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Old January 5th 06, 09:16 PM posted to
Peggie Hall
Posts: n/a
Default Head maintenance (was) Vented loops and suction

Skip Gundlach wrote:
This discussion reminded me that in another mailing list I'm on, the topic
of keeping the pipes clean came up. I gave them your vinegar prescription,
but a couple of posters have advocated Muriatic acid, sometimes with a
dollop of veggie oil for the lube.

My thought was that was pretty harsh stuff, but, certainly, it ought to do a
number on calcium. What are your thoughts on the subject (Muriatic, i.e.,
vs vinegar as effective/more effective/harmful to components)?

A 12% solution of muriatic acid in water has long been the recommended
"cure" for mineral buildup in hoses--sanitation, exhaust, engine
intake--and also to clean the electrodes in a Lectra/San. It is nasty
stuff and needs careful handling, but it won't hurt anything in the system.

White vinegar--which is more acidic than cider--also works, but easier
to use a preventative than a cure. Repeated applications will eventually
dissolve a heavy buildup--and vinegar is a lot safer to handle, whereas
a single "dose" of muriatic acid will do it. So prevention is the best
approach--a cupful flushed through the hoses once a week. Do that and
you'll never need to choose between muriatic and vinegar.

Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"

  #52   Report Post  
Old January 6th 06, 05:35 AM posted to
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Default Vented loops and suction

On Thu, 05 Jan 2006 15:51:35 GMT, Peggie Hall

Quicksilver is a petroleum based lubricant...not recommended for use in
toilets 'cuz petroleum degrades rubber. You really should look for a
synthetic based teflon grease--which SuperLube is--next time you have to
buy a tube of it. If you can't find it anywhere else, try swimming pool
supply's the recommended lubricant for pool pumps, filters
etc too.

OK, good point, Peggy. I use it in the raw water pump as the vane is
neoprene/nitrile, not rubber, and I tend just to use it for seating
O-rings, not general lubing. For that, I run some vegetable oil in the

But I will take your advice nonetheless.


  #53   Report Post  
Old January 27th 06, 04:47 AM posted to
Posts: n/a
Default Boat Sank due to Syphoning Effect

Peggie Hall wrote in news:4jmnf.32927$q%.3104

Jeff wrote:
Just curious - do most new boats come without the vented loop,

Toilet mfrs do not include vented loops because they're only needed if
the toilet is below the waterline and/or discharges below the the a good number would be discarded, adding needless cost

all units. So it's up to the builder or the owner to install 'em.

builders do, most production builders don't.

or is
this caused by poor refits (or both)?

For production builders, it's about cost. Among owners, many don't even
know what a vented loop is, much less whether they need one...I fielded
a post on a forum recently from someone who'd just replaced his toilet
and reported how he was able to discard about 8' of intake hose because
his new toilet had only a short piece of hose connecting the pump to

bowl instead of all that extra hose and a fitting he couldn't figure

the need for.

Also, do the vents get clogged or
fail on their own? How often should they be cleaned out?

The vent should have an air valve in it that only allows air INTO the
line to break a siphon (which is why the intake loop has to be between
the pump and the bowl...if it's installed between the thru-hull and the
pump, it interferes with the pump's ability to prime)...and yes, the

valves do get clogged up with salt or waste...and yes, they wear
out...requiring periodic cleaning and/or replacement.

But because the air valve in most loops is a replaceable item, often
only sold separately instead of being included with new loops, many

owners don't know air valves exist...and without the valve, the
waste/flush water will squirt out the hole in the top of the loop where
the air valve should go when the toilet is flushed. It never occurs to
most people that there's a part missing...instead, they put a vent line
on it...which is the WRONG thing to do because that line can only be
1/4", and so it quickly becomes clogged by waste squirting into it,
turning the vented loop into an UNvented loop that no longer can
function as a siphon becomes just a high arch in the line.

Although a vented loop can break a siphon--which is always started by
PULLING liquid through a line--it cannot prevent water from being

through a line...which can happen while underway due to the pressure of
water against the hull and any open thru-hull. It's an effect known as
"ram water"--water being rammed up a line. So a vented loop will not
prevent water from flooding and overflowing the bowl while underway,
only while the boat is at rest. So it's advisable to keep all head
seacocks closed except when actually in use while aboard AND when away
from the boat...and any tank overboard discharge thru-hull closed at

times except when actually dumping the tank...'cuz if water can flood
the toilet, it can also flood the tank. If the head seacocks are in
locations that are so inaccessible as to make keeping 'em closed while
aboard except when using the toilet, install shutoff valves in 'em

next to the toilet.

Btw...something the first poster said:

The boat has now been pumped out and is afloat again and on inspection
there is no obvious reason why the boat would take on so much water to
sink the boat in a 12 hour period since it was last viewed...the only
explanation as to the cause that has been offered is that the bow wave
caused the toilet to overflow and created a syphoning effect which in
turn filled the yacht with water.

That possible explanation makes it obvious it was noticed that the head
seacocks were much MORE obvious a reason would anyone
qualified to inspect the boat need???? And if they weren't closed

raising the boat, that boat is gonna sink again (if it hasn't already)!

Oh jes can you draw usa a picture?
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