[C320-list] Hoses for toilet

[Greg Arnold]

Charles,

I have a boat of similar vintage to yours.  What you describe seems
accurate.  I don't know about the situation on older boats.

I think the best plan is to remove the hoses and the vented loops from
the cabinet/cupboard/medicine chest.  Then, remove the cabinet.  Working
through the opening, glue two wood blocks to the hull, then screw the
vented loops to them and reattach the hoses. This way, in the  future
you can easily remove the cabinet.  Also, the hoses no longer are in the
cabinet so you can store stuff there.

Once the cabinet is removed, you will find that the pumpout hose
essentially blocks access to the vent hose and the vent.  At this point,
you may feel like giving up.  However, there is an easy way to remove
the hose and the vent despite the poor access.

First, remove the vent hose from the fitting at the holding tank. Then,
go outside the boat and unscrew the visible part of the vent below the
toerail (yes, you can unscrew it from the outside). Then, from the
outside, push the remaining part of the vent inside the hull.  Go back
inside the head, locate the vent hose, and give it a good pull.  The
hose and the remaining vent fitting should come out.

The next problem is that the vent is so close to a liner that you
probably don’t have room for the barbed end of a larger vent.  The
solution to this and the access problem is to drill a new larger hole a
few inches aft of the original vent.  Access to this new hole from the
head is very easy.

What size of new vent to install?  On my boat, the vent hole in the
holding tank is 3/4" female NPT.  The actual diameter of the opening is
1.050".  Catalina did not take advantage of this large hole, but instead
used a 3/4" NPT x 5/8" barbed fitting with a 5/8" hose that runs to a
5/8" vent below the toerail.  This vent has a couple of minuscule
openings for air to escape or enter.

It makes sense to upgrade to a 3/4" NPT x 1" barbed fitting at the
tank.  Attach a 1" hose, and run it to new 1" mushroom vent in the new
hole you drilled.  Your holding tank ventilation now has increased
one-hundred fold.  Plug the original vent hole.

This describes my plan – I have not actually gotten around to
implementing it yet!

Greg
2005 C320 #1054
SoCal


On 9/20/2024 6:27 PM, Charles Munro via C320-list wrote:
> I have been trying to work out how to access and inspect the holding tank vent hose connection to the through hull vent. It seems that I have to remove the vanity cupboard above the head. To. do this firstly seems to require the removal of the two toilet vented loops and to push the hoses back down to allow the cupboard to be removed? Is there an easier way ?
> Charles Munro
> Sabi Star #1011 2005
>
> Sent from my iPad