Couple:
Why paint only the top half black? surely you'd want as much heat in there
as possible.

Most fabric doesn't conduct heat very well.

If you have an alloy mast you have a chimny already, thermal coefficient is
good (probably don't have to paint it), large surface area , height is also
a positive factor (velocity). Only mod's req'd are to connect the bottom to
the cabin airspace and the top to "outside" without letting rain in.

Could go further if you don't mind a little extra windage up the fit a
weathercocking venturi at the masthead, any lurking breeze will add to the
effect, although it's probably something you'd only consider if performance
at anchor is more of a concern than racing.....

Mark.

"Parallax" wrote in message
om...

So..... Make a long fabric tube, say 10" diameter and 15' long with
upper end held up with the jib halyard and lower end in the forward
hatch with edges around it sealed. Upper half of the tube is black
and lower half is white.

Any thoughts?

"Mark W" wrote in message ...

Mark:

I actually thought about using the mast as the chimney except my boat
has a deck stepped mast so this would be difficult. It might work
well on those Freedom boats with large diameter masts.

Couple:
Why paint only the top half black? surely you'd want as much heat in there
as possible.

Most fabric doesn't conduct heat very well.

If you have an alloy mast you have a chimny already, thermal coefficient is
good (probably don't have to paint it), large surface area , height is also
a positive factor (velocity). Only mod's req'd are to connect the bottom to
the cabin airspace and the top to "outside" without letting rain in.

Could go further if you don't mind a little extra windage up the fit a
weathercocking venturi at the masthead, any lurking breeze will add to the
effect, although it's probably something you'd only consider if performance
at anchor is more of a concern than racing.....

Mark.

"Parallax" wrote in message
om...

So..... Make a long fabric tube, say 10" diameter and 15' long with
upper end held up with the jib halyard and lower end in the forward
hatch with edges around it sealed. Upper half of the tube is black
and lower half is white.

Any thoughts?

So build a hollow tabernacle which projects back (or fwd) far enough to
allow a dorade type baffle and a vent down into the cabin. Keep the mast
heel support low enough (not too much less than cross section area of mast
(about 30mm for a 125mm dia. spar) and you probably don't even have to trim
the mast.

I'm trying to figure out how to do it for bilge ventilation on my keel
stepped schooner but with internal halliards I'd get way too much wet down
there. Also the main is in the engineroom which is supposed to be able to be
made airtight if combustion becomes "external".

Luck,
Mark.

PS: don't have much simpathy anyway, it's bloody freezing here at the moment
)


"Parallax" wrote in message
m...

Mark:

I actually thought about using the mast as the chimney except my boat
has a deck stepped mast so this would be difficult. It might work
well on those Freedom boats with large diameter masts.

"Mark W" wrote in message ...
So build a hollow tabernacle which projects back (or fwd) far enough to
allow a dorade type baffle and a vent down into the cabin. Keep the mast
heel support low enough (not too much less than cross section area of mast
(about 30mm for a 125mm dia. spar) and you probably don't even have to trim
the mast.

I'm trying to figure out how to do it for bilge ventilation on my keel
stepped schooner but with internal halliards I'd get way too much wet down
there. Also the main is in the engineroom which is supposed to be able to be
made airtight if combustion becomes "external".

Luck,
Mark.

PS: don't have much simpathy anyway, it's bloody freezing here at the moment
)



Mark, being in NZ, even in summer, you are surrounded by a big heat
sink called the pacific Ocean. In summer, we have a huge heat source
called the Gulf of Mexico very close by. Last week, the water temp
was 91 F (about 32C) and the air temp was 38 C with not even a breath
of wind and 95% humidity.
"Parallax" wrote in message
m...

Mark:

I actually thought about using the mast as the chimney except my boat
has a deck stepped mast so this would be difficult. It might work
well on those Freedom boats with large diameter masts.

Now you're just being mean.
Actually it's worse, normal weather comes from ESE but every couple of weeks
through winter we get a southerly direct from Antarctica. Still rather live
where it actually changes...

Mark.

"Parallax" wrote in message
om...

Mark, being in NZ, even in summer, you are surrounded by a big heat
sink called the pacific Ocean. In summer, we have a huge heat source
called the Gulf of Mexico very close by. Last week, the water temp
was 91 F (about 32C) and the air temp was 38 C with not even a breath
of wind and 95% humidity.

"Mark W" wrote in message ...
Now you're just being mean.
Actually it's worse, normal weather comes from ESE but every couple of weeks
through winter we get a southerly direct from Antarctica. Still rather live
where it actually changes...

Mark.

"Parallax" wrote in message
om...

Mark, being in NZ, even in summer, you are surrounded by a big heat
sink called the pacific Ocean. In summer, we have a huge heat source
called the Gulf of Mexico very close by. Last week, the water temp
was 91 F (about 32C) and the air temp was 38 C with not even a breath
of wind and 95% humidity.

The heat just makes me cranky.

"Mark W" wrote in message ...
Now you're just being mean.
Actually it's worse, normal weather comes from ESE but every couple of weeks
through winter we get a southerly direct from Antarctica. Still rather live
where it actually changes...

Mark.

"Parallax" wrote in message
om...

Mark, being in NZ, even in summer, you are surrounded by a big heat
sink called the pacific Ocean. In summer, we have a huge heat source
called the Gulf of Mexico very close by. Last week, the water temp
was 91 F (about 32C) and the air temp was 38 C with not even a breath
of wind and 95% humidity.

I would take a while getting used to weather coming from the ESE rather than WNW.