Tue Nov 24, 2015 11:03 am
#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.