Rick Morel wrote:

On Thu, 15 Feb 2007 23:24:19 GMT, Don W
wrote:

Hey, I know that the v-berth is unusable for
sleeping at sea in anything but benign conditions
anyway. Ask me how I know ;-) Might as well use
it as a big (well... sorta) walk in closet.


Don't have to ask. I know :-)
As an aside, my ex could take anything short period, in shallow water.
Offshore she got very seasick. To the point of considering her flying
to the next from-offshore destination. She found a fix - stay in the
forward stateroom and sleep on the vee-berth. It was the sloooow up
and down that got to her; no problem with the FAST up and down.

Wow, who would have thought. Myself I had a
problem with the weightlessness, and then crashing
back into the mattress. It kept waking me up ;-)

Vee-berth will be our "bedroom" cause it's the only double. Settee
berth will be the single off-watch berth when needed. With added, what
are they called, rod and canvas thing that comes up and attaches so
you don't roll out.

"Lee cloths"?

As far as making up the settee, which is what we
do on the Irwin right now, we'll see. The problem
is that the aft cabin is pretty low, and my wife
can not seem to remember to not bang her head on
it for more than two weeks at a time. Since she's
slightly claustrophobic anyway, but doesn't seem
to mind folding the bedding, I figure that we've
got _two_ walk in closets, and no eating after
bedtime. Of course, if you just want to catch a
quick nap, there is the qtr-berth on the other
side of the aisle from the settee, and its always
available.


One reason we passed on the S2 30 center cockpit. The other is that
one had to sit on the shelf of the tiny bathtub and hunker over to
take a shower. As I recall, lots of room between the dinette and
settee - a friend has an Irwin 37. Folding table at the settee?
"Dinette" for two? Leave the bed made? Just rambling....

Our Irwin is a Citation 38, and its got a really
stupid setup for the table (Sorry Ted, but its
true.) Our C27 seats four comfortably for
dinner, but you can't even get four placemats on
the IC38 table One of my projects is to
redesign it, where it is big enough for six and
quickly and easily folds up around the mast out of
the way.

I did some checking.
Princess 3-burner Marine Stove, which seems typical.
1 simmer (550 watt) and 2 high speed (1100 watt) burners
1250 watt bake element
1300 watt broiler element

So less than I was thinking. Dang, I do remember a factory printed
placard next to my friend's stove listing combinations of
burners/oven. But then the stove in that monster was more of a home
type!

Anyway it's 1,876 BTU, 3,753 BTU and 4,265 BTU respectively, leaving
out the broiler and assuming 100% electric to heat conversion.

Doing the conversion propane, with 5,000 BTU and 8,000 BTU burners,
and 6500-16250 BTU oven (from checking) works out to 1,465 W, 2,344 W,
1,905-4,762 W output respectively.

Okay, so looking at the marine electric vs. propane, and factoring in
the home electric, it seems the marine electric is designed more to
fit the genset and shore power socket. Specs on home electric stoves
are harder to find. In any event, electric should give better heat
tranfer to the pot, no airpace under to radiate heat, and one seldom
uses a propane stove full blast except to quickly bring to a boil.

Where am I going with this? Noplace, really. It's just information.

No doubt propane is nicer to cook with. I'm just
trying to eliminate one whole system from the
boat, and regain some usable counterspace at the
same time.

BTW, the wattages I wrote up above came right off
of the placards in our kitchen 5 minutes before I
posted. I've still got the post-it with the notes
I jotted down while checking them all.

Note that the entire cooking time is only 1/4 hour
at 1/3 gal/hr so you use a little over a pint of
fuel to cook breakfast. At $5/gallon this works
out to 72 cents for fuel. The potato probably
cost that much! I could go through lunch and
dinner, but for us they would typically be even
less, since the griddle and coffee maker are not
in use. Often for dinner we have a salad, or heat
up homemade soup in the microwave. Lunches are
typically sandwiches, or a salad or re-heated soup.

After breakfast is cooked, the genset can power
the watermaker and the hot water heater while we
eat and do dishes. Our water heater is a 11
gallon Force 10 which draws 1500W. If the
watermaker draws 1000W like you say down below,
we've got 500W left over (12V @ 41A!) to charge
the batteries for the day.


Sounds like a well thought out plan! $5 a gallon for gas? Is this what
the marinas are charging these days? Wow! I'd consider dinghying in
with a few jerry cans and looking for a regular auto gas station!

We're paying about $2/gallon here at the gas
station, but I'm assuming it will be a lot more in
Turks and Caicos, the Caymans, or Martinique.
Anyone have any current info?


Also, I don't really expect to use anywhere near
70 Gallons per day of water, but don't really know
for sure.


We used 4 to 6 gallons a day. High compared to many. One of the most
wasteful water things is running the hot water tap, waiting for the
hot to get there. Some folks put a valve in the line and route it back
to the tank until it gets hot, close the valve and turn on the hot
water tap.

Well, you didn't have a watermaker either, so you
were trying to conserve a lot. I measured what we
used at home for showers one time, and was really
surprised. Something like 20+ gallons each even
with the low flow shower head. I could easily see
us using 30-50 GPD with the two of us, and more
with guests.

Okay. Let's try it this way. Cooking two meals a day (SNIP)

Amazingly we came really close to the same answer
for fuel burn. Must be right ;-)

Oh, us engineering types :-)

LOL

Agreed. The aussies have some triple junction
research solar cells that reach in the low 60%
efficiency IIRC. Now if somebody would just start
massive production to get the cost down. BTW, I
had to take thermodynamics to get the degree, so
I'm with you on the energy conversion losses.
Entropy always wins.


Agreed. I came across the following:
"Today, commonly available solar panels are 12% efficient, which is
four times greater than only a few years ago."
and
"Silicon solar cell efficiencies vary from 6% for amorphous
silicon-based solar cells to 40.7% with multiple-junction research lab
cells. Solar cell energy conversion efficiencies for commercially
available mc-Si solar cells are around 14-16%. The highest efficiency
cells have not always been the most economical -- for example a 30%
efficient multijunction cell based on exotic materials such as gallium
arsenide or indium selenide and produced in low volume might well cost
one hundred times as much as an 8% efficient amorphous silicon cell in
mass production, while only delivering about four times the electrical
power."

Also came across a company claiming they've got 22%, "up to 50% more",
that are available now. Couldn't find a price anywhere. Their size
specs show they're about 71% of the area of the others.

Bottom line for us is try to find the space needed for "regular"
panels. I have a source for inexpensive removals from our offshore oil
industry.

That is a nice source. Solar is great except for
the initial cost, and that cost is coming down.

Please don't get a 25 GPH watermaker, unless you plan on using at
least 50 Gallons of water per day!
SNIP
I'm
considering buying the membrane and pump(s) and
constructing my own watermaker--and yes, I'm aware
that the sea water membranes are quite different

from freshwater ones like I have under the sink at

home. It's not rocket science though, and that
way when it breaks down, I'll have a clue how to
go about fixing it.


Lot's of stuff on the web by Brent Swain re rolling your own. No
details except "buy my book". Ran across at least one web site with
details. Most are high output with a pressure washer pump. Right, it's
not rocket science. I'm looking at what it would take to build that
ideal-for-me 3 GPH one with a 12V drive.

With an engineering background you should be able
to do it easily. Its just a matter of maintaining
pressure and flow across the membrane. The rest
is filtering and flow to keep the sludge off of
the membrane.


Yes, the home and seawater ones are diffenent and as I understand
seawater requires about 800 PSI and a finer membrane as opposed to the
home 30 or 40 PSI regular water pressure.

You are correct about the pressures, but the
difference is not so much that the membrane is
finer, but that it is a different composition to
be able to withstand the higher pressure.

However, I did come across something that makes me wonder. First, PUR
says "Salt Rejection: 98.4% average (96% minimum).."

GE has a new home RO and says, "GE Infrastructure Water and Process
Technologies has achieved a revolutionary breakthrough in the water
treatment industry." 720 GPD and $400. They use salt for the TDS specs
and it is, "TDS Rejection (NaCl) 90% Min, 99% Max, 93% Average."

Okay. Never tasted salt or anything in those years of drinking RO from
a PUR. Did taste salty at some marinas in FL (guess it was in the
ground water). So taking worse case, maybe twice the salt left with
the GE. How "tasty" is twice no taste?

GE says the "Inlet TDS" is from 50 MG/L to 2 G/L. A quick check finds
seawater is 35 G/L. Oh oh! 17.5 times the max! Is the max really the
max? Or is it a convient and/or tested figure because that's the most
ever expected from city and/or well water? What happens if seawater
were used? Would it clog/ruin the membrane? Would it remove 1/17 or
1/X as much TDS? What is the criteria for TDS?

I'm not an expert on RO, but I believe that the
higher the salt concentration the higher the
osmotic pressure, and therefore the higher the
pressure required to reverse the osmotic process.
I've done some initial research, but need to do
more.

The above presented really to point out one has to research things all
the way, as you've done. Not very difficult these days with the
internet. How I remember spending hours, even days at libraries in the
past.

Isn't that the truth. I used to go down to the UT
engineering library to research patents on
microfilm. Now you can pull them up for free off
the internet.

Hmmm... Another research project. If one has say 25 GPH membranes, can
one run less water through them, say from a 12V pump, and get 2 or 3
or 8 or whatever GPH? Say an engine driven or AC genset driven, if you
have one, high volume pump and a 12V low volume? Less efficient? Would
it even work? I honestly don't understand everything I know about RO!

You have to have enough pressure to reverse the
natural osmosis.

Basically, its pre-filtering, pressure across the
membrane, and flow on the "dirty" side of the
membrane to keep the "debris" moving along so as
not to clog the membrane.

I notice there are two RO manufacturers within 30 minutes from here.
They do the BIG stuff for the oil industry, 10,000 GPD. I think I
might visit one or both. Okay Rick. Next project is to research and
learn everything currently known about RO watermakers.

Cruise ships have some monstrous systems, and I
had the opportunity to view and discuss one with
the chief engineer a few years back. The
requirement for generating clean water on ships
goes all the way back to the water used in steam
boilers. The Navy was doing it back in
WWII--probably before.

Our Cornado's aft deck, under the mizzen boom, had a solar "patio
roof". Took up the whole aft deck and hung a bit over the sides on the
aft end. 5 X 7 feet as I recall. The new owner moved them to the
lifelines. He added stainless tubing and fashioned mounts so they
could swing down, vertically. Seems to work. This is probably what
I'll have to do with at least a couple. The other two can go on an
arch over the davits.

I've seen boats outfitted like that. I always
wonder what's going to happen to those panels when
they catch a good boarding wave over the bow, but
maybe they just plan on not doing that.

Psych 101. "WE'LL get used to it."

Gotcha ;-)

Honestly, don't pretend you're 100% in heaven. In truth you'll have to
get used to it too. Well, unless your idea of comfort is a 30-day
canoe trip down the Amazon. :-)

Well, I'm not 100% sure that I'll like living on
the sailboat and cruising although I think I will.
We're going to try it in small doses for a while
and see how it goes.

Thanks! Yep. Been there done that. Gonna do it again!!!! Hot dawg!!!!

Well, _you_ must have liked it...


Speaking of there. I'm in New Iberia, LA. Middle of the state about as
close as you can get to the coast without living with the gators. I
saw in another post you're Texas coast. What part? Just curious.

We're in Austin, but the boat is in Palacios on
the northern side of Matagorda Bay.

Rick

Don W.