Al Thomason wrote in
:

For heating water though

One wonders why we don't see the obvious solution to this hot water
problem more often....for free.....
http://tinyurl.com/sxuql

Australia has lots of water bladder websites. I suppose the simplest
solution is too simple for us Americans used to advanced technology they
don't have on the Outback.

http://www.fabricsolutions.com.au/liquid_bladders.htm

We are sold these rugged inflatable dingys and rafts made of nylon
materials that can easily withstand more pressure than your 12V water
pump can generate. So why can't we have a 6 gallon, flat black little
bladder that hangs off the stern with two black hoses, inlet bottom and
outlet top that pumps itself up and sits there in the FREE sunshine,
saving gallons of fuel by getting so hot you can't hold your hand on it
all day?? Make it with ears like dingy oarlocks to tie it down to a
wasted deck or even over the stern under the nav light like a big fender.
Sailboats have a big, wasted deck space on the centerline, under the
swinging boom, where an even bigger flat bladder heater would nearly boil
water all day, giving lots of free hot water, while keeping the sun off
the cabin roof.

Boaters are used to compromises, like taking showers when conditions
permit. Sailors will put up with a lot to NOT have to crank that noisy
diesel just to get hot water. This solution is totally quiet, uses no
energy from house batteries or fuel tanks, except to run the pump they
were already going to have to.

Win-Win?

A big ol' Navy fuel bladder made of heavy, flat black neoprene rubber
makes a HUGE hot water heater! Fresh water washdown? No, HOT water
washdown!...(c;

Another plus for the flat bladder heater on top of the main cabin of a
sailboat would be it puts the cabin IN THE SHADE, under the bladder! No
crazy-looking canvas awning would be necessary! The cabin would be
"water cooled" until the tank got hot...A thin layer of foam pad under
the bladder would insulate the "tank" and keep the cabin even cooler!

Of course, boat manufacturers COULD build us a little flat tank as wide
and long as the cabin top, about 3" deep, right INTO the cabin's black
fiberglass top. It would be permanently plumbed to the hot water pipage.

Another stupid idea like the Coleman RV air conditioner.....(c;