Where could I find some good insight into designing the plumbing to get
water out of my shower drain to an underwater thru-hull, and staying
out of the shower? The plumbing in my Beneteau allows some water to
come back into the shower drain at the base of my head, enough that
when I heal the boat, it coats the bottom of the head floor.

Seems after the pump stops, the extra water in the hoses to the pump
slowly let out water, maybe only 4-6 ounces, but enough to fill the
bottom and come up a small amount above the drain.

I suspect its designed poorly and I could upgrade it myself. I noticed
for example the diaphram pump wasn't design to be connected to
underwater thru-hulls.

The current plumbing has a hose running up then down the wall to a thru
hull, in a loop,with an in-line filter and a diaphram pump at the top
of the loop. After I pump the water out of the head, even if I close
the thru hull, water runs back into the shower drain within a minute or
two. If I stick a cork in the bottom of the drain, the water gets
around it and forms a tiny pudle in the middle of the head anyhow.

Dan

b393capt wrote:

The current plumbing has a hose running up then down the wall to a thru
hull, in a loop,with an in-line filter and a diaphram pump at the top
of the loop. After I pump the water out of the head, even if I close
the thru hull, water runs back into the shower drain within a minute or
two. If I stick a cork in the bottom of the drain, the water gets
around it and forms a tiny pudle in the middle of the head anyhow.

I THINK there's a simple solution to your problem: pump longer.

The water that's running back into the sump is the water that's left in
the line between the sump and the top of the loop. Pumping longer should
move it over the top of the loop. If it doesn't--if dropping the water
level in the sump causes the pump to suck air that breaks its prime--a
one-way valve in the line just above the top of the sump may solve that
problems.

The thru-hull should always be closed except when actually dumping the
sump.

Btw...why would there be a filter in a sump drain line? Or do you mean a
strainer to trap hair etc?

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

Peggie,

This one will be a little tough. Yes, I did try pumping longer in fact
for a very long time, it didn't even improve a little bit.

Yes, your right, I did mean a strainer rather than a filter. Says
Jabsco on the outside and is maybe 3 inches wide and round.

I am leary about adding a one-way. Will adding a one-way valave just
after the sump really be a solution, or just delay the water coming
back into the sump by another 30 minutes or so? I was thinking it
won't work because the seal isn't very good on these things, and any
hair in the line will just make it worse.

Dan

p.s. Your book was great !

Peggie Hall wrote:
b393capt wrote:

The current plumbing has a hose running up then down the wall to a thru
hull, in a loop,with an in-line filter and a diaphram pump at the top
of the loop. After I pump the water out of the head, even if I close
the thru hull, water runs back into the shower drain within a minute or
two. If I stick a cork in the bottom of the drain, the water gets
around it and forms a tiny pudle in the middle of the head anyhow.

I THINK there's a simple solution to your problem: pump longer.

The water that's running back into the sump is the water that's left in
the line between the sump and the top of the loop. Pumping longer should
move it over the top of the loop. If it doesn't--if dropping the water
level in the sump causes the pump to suck air that breaks its prime--a
one-way valve in the line just above the top of the sump may solve that
problems.

The thru-hull should always be closed except when actually dumping the
sump.

Btw...why would there be a filter in a sump drain line? Or do you mean a
strainer to trap hair etc?

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

On 16 Nov 2006 20:05:38 -0800, "b393capt"
wrote:

Peggie,

This one will be a little tough. Yes, I did try pumping longer in fact
for a very long time, it didn't even improve a little bit.

Yes, your right, I did mean a strainer rather than a filter. Says
Jabsco on the outside and is maybe 3 inches wide and round.

I am leary about adding a one-way. Will adding a one-way valave just
after the sump really be a solution, or just delay the water coming
back into the sump by another 30 minutes or so? I was thinking it
won't work because the seal isn't very good on these things, and any
hair in the line will just make it worse.

Hi,

Is there space for a/the filter after the sump?

cheers,
Pete.

Is there apec for the shower to drain into a small sump tank and the
pump empties the sump tank - float switch in the tank switches it on.
Any water running back will merely go into the sump tank. Attwood and
Jabsco make small ones, or a plastic sandwich box can be adapted.

Is there space for the shower to drain into a small sump tank and the
pump empties the sump tank - float switch in the tank switches it on.
Any water running back will merely go into the sump tank. Attwood and
Jabsco make small ones, or a plastic sandwich box can be adapted.

Is there space for the shower to drain into a small sump tank?? The
pump then empties the sump tank - float switch in the tank switches it
on. Any water running back will merely go into the sump tank. Attwood
and Jabsco make small ones, or a plastic sandwich box can be adapted.

b393capt wrote:
Peggie,

This one will be a little tough. Yes, I did try pumping longer in fact
for a very long time, it didn't even improve a little bit.

Weeelll...it was an idea.

I am leary about adding a one-way. Will adding a one-way valave just
after the sump really be a solution, or just delay the water coming
back into the sump by another 30 minutes or so?

My thought was, it would allow the pump to retain prime long enough to
pump the rest of the water out the line...but it would also prob'ly get
clogged up, so it wasn't the best idea I ever had.

p.s. Your book was great !

Thanks!

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://shop.sailboatowners.com/books...ku=90&cat=1304

b393capt wrote:

This one will be a little tough. Yes, I did try pumping longer in fact
for a very long time, it didn't even improve a little bit.

Use a manual diaphragm pump such as a Whale 10.

It does not require full prime to operate.

Lew

Is there some best practices guide in boat building for designing the
plumbing for a shower drain ?