On Nov 24, 2:38*pm, Papa3 wrote:
On Nov 24, 12:26*pm, T8 wrote:



You mentioned Dan & Dave Cole in another thread in the context of
getting good, conservative advice. *Ask them. *I predict you'll get
some more good, conservative advice :-).

Temptation to fly with ballast in extremely cold weather is sometimes
an indicator of an excessive BCS ratio.

-Evan Ludeman / T8

Ditto on that. *We at Blairstown fly ridge all year round, and over
the years folks have fiddled with this stuff. *There are just too many
things to go wrong. * I have a great photo somewhere of Dave Michaud
(UM) with like 8 lbs of ice (okay, probably not 8) hanging off his
tail boom. * Some combination of leaking dump valve in the wing and
getting the mixing ratio of anti-freeze wrong.

*Frankly, the days are too short for record flights, so the only
reason to carry ballast is to smooth out the ride a bit or go a little
faster. * I submit that it's just not worth it.

P3

The concern over ballast freezing in the wing is not the issue.
Forget about all antifreeze additives, particularly alcohols and
salt. As pointed out, leaking valves is the issue. Water cools
slowly to zero and then it has to jump 80 calories per gram to freeze
(heat of fusion). Starting with relatively warm water gives you many
hours of sloshing; I have contest experience in New Zealand with
flights of many hours in the wave (-20 degrees) without ballast
freezing. The wing's foam cores serve as insulation and freezing is
not a problem in all but the most extreme circumstances of time and
temperature. Warm water can extend the hours significantly. Carry
water all year if you like, just make sure you have water tight
valves. Freezing the valves shut is more of a concern than dangling
ice for wing-mounted dumps; fuselage dumps are another matter due to
possible CG shift from accumulation on the tail boom. Overall, it is
not a big concern.

ron tabery