What would cause the Al to corrode? You have relatively pure fresh
water. Trying to think if I've seen any examples of Al in fresh water
part time, but nothing comes to mind.

Hmm. On second thought. Al siding and gutters seems to survive pretty
well, but that mostly has paint on it. Al is widely used as lightweight
flashing and although I would personally use something else, there have
been no code restrictions or other gross problems with it as far as I
know. That usually means that the product can give expected service
provided it's installed well, and that would means that 26gauge Al
provides at least 5 years of exterior service, probably much more since
roofing is usually guarranteed for 20 years or more.

Rufus


Glenn Ashmore wrote:
On our recent BVI cruise I started thinking about cockpit drink coolers.
The beneteau 505 has a very poorly insulated cooler in the cockpit
table that is a total waste of ice. RUTU, being derived from a modern
high performance design, has a very wide fairly shallow cockpit. It
will need foot rests to keep braced in the seats on a heel. I am
thinking about building a perminent heavily insulated box down the
center. It could also be used as a seat at anchor when the table is
folded up and the cushion would serve as additional insulation.

Now the question is how to keep it cold. I am thinking that a small
evaporator type system would work. Drinks cool fastest in water so
stocking originally with drinks and ice would provide the water. Once
the ice melts the evaporator would maintain the temperature and the
water would serve as a heat sink.

What I am worried about is that the aluminum evaporator would corrode
rather quickly constantly submerged in water. I am wondering if several
loops of copper tube might make a better evaporator.