Posted by katorpus (jrb@…>)
Lance
Here’s what’s going on…
You are living in the boat, breathing in it and emitting moisture
constantly while occupying it and from other things like bathing,
cooking, etc. All of this moisture evaporates into the air which is
warmer than that outside the boat, and warmer than the water in which
the boat sits.
Both the outside air and the water serve as a “heat sink”, cooling
the areas of the boat which are in contact with them.
The hatches, drop boards, and any uncored areas of hull above the
water line are the “least insulated” areas, meaning that the inside
surface of these areas is also cooler than the air in the boat.
The same thing happens to the inside surface of the hull below the
water line. It is cooler than the air, and cooler than the inside
surface of the hull above which is only in contact with the outside
air. The water is a more efficient cooling mechanism for the hull
than the air which flows over the portion of the hull above the water
line.
The coolest surface inside the boat is the first thing that will
cause the moisture in the air to condense. This is what is happening
when your cocktail glass full of ice and liquid sweats.
The only way to stop condensation is to lower the humidity in the
inside air, otherwise, there will always be SOME.
If you insulate and/or apply a vapor barrier inside the closet, you
won’t really be “stopping” the sweating, you’ll just be moving it
elsewhere (which is what you want to do). As you increase the area of
the hull which is insulated, you’ll increase the sweating on the
areas of the hull which AREN’T insulated…up to a point.
You could superinsulate the entire inside of the boat down to the
level of the cabin sole, and the hull sides in the bilge area would
probably produce about the same amount of moisture that the whole
boat is producing now (except that they would be “warmer” than they
are now, for a given amount of heating, due to the fact that you
wouldn’t be losing as much heat through the insulated areas.
I think you are on the right track, insulating the closet area as
you’ve described. Rather than using pink foam, why not use
the “Reflectix” type of “double bubble pack” with foil facing?
This is available in “big box” home centers (by the roll) in various
widths and thicknesses. Cut your piece to fit tightly within the
spaces between the stringers that support the closet lining, but
DON’T glue it to the hullsides. If you extend the insulation below
the level of the cabin sole inside the closet, it will effectively
create its own “moisture barrier” (where the closet is concerned) by
allowing any condensation that’s behind it to run down the hullside
into the bilge.
Other than “tarnishing” the foil, the moisture won’t harm either the
insulation or the effectiveness of it. The same cannot be said for
the moisture in contact with the foam.
I use this stuff (with the cut edges bound in aluminum foil tape) to
block off my hatches from the inside…for a purpose opposite that
which you need it for…the summer sun is brutal on the Texas coast,
and this makes a tremendous difference in heat gain inside the boat.
I’ve also lined the insides of my ice and freezer box with
(removable) “panels” of this stuff, in a double thickness, with
edges “bound” and a “floating” piece that sits on top of the ice &
beer or whatever is in there. It makes an incredible difference in
the efficiency of the box. When I drain the box and leave the boat, I
just pull out the liner and leave it standing loose inside the box to
allow everything to dry out while I’m gone. When I (ever) get around
to installing refrigeration, I’ll just leave it in any time the thing
is running.
As for the dehumidifier, if you want to run one, forget about
the “warm wand” thingies and get one with a reservoir, or one
that “sits over” the sink and drains into the sink. They are fairly
noisy, and depending on the ambient air inside the boat, they tend to
freeze up in winter, but since you have “both halves” of the air
conditioning cycle going on inside the boat, you’re actually adding
btu’s by running it, and thus cutting down on btu’s needed from
another heat source. You don’t need to put it in the closet, but you
do need to have some way for the air to circulate around in otherwise
closed-up spaces.
Mine works well enough that I’ve managed, here or there, to dry out
the water that stands in the bottom of the head and leave the
bilge “bone dry” and covered in dust and salt crystals (it takes a
couple of months of a completely closed-up boat to do this, however).
Hope this is helpful
John
— In FreedomOwnersGroup@yahoogroups.com, “lance_ryley”
<lance_ryley@…> wrote:
I love the new-boat experience. Living aboard is great, but… we
pretty much had the winter down to a good routine on Bright Star,
and
we’re finding some things work on Glory and some don’t. Glory has
more portholes, and the ventilation down below’s not great to begin
with, so of course all of the windows fog and drip with
perspiration.
I’ve fixed them by putting bubblewrap in the hatches and non-
opening
ports, and taping bubblewrap over the outsides of the portholes. It
is amazing just how much difference that makes.
Unfortunately, we have a different issue now. My lovely wife
reached
into the hanging locker in the aft cabin for her clothes and they
all
came out wet. We unloaded the closet and sure enough, the lower
half
of the cedar lining was soaked. It was extremely clear where the
waterline of the boat is - everything above it was bone dry,
everything below it, soaked. It makes the closet useless, and it’s
not exactly easy to get a dehumidifier in there either because of
the
shape.
My thought is to take out the cedar lining, dry the inside of the
locker out, and line the hull with a thin piece of pink foam
insulation from top to bottom. Then I would screw the cedar lining
back into place. any chance in hell this will actually work, or do
I
need some sort of moisture barrier as well? I’m not inclined to put
one in, because I don’t really want to trap moisture against the
hull, but this seems like it must be a fairly common problem.
Anyone?
thanks,
Lance
Georgelance_ryley <lance_ryley@…> wrote: I love the new-boat experience. Living aboard is great, but… we pretty much had the winter down to a good routine on Bright Star, and we’re finding some things work on Glory and some don’t. Glory has more portholes, and the ventilation down below’s not great to begin with, so of course all of the windows fog and drip with perspiration. I’ve fixed them by putting bubblewrap in the hatches and non-opening ports, and taping bubblewrap over the outsides of the portholes. It is amazing just how much difference that makes. Unfortunately, we have a different issue now. My lovely wife reached into the hanging locker in the aft cabin for her clothes and they all came out wet. We unloaded the closet and sure enough, the lower half of the cedar lining was soaked. It was extremely clear where the waterline of the boat is - everything above