Frost removal

Dan Thomas said:
This type of frost is caused by radiative cooling. A clear sky allows the latent heat in the metal to radiate off into space and the surface drops below the dewpoint and frost forms. The light metals used in airplanes contributes to it, and aluminum transmits the heat faster than steel, too. It doesn't happen in the hangar because the roof prevents the radiation off into space, relecting it back to the metal.

We used to have it happen a lot when pulling the flight school airplanes out on a cool morning. The metal can actually fall below the ambient air temperature, forming the frost even though there's no fog. You would normally see fog if the air temp got below the dewpoint.

Unless you buy 99% industrial isopropyl, you'll end up with a mix of water and IPA. The alcohol evaporates, cooling the wing even further, and the water left behind freezes. Use the right stuff.

https://www.linkedin.com/pulse/frost-result-radiational-cooling-arjen-piest
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Best reply yet. thanks for the info!
 
I've used just a plain ol chamois cloth to wipe off patches of frost before. That is probably all you need to do for small patches of frost like that.
 
Angle228 said:
... because then I would not even be able to see what I am about to crash into!
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Well if you're going to crash into something either way, that'd be my preference.
 
I'd just run a space heater inside the hangar, big enough to raise the ambient a degree or two. Just enough to warm the metal to where it isn't forming ice crystals. The blanket idea is good too, moving blankets are cheap.
 
The frost doesn't form in the hangar. The airplane is clean when it's pulled out, but then the metal cools and frost forms in the short time it's sitting on the ramp. Dan has the explanation in post #21.

I've seen this once when an airplane was pulled from a hangar in the early AM in Jan, the hangar is near a swamp. The only way I can think to delay it is to get the wing warmer so it doesn't go below freezing when you pull it out...but that's just a delay, eventually the wing will cool down.
 
bflynn said:
The frost doesn't form in the hangar. The airplane is clean when it's pulled out, but then the metal cools and frost forms in the short time it's sitting on the ramp. Dan has the explanation in post #21.

I've seen this once when an airplane was pulled from a hangar in the early AM in Jan, the hangar is near a swamp. The only way I can think to delay it is to get the wing warmer so it doesn't go below freezing when you pull it out...but that's just a delay, eventually the wing will cool down.
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Or just leave the blankets on the wing until right before firing it up. Frost can't form on a surface it can't get to.
 
So some of the replies have been on the lines of "clean up the wings and get it airborne before frost re-forms". Is there some reason frost couldn't form after takeoff? I'd think that unless you are climbing high enough to reach an altitude of reduced water vapor, frost could still form.
 
AlleyCat67 said:
So some of the replies have been on the lines of "clean up the wings and get it airborne before frost re-forms". Is there some reason frost couldn't form after takeoff? I'd think that unless you are climbing high enough to reach an altitude of reduced water vapor, frost could still form.
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The airflow over the wings keeps the metal at ambient temperature. Sitting still, it can drop below ambient as it forms a thin layer of colder air over it. That's also the reason why you often don't get frosting when it's windy.
 
Moving air= sublimation. I've flown plenty of frost and ice off my planes. It doesn't matter what the temp is.
 
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