[C320-list] Holding Tank Vent

Mon Apr 16 14:49:16 PDT 2012

I know everyone has their recommendations, but I would certainly not replace
the vent with the same old fuel/water type tank vent after having both. I'd
suggest using a mushroom type through-hull something like this:

3/4" Marelon Mushroom Head, 2-1/4"L    WM#: 209460  ForeSpar#: 906024

I didn't use one with an L on it, rather I just shortened it enough to make
the bend in the hose work in the space I had.  The white plastic 3/4" hose
is so stiff  it won't kink.  If you can find a 3/4" white mushroom fitting
with an "L" barb end, that would be perfect but I couldn't find a white
forespar one.

If you replace it with one of the fuel vents (made for a 5/8" hose), it will
allow air in/out but won't ventilate the tank like you really need done, so
that's work done that probably won't solve the odor problem.  Unfortunately,
the factory just didn't use the right parts here and replacing them with new
parts won't cut it.  Don't forget to replace the vent hose to the tank.
This is really important!  If you rub your fingers on the outside of the
hoses and smell them, you'll understand.

-Jeff

PS:  The aft cabin closet still smells like aromatic cedar now after a light
sanding back when I did this project.

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Paul Rickman
Sent: Monday, April 16, 2012 4:41 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Holding Tank Vent

Today I started taking everything apart to replace the holding tank vent.
What a job and I'm not done yet. What I found when taking the outside
fitting off is a cotton like substance that was plugging up the vent. I took
a small screw driver and raked it into and back out of the thru hull portion
and found the same substance. It was completely stopped up. Now with some
reasoning and logic, there was no stink when I bought the boat but over time
the stink became worse and worse until last year it was unbearable.  Since I
now have the cabinet out, and messenger lines tied to all hoses and so
fourth, I'll complete the job and replace the fitting -- I don't want to
have to do this again. Now, for those of you who have not started I would
take the outside fitting off and clean it out, using something like pipe
cleaners back and forth in the thru hull. You could even run a little water
thru it. Put it back together to see if you have any improvement. If so,
keep cleaning it once every 5 years or so.
So far I haven't looked for the thru hull but I think it must have an L
fitting, otherwise the hose will eventually colapse onto itself and stop the
venting process.  

Paul
Affinity 657
Bay Bridge Marina
Chesapeake Bay, Maryland

________________________________
 From: Mike Ott <wmo48 at yahoo.com>
To: C320-List at Catalina320.com
Sent: Monday, April 2, 2012 2:37 PM
Subject: Re: [C320-list] Holding Tank Vent

Pat,
Thanks. I sewed seizing line to the hoses and will lube the hell out of them
when I put it back together.  I tried the technique before I went to far and
it work, so on to replace the vent.
Mike

________________________________
From: Pat Ireland <cherie320 at gmail.com>
To: C320-List at catalina320.com
Sent: Mon, April 2, 2012 1:58:39 PM
Subject: Re: [C320-list] Holding Tank Vent

Mike

There are two approaches.  Use a messenger line tied to each hose to pull
them back into the holes in the cabinet.  Wire worked better for me.  The
other approach is to take the back off the closet and access the hoses from
behind the liner.  I did the messenger route.  It's not a snap, but works.
The closet back sounds like the trick, but I have not tried it yet.  Search
the forum history.  Jeff discussed.  Would never have figured it out without
the help.

Pat, Cherie, 801

On Mon, Apr 2, 2012 at 9:49 AM, Mike Ott <wmo48 at yahoo.com> wrote:

> 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
>
>