Peggie Hall wrote:

Don W wrote:

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.

Only if you want to spend up to 3x more than you need to have everything
the Vacuflush offers and more.

You haven't said what size your boat is, whether it's power or sail, and
what kind of space is available...your budget...or what part of the
country you're in. I need the answers to all those questions to be able
to advise what (IMO) is the best system for YOUR boat.

Hi Peggie,

The first post states the boat is an Irwin 38
which makes it a 38' sailboat. The boat is 38'
long with a 12' beam, two cabins, and a single
head with a small vanity, toilet, and shower. The
holding tank is currently installed in space
between the back wall of the aft cabin, and the
downward sloping hull. This space is accessible
through the cockpit lockers, and has room for a
sizeable tank if it is the right dimensions.

In

any case, I will put in a larger holding tank.


Well...maybe. Or maybe a Type I MSD. Again, that depends on your
location...whether inland on "no discharge" waters, or in coastal waters
where the discharge of treated waste is legal.

We're on Matagorda Bay on the Texas gulf coast in
a small marina.


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.


Nope...the vacuum generator doesn't drain by gravity...it pushes the
waste to its ultimate destination.

Which is just fine with me, as long as it ends up
in 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.


Not true...the holding tank vent has nothing whatever to do whether a
siphon can start from the overboard thru-hull, 'cuz a tank vent can't
break the flow of water in the tank discharge hose.

Actually, it is true, but you probably aren't
thinking of the system being routed the way I
described. The holding tank is above the water
line, and the vent(s) are horizontal. The
Vacuflush vaccum generator goes directly to the
holding tank, and the holding tank is connected to
the at-sea discharge thru-hull. There is no
possible way for a siphon to develop from the
thru-hull back into the head--ergo no need for a
vented loop.

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.


Again...not quite true. The V/flush does suck all the bowl contents all
the way to the vacuum pump, but it also splatters 'em all over the
inside of the hoses on the way to the pump.

True.

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.


That would depend on where you put the macerator.

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??


There are much better, less expensive ways to do it. I'll be glad to
help you sort out the best ones for your boat and use.

I'll give you a call and talk it over. The main
thing I'm shooting for is a trouble-free head
system that is not easily plugged, and is easily
maintained. Additionally, it should be intuitive
for the landlubbers, because if they mess it up
guess _who_ will be fixing it.

Don W.