Pickling

[Alan Maurer]

Hello Mooney People

I probably cannot fly my Ovation for three or four months. It is in a hangar and would like advice in having  the engine. pickled. I was  a bike crash  in ....Sarasota 

and have a broken arm and out of commission for a few months. ....bummer

thanks

Alan

[ArtVandelay]

When my plane was down for avionics work I just did an oil change. I use Camguard as always.
I have my old camshaft sitting on the floor of the hangar, it’s not showing rust after 5 years and Im in Florida. Based on this I think dirty oil is what destroys engines.

[jcolgan]

When I had mine painted I was told I would have it back in 6 weeks which is longer than I like to let it sit idle, but I didn’t take any preservation actions. 

They actually didn’t get my plane finished for a few days 5 MONTHS.  I was livid (and they didn’t do a particularly good job to add insult to injury).  

It has been 9 years ago and no metal in the oil filter or rust seen as cylinders 3 and 4 were pulled years later for non corrosion issues. 

I was using Camguard during the paint job and still do now. This is all with the humidity we have here in Alabama. 

[anthonydesmet]

Sorry about your arm.  That s*cks!  I think the engine part has been answered. Only thing I’d add is if someone here close by and has some “R” time maybe you guys could fly together a few times.

other things I’d think about is topping off your tanks, every once in awhile reposition the plane so your tires don’t get a flat spot. Maybe a wash once or twice to get the hanger dust off? All can be done with one arm and a hanger elf I would think.

one I first had my plane I was working on and off offshore oil rigs a couple months at a time.  Above is what I had my mechanic’s assistant do while I was gone.

[EricJ]

Three or four months isn't going to be too big of a deal, but if you can have somebody just start it and run it for a bit every month or so, that's a bit better than just leaving it sit.

[Rick Junkin]

You might want to consider using an engine dehydrator. Along with using Camguard, I keep one of these plugged into my engine as a matter of course. Reduced moisture = no corrosion.

https://www.aircraftspruce.com/catalog/eppages/engsaver.php?clickkey=5716

[ArtVandelay]

Three or four months isn't going to be too big of a deal, but if you can have somebody just start it and run it for a bit every month or so, that's a bit better than just leaving it sit.

I think thats a bad idea, this will add combustion byproducts (water) to your clean dry oil.

[EricJ]

2 minutes ago, ArtVandelay said:

I think thats a bad idea, this will add combustion byproducts (water) to your clean dry oil.

Not if it's run up to temperature.  That will drive the water out.  Doesn't take very long.   

[ArtVandelay]

Not if it's run up to temperature.  That will drive the water out.  Doesn't take very long.   

Next time you shut down your engine, pull the dipstick, you’ll see a lot of water vapor that wasn’t driven out.
I do this every time I fly.

[EricJ]

Just now, ArtVandelay said:

Next time you shut down your engine, pull the dipstick, you’ll see a lot of water vapor that wasn’t driven out.
I do this every time I fly.

Exactly, it'll be in vapor and not in the oil.   It may have come out of the oil if it had been sitting for a while.

[anthonydesmet]

2 hours ago, Rick Junkin said:

You might want to consider using an engine dehydrator. Along with using Camguard, I keep one of these plugged into my engine as a matter of course. Reduced moisture = no corrosion.

https://www.aircraftspruce.com/catalog/eppages/engsaver.php?clickkey=5716

That’s a good idea.  I also have a Home Depot crawl space dehumidifier in my hanger set at 55% humidity.  I’m also in central Florida.  It has a pump attached to a hose I run out the side of the hanger.  Keeps the entire airplane dry.

[MikeOH]

57 minutes ago, EricJ said:

Exactly, it'll be in vapor and not in the oil.   It may have come out of the oil if it had been sitting for a while.

Ok, this is as good as time as any to start a debate I've been meaning to have for a long time

Namely, where is all this 'moisture' that is going to destroy your engine coming from.  Seems like there are only two possibilities:

1) From moisture due to the combustion process getting into the crankcase past the rings. I've always thought that was the 'vapor' seen coming out the dipstick tube after the engine has been run to temperature (and one of the reasons there is a breather tube)

2) From sitting and equalizing with the surrounding atmosphere's humidity.

 

Next, near as I can tell, and have been taught, oil and water are NOT miscible. So, I've never quite understood the idea of 'getting the water out' of the oil.  So, is the water just 'sitting' as a liquid at the bottom of the oil in the case?  If so, why would it matter if you ran the engine up on the ground or went for a flight as long as you reached operating temperature?  And, as soon as you shut-down, either way, as the engine cools the moisture in the 'air' is going to condense out on everything.

Seems to me that after a few days of sitting whatever moisture there was from a flight or op-temp run-up is going to equalize with the surrounding atmosphere (or have sunk to the bottom of the case where it isn't going to hurt anything)

The difference is how LONG the plane sits.  The oil on the parts (e.g. camshaft) is going to drain/drip/evaporate away allowing the ambient moisture to attack the now exposed metals.  I would also think 'dirty' oil with a high acid level would aggravate this process.

Based on the above, I'd put in fresh oil, run the engine up to temp on the ground once a week to recoat the parts.  And, if in a high humidity environment (like FL) using a dehumidifier would be a great idea.

[Rick Junkin]

1 hour ago, ArtVandelay said:

Next time you shut down your engine, pull the dipstick, you’ll see a lot of water vapor that wasn’t driven out.
I do this every time I fly.

I think what you meant is the water was driven out of the oil into vapor but you need to pull the dipstick to let it vent out to keep it from condensing back on the engine and into the oil. I do the same thing immediately after shutdown. I wait until I no longer see vapor coming from the oil fill tube, which is usually about the time I've completed all my post flight stuff, and then I plug my dehydrator into the fill tube. I use a silicone stopper to seal the dehydrator line in the tube. This is contrary to the instructions that came with the Engine Saver, which tells you to put the dehydrator into the vent tube. I didn't like how that was working for me (messy, OEM seal wrong size/deteriorating) so I did some research and settled on using the fill tube instead. Seems to be working well, or at least not hurting anything. I'm not seeing any corrosion in my cylinders or on the parts of the cam I can see with a borescope.

Cheers,
Junkman

[Rick Junkin]

5 minutes ago, MikeOH said:

Based on the above, I'd put in fresh oil, run the engine up to temp on the ground once a week to recoat the parts.

I've seen two schools of thought on this. One says don't run the engine unless you can run it for at least an hour at operating temperature (i.e. fly it) and the other as you've suggested. I've not delved into it enough to form an opinion either way, but I know that if I can keep the relative humidity inside the engine below about 40% and no condensation occurs then I don't need to worry about corrosion. And that's my objective.

[ArtVandelay]

Ok, this is as good as time as any to start a debate I've been meaning to have for a long time
Namely, where is all this 'moisture' that is going to destroy your engine coming from.  Seems like there are only two possibilities:
1) From moisture due to the combustion process getting into the crankcase past the rings. I've always thought that was the 'vapor' seen coming out the dipstick tube after the engine has been run to temperature (and one of the reasons there is a breather tube)
2) From sitting and equalizing with the surrounding atmosphere's humidity.
 
Next, near as I can tell, and have been taught, oil and water are NOT miscible. So, I've never quite understood the idea of 'getting the water out' of the oil.  So, is the water just 'sitting' as a liquid at the bottom of the oil in the case?  If so, why would it matter if you ran the engine up on the ground or went for a flight as long as you reached operating temperature?  And, as soon as you shut-down, either way, as the engine cools the moisture in the 'air' is going to condense out on everything.
Seems to me that after a few days of sitting whatever moisture there was from a flight or op-temp run-up is going to equalize with the surrounding atmosphere (or have sunk to the bottom of the case where it isn't going to hurt anything)
The difference is how LONG the plane sits.  The oil on the parts (e.g. camshaft) is going to drain/drip/evaporate away allowing the ambient moisture to attack the now exposed metals.  I would also think 'dirty' oil with a high acid level would aggravate this process.
Based on the above, I'd put in fresh oil, run the engine up to temp on the ground once a week to recoat the parts.  And, if in a high humidity environment (like FL) using a dehumidifier would be a great idea.

Water is a byproduct of the combustion process, and there’s usually a small amount of sulfur in the fuel, that creates sulfur acid, very bad for metal.

You can mix water and oil (at least for a little while), in boating world this happens and oil turns a light brown milky color.

I think allowing the water vapor to escape after shutdown can only help preventing it from condensing out on internal surfaces.

[PT20J]

If you are worried about it you could try this https://www.phillips66lubricants.com/product/aviation-anti-rust-oil/

[EricJ]

19 minutes ago, MikeOH said:

Ok, this is as good as time as any to start a debate I've been meaning to have for a long time

Namely, where is all this 'moisture' that is going to destroy your engine coming from.  Seems like there are only two possibilities:

1) From moisture due to the combustion process getting into the crankcase past the rings. I've always thought that was the 'vapor' seen coming out the dipstick tube after the engine has been run to temperature (and one of the reasons there is a breather tube)

2) From sitting and equalizing with the surrounding atmosphere's humidity.

Condensation can account for a lot of it, and is how the amount of water in the engine can increase over time when it is just sitting. 

19 minutes ago, MikeOH said:

Next, near as I can tell, and have been taught, oil and water are NOT miscible. So, I've never quite understood the idea of 'getting the water out' of the oil.  So, is the water just 'sitting' as a liquid at the bottom of the oil in the case?  If so, why would it matter if you ran the engine up on the ground or went for a flight as long as you reached operating temperature?  And, as soon as you shut-down, either way, as the engine cools the moisture in the 'air' is going to condense out on everything.

Oil can suspend water, especially from condensation.    Getting the oil up to temperature (i.e., above the boiling point of the water) vaporizes the water and separates it from the oil.  This allows it to get out via the vent.

19 minutes ago, MikeOH said:

Seems to me that after a few days of sitting whatever moisture there was from a flight or op-temp run-up is going to equalize with the surrounding atmosphere (or have sunk to the bottom of the case where it isn't going to hurt anything)

The idea is to reduce the amount of moisture in the engine.   You're right that you can't eliminate it in a humid environment, but you want to get out the moisture that has accumulated from condensation, or at least reduce it to the ambient level.   Getting the engine warm enough to vaporize all of the water allows it to get out the vent (pushed out by blow-by, etc.)

19 minutes ago, MikeOH said:

The difference is how LONG the plane sits.  The oil on the parts (e.g. camshaft) is going to drain/drip/evaporate away allowing the ambient moisture to attack the now exposed metals.  I would also think 'dirty' oil with a high acid level would aggravate this process.

Based on the above, I'd put in fresh oil, run the engine up to temp on the ground once a week to recoat the parts.  And, if in a high humidity environment (like FL) using a dehumidifier would be a great idea.

Dehumidifier shouldn't hurt, for sure.    Running it once in a while also helps to maintain oil distribution on parts as you mention.

[Pinecone]

3 hours ago, EricJ said:

Exactly, it'll be in vapor and not in the oil.   It may have come out of the oil if it had been sitting for a while.

And then when the engine cools, it will become liquid again.

The steam you see from pulling the dipstick is from fresh combustion.   The recommendation is you need to FLY the aircraft for at least an hour to drive the water out of the oil.

Do what you want, but there are LOTS of reports of engines being run up on the ground ending up with serious corrosion.  Also, show me ONE reasonable source that says that a ground run is good enough?

From Philips 66 - "Ideally, aircraft engines should be used on a regular basis. Rust can occur when an engine is used infrequently or operated for a short period without reaching an operating temperature sufficient to evaporate the water generated from the fuel combustion process. Flying at least once a week for 30 minutes to an hour while maintaining an oil temperature in the 180°F range, should eliminate this problem."

From EAA - "Continental states that the best way to care for and preserve the engine is to fly once a week. Lycoming also goes along with this."

Continental Service Instruction for storage - https://www.reiffpreheat.com/Continental SIL99-1.pdf

From Lycoming - "Engine temperature and length of operating time are very important in controlling rust and corrosion. The desired flight time for air cooled engines is at least one continuous hour at oil temperatures of 165°F to 200°F at intervals not to exceed 30 days, depending on location and storage conditions. This one hour does not include taxi, take-off and landing time."

Lycoming Service Letter - https://www.lycoming.com/sites/default/files/attachments/Engine%20Preservation%20for%20Active%20and%20Stored%20Aircraft.pdf

From Aviation Consumer - "

More than one tech told us that engines that are not operated in flight to normal operating temperatures at least once a week should be managed under some preservation or storage program to reduce the effects of corrosion.

In our view, the ground running of an engine is not a substitute for flying it when it comes to dispelling moisture. Running it on the ground simply doesn’t get the engine hot enough, plus it tends to cause uneven heating at higher power, so you’re likely just wasting fuel doing so."

[EricJ]

2 hours ago, Pinecone said:

And then when the engine cools, it will become liquid again.

The idea being, by then it is outside of the engine.

It is not hard to get the engine oil and case above the boiling temp of water while on the ground.   A few minutes of that to assure the water vaporizes and then has a chance to cycle out the vent will decrease the amount of water in the engine if it has been sitting and accumulating water due to condensation.

Running an engine periodically also pumps the oil around to relubricate everything.

There are tradeoffs to everything, though.  YMMV.  You can also leave an engine sit for as long as you wish.    

[LANCECASPER]

20 hours ago, Alan Maurer said:

Hello Mooney People

I probably cannot fly my Ovation for three or four months. It is in a hangar and would like advice in having  the engine. pickled. I was  a bike crash  in ....Sarasota 

and have a broken arm and out of commission for a few months. ....bummer

thanks

Alan

Three or four months isn't going to make much difference. I wouldn't lose any sleep over it.

[Schllc]

Somewhat tangential to the op topic. But if you pickle an engine for any reason, shouldn’t that be logged?  
I don’t know if it’s required, but seems like a helpful thing to do if will be sitting up for an extended period of time. 
I recently looked at a plane that was out of annual for 20+ years. They elected to dismantle the plane and ship it for a thorough annual.   The shop it went to is very well known and respected in the community as a top shop for this make. 
the seller told me the engines were pickled for the 20 years, prior to storing.  
The shop told me personally when I called, that they were not pickled. 
There is no log entry.  
I would assume preservation oil does not look the same and is easy to distinguish? 
The seller was likely told it was pickled and is repeating…

A log entry seems prudent. 

[EricJ]

5 minutes ago, Schllc said:

Somewhat tangential to the op topic. But if you pickle an engine for any reason, shouldn’t that be logged?  
I don’t know if it’s required, but seems like a helpful thing to do if will be sitting up for an extended period of time. 
I recently looked at a plane that was out of annual for 20+ years. They elected to dismantle the plane and ship it for a thorough annual.   The shop it went to is very well known and respected in the community as a top shop for this make. 
the seller told me the engines were pickled for the 20 years, prior to storing.  
The shop told me personally when I called, that they were not pickled. 
There is no log entry.  
I would assume preservation oil does not look the same and is easy to distinguish? 
The seller was likely told it was pickled and is repeating…

A log entry seems prudent. 

"Maintenance" is required to be logged by regulation, and the FAA defines "maintenance" to include "preservation":

Maintenance means inspection, overhaul, repair, preservation, and the replacement of parts, but excludes preventive maintenance.

So I think it's arguable that "pickling", if done for "preservation" should be logged, but clearly lots of stuff that should be logged or would be helpful to be logged doesn't get logged.

 

[FoxMike]

I would suggest you locate a CFI to go along with you and help out with the flying duties.  That way the airplane is being flown regularly.

[A64Pilot]

Actual pickling is a lot more than merely putting preservative oil in it, and maybe others can tell the difference but to me it just looks like oil.

Pickling amounts to following the directions on the oil, and sealing every air entry point into the engine including the intake and exhaust, as well as fogging the cylinders with preservative oil, and installing at least one dessicant plug in each cylinder, and the dessicant plugs should be monitored and the dessicant changed if it changes color.

Usually there are several levels of preservation from flyable storage, short term, long term and permeant which means it comes off and goes into a sealed can, different levels require more and more work to preserve and de-preserve.

For three or four months I’d just put the preseravitive oil in it following the directions on the oil, assuming of course it’s stored inside a hangar. Keep the oil it can be reused without any problem. You can even fly with the preservative oil for some number of hours

I pickled my C-85 for over four years and has zero problems, I also stored two autos for the same four years in the same hangar and all I did for the cars was put Sta-bil in the tanks that were filled and disconnected the batteries, and both cars were fine. Both are currently in storage driven rarely and only in the neighborhood as they don’t have tags because I don’t want to pay insurance on cars in storage

I’ve also seen engines that were literally filled to the top with the cheapest Auto oil, sit for years and were just fine.

 

Preservative oil can be bought one of two ways, concentrated where you add 10% to regular oil and already mixed which is of course just that.

Pretty good article, just be aware that our engines are NOT new engines, a broken in engine has a layer of varnish like material on its cylinder walls and is a whole lot less likely to rust than a “new” engine so don’t freak on the 2 day comment, that for zero time cylinders surely.

https://www.cessnaflyer.org/magazine/article-archives/maintenance-technical/flying-interrupted-modern-engine-preservation.html

 

Oh and somewhere near a half of my neighborhood just leaves their aircraft in the hangar and goes “home” up North every Summer and comes back about November and has done that for years with seemingly no harm.

Edited October 27 by A64Pilot

[A64Pilot]

Can’t you fly with a broken arm? It only took me a couple weeks before I could fly with knee replacements.