[C320-list] Holding Tank Vent

[Mike Ott]

Jeff,
I checked out your photo gallery but I'm having a real bear of time getting the 
'medicine cabinet' out.  I have removed 4 screws holding the cabinet to the IGU 
and the 2 anti-siphon valves so now I have a loose cabinet with 4 hose sticking 
into it.  The cabinet won't swing out far enough from the top to pull it out, 
there is not enough clearance in the IGU cutout.  There is a lot of slop in the 
hoses so they can be pushed below the cabinet which would free the cabinet but 
how would I thread the hoses back into the cabinet ?  Did you have this same 
problem ?
Mike  




________________________________
From: Jeff Hare <catalina at thehares.com>
To: "C320-List at Catalina320.com" <C320-List at Catalina320.com>
Sent: Sun, April 1, 2012 7:49:46 PM
Subject: Re: [C320-list] Holding Tank Vent

Hi Mike,

The holding tank vent from the factory is a 5/8" fuel vent and vents out the 
side of the boat.  The hose leading to that is 3/4".  The factory used a 
makeshift technique to adapt the 3/4" hose to the 5/8" fitting. Not only is this 
prone to leak fumes, it isn't particularly waterproof.  If you have a boat with 
the Black plastic vent, this is designed in a way that can actually vent gasses 
back into the boat since no sealant is used on the fitting.  On top of that the 
baffles or screens in the vent prevents the tank from breathing.

Last summer I did a fairly simple project to replace the vent hose with a 
quality hose and installed a 3/4" thru hull fitting similar to the bilge pump 
outlet thru hull.  The result was instant and dramatic.  Went from having 
holding tank smell in the head and aft cabin closet whenever the head was 
flushed to zero smell inside or outside the boat.

This is (in my opinion) a must-do project.  Even though we flush with fresh 
water, there was always a smell in the aft cabin closet.  That is completely in 
the past now.  


There are pictures in my c320 website photo gallery of this project.  It took me 
a few hours one evening after work to do.

Jeff Hare
#809 Woodbine II




On Mar 30, 2012, at 7:03 PM, Jane & Ken <obuoy4848 at sbcglobal.net> wrote:

> Mike,
> On hull #219 (OBUOY) the tank vent is the one under the rub rail and no 
>stantion vent is present.  The "old" catalina boats did use the stantion as a 
>vent--bad stuff on deck when over full.  Ken
> 
> --- On Fri, 3/30/12, Mike Ott <wmo48 at yahoo.com> wrote:
> 
> 
> From: Mike Ott <wmo48 at yahoo.com>
> Subject: [C320-list] Holding Tank Vent
> To: c320-list at catalina320.com
> Date: Friday, March 30, 2012, 12:53 PM
> 
> 
> According to my owners manual ('98), it shows the holding tank vent exiting 
>into 
>
> a deck stanchion.  The stanchion has a small hole (1/8" +/-) through which the 

> tank vents.  I also have, what appears to be, an overflow vent located in the 
> hull just below the holding tank pump out deck-fitting.  Is this also acting a 

> vent for the holding tank ?  The reason for my question is the Feb '12 article 

> in Practical Sailor that says holding tanks should have at least a minimum 3/4" 
>
> vent to have an effective bacterial reaction.  Now maybe in '98 this 
> installation was acceptable but now ?  If my vent is only the 1/8" hole in a 
> stanchion, maybe I should go back to using bucket.  Knowing our group, I'm sure 
>
> someone out there can give me the poop on this fragrant issue (I know, pretty 
> bad puns).
> Mike Ott
> 'Amanda Lu'
> #508