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.

Don W wrote:
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.

Learn how to take boat showers. Turn shower on, wet body, turn shower
off, wash body, turn shower on and rinse off soap. Use maybe 2 gallons.
Our 196 gallons will last about 2 weeks, not counting the bottle water
we drink. We use sea water for washing dishes and depending where we are
bathe in the sea and come aboard and rinse in fresh.
krj

Learn how to take boat showers. Turn shower on, wet body, turn shower
off, wash body, turn shower on and rinse off soap. Use maybe 2 gallons.
Our 196 gallons will last about 2 weeks, not counting the bottle water
we drink. We use sea water for washing dishes and depending where we are
bathe in the sea and come aboard and rinse in fresh.
krj

I'm with you in theory, but in practice its just
one more thing to not like about cruising. Its
much easier to put in the _big_ RO watermaker, and
not have to complain about how long the shower
runs when she is doing her hair.

Also, our 70 gallon tank would only last you 5
days at your rate of consumption, so on our boat
you would either have to stay pretty close to a
water tap, or have a good catchment system and
only sail in rainy areas if you wanted to get by
without a watermaker.

YMMV,

Don W.

"Don W" wrote

I'm with you in theory, but in practice its just one more thing to not like about cruising. Its much easier to put in
the _big_ RO watermaker, and not have to complain about how long the shower runs when she is doing her hair.

Every girl wants a man like you. Easy to control!

Also, our 70 gallon tank would only last you 5 days at your rate of consumption, so on our boat you would either have
to stay pretty close to a water tap, or have a good catchment system and only sail in rainy areas if you wanted to get
by without a watermaker.

Don't forget to buy her a dishwasher, washer/drier, and an
ice maker while you're at it. There's a good little boy!
Freaking wimp! There's plenty of hot water at home in the
shower. A boat's a boat - not a floating condo. And if it isn't
a sailboat then it's worthless to begin with.

Cheers,
Ellen

Ellen MacArthur wrote:

"Don W" wrote

I'm with you in theory, but in practice its just one more thing to not like about cruising. Its much easier to put in
the _big_ RO watermaker, and not have to complain about how long the shower runs when she is doing her hair.


Every girl wants a man like you. Easy to control!


Also, our 70 gallon tank would only last you 5 days at your rate of consumption, so on our boat you would either have
to stay pretty close to a water tap, or have a good catchment system and only sail in rainy areas if you wanted to get
by without a watermaker.


Don't forget to buy her a dishwasher, washer/drier, and an
ice maker while you're at it. There's a good little boy!
Freaking wimp! There's plenty of hot water at home in the
shower. A boat's a boat - not a floating condo. And if it isn't
a sailboat then it's worthless to begin with.

Cheers,
Ellen

**** you Ellen. How long have _you_ been married?
For me its been nearly 1/4 century so far and I
like her and she likes me.

I'm not going to tie her to the mast and flog her
if she complains.

Cheerfully,

Don W.

Charlie Morgan wrote:

Don't forget to buy her a dishwasher, washer/drier, and an
ice maker while you're at it. There's a good little boy!
Freaking wimp! There's plenty of hot water at home in the
shower. A boat's a boat - not a floating condo. And if it isn't
a sailboat then it's worthless to begin with.

Cheers,
Ellen

**** you Ellen. How long have _you_ been married?
For me its been nearly 1/4 century so far and I
like her and she likes me.

I'm not going to tie her to the mast and flog her
if she complains.

Cheerfully,

Don W.


Before you get too excited, here's Ellen's website and photo:

http://www.homestead.com/captneal/Captain.html

CWM

LOL.


Charlie, If someone really annoys me, I just
killfile them and move on. That banter was just a
little "newsgroup sex"

Don W.

I'm glad that mystery is solved.

--
Roger Long

On Fri, 16 Feb 2007 17:06:52 GMT, Don W
wrote:

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.

No. Well actually yes we did have a watermaker. Of course we could
have run it 24/7 and made 40 GPD, but the whole idea is it "costs"
energy to run. Over about 8 to 10 GPD it would have overdrawn the
solar "bank". Add in it was fairly noisy.

"Navy" showers are the way to go. Wet, push the button on the shower
head to turn it off. Soap, push the button and rinse. We used about a
gallon. Okay, sometimes 2 gallons :-)

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.

Watermakers 101 (maybe we should change the subject line!):

Not a real lot of system type info out there, but some neat equations
and stuff. Yep, pressure is a function of molecular weight,
dissociation and solute concentration, and in the case of salt the
"osmotically effective" concentration of solute. All that to determine
the osmotic pressure of seawater is approx 460 PSI and that it takes a
higher pressure than that for it all to work. Note "higher", not a
specific pressure.

All the talk about reducing pressure for brackish water, etc., is not
due to the process directly, but to the second requirment. To properly
wash off stuff from the membrane. Some sources say 5% of the water
should go through, others, specifically membrane manufacturers, say
something else. One says a range of 10% to 20%. As an aside and real
world observation, PUR said for the 40E it didn't matter - they said
run in in the lake or canal (fresh), in the bay (brackish) or in the
ocean (salt). And we did, with no damage or noticable increase or drop
in product water output. Guess it was "made" to operate at the
percentages encountered under all those conditions.

Sooooo... One has to supply the proper volume of water per time unit
at the proper pressure for a given size membrane/pressure vessel. Make
that within a low to high range for both. That says a piston or
plunger pump of X volume per stroke, operating at Y strokes per minute
to supply that volume. So nice that water is incompressible :-) Force
required to the piston/plunger = PSI required / area of
piston/plunger. Strokes per minute = volume required / volume per
stroke.

Next is some way to regulate the brine flow out of the pressure vessel
to maintain that pressure at that volume. Apparently the most used
method is an orifice or needle valve. Adjust it to "bleed off" the
brine at such a rate to maintain pressure from the properly sized
pump. Another way I ran across is a pressure regulator. This on one
that had an engine driven pump. The reason was that the pump output
would vary with engine RPM. Even so the engine had to be run within
certain RPM ranges.

So now to my "ideal" 3 GPH, 12V watermaker. Research pumps. Maybe do
some experimentation with a plain old pressure washer pump. Noticed
Walmart has a cheap 1,600 PSI 3.8 GPM pressure washer. Little bitty
thing. Must have a small motor. No, I'm not advocating turning it into
a watermaker pump. Probably would turn to rust in weeks, if not days.
Just shows high pressure water pumps are no big deal. Come to think of
it, I've seen some really neat little plunger pumps around here. Back
to the good old oil industry.

3 GPH output should take 20 GPH, .33 GPM at 15% product water. Subject
to adjustment.

Build a pump from scratch? Why not. I've got a metal lathe and other
stuff in the shop. Have built stuff that operated at 10,000 PSI. Have
built steam engines and very small, less than 1 CI, model diesel
engines. Got a geared down wheelchair motor that'll run all day on 12V
at 5 to 15 AMPS.

Oops. Sorry to use this group for a napkin!!!

Rick

Rick Morel wrote:
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.


No. Well actually yes we did have a watermaker. Of course we could
have run it 24/7 and made 40 GPD, but the whole idea is it "costs"
energy to run. Over about 8 to 10 GPD it would have overdrawn the
solar "bank". Add in it was fairly noisy.

That noise is the worst problem in my estimation.
I don't mind paying to run the genset or the
watermaker, I just don't want to hear it or feel it.

"Navy" showers are the way to go. Wet, push the button on the shower
head to turn it off. Soap, push the button and rinse. We used about a
gallon. Okay, sometimes 2 gallons :-)

We'll give it a try. I can see how it works, but
won't know if it will work for us until we're
actually doing it. Right now, the marina we're in
has nice hot showers available, so guess where we
go to shower on mornings we sleep on the boat.


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.

Well, I was trying to be succinct.

Watermakers 101 (maybe we should change the subject line!):

Not a real lot of system type info out there, but some neat equations
and stuff. Yep, pressure is a function of molecular weight,
dissociation and solute concentration, and in the case of salt the
"osmotically effective" concentration of solute. All that to determine
the osmotic pressure of seawater is approx 460 PSI and that it takes a
higher pressure than that for it all to work. Note "higher", not a
specific pressure.

Right. Although for a given effective size of
membrane, you get more purified water out of it
the higher the pressure is above the natural
osmotic pressure. This works right up to the
point where the membrane ruptures at which point
you get a lot more water, but its not purified ;-)

All the talk about reducing pressure for brackish water, etc., is not
due to the process directly, but to the second requirment. To properly
wash off stuff from the membrane. Some sources say 5% of the water
should go through, others, specifically membrane manufacturers, say
something else. One says a range of 10% to 20%. As an aside and real
world observation, PUR said for the 40E it didn't matter - they said
run in in the lake or canal (fresh), in the bay (brackish) or in the
ocean (salt). And we did, with no damage or noticable increase or drop
in product water output. Guess it was "made" to operate at the
percentages encountered under all those conditions.

Sooooo... One has to supply the proper volume of water per time unit
at the proper pressure for a given size membrane/pressure vessel. Make
that within a low to high range for both. That says a piston or
plunger pump of X volume per stroke, operating at Y strokes per minute
to supply that volume. So nice that water is incompressible :-) Force
required to the piston/plunger = PSI required / area of
piston/plunger. Strokes per minute = volume required / volume per
stroke.
Next is some way to regulate the brine flow out of the pressure vessel
to maintain that pressure at that volume. Apparently the most used
method is an orifice or needle valve. Adjust it to "bleed off" the
brine at such a rate to maintain pressure from the properly sized
pump. Another way I ran across is a pressure regulator. This on one
that had an engine driven pump. The reason was that the pump output
would vary with engine RPM. Even so the engine had to be run within
certain RPM ranges.

These are the basics. Obviously, the pressure
regulator approach is better given a variable flow
source.

So now to my "ideal" 3 GPH, 12V watermaker. Research pumps. Maybe do
some experimentation with a plain old pressure washer pump. Noticed
Walmart has a cheap 1,600 PSI 3.8 GPM pressure washer. Little bitty
thing. Must have a small motor. No, I'm not advocating turning it into
a watermaker pump. Probably would turn to rust in weeks, if not days.

Don't count on it. The pump in my pressure washer
has a bronze housing, and 316 stainless balls and
springs.

Let's see. At 10% that would yield .38 GPM, or a
little over 1 gal/3 minutes, so if mated with the
appropriate membrane it would be a 20GPH system.
Didn't you tell me not to get a 25GPH system?? ;-)

Just shows high pressure water pumps are no big deal. Come to think of
it, I've seen some really neat little plunger pumps around here. Back
to the good old oil industry.

3 GPH output should take 20 GPH, .33 GPM at 15% product water. Subject
to adjustment.

15% might be a little high, but not much. Maybe
figure 10%. There you go again. We got the same
number by different methods. Must be right ;-)

Build a pump from scratch? Why not. I've got a metal lathe and other
stuff in the shop. Have built stuff that operated at 10,000 PSI. Have
built steam engines and very small, less than 1 CI, model diesel
engines. Got a geared down wheelchair motor that'll run all day on 12V
at 5 to 15 AMPS.

Sounds like neat projects. My cousin Mark built a
minature four cylinder steam or compressed air
engine complete with cam and valve train in the
engineering shop at WSU while I was there. The
total displacement was about .2 CI.

BTW, the high pressure pump on my airless sprayer
is a kind of neat design. It basically has a
spring loaded inlet valve, an spring loaded outlet
valve, a liquid chamber, and a piston that
intrudes into the liquid chamber. It is low flow
rate, but puts out 2000PSI and will pump almost
anything you want to run through it. You can
adjust the pressure as well. The valves are ~$25
each, and the liquid chamber is milled aluminum.
Really a pretty neat design all in all, and
practically indestructible.

Oops. Sorry to use this group for a napkin!!!

Rick

You can do it! But you will have to buy the
membrane and filter housings. Remember that if
you are going to pressurize the whole thing the
pre-filter housings have to be stout as well. Of
course, I don't know why you would do that... ;-)

Don W.

On Fri, 16 Feb 2007 23:46:47 -0600, Don W
wrote:

You can do it! But you will have to buy the
membrane and filter housings. Remember that if
you are going to pressurize the whole thing the
pre-filter housings have to be stout as well. Of
course, I don't know why you would do that... ;-)

Don W.

Oddly the membrane seems to be the cheapest part. Well next to the
pre-filters. Smallest membrane I found was a 6 GPH for $147. Pressure
vessel for same was around $400. Okay, so 6 GPH is workable at 12V.

Gonna' rest my brain... Then pick brain of an oilfield friend quite
familiar with high pressure pumps and visit the two nearby oil field
RO manufacturers.

Rick