Winter Water Ballast

[Scott Alexander[_2_]]

Anyone have any bright ideas on how to keep the water from freezing?

Salt?
Antifreeze?
Anything?

[sisu1a]

On Nov 23, 9:20*pm, Scott Alexander >
wrote:
> Anyone have any bright ideas on how to keep the water from freezing?
>
> Salt?
> Antifreeze?
> Anything?

Yes antifreeze, but the type of antifreeze that is made for
winterizing RV drinking water tanks. (not toxic when dumped)

-Paul

[Tim Taylor]

On Nov 23, 10:20*pm, Scott Alexander >
wrote:
> Anyone have any bright ideas on how to keep the water from freezing?
>
> Salt?
> Antifreeze?
> Anything?

The two best solutions are Methanol and Propylene glycol. Salt
absolutely not! Cost wise it will depend on how much of a freezing
point depression you need.

Freezing Point
Propylene Glycol Solution
(% by mass) F

0 32
10 26
20 18
30 7


Methanol Concentration
(% by mass) F
0 32
10 20
20 0
30 -15

Methanol will cost about $3 to $4 per gallon, Propylene Glycol can be
purchased as RV antifreeze in either -50 or -100 solutions. These are
25% and 50% solutions so you will need to to dilute accordingly.
Price for the -50 runs about $4 a gallon.

Lets do a back of the envelope calculation of what you need for a day
where you want to protect down to about 15 F.

Propylene Glycol you will need a 22% solution by mass or about 27% by
volume so you for a 40 gallon total load in your glider you will need
about 35 gallons of off the self -50 antifreeze. Cost of about $140
per flight.

Methanol you will need about 13% by mass or 16.5% by volume. So you
will need about 6.6 gallons of menthanol at a cost of about $25 USD
per flight.

[flymaule]

In the USA methanol (CAS #67561) is a HAP (hazardous air pollutant).
Your state environmental agency will not be happy about your discharge
of about 210 lbs of a HAP into the atmosphere. In the concentrations
above I suspect the solution would also be classified as flammable by
OSHA to say nothing of the risk to your glider and youself in the
event of an incident (yes--sparks can happen in a glider accident).

Stay away from the methanol.

Skip Guimond

[T8]

On Nov 24, 12:20*am, Scott Alexander >
wrote:
> Anyone have any bright ideas on how to keep the water from freezing?
>
> Salt?
> Antifreeze?
> Anything?

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

[Tim Taylor]

On Nov 24, 8:39*am, flymaule > wrote:
> In the USA methanol (CAS #67561) is a HAP (hazardous air pollutant).
> Your state environmental agency will not be happy about your discharge
> of about 210 lbs of a HAP into the atmosphere. *In the concentrations
> above I suspect the solution would also be classified as flammable by
> OSHA to say nothing of the risk to your glider and youself in the
> event of an incident (yes--sparks can happen in a glider accident).
>
> Stay away from the methanol.
>
> Skip Guimond

Actually the mixture in these concentrations (under 20%) and
temperature ranges (under 10C) will not be flammable and methanol is
highly biodegradable.

From Wikipedia:
"Methanol is readily biodegradable in both aerobic (oxygen present)
and anaerobic (oxygen absent) environments. Methanol will not persist
in the environment. The "half-life" for methanol in groundwater is
just one to seven days, while many common gasoline components have
half-lives in the hundreds of days (such as benzene at 10-730 days).
Since methanol is miscible with water and biodegradable, methanol is
unlikely to accumulate in groundwater, surface water, air or soil.
(Reference: Evaluation of the Fate and Transport of Methanol in the
Environment, Malcolm Pirnie, January 1999)."

No one is recommending that we ingest it or handle the concentrated
methanol with bare hands. It is commonly used in windshield washer
fluid and other applications. How many gallons of that are sprayed
each day? Being a relatively simple organic compound (CH3OH) it breaks
down quickly.

A better alternative, but I don't know where to buy it would be simple
ethanol (95% ETOH and 5% H2O azeotrope) denatured with a few percent
methanol. The price should be in the $2 to $3 per gallon range but it
is difficult to find currently in mostly pure form do to the concern
that you will want to drink it rather than use it for other purposes.

Overall you have to have a really good reason to want to carry water
in winter conditions to justify the hassle and cost.

[Guy Byars[_2_]]

>
> > Stay away from the methanol.
>

Agreed, methanol is bad, you should use Ethanol instead. It is
virtually identical to methanol in antifreeze properties, but is non
toxic and certainly biodegradable. Plus you can use any leftover
ballast as a pre-chilled refreshing post flight celebration beverage.

You can also make it yourself for just pennies a gallon.

http://www.appropedia.org/Amal's_ethanol_still

Just be sure to keep your eyes peeled for those dang revenuers.

[Papa3]

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

[Ronald Tabery]

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

[Scott Alexander[_2_]]

If there is a concern of water freezing when dumping it out over the
rudder, flaps or ailerons, then consider this.

The CRJ-200 has a limitation during certain icing parameters to move
the ailerons (wiggle them) every 5,000 feet during climbout. There's
been a few CRJ's that had the ailerons freeze up due to ice.

Seems like if we were to dump ballast, then during the dumping move
the control surfaces back and forth that are going to get wet until
the water is all dumped out.

[vontresc]

On Nov 25, 10:45*am, Scott Alexander >
wrote:
> If there is a concern of water freezing when dumping it out over the
> rudder, flaps or ailerons, then consider this.
>
> The CRJ-200 has a limitation during certain icing parameters to move
> the ailerons (wiggle them) every 5,000 feet during climbout. *There's
> been a few CRJ's that had the ailerons freeze up due to ice.
>
> Seems like if we were to dump ballast, then during the dumping move
> the control surfaces back and forth that are going to get wet until
> the water is all dumped out.

Hmmm this whole discussion got me to thinking. What if you changed the
ballast tanks to handle something like extremely fine silica sand.
This would be denser, and if kept sufficiently dry would flow quite
well. IIRC balloonists have been using and dumping sand bags for
years, why not in a sailplane?

Pete

[Papa3]

On Nov 25, 11:45*am, Scott Alexander >
wrote:
> If there is a concern of water freezing when dumping it out over the
> rudder, flaps or ailerons, then consider this.
>
> The CRJ-200 has a limitation during certain icing parameters to move
> the ailerons (wiggle them) every 5,000 feet during climbout. *There's
> been a few CRJ's that had the ailerons freeze up due to ice.
>
> Seems like if we were to dump ballast, then during the dumping move
> the control surfaces back and forth that are going to get wet until
> the water is all dumped out.

It's not so much about the control surfaces (though the rudder in the
example I gave actually was fairly limited in travel as a rsult of the
icing). It's the assymetric dumping and other stuff. For example:

On the LS8, the wing dumps orifices are about 1" give or take. The
tail dump is maybe 0.25". Which one is more likely to ice-up if you
get something wrong? Now, depending on the empty CG, dumping all
the wing ballast and not being able to dump the tail may (or may not)
be a big deal. In other ships with fiddly valves (pretty much any
Schleicher OEM system), what if one wing dumps and the other doesn't?
Big dieal? Sometimes yes, sometimes no. Obviously, these same risks
exist in warm weather, but they are clearly greater in cold weather.
So again, what are the real percentages in carrying water ballast in
our neck of the woods in winter? Most of the big records are done in
April/May or September/October when the days are long enough to get
started early and fly late.

Not to mention the fact that it's just damned uncomfortable messing
with water when it's cold outside :-)

[cernauta]

On Wed, 25 Nov 2009 08:50:13 -0800 (PST), vontresc
> wrote:

>Hmmm this whole discussion got me to thinking. What if you changed the
>ballast tanks to handle something like extremely fine silica sand.
>This would be denser, and if kept sufficiently dry would flow quite
>well. IIRC balloonists have been using and dumping sand bags for
>years, why not in a sailplane?

It's been tested decades ago in a Morelli sailplane, which had a sand
tank inside the fuselage and a huge dumping duct.
It worked fine on the ground; in the air, after repeated altituted
change, the igroscopic sand became almost solid and would not flow
through the large ducts.

Aldo Cernezzi

[Andreas Maurer]

On Wed, 25 Nov 2009 08:59:08 -0800 (PST), Papa3 >
wrote:


> In other ships with fiddly valves (pretty much any
>Schleicher OEM system), what if one wing dumps and the other doesn't?
>Big dieal? Sometimes yes, sometimes no.

Inflight it's no problem at all - you don't even feel the asymmetric
loading.
On the ground you are going to drop a wing sooner or later (I'd
estimate at about 25 kts, far below touchdown speed), but with braking
you'll have at maximum 100 ft of ground run with one wing on the
gound. No big deal on grass, maybe a little problematic on a hard
surface.
I had the pleasure to test this with an ASW-27 and the AS-22, both
times with full water ballast in one wing and the other one completely
empty.

[Papa3]

On Nov 25, 11:24*pm, Andreas Maurer > wrote:
> On Wed, 25 Nov 2009 08:59:08 -0800 (PST), Papa3 >
> wrote:
>
> > In other ships with fiddly valves (pretty much any
> >Schleicher OEM system), what if one wing dumps and the other doesn't?
> >Big dieal? Sometimes yes, sometimes no. *
>
> Inflight it's no problem at all - you don't even feel the asymmetric
> loading.
> On the ground you are going to drop a wing sooner or later (I'd
> estimate at about 25 kts, far below touchdown speed), but with braking
> you'll have at maximum 100 ft of ground run with one wing on the
> gound. No big deal on grass, maybe a little problematic on a hard
> surface.
> I had the pleasure to test this with an ASW-27 and the AS-22, both
> times with full water ballast in one wing and the other one completely
> empty.

You obviously never flew LS gliders :-) I've had 2 or 3 instances
of asymmetric dumping over the years, and an LS8 with one outboard
tank empty and one full will head off at 90 degrees once you hit about
35kts even with full aileron deflected. With the weak to non-
existent wheel brake, you're heading for the weeds or the trailers or
the staged gliders with very little you can do about it. If it's a
hard surface runway, especially one with runway lights, you're
probably looking at some (hopefully) minor damage as a wing or
fuselage takes out a light.