Can engine heater reduce/prevent engine corrosion?

You may of heard of a WWII P-38 that was buried under deep snow in Greenland for maybe 60+ years dubbed Glacier Girl. Plane was dugout with great effort, restored and flown. Saw it at Reno Air Races. So corrosion could not have been too bad.
 
You may of heard of a WWII P-38 that was buried under deep snow in Greenland for maybe 60+ years dubbed Glacier Girl. Plane was dugout with great effort, restored and flown. Saw it at Reno Air Races. So corrosion could not have been too bad.

They replaced 80+% of the aircraft's structure. It was badly crushed. I dunno about the corrosion. But it wouldn't be a viable point of reference...
 
The best way to prevent corrosion is to fly the airplane frequently. Even if you don't have somewhere to go, try to fly it every week, long enough to get the oil temperatures up. Oil additives such as Camguard may be helpful too. To answer to question, using an electric engine heater will not prevent corrosion.
Jon
I have heard this undocumented claim many times. If you are looking for an excuse to fly then this is a good way to justify it. However, to put on 50 extra hours per year going no where and costing say $10,000 fuel and airframe and engine wear flying the most dangerous hours: takeoff, landing and close to heavier traffic make this approach questionable.
 
I have heard this undocumented claim many times. If you are looking for an excuse to fly then this is a good way to justify it. However, to put on 50 extra hours per year going no where and costing say $10,000 fuel and airframe and engine wear flying the most dangerous hours: takeoff, landing and close to heavier traffic make this approach questionable.

why own a plane if you aren’t going to fly it?
 
They replaced 80+% of the aircraft's structure. It was badly crushed. I dunno about the corrosion. But it wouldn't be a viable point of reference...
I did know a lot was crushed. Since 20+/- percent was reusable there probably was little corrosion damage unless these parts were just cosmetic. I would think the excavation would have never been started unless the excavators had good evidence that corrosion would be minimal.
 
Note, make sure you have an insulated prop cover on. Otherwise the prop acts like a heat (cold) sink and will cause your crankshaft to be colder than the rest of your engine. If that happens all of that moisture that's being pushed out of your oil will condense on your crankshaft.

What if you have a composite prop? Mine doesn't have any metal in it.
 
I did know a lot was crushed. Since 20+/- percent was reusable there probably was little corrosion damage unless these parts were just cosmetic. I would think the excavation would have never been started unless the excavators had good evidence that corrosion would be minimal.
What if you have a composite prop? Mine doesn't have any metal in it.

A composite prop is unlikely to transmit much heat from the crank to the prop to the atmosphere.
 
I understand they need to be changed weekly or so. Which silica can last 3 months n the PNW?
It's not about the silica, it's about the system you build. A closed system with one end on the oil filler and the other on the crankcase breather tube will keep the total system humidity much lower than if the pump is pumping atmospheric air. The result is that the silica lasts longer. Additionally, I use about 7.5 lbs of silica in mine. So...it takes longer to saturate.
 
A composite prop is unlikely to transmit much heat from the crank to the prop to the atmosphere.
Yes. So I would think. A prop sock is pretty simple, cheap, and easy to put on... but even so, I don't know if it's worth the effort.
 
Yes. So I would think. A prop sock is pretty simple, cheap, and easy to put on... but even so, I don't know if it's worth the effort.

To test: Install engine heater. Turn on on a cold day. Come back 3 hours later and see how warm your prop is.

I run this test several times a winter. No noticeable heat in my composite prop. But I'm doing this on days where it is 35+, not in artic conditions...
 
Turn the heater on when you want to fly it.... leave it off till you need it. Easy peasy.... lemon squeezy
 
To test: Install engine heater. Turn on on a cold day. Come back 3 hours later and see how warm your prop is.

I run this test several times a winter. No noticeable heat in my composite prop. But I'm doing this on days where it is 35+, not in artic conditions...

Interesting test...I live in Minnesota. I'll bring my infrared thermometer out to the hangar with me as the season progresses.
 
Only if your heater schedule can keep the temps inside the crankcase above the dew point 24/7/365
That's pretty easy in cold weather. I don't plug in the heater until daytime temps here in Ottawa are regularly below 5°c, and it keeps everything in the engine compartment warm to the touch, so at least 10°c above dewpoint even on "warm" days in late fall/winter/early spring.

If I didn't plug in, I'd get internal condensation every time the engine cooled down after a flight in cold weather. I think that's why Tanis recommends leaving the heater plugged in.
 
Turn the heater on when you want to fly it.... leave it off till you need it. Easy peasy.... lemon squeezy
But then you're warming up the engine with every flight, creating lots of moisture as a byproduct of combustion, then letting it cool enough that all the moisture condenses on surfaces.
 
But then you're warming up the engine with every flight, creating lots of moisture as a byproduct of combustion, then letting it cool enough that all the moisture condenses on surfaces.

Where does it condense first? The aluminum crankcase, possibly the cylinders, not the cam, rods, crank, gears, etc.
 
But then you're warming up the engine with every flight, creating lots of moisture as a byproduct of combustion, then letting it cool enough that all the moisture condenses on surfaces.
Not a problem. When the engine cools....The moisture will freeze/vaporize out. Corrosion stops.
 
Not a problem. When the engine cools....The moisture will freeze/vaporize out. Corrosion stops.
It will evaporate or sublimate eventually, but that happens more slowly at cool temperatures than warm ones.

When you get your socks wet from walking in the snow, what do you do to dry them: hang them outside in the cold, or inside in front of the fire?
 
And then, let's say the temp goes up to 5°c on a cool damp day, then down again at night, you'll get another round of condensation when the engine cools just from the moisture in the air. And then another, and another...
 
That's pretty easy in cold weather. I don't plug in the heater until daytime temps here in Ottawa are regularly below 5°c, and it keeps everything in the engine compartment warm to the touch, so at least 10°c above dewpoint even on "warm" days in late fall/winter/early spring.

If I didn't plug in, I'd get internal condensation every time the engine cooled down after a flight in cold weather. I think that's why Tanis recommends leaving the heater plugged in.
Keeping the heater plugged in is one way keeps the engine temp above the dew point and prevent condensation. Other way is to decrease the humidity in the engine. I have a Rieff Turbo XP (soon to be on a Switcheon so I don't have to drive to the airport for my 4-hour warmup) and a dehydrator that I built to prevent condensation by lowering the crankcase humidity. I hook up the dehydrator within minutes after putting the plane back in the hangar and it runs 24-7 when the plane isn't flying.
 
Re: humidity. Read and learn. https://www.zehnderamerica.com/absolute-vs-relative-humidity-whats-the-difference/

With respect to engine corrosion, a deep freezer would be the ideal way to preserve aircraft engines between flights. Some of us have been lucky and live in such an environment. Me? Now I have a hangar. Corrosion concerns take on a whole new complexion. Thus the inert gas purge experiments.

Rust never sleeps.
 
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I did know a lot was crushed. Since 20+/- percent was reusable there probably was little corrosion damage unless these parts were just cosmetic. I would think the excavation would have never been started unless the excavators had good evidence that corrosion would be minimal.

It was under 270' of ice and snow. 'Good evidence' would have been difficult to ascertain
 
IMG_2437.JPG Here's a +20 yo crank case with an oil pan heater.....it only comes on the night before flight.
 

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Re: humidity. Read and learn. https://www.zehnderamerica.com/absolute-vs-relative-humidity-whats-the-difference/

With respect to engine corrosion, a deep freezer would be the ideal way to preserve aircraft engines between flights. Some of us have been lucky and live in such an environment. Me? Now I have a hangar. Corrosion concerns take on a whole new complexion. Thus the inert gas purge experiments.

Rust never sleeps.
A "deep freezer" would have to be near absolute zero. While chemical processes no doubt slow down as it gets colder, it's on a bigger scale. Going from 70*F to 30*F is a lot to us. Our engines have temps from 300-1500*F. On that scale, a difference of 40*F makes a negligible difference in the speed of chemical processes.

I agree about removing oxygen, I'd be fascinated to see how that works out.
 
But then you're warming up the engine with every flight, creating lots of moisture as a byproduct of combustion, then letting it cool enough that all the moisture condenses on surfaces.
Ummm, I think flying the plane warms the engine up too....that’s the point. If you want your engine to last forever and never warm up, then follow these instructions.

Step one - remove engine from plane.
Step two - place entire engine in barrel of preservative oil.
Step three - enjoy the feeling of satisfaction knowing that your engine and can will not be corroding.
 
Ummm, I think flying the plane warms the engine up too....that’s the point. If you want your engine to last forever and never warm up, then follow these instructions.

Step one - remove engine from plane.
Step two - place entire engine in barrel of preservative oil.
Step three - enjoy the feeling of satisfaction knowing that your engine and can will not be corroding.
You're agreeing with my point. If an engine stayed cold all the time in the winter, it would be fine without an engine heater. But since we do like to actually fly our planes, it's good to leave the engine heater all the time when we're not flying in cold weather, so that the engine doesn't cool below the dewpoint between flights.
 
@MountainDude Here's real data from Reiff, not anecdotal BS:
http://www.reiffpreheat.com/FAQ.htm#QA3

I leave mine plugged in 24/7 in the cold months. Like others have stated, it's the on/off cycles of the heater that cause damage and condensation. My rule of thumb is, if I'm going to unplug the heater, I'm going to fly. The heater will ALSO decrease humidity just like a dehumidifier will.

Edit: I do fly weekly and don't leave the plane unattended for more than a week.

We did the same with a SR22 I was flying years ago. There were four of us in the group, so it flew pretty regularly. When the temps were down we'd plug it in, pop the oil cap and wrap a cloth around it and put a sleeping bag over the cowl.

The engine was rebuilt around 2,500 hours.



Wayne
 
Corrosion requires moisture. Corrosion does not require heat. Heat only accelerates corrosion in the presence of moisture at the surface of the metal. Get rid of the condensation.
the colder the air.....it can not contain moisture. Plain and simple physics.
 
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Corrosion requires moisture. Corrosion does not require heat. Heat only accelerates corrosion in the presence of moisture at the surface of the metal. Get rid of the condensation.
Exactly. And if the surrounding air is relatively dry, heating something is a great way to remove the moisture from it (whether it's laundry hanging in the sun on a line, or wet mittens sitting on a heat vent in the winter).
 
the colder the air.....it can not contain moisture. Plan and simple physics.
Exactly right. So as the air cools, the moisture condenses and settles on a cool surface instead, as we've all seen with dew on morning grass, or frost on a car windshield. If you keep the surface warmer than the dewpoint, the moisture won't settle on it (e.g. if you have a ceramic heater in your car overnight, you won't wake up to frosted windows).
 
Most of my opinion comes from having torn down engines and seeing what's inside. The balance is from watching others tear down engines. There is no question in science that heat accelerates corrosion. It applies to heated hangars, too. Leaving your engine in cold storage is better for it than heated storage. Heat reduces relative humidity but increases total humidity.
Only if there is a source of water to evaporate. As someone else mentioned, heating homes cause the relative humidity to go down greatly.

With your heaters on you're making a greenhouse. Warm moist air rises and meets the coolest surface available. If you use a reiff system that'll be the top of the case, where it condenses and rains down to go through the cycle again. With oil pan heat and no cylinder heat? It'll condense in the heads. Pull the rocker drains on a Lycoming that operates in the cold and is kept warm in between flights. Heater or hangar won't matter. Tap the drains and watch the water come out.
If the whole engine is warm (heated hangar), no temperature differential, so no cycle.

Personally I've been experimenting with inert gas purging of airplane engines for storage to reduce cam corrosion. Rust is oxidation. Removing oxygen is easier than removing water. With Continental's low cams argon seems to be the best choice. With Lycoming's high cam I'm using nitrogen. In both cases the gas flows out at the cylinders so that's the threshold level for the gas to remain. There's no practical way to seal the cylinders. I have more testing to do but there's promise.
Argon or nitrogen shouldn't make any difference if you are simply displacing oxygen. A liquid nitrogen tank will provide gaseous nitrogen for a month (whether you use it or not). When the gas flows out of the engine, it gets replaced. I use a setup with a LN2 tank to run several mass spectrometers and light scattering detectors, each needing several liters a minute of gas @STP. Overall, cheaper than tanks, and easier to replace, too.
 
Isn't the O in H2O for Oxygen? Stuff corrodes in the ocean with no gaseous O2. Not seeing how removing gaseous O2 is going to make any difference.
 
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the colder the air.....it can not contain moisture. Plain and simple physics.
Even here in Minnesota it occasionally get warm and, according to you and several of the other physicists in this thread, will therefore contain moisture. Now...plugging in the heater in your plane 24/7 will still keep its internals above the dewpoint, so no condensation. Do you propose keeping the heater plugged in year round?
 
But then you're warming up the engine with every flight, creating lots of moisture as a byproduct of combustion, then letting it cool enough that all the moisture condenses on surfaces.
That point seems to be escaping several people in this thread...
 
Isn't the O in HO2 for Oxygen? Stuff corrodes in the ocean with no gaseous O2. Not seeing how removing gaseous O2 is going to make any difference.
Think about fish. How do they "breathe"? Oxygen dissolves in water, as does nitrogen and other gasses.
Having said that, water is continually changing, with hydrogens being removed (OH- ions) and added (H3O+ ions).

Even here in Minnesota it occasionally get warm and, according to you and several of the other physicists in this thread, will therefore contain moisture. Now...plugging in the heater in your plane 24/7 will still keep its internals above the dewpoint, so no condensation. Do you propose keeping the heater plugged in year round?
There's something missing in the bolded statement. I read it as "it gets warm, so moisture increases", which isn't what you meant to say.
 
Think about fish. How do they "breathe"? Oxygen dissolves in water, as does nitrogen and other gasses.
Having said that, water is continually changing, with hydrogens being removed (OH- ions) and added (H3O+ ions).

There's something missing in the bolded statement. I read it as "it gets warm, so moisture increases", which isn't what you meant to say.
Yes. An internal combustion engine is like a fish :D

In Minnesota in the winter it gets cold, and the colder it gets, the less moisture the air can hold. At -30 F, it holds very little moisture and managing condensation in your airplane engine becomes less of an issue. And then winter becomes spring and then summer, at which point in Minnesota the air can hold enough moisture that condensation IS a problem, with the dew on the grass every morning accurately demonstrating the daily cooling/warming cycles and mimicking what's happening inside your engine inside your hangar. Condensation/moisture in your engine is bad...it can react with the acid combustion byproducts and cause corrosion. None of this is to mention the fact that your engine itself generates a lot of moisture while running. How do we manage that moisture? We can't prevent it, so how do we get rid of it? Since we can't keep our airplanes in a freezer, nor can we (practically) keep its temperature above the dewpoint 24/7/365, we need an alternate practical solution to manage moisture in our engines year round. This is the concept behind using an engine dehydrator.
 
Interesting that you say that. I ordered two of the Barker Aero dehydrator kits yesterday to test. After 25 years of parking outside in Alaska including stored and semi-active airplanes in winter and understanding my preferred way to deal with that? Now my planes are in a hangar that's kept around 45* most of the winter and corrosion is more active than what I've been used to. No conjecture, just fact. I'll continue to experiment with gas purging but the dehydrator, being an active system, may be the best solution.

Unlike you guys who think you have it all figured out? I'm always looking for something better.
 
Yes. An internal combustion engine is like a fish :D
No one said that, nor implied that. Merely an observation that oxygen dissolves in water, and trying to straighten out some of the bad science here in this thread. The comment about the fish was an attempt to show that the animal gets oxygen from someplace.

In Minnesota in the winter it gets cold, and the colder it gets, the less moisture the air can hold. At -30 F, it holds very little moisture and managing condensation in your airplane engine becomes less of an issue.
If you use the plane, it is perhaps more of an issue. You have the same moisture from combustion products, and colder temperatures to condense it even more.
I'll point you to this comment of yours below when someone raised this topic:
That point seems to be escaping several people in this thread...

And then winter becomes spring and then summer, at which point in Minnesota the air can hold enough moisture that condensation IS a problem, with the dew on the grass every morning accurately demonstrating the daily cooling/warming cycles and mimicking what's happening inside your engine inside your hangar. Condensation/moisture in your engine is bad...it can react with the acid combustion byproducts and cause corrosion. None of this is to mention the fact that your engine itself generates a lot of moisture while running. How do we manage that moisture? We can't prevent it, so how do we get rid of it? Since we can't keep our airplanes in a freezer, nor can we (practically) keep its temperature above the dewpoint 24/7/365, we need an alternate practical solution to manage moisture in our engines year round. This is the concept behind using an engine dehydrator.
Won't hurt anything, at least, to use the dehydrator.
 
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