wrote:
2. Before you start, measure the OD (outer diameter) of the
fittings....'cuz some nominal 1.5" fittings are actual 1 5/8"--or
they're metric and slightly larger than 1.5", which can make putting
toothpaste back into a tube a walk in the park compared to trying to get
a 1.5" hose onto 'em. Avoid gray PVC 1.5" tank fittings...use marelon or
nylon fittings. Btw, this anomaly only seems to apply to 1.5"...other
sizes are likely to be true.


Ya think...?

Yep.

But when you start changing out bronze seacocks afloat because their
(decades-standard & perfectly correct) hose fitting OD is on the fat
side for the new vinyl sadistic hose, lemme know.

If it's impractical to replace the seacock, buy hose that'll fit it.
Hose sizes aren't limited to only the ones shown in the marine retail
catalogs, and a splice to mate a section of hose to a seacock is
preferable to stretching a hose to the point of tearing it to get it
onto an oversized seacock.

Wasn't an issue, but that inserts a major obstruction to smooth flow, &
is beginning to negate the seemingly sole advantage of hose over a good
piping job...

What's the difference between an inline radius fitting in a hose and one
in hard pipe? Plus, radius fittings in a hose are only required for
tight bends...because hard pipe doesn't bend more than few degrees,
you're likely to need a lot more of 'em in hard pipe than in hose.

6. Double clamp all connections, putting the screws on opposite sides of
the hose--or at least offset a minimum of 90 degrees.


SOP

To you maybe...but you're not the only person who reads NGs.


1) How may anyone effect a voyage repair aboard a small craft at sea
with this stuff?

You shouldn't have to if you've done it before you left--and have done
it right.

Do it as PREVENTIVE maintenance before you leave the dock, and you won't
have to do it at sea unless you turn into the "Man Without a Country,"
unable to make landfall anywhere ever again.


I feel this is copout reasoning (not in the personal sense please).

No, it's not (and I didn't take it personally). Most emergency repairs
at sea can be avoided if preventive maintenance is done at the
dock....but too many boat owners ignore preventive maintenance in favor
only fixing what breaks. Some--especially engine repairs--may be
unavoidable...but there's no valid excuse for a seacock or hose
connection failure at sea.


I referred to a section of hose which responded oppositely to warming &
could no longer be made to accommodate a fitting it had been fitted
correctly to 27 years ago.

I've never heard of heat shrinking a hose (not saying it's impossible,
just never heard of it happening)...I have heard of hose that was
stretched too much to get it onto an oversized fitting not shrinking to
fit tight again though.


Several reasons: 1. unless every connection to any fixed component in
the system (toilet, tank, thru-hull, y-valve, etc) is "soft coupled"
with enough hose to cushion shock and protect from flexing,


SOP - many decades...

Again...to YOU maybe, but not to someone else who's about the tackle
this job for the first time.

hard PVC is
likely to crack, especially in cold weather.

Not. (incompetently piped?)

Incompetently piped is only one cause. Schedule 40 gets very brittle
below 40F. Even a sharp rap against a dock can crack it. The kinds of
stresses a boat can be subjected to in a storm at sea can crack sch 40
even in warm temps. PVC glue can crack, resulting in a leak.

Have you never worked with PVC fittings & layout? It is very fast &
easy.

You've obviously never had to pay for labor. 5 extra minutes per
union on your own boat is one thing...multiply that by several hundred
or even several thousand boats, and the cost to builders becomes
prohibitive.

In the case of blackwater wouldn't it last far
longer & be more vapor-impermeable?

More impermeable, yes. But the stresses on the glue in unions results in
more maintenance (or repairs at sea).

(not to mention that you could
*work* on it, pitch it so it'd drain & clean it if/when needed)

It shouldn't ever be necessary to remove a piece of hose OR pipe to
clean it out or remove a clog (the operative word in that sentence being
"shouldn't"). Regular doses of white vinegar will prevent sea water
mineral buildup--and even dissolve it, though muriatic acid is faster.
And unless someone has flushed something they shouldn't have--which a
guest is far more likely to do than an owner, making that highly
unlikely at sea--an "overload" of solids and quick-dissolve TP will
dissolve by itself in an hour. Again, it comes down to preventive
maintenance...and using top quality hose.

AVS96, made an Australian company http://www.aussieglobe.com/avs96.htm
has been proven in independent testing to be at least 16x more resistant
to odor permeation than any other hose on the planet. It was the hose
that SeaLand originally sold exclusively in the US as their "OdorSafe"
brand, now sold direct--and for a LOT less than SeaLand charged for
it...$5.50/ft, cut to any length. I've yet to see it permeate unless an
owner has used bleach or household chemical bowl cleaners.


not seeing an advantage to a very pricy hose that has R/R issues,
offers no timesavings in fitup, seems dicey to have to deal with at sea
& often (I am told) lasts only 2-3 years.

That's not true...white PVC or black rubber hose can last decades with
no deterioration, provided it hasn't been overheated, bent too tightly
or hasn't been chafed through by poor installation. The only reason most
hose is replaced is because it becomes permeated with odor and stinks.


Which is exactly what I was talking about.

The better quality the hose, and the more planning that goes into the
installation of the system (i.e. hose routing to eliminate as many low
spots as possible--and again, some preventive maintenance (i.e. fresh
water down the toilet to rinse out the hose before the boat will sit),
the less likely a hose is to permeate.

The hose is otherwise fine. As a general rule, the stiffer the hose, the
less likely it is to become permeated with odor...the softer it is, the
more likely. Many owners don't realize that not all white PVC hose is
created equal or rated for sanitation...so they use hot tub hose from
the hardware store because it's considerably cheaper than sanitation hose.
I tried to caption the matter "marine sanitation hose"...

A caption doesn't guarantee that you (or anyone else) know there's a
difference between hose that's rated for sanitation and any hose used in
a sanitation system.

What am I missing here? ;-)

Nothing that most boat owners aren't also missing.


So, far, I am thinking even moreso that most boat owners are missing
all the benefits of simple, properly properly piped, inexpensive,
never-stinks, long-lived, easily maintained PVC.

So? It's your boat...if you want to use hard PVC, use it!

Bonus Q for the jaded: is there a implicit, international agreement
among those plan & specify such things, that the macerator pump shall
be mysteriously concealed within an inaccesible void locatable by
occultic divination, x-ray services or systematic disassembly of the
head compartment & foreship?

No...in fact, just the opposite SHOULD be true. It--and all
seacocks--should be readily accessible for use and servicing.


I didn't realize a macerator pump was called a seacock by boating
peopleg.

You apparently missed the word "and"... All the components in the
system--y-valves, pumps (manual or electric) AND seacocks--should be
readily accessible. Regrettably, as "decor" has replaced safety, that's
something many boat builders are ignoring. As a result, owners (some of
whom shouldn't even own boats) leave seacocks open all the time, never
inspect hose connections...some don't even know where half (any?) of
their their thru-hulls are. And when a hose connection fails due to lack
of maintenance, they can't close the seacock even if they can find it
'cuz it's frozen open.

ISTM you may be doing a better job of making my case (which began as a
question) than I am. I haven't noted any general advantage of this
hose product over piping.

As I said...it's your boat...

--
Peggie
----------
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"
http://www.seaworthy.com/store/custo...0&cat=6&page=1