
some clips to be sure they stay in place though.


Where's the intake for the Whale manual pump, anyways?

It's at the very aft end of the sump just behind the stanchion and out
of the first picture. In the second picture, it's the big black hose
with the lettering.

--

Roger Long

"Roger Long" wrote in
:

It's at the very aft end of the sump just behind the stanchion and out
of the first picture. In the second picture, it's the big black hose
with the lettering.

--

Thanks. That's one of the nicest-looking used boat bilges I've seen.