Don W brought forth on stone tablets:
Hi Everyone,

I got around to fixing problems with our Irwin 38's head recently, and
as a result, I'm seriously considering completely rebuilding the
sanitation system. For one thing, the 1-1/2" sanitation hose was
original, and it was quite brittle. For another, the holding tank is
only 8-1/2 gallons, which is ludicrously small even for just two people.

We currently have a small electric head with a macerator which pumps
through a vented loop directly to a 1-1/2" thru-hull under the floor in
the aft cabin. If you shut off the valve at the thru-hull, and open
another valve, it pumps to the holding tank in the back of the boat
(behind the aft cabin).

Right now, I'm "cogitating" (that's a Texas expression) on whether it
would be better to pull the electric head, and install a Sealand
Vacuflush head and vacuum generator while I'm re-doing everything. In
any case, I will put in a larger holding tank.

An advantage to the Vacuflush system is that I can install the vacuum
generator in the top of my starboard cockpit locker, and let it drain by
gravity into the holding tank. Since the holding tank is vented at the
top, this does away with the need for a vented loop since there would be
no way that a siphon could develop from the thru-hull. Also, since the
vacuum generator effectively "sucks" the line clean there is an added
advantage of not having anything standing in the sanitation hose--a
disadvantage of the present system.

I'm thinking that I might use an electric macerating pump to pump the
contents of the holding tank to the thru-hull when emptying at sea,
rather than relying on gravity to do the job. I'm a little concerned
about having the macerator head sitting in raw sewage all of the time.

All of this is likely to cost a few boat bucks, so I'd like to be sure
I've thought it through before commiting the money.

Any thoughts or comments you'd like to offer??

Don W.


I'd skip the use of the head hose, except as for flexible connections to
hard-mounted items, unless the runs are very short. Instead, plumb with
rigid white PVC pipe - it has an essentially infinite permeation time -
unlike the hose.

bob
s/v Eolian
Seattle

RW Salnick wrote:


I'd skip the use of the head hose, except as for flexible connections to
hard-mounted items, unless the runs are very short. Instead, plumb with
rigid white PVC pipe - it has an essentially infinite permeation time -
unlike the hose.

bob
s/v Eolian
Seattle

Hi Bob,

I'd love to plumb with PVC pipe, but I've heard
that the flexing of the boat causes it to develop
cracks over time. Is that true?

Don W.

On May 17, 11:38 pm, Don W
wrote:
RW Salnick wrote:
I'd skip the use of the head hose, except as for flexible connections to
hard-mounted items, unless the runs are very short. Instead, plumb with
rigid white PVC pipe - it has an essentially infinite permeation time -
unlike the hose.

bob
s/v Eolian
Seattle

Hi Bob,

I'd love to plumb with PVC pipe, but I've heard
that the flexing of the boat causes it to develop
cracks over time. Is that true?

Don W.

Hi, Don, and group,

I'm not an expert, but I can provide some RW experience.

Most of you know that I had about the most boat flexing one can
experience and still float, after it's over, a few months ago.

Before that time I had installed PVC exhaust plumbing on both heads.
The forward head, which I'd originally thought would be impossible,
turned out to be feasible with lots of joints, and some creative
vocabulary. The aft, which I originally thought would be a piece of
cake, I then thought couldn't be done at all, actually turned out
pretty simple.

However, I learned a bit along the way. As nobody's going to be
grading you on neatness, slop the crap (pardon the expression) out of
the joints with cleaner, and then with the glue, when you're making
the assembly (do it all dry first, of course, and allow for the full
depth of insertion as the glue will act as a lubricant, letting you
seat it fully where it won't go, dry).

I didn't do that in my forward head installation. As a result, I had
two very minor seeps at two joints after the incident (more below).
Those were cured with careful sanding and addition of, first, more
glue preceded by an acetone wipe (to clean and soften the plastic),
and followed by some penetrating epoxy (more flexible than laminating
or general-purpose epoxy) with a thickener added to keep it in place.
As I'm currently on the hard, I shut the thru-hull connection, opened
the anti-siphon valve (like you'd see in a laundry connection), and
poured water into the system until it was full (both toilet and hull
ends of the line), and waited a week. No seeps. The aft didn't leak
anywhere.

So, from that, I get...

First, if you think you're being ridiculous in your application of
cleaner and glue, and follow up each joint with swabs around the
perimeter for good measure, it's unlikely you'll ever have a leak.

Second, if there *is* a very small leak, it can be addressed, if you
can get to it. I'd originally thought I'd have to cut out the
offending joint - but even that's possible to do.

Meanwhile, as an establishment of the bona fides of this process, this
hard pipe stood up to huge hull flexing and pounding (impacts) - more
than you'll ever encounter in normal seagoing life. As seen in my
"Thanksgiving" post, I estimate, based on time and wave interval, that
our hull took not less than 3000 and probably more than 5000 huge
crashes on rock. The flexing our hull provided in her defense is
totally awesome, and for which we're without words to adequately
express how grateful we are that was so. From that I can provide my
own assurances that, done right (joints fully glued) and supported (no
flailing around) that it's unlikely you'll ever have to deal with that
again.

Given the stench of the hose we took out (the good stuff), I'm very
happy to not have to face that thought in this boat's lifetime.
Meanwhile, I have the 15' of AVS96 that I bought to do the forward
head available, now (after the wreck, I'm sure I won't need it),
should anyone want it.

And, finally (you knew I'd get here, eventually, right??), for those
so inclined, my galleries have the gory details on the installations
of both heads' hard pipe, and I can give you the links if you like.
However, in general, I think the forward head (the more complex of the
two) was Feb06 in the refit gallery.

Hope that helps...

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.google.com/group/flyingpiglog and/or
http://groups.yahoo.com/group/TheFlyingPigLog

There is no such thing as a problem without a gift for you in its
hands.

You seek problems because you need their gifts.

Skip - a few simple questions -

I'm thinking of putting some pvc in my from the head (lavac) to the
holding tank. What size pipe do you use, and how do you connect it?
Is there a size that you can simply clamp the normal flexible hose around?

On May 18, 10:32 am, Jeff wrote:
Skip - a few simple questions -

I'm thinking of putting some pvc in my from the head (lavac) to the
holding tank. What size pipe do you use, and how do you connect it?
Is there a size that you can simply clamp the normal flexible hose around?

you use standard Sch40 1 1/2" PVC and fittings. The end to take the
hose can be had in the proper size from SeaLand, who sells a hose they
claim (but which Peggie disagrees with) is superior to their prior
OdorSafePlus, sells PVC end fittings.

However, I just used barbed screw-in (to a pipe thread coupler)
fittings which I ground down to fit properly.

Better yet, I've learned (too late for the forward head) that you can
use a rubber coupling, flush fit, to whatever fitting you're using
(1.5" pipe and the barb described, but with a collar of 1.5" hose,
which makes it identical in size to the PVC). Three clamps - one each
at the ends, and one at the joint. The joint is contained in the
clamp in the middle, making any odor products have nearly an
impossible (I'm saying nearly because I don't have 5 years' experience
to back up my expectation of NO) chance of getting to the rubber
exterior. I've got that setup (flush - pardon the expression - rubber
coupling) at the head and at the through hull on the aft. All that's
to stop any future odor issues...

Hope that Helped...

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.google.com/group/flyingpiglog and/or
http://groups.yahoo.com/group/TheFlyingPigLog

"Believe me, my young friend, there is *nothing*-absolutely nothing-
half so much worth doing as simply messing, messing-about-in-boats;
messing about in boats-or *with* boats.

In or out of 'em, it doesn't matter. Nothing seems really to matter,
that's the charm of it.

Whether you get away, or whether you don't; whether you arrive at your
destination or whether you reach somewhere else, or whether you never
get anywhere at all, you're always busy, and you never do anything in
particular; and when you've done it there's always something else to
do, and you can do it if you like, but you'd much better not."

* Skip Gundlach wrote, On 5/18/2007 9:45 PM:
On May 18, 10:32 am, Jeff wrote:
Skip - a few simple questions -

I'm thinking of putting some pvc in my from the head (lavac) to the
holding tank. What size pipe do you use, and how do you connect it?
Is there a size that you can simply clamp the normal flexible hose around?

you use standard Sch40 1 1/2" PVC and fittings. The end to take the
hose can be had in the proper size from SeaLand, who sells a hose they
claim (but which Peggie disagrees with) is superior to their prior
OdorSafePlus, sells PVC end fittings.

However, I just used barbed screw-in (to a pipe thread coupler)
fittings which I ground down to fit properly.

Better yet, I've learned (too late for the forward head) that you can
use a rubber coupling, flush fit, to whatever fitting you're using
(1.5" pipe and the barb described, but with a collar of 1.5" hose,
which makes it identical in size to the PVC). Three clamps - one each
at the ends, and one at the joint. The joint is contained in the
clamp in the middle, making any odor products have nearly an
impossible (I'm saying nearly because I don't have 5 years' experience
to back up my expectation of NO) chance of getting to the rubber
exterior. I've got that setup (flush - pardon the expression - rubber
coupling) at the head and at the through hull on the aft. All that's
to stop any future odor issues...

Hope that Helped...

I think so ... thanks

On Fri, 18 May 2007 03:38:01 GMT, Don W
wrote:

RW Salnick wrote:


I'd skip the use of the head hose, except as for flexible connections to
hard-mounted items, unless the runs are very short. Instead, plumb with
rigid white PVC pipe - it has an essentially infinite permeation time -
unlike the hose.

bob
s/v Eolian
Seattle

Hi Bob,

I'd love to plumb with PVC pipe, but I've heard
that the flexing of the boat causes it to develop
cracks over time. Is that true?

Have you considered a composting head?
Seems it would save space and cut out all the plumbing
and leaking crap. Not cheap.

Here's somebody who uses one and give a good account of his/her
experience with it.
http://www.sailsarana.com/FAQ.htm#why

--Vic

Vic Smith wrote:

Have you considered a composting head?
Seems it would save space and cut out all the plumbing
and leaking crap. Not cheap.

Here's somebody who uses one and give a good account of his/her
experience with it.
http://www.sailsarana.com/FAQ.htm#why

--Vic

Yes, I considered a composting head. The ones
that I'm aware of have significant issues yet to
be overcome in terms of the space and power that
they use.

Don W.