ahoy wrote:

What excitement. I'm trying to install a new 6 gal waste tank next to
my head which was designed long ago as an intake-pumpout-to-the-sea
arrangement. The sanitary looking, white plastic tank has two 1.5"
in/out stubs and a 5/8" vent all sticking out the TOP.
So how do you evacuate the tank at sea? This all seems reliant on the
pump pressure of the hand pump which can't be much and would seem to
pump the waste but then leave the tank full of seawater. (48 pounds of
unpaid freight!). I'm not bright at things I've never seen. What am I
missing here? If the outlet were at the bottom of the tank it could
just run out as you opened a valve and vented, hmm? Thanks as always.

The outlet needs a pickup tube inside the tank that goes to the bottom.

Take the 1.5" thread-barb tank fitting to a hardware store...find a
piece of PVC that fits snugly inside the threaded end...it'll most
likely be 1.25" OD, but because wall thicknesses of both fittings and
pipe can vary, you want the fitting with you to make sure of a good fit.
You'll secure it with PVC cement.

The tube should just touch the bottom of the inside of the tank...then
be cut at about 25-30 degree angle. If it's flat across the bottom and
any closer than 3/4"-1", it's likely to become clogged.

Putting all fittings on the top of the tank is actually the best way to
do it...because a) it eliminates standing waste in any hose, which helps
prevent hoses from becoming permeated with odor...and b) hoses can be
disconnected from pumps/macerators/through-hulls to service 'em without
a spill. It also increases the useable capacity of the tank by 5-10%
depending on the size of the tank.

Btw...a 6 gal tank only holds a dozen flushes at most...for two people,
barely enough for an overnight stay in a marina or anchorage.

--
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://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/detai...=400&group=327

ahoy wrote:
Hi Peggy, thanks for your response. I looked at my tank with a back
light and the "waste out" line does go to the bottom of the tank as
per your recommendation.
So, the tank empties out by siphoning after I'm done pumping it out?

No...there'll be an inch or less left in the bottom of the tank after
pumpout.

Does the boat have to be moving?

No...though it's a good idea, 'cuz it lessens the impact on the
environment by spreading out the contents instead dumping it all in one
spot.

I end up with an empty tank and a
clean toilet ideally, correct? I've never used one.

Emptying the tank has nothing to do with the toilet.

Also, the head approved type hose that I bought has a bit of play when
dry fitted to the tank. What do I use to seal it all tight? Stainless
hose clamp and plumbers putty? silicon caulk? teflon tape? Thanks
again.

There shouldn't be any play, nor should ANY kind of sealant or caulk be
used. The hose should fit tight enough to require warming it a bit and
some dish soap as lubrication to get it onto the fitting. If the hose is
1.5" sanitation hose, I suspect the hose barbs on the fittings are too
small. Double clamp all connections, with the screws on opposite sides
of the hose--or at least 90 degrees offset.

And btw, the tank MUST be vented to the outside of the hull...CG regs.

--
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://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/detai...=400&group=327

On Wed, 17 Aug 2005 10:01:14 GMT, ahoy wrote:


So, the tank empties out by siphoning after I'm done pumping it out?
Does the boat have to be moving? I end up with an empty tank and a
clean toilet ideally, correct? I've never used one.

No - you have to pump the stuff out - it does not siphon out
automagically - that would defeat the whole purpose.

The whole point of having the holding tank is to retain the material
on-board until it can be discharged in an acceptable location. In
most areas of the US, I understand that this means you take the boat
to a marina or other facility that has a pump-out station. The
pump-out station will suck the goop out of your tank, and deliver it
to the municipal sewage system.

Here in coastal British Columbia, we are permitted to discharge
overboard into the sea in most areas, but require holding tanks in
certain popular harbours and anchorages. My holding tank system has a
discharge pump to dump the stuff overboard - I do that while running
in open water. (pump-out stations are quite rare around here, as many
marinas don't have access to a municipal sewage system.)

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca