Antifreeze that is safe with integral water ballast tanks

[Tim Taylor]

As the cold weather is appraoching in the northern hemisphere what
antifreeze can be used safely in integral water ballast tanks such as
in my Ventus? Also where do you buy it at a reasonable price?

I am guessing the maximum use would be about 25% v/v at any time. I
think I could often use 2gal Ethanol to 13gal of water in each wing.

Methanol
Ethanol
Isopropyl alcohol
Propylene glycol
Others?

Thanks,

Tim

[GrahamBrown]

Hi Tim,

Applying absolutely NO aviation-specific knowledge here, but your best bet is
probably to buy plumbing antifreeze. Available at Canadian Tire (if in Canada)
, or (I assume) at Walmart if in the U.S.

If all else fails, you can buy it at ANY trailer parts / supply store.

I assume winterization is the same for any form of water tank (perhaps a bad
assumption), but you only need to use the winterizing fluid to displace /
dilute the water, you don't need to fill the tank with winterizing fluid (in
fact, air probably handles temperature change better than the best form of
antifreeze).

The main goal is to use the antifreeze to displace any water left at the
bottom of the tanks, or iany fluid that is vapour locked in the tubes / dump
valves. As such, put in enough fluid to ensure coverage, then allow it to
flush through any tubing / valves that may have water in them.

You should be able to do everything you need with a couple of 1-gallon jugs
(windshield washer size), i.e. for about $6-10 dollars spent.

Hope this helps,
Graham
Tim Taylor wrote:
>As the cold weather is appraoching in the northern hemisphere what
>antifreeze can be used safely in integral water ballast tanks such as
>in my Ventus? Also where do you buy it at a reasonable price?
>
>I am guessing the maximum use would be about 25% v/v at any time. I
>think I could often use 2gal Ethanol to 13gal of water in each wing.
>
>Methanol
>Ethanol
>Isopropyl alcohol
>Propylene glycol
>Others?
>
>Thanks,
>
>Tim

[[email protected]]

For flights limited to a single day and the ballast added the day of
flight, I do not believe antifreeze is necessary. Given the very high
heat capacity of water, the large volume, and the agitation that
occurs during flight, it would not freeze. Dumping partial loads
might be a problem in that the valves may ice up, preventing further
dumping.

Environmentally, ethanol would be the safest. Propylene glycol iand
isopropyl alcohol are very toxic and very attractive to mammals.

[Eric Greenwell]

wrote:
> For flights limited to a single day and the ballast added the day of
> flight, I do not believe antifreeze is necessary. Given the very
> high heat capacity of water, the large volume, and the agitation that
> occurs during flight, it would not freeze. Dumping partial loads
> might be a problem in that the valves may ice up, preventing further
> dumping.
>
> Environmentally, ethanol would be the safest. Propylene glycol iand
> isopropyl alcohol are very toxic and very attractive to mammals.

Propylene glycol is used in RV drinking water systems because it is
non-toxic to humans, though Wikipedia.org states:

> The U.S. Food and Drug Administration has determined that propylene
> glycol in or on cat food has not been shown by adequate scientific
> data to be safe for use.

Ethylene glycol is commonly used in engine coolant systems and is as you
describe. I don't know if propylene glycol is safe to use in glider
wing tanks, however. Schempp-Hirth or the USA dealer should know.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[GrahamBrown via AviationKB.com]

My mistake, I was assuming this was for winterization, not for use during
flight.

--
Message posted via AviationKB.com
http://www.aviationkb.com/Uwe/Forums.aspx/soaring/200710/1

[Paul Hanson]

At 07:42 13 October 2007, wrote:
>For flights limited to a single day and the ballast
>added the day of
>flight, I do not believe antifreeze is necessary.
>Given the very high
>heat capacity of water, the large volume, and the agitation
>that
>occurs during flight, it would not freeze. Dumping
>partial loads
>might be a problem in that the valves may ice up, preventing
>further
>dumping.
>
>Environmentally, ethanol would be the safest. Propylene
>glycol iand
>isopropyl alcohol are very toxic and very attractive
>to mammals.
>
It is good to see glider pilots considering environmental
concerns, so I will add this. Isopropanol is mildly
toxic yes, but evaporates molecularly free (this is
why surgeons used it to clean instruments before autoclaves),
at pretty low temps and would very likely evap before
hitting the ground with the rest of the water it was
entrained in. Also it is not at all attractive to animals,
as in liquid form it is fumy, bitter, and really smells
bad (offer your dog some on a rag, you'll see).
Propylene glycol is what is used in eco-friendly antifreeze,
as opposed to the highly toxic ethylene glycol which
as already pointed out, is what is in regular antifreeze
(and tastes good to cats/dogs).
To wrap it up, ethenol, although not toxic in and of
itself, is not available without spending a great deal
of money/gallon, or being denatured--made toxic. This
keeps the bartender in business, and makes the otherwise
drinkable effluent rather poisonous (more so than isoproanol)
to man or beast, rendering it a poor choice for eco
friendly ballast tank antifreeze.
The non-toxic propylene glycol based antifreeze (commonly
called RV Antifreeze), at around $5-$7 a gallon would
probably be the best, cheapest 'responsible' choice.
If you are right about the valves being the weak link
in the freezing chain, it surprises me that none of
the manufacturers offer heated dump valves. (after-market
retrofit maybe?) Winter temps at altitude can be...well
a little balmy. I wonder, what kind of studies have
already been done on this?

Paul Hanson

[Nyal Williams]

Heated dump valves????

How big a battery would that take?

At 16:36 13 October 2007, Paul Hanson wrote:
>At 07:42 13 October 2007, wrote:
>>For flights limited to a single day and the ballast
>>added the day of
>>flight, I do not believe antifreeze is necessary.
>>Given the very high
>>heat capacity of water, the large volume, and the agitation
>>that
>>occurs during flight, it would not freeze. Dumping
>>partial loads
>>might be a problem in that the valves may ice up, preventing
>>further
>>dumping.
>>
>>Environmentally, ethanol would be the safest. Propylene
>>glycol iand
>>isopropyl alcohol are very toxic and very attractive
>>to mammals.
>>
>It is good to see glider pilots considering environmental
>concerns, so I will add this. Isopropanol is mildly
>toxic yes, but evaporates molecularly free (this is
>why surgeons used it to clean instruments before autoclaves),
>at pretty low temps and would very likely evap before
>hitting the ground with the rest of the water it was
>entrained in. Also it is not at all attractive to animals,
>as in liquid form it is fumy, bitter, and really smells
>bad (offer your dog some on a rag, you'll see).
>Propylene glycol is what is used in eco-friendly antifreeze,
>as opposed to the highly toxic ethylene glycol which
>as already pointed out, is what is in regular antifreeze
>(and tastes good to cats/dogs).
>To wrap it up, ethenol, although not toxic in and of
>itself, is not available without spending a great deal
>of money/gallon, or being denatured--made toxic. This
>keeps the bartender in business, and makes the otherwise
>drinkable effluent rather poisonous (more so than isoproanol)
>to man or beast, rendering it a poor choice for eco
>friendly ballast tank antifreeze.
>The non-toxic propylene glycol based antifreeze (commonly
>called RV Antifreeze), at around $5-$7 a gallon would
>probably be the best, cheapest 'responsible' choice.
>If you are right about the valves being the weak link
>in the freezing chain, it surprises me that none of
>the manufacturers offer heated dump valves. (after-market
>retrofit maybe?) Winter temps at altitude can be...well
>a little balmy. I wonder, what kind of studies have
>already been done on this?
>
>Paul Hanson
>
>
>

[Paul Hanson]

At 02:48 14 October 2007, Nyal Williams wrote:
>Heated dump valves????
>
>How big a battery would that take?
>
If you reread the post, I was skeptical about the
valves freezing being the only problem. That said,
deicing cable for roofs only use about 5 watts/foot
max. So if simply heating the dump valves would solve
the problem of ballast freezing/not dumping I think
heated valves would have long ago become an option,
as it does not take a whole lot of power to simply
keep water from freezing. It's not like your boiling
it, just keeping it well within the liquid temp range.
I can't imagine it hogging a lot of battery, and compared
to the weight of the water being carried the additional
few pounds of battery would be insignificant. It only
would have to operate shortly before, and while dumping.
Even if it took 100 watts, since it would only be needed
for less than 15 minutes, a 2 amp/hour battery would
cover it, and a 3 amp hour battery would still be chargeable
afterwards so a dedicated 7 amp/hour batt would be
more than sufficient, even at 100w/wing. Again, I think
that ice IN the ballast box/bag is the problem, not
frozen valves, so the heated valve was just a theoretical
solution to what I perceived as an oversimplification
of a 'possible' dangerous problem folks have encountered
in the past.
Again, I wonder if any proper studies have been done
on the subject. Till then, if I need to load up during
winter high flights, I will just use RV Antifreeze
(non-toxic propylene glycol based antifreeze)

Paul Hanson
"Do the usual, unusually well"--Len Niemi