Primarily for general aviation discussion, but other aviation topics are also welcome.
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By marioair
#1419737
So with the cold snap I'm sure it's time for the annual question on de-icing.

I'm usually happy just leaving the sun to do its magic but if I want to use product, what should I use (airframe only).

A 5l bottle of TKS 1 fluid costs about £45 and it states it can be used for ground based use as well. I think these are glycol based and hence a bit less viscous for in flight use - which having a non FIKI piper doesn't really matter for me.

So what's stopping me from using generic automotive de-icer? These seem to be ethanol/methanol based. Does this damage the airframe?
By Lefty
FLYER Club Member  FLYER Club Member
#1419874
Have you tried doing a search on the forum for "de-icer" ?
I know it has been covered several times.

Car de-icer are not recommended - they damage a/c paint.
Recommended is either TKS or Kilfrost - diluted at perhaps 4 or 5 parts water to 1 part de-icer.
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By marioair
#1419912
Post by Lefty » 22 Nov 2015 20:50

Have you tried doing a search on the forum for "de-icer" ?
I know it has been covered several times.

Car de-icer are not recommended - they damage a/c paint.
Recommended is either TKS or Kilfrost - diluted at perhaps 4 or 5 parts water to 1 part de-icer.


I had a quick google. What is it in the automotive stuff that's bad.

It seems like a waste of money using finely filtered TKS for ground de-icing. Also, as its glycol based I think it's fairly dubious from an environmental perspective draining litres of the stuff into the ground?
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By Paul_Sengupta
FLYER Club Member  FLYER Club Member
#1419924
TKS and other aeroplane de-icing fluid uses propylene glycol which is bunny safe as opposed to ethylene glycol which is normally used in car anti-freeze.

In fact the formula is normally 45% propylene glycol, 5% isopropyl alcohol, 50% de-ionised water.

Car de-icer is normally either mostly isopropyl alcohol, or methanol I believe.

When I worked in Kiev, the anti-ice screen wash in the pool cars smelled pretty much the same as the vodka there.
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By Flintstone
FLYER Club Member  FLYER Club Member
#1419927
Paul_Sengupta wrote:When I worked in Kiev, the anti-ice screen wash in the pool cars smelled pretty much the same as the vodka there.


I've seen Russian bizjet flight attendants use vodka to clean down the galley, cabin, toilet.....everything.
By beerdrinker
#1419969
One of our American cousins recommended a 50:50 mix of water and automotive radiator anti ice applied via a garden spray.

BD
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By Paul_Sengupta
FLYER Club Member  FLYER Club Member
#1419975
beerdrinker wrote:One of our American cousins recommended a 50:50 mix of water and automotive radiator anti ice applied via a garden spray.


Don't use standard car radiator stuff, that's ethylene glycol, it's poisonous. Use propylene glycol.

Chuck in a bit of isopropyl alcohol and you've got what I wrote above! :D
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By marioair
#1420057
My understanding was that propylene glycol is less harmful but still has a large biochemical oxygen demand and hence if fluid is running off into a watercourses near the airport, rather than sewerage, then your are effectively illegally disposing of hazardous waste?
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By Paul_Sengupta
FLYER Club Member  FLYER Club Member
#1420062
Yes, this will be so, for the huge quantities used in commercial operations. For personal de-frosting of wings, it'll drip onto the grass and harmlessly soak away, making the grass taste nice for the aforementioned bunny rabbits to lick. Ethylene glycol also makes the grass taste nice, but then it kills the bunny rabbits after they've licked it. Or at least makes them ill.

You may find it makes its way into the well water in homeopathic quantities.

Or you could use the aforementioned vodka. I don't know how partial bunny rabbits are to that.
By Lefty
FLYER Club Member  FLYER Club Member
#1420068
Has anyone tested the de-icing properties of vodka? Probably a lot cheaper than TKS.

JFYI, we found great problems trying to buy TKS in Oshkosh, to top up our anti-ice for the home run.
"Surface temp 37 C, who wants to buy de-icing fluid?"
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By Jandakot1
#1420136
[quote="Lefty"]Has anyone tested the de-icing properties of vodka? Probably a lot cheaper than TKS.

YES.
Tried 2 bottles the other day, warmed me up nicely and I couldn`t see any ice on the plane at all. :cheers:
By cockney steve
FLYER Club Member  FLYER Club Member
#1420159
Be aware that automotive antifreeze comes in 2 forms nowadays,
The standard, old-fashioned blue stuff is ,as already stated, ethylene Glycol -based. There are corrosion-inhibitors as well.....consider the average engine....aluminium cylinder-head, cast-iron block,, steel liners, brass, copper and stainless steel in sensors and thermostat......all these different metals and more, in contact with the coolant..to prevent electrolytic corrosion, there are corrosion-inhibitors incorporated....they lose there effectiveness, which is why a change is recommended every 2 years....it still protects against frost,but that's not a lot of good if it eats the radiator from the inside!

Then, we have the modern,orange-coloured antifreeze....other than being "organic" it attacks 1980's and earlier cooling system rubbers, seals and gaskets and causes leaks....a similar story to this alcohol-dosed petrol that eats brass filters and carb jets..... I read briefly about it, anyone interested can research.


Now we come to de-icers and windscreen-washer fluid.
This is Isopropyl Alcohol aka isopropanol. As explained to me, by an industrial research chemist :-
Ethyl alcohol....the stuff you can drink.....Methyl, is very similar but highly poisonous and both are inflammable....methyl is readily available but made noxious to drink, as methylated-spirit and surgical spirit.
then we have isopropyl. a common use is in Lithograph printing presses, where the machine has a water-wetted "blanket" the addition of isopropanol, which is , like the others, miscible in water and breaks the surface-tension , making it "wetter"....the molecular chain is longer than the others, making it thicker and less volatile..

There are a lot more cars, vans and trucks than light aircraft in fegular use.

The windscreen-washer fluid vendors are not overwhelmed with claims for body-rot or damaged paintwork.
This leads me to think that it's perfectly safe as a trigger-spray, or a garden pressure-spray, or even a backpack-spray, to DEFROST aeroplane flying-surfaces.

I would be inclined to allow it to dissolve frost and drain, then wipe all surfaces with something absorbent. AIUI, a coating of frost can ruin a wing's ability to generate lift. so you don't want lumps of re-frozen icy mush clinging to edges.
Don't know enough about in-flight icing and the effects of wind-chill, to comment on it's suitability as an in -flight de-icer....I believe the "proper"stuff has a finite "ground-life" after application and leaves a surface-film behind when the majority is dispersed by airflow during takeoff and initial flight.
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By marioair
#1420245
TKS and other aeroplane de-icing fluid uses propylene glycol which is bunny safe as opposed to ethylene glycol which is normally used in car anti-freeze.


Not so I'm afraid. At least not for what everyone is recommending in the UK: Killfrost TKS 80 or AeroSense TKS AL-5 DTD406b. I requested the data sheet from each supplier - both are ethylene glycol as far as I can tell.
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By Paul_Sengupta
FLYER Club Member  FLYER Club Member
#1420276
Hmm. I suppose small amounts spread over the country from high altitude isn't much of a hazard to animals.

It would be more so if you were to spray it all over the wings before starting up and it all dripped off in one place.