SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Sep 21, 2014, 11:05 AM
Registered User
FlyBoy20's Avatar
United Kingdom, Wales, Swansea
Joined Aug 2012
656 Posts
Question
After-run oil?

First questiion - what's so special about it? If you want to prevent gumming up or rust, why not just use WD-40?
FlyBoy20 is offline Find More Posts by FlyBoy20
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 21, 2014, 11:15 AM
Glow is Great !
Gary Cee's Avatar
United States, MI, Marysville
Joined Apr 2010
2,306 Posts
I wonder if you tried a search on this subject here ? You will be amazed , WD-40 is simply a light oil mixed with mineral spirits . Marvel "Mystery" oil is basically the same thing with a little oil of peppermint or the flavor of the month added .
This fall , spray some WD-40 on cast aluminum parts under the hood of a car , leave other parts bare . Open your hood in the spring and the WD-40 side looks worse than the bare side ! Been there , first hand .

Automatic trans fluid is far better at preventing rust . There are fogging oils and products like Boeshield that leave a waxy film to protect and they work OK but may wind up gumming up the works , sticking up bearings etc . .


WD-40 is great for removing old masking tape and adhesive goo .
Gary Cee is offline Find More Posts by Gary Cee
Reply With Quote
Old Sep 21, 2014, 11:53 AM
Registered User
FlyBoy20's Avatar
United Kingdom, Wales, Swansea
Joined Aug 2012
656 Posts
Quote:
Originally Posted by Gary Cee View Post
I wonder if you tried a search on this subject here ? You will be amazed ,
I did a search, and found two threads, but only at the bottom of the page - after the search comes up. Must be doing something wrong..

Quote:
Originally Posted by Gary Cee View Post
WD-40 is simply a light oil mixed with mineral spirits . Marvel "Mystery" oil is basically the same thing with a little oil of peppermint or the flavor of the month added .

Automatic trans fluid is far better at preventing rust . There are fogging oils and products like Boeshield that leave a waxy film to protect and they work OK but may wind up gumming up the works , sticking up bearings etc . ..
Anyway, it seems no one can agree what is best. Every time someone recommends a product, someone else points out a downside! That's why I asked what's so special about this 'After-run oil' stuff - advertised as an essential/specialist product. Or is it just more marketing BS?

I'm new to IC (more or less), and yet to run one in an actual plane, so after a bit of bench running, I've squirted some Tesco scented 'WD-40' type of releasing oil down the plug hole and into the carb, and spun the prop a few times afterwards. I'm guessing neat castor will prevent rust well, but will gum up the works over time? WD-40 might be a bit 'dry' for the purpose, so I was thinking sewing machine oil or similar would do the job?

Out of interest, my 80-year old timer pal just pulled out his collection of vintage Mills/AMCO and DC diesels - after 40 years. They were dunked in paraffin (kerosene) and then stored in tied plastic bags for all this time - and they still work!

I just wish someone would come up with some definitive answers, rather than opinions/anecdotes - because I hate the stink of paraffin and WD-40 proper. It's nauseating.
FlyBoy20 is offline Find More Posts by FlyBoy20
Reply With Quote
Old Sep 21, 2014, 12:30 PM
Glow is Great !
Gary Cee's Avatar
United States, MI, Marysville
Joined Apr 2010
2,306 Posts
Yes , the ARO threads are numerous and hotly contested , some even insist it will destroy your engine . The typr of ARO chosen is another sub set argument . I have just offered up what the actual components of WD-40 type juice - brews . Also the fact that it does very little to protect .
How the ARO is applied and how you purge the fuel is every bit as important as the type of oil you choose .
Another fact : Tests for corrosion inhibiting properties have generally turned up ATF as high on the list .
Take from that what you will .


Diesel fuel is less reactive than glow / nitro fuel so the diesel anecdote may not fully apply to glow fueled engine storage .
If I intend to longterm store , a dis-assembly and complete cleaning is performed . That make the type of oil less critical . But watery , low oil content WD-40 would not get the nod here .

Some of us are a bit jaded by the discussion and 50 years experience is often discarded as "anecdotal " by newbies anyhow . Good luck .
Gary Cee is offline Find More Posts by Gary Cee
Reply With Quote
Old Sep 21, 2014, 01:12 PM
Registered User
Reginald's Avatar
Belgium
Joined Aug 2004
3,645 Posts
I have been collecting engines for more years than I care to remember and do have a few and I have been using this Castrol DWF for the last 20 years. This very thin oil does turn into some kind of vaseline after a while. The advantage of it is that there is no leaking of the engines in the glass cabinet. I must add that ALL the engines on display have been completely dismantled and ultrason cleaned first. I can take out any engine after some years and the engines do turn round completely free and never do feel dry. When storing the engines I do fly I use the same stuff. It all depends on where and how you store, in my case the whole garage and workshop is heated. I have recently used Shell turbine oil, as used in model turbines, this is of course much thicker oil, not cheap stuff but then you will never empty a complete thin within years to come. Like Gary says, little diesels are another matter with that kerosene used because kerosine is rather greasy. When cleaning delicate parts of our printing presses at the time we used white spirit mixed with kerosene. Never used 3-in-one so cannot comment. But like Gary says the discussions on the matter are endless and hopeless.
Reginald is offline Find More Posts by Reginald
Reply With Quote
Old Sep 21, 2014, 01:32 PM
Registered User
kimchiyuk's Avatar
United States, NY, Eldred
Joined Jun 2012
633 Posts
To the OP....just do a google search on "after run oil rc". You will be content for days.....after seeing the same threads over and over you just don't want to post the same info. It's all all of the rc sites.
kimchiyuk is offline Find More Posts by kimchiyuk
Reply With Quote
Old Sep 21, 2014, 09:09 PM
The Prez....... again
kenh3497's Avatar
United States, IA, Rockwell
Joined Jul 2011
4,051 Posts
My two favorite ARO's are plain old 30W engine oil and ATF. Never an issue with either protecting an engines innards. WD 40 and its lookalikes do not protect over the long term.

Ken
kenh3497 is offline Find More Posts by kenh3497
Reply With Quote
Old Sep 22, 2014, 01:05 AM
Registered User
Joined Jun 2011
1,529 Posts
I've been using WD-40 for years with no problem. There is a lot of misinformation about it going around. When I lived in San Diego I visited the plant that makes it and they showed me most of the BS that is posted about it.. Just for the heck of it about two years ago I disassembled a broken engine and cleaned it thoroughly then lubed with straight WD-40. After about a year I opened up and there was no damage at all and it was "oily" inside.
datsunguy is offline Find More Posts by datsunguy
Reply With Quote
Old Sep 22, 2014, 01:17 AM
Registered User
Joined Jun 2011
1,529 Posts
Here's just one page of dozens on WD-4- I picked the one about aluminum. There are zillions of uses and one of them is for ALUMINUM.

http://www.wd40.co.uk/uses-tips/uses...ps-garden.html
datsunguy is offline Find More Posts by datsunguy
Reply With Quote
Old Sep 22, 2014, 06:31 AM
Registered User
Cougar429's Avatar
Canada, ON, Windsor
Joined Apr 2008
1,019 Posts
Hoo Boy. Here we go again.

As stated prior, there have been countless threads from everyone in the "I've Been Doing This For So Long".

So, I guess I should add my own: Been rebuilding and storing engines for 3 decades and learned in one of my prior trades the uses for ATF. Mixed with Varsol it made the best penetrating oil I ever used-ON ANYTHING!!!! The Varsol would cut through layers of contamination and wick into the fused parts, the ATF following along to do the lubrication once the parts were broken loose.

Not specifically what you were requesting, but the long term benefits of ATF for alloy/ferrous protection are pretty much proven on every automatic, (and many manual) transmission vehicles on the road. You just need to use it correctly here to get those same effects.

That means trying to remove as much of the unburnt fuel at the end of the session as possible, as nitro and water vapor present in the air mix to form corrosive compounds so anything sitting in the case is a recipe that wants to go to work as soon as the engine cools down. Cleaning that out as much as possible limits what can start the process.

The usual method is to pinch the fuel line to the carb to stop the engine, but the key is to leave that line closed as fuel can siphon back into the carb and then into the case on 2 strokes if the carb is sitting even slightly open. On a 4-stroke you want to avoid tying the vent fitting for the case to the pressure fitting from the exhaust to the tank for many reasons, one is that it can provide a path for fuel to siphon back inside the crankcase.

On a final note, there is another example of oil protecting alloy/ferrous combinations I worked with every day in my aviation career, that of what is used in turbine engines. In this case the environment was generally under much higher RPM and thermal stress and temp extremes between off and running.

That highly refined turbine oil is generally found for us under the label of "Air Tool Oil" and I have been using my 50/50 mix of ATF and Air Tool Oil as an after run for more years than I can count.

Flyboy20, regardless of the many different stories, the long and short of it is you want something that will protect the engine during any length of sitting inactive, yet clear out shortly after firing it back up again. This is why you would avoid anything that creates a heavy binding layer such as gear oils or even LPS-3, (that one was designed and used for alloy protection and I use it to waterproof my electronics, but that's an argument for another day).

Datsunguy, would love to compare notes, but we were STRONGLY recommended against using WD-40 in the presence of synthetics, such as teflon. On an aside, we have that same warning for Loctite and plastics, so not that uncommon.
Cougar429 is offline Find More Posts by Cougar429
Reply With Quote
Old Sep 22, 2014, 08:06 AM
Glow is Great !
Gary Cee's Avatar
United States, MI, Marysville
Joined Apr 2010
2,306 Posts
Quote:
Originally Posted by Reginald View Post
I have been collecting engines for more years than I care to remember and do have a few and I have been using this Castrol DWF for the last 20 years. This very thin oil does turn into some kind of vaseline after a while. The advantage of it is that there is no leaking of the engines in the glass cabinet. I must add that ALL the engines on display have been completely dismantled and ultrason cleaned first. I can take out any engine after some years and the engines do turn round completely free and never do feel dry. When storing the engines I do fly I use the same stuff. It all depends on where and how you store, in my case the whole garage and workshop is heated. I have recently used Shell turbine oil, as used in model turbines, this is of course much thicker oil, not cheap stuff but then you will never empty a complete thin within years to come. Like Gary says, little diesels are another matter with that kerosene used because kerosine is rather greasy. When cleaning delicate parts of our printing presses at the time we used white spirit mixed with kerosene. Never used 3-in-one so cannot comment. But like Gary says the discussions on the matter are endless and hopeless.
Reginald ,
This is very similar to products like Boeshield and LPS made "TKX" protectants . It leaves behind a waxy film that feels like a light Cosmolene which is what the military has used for years to protect metal parts in harsh environments .

Since I ride motorcycles year round , TKX spray gets applied to the aluminum parts for corrosion protection and it works well . In fact it even smells like Cosmolene . Many years ago I had tried WD-40 and it seems the parts that were sprayed with that actually faired worse ! When I picked up a used Saturn a few years ago I made a little test where I sprayed half of the aluminum castings with WD-40 and left the rest bare . In the spring , the WD-40 sprayed area was discolored and had a chalky surface while the bare areaa were quite normal . Aluminum naturally protects itself to some degree by forming a layer of oxide that is quite hard . It seems that perhaps the light oil / mineral spirits/ surfactant combination actually may interfere with that formation .

ATF on the other hand is specifically blended to clean surfaces and prevent corrosion . ATF costs far less than magic potions and is readily available .
Gary Cee is offline Find More Posts by Gary Cee
Reply With Quote
Old Sep 22, 2014, 11:00 AM
Registered User
United States, TX, Weatherford
Joined Dec 2006
1,658 Posts
WD-40 is really a "water dispersant," a solvent. ATF is pretty good stuff. Almost any oil will work as an ARO. There are many preferences. Some is better than none. WD-40 tends to evaporate and has little long term benefits. Mobil 1 is good too but expensive in my mind.

I use a mixture of compressor oils (which tend to have no additives) and ATF. It will all burn off during the first run.

Daily use of Castor does not gum up anything. It takes some time to "gel," like over winter storage. It is a superior lubricant that mixes with both gasoline and alcohol. Not all oils will do that. Synthetic oils have a lower burn temperature and tend to be consumed by combustion in the alcohol engines. Castor's burn temperature is much higher and thus is not consumed but expelled during and after combustion. It also carries away heat, so you engine will run smoother and cooler when there is some Castor oil in the fuel. It basically gets slicker as it gets hotter. Yes, it will discolor the engine after a time due to being baked on so to speak and is a mess to clean up after flying. So it does have its down side but is the best lubricant for our alcohol engines around.
Chip01 is offline Find More Posts by Chip01
Reply With Quote
Old Sep 22, 2014, 02:32 PM
-insert witty saying here-
Hemikiller's Avatar
United States, CT, Killingworth
Joined Dec 2005
1,813 Posts
Quote:
Originally Posted by Gary Cee View Post
ATF on the other hand is specifically blended to clean surfaces and prevent corrosion . ATF costs far less than magic potions and is readily available .
Bingo..

After many years of working on cars, the inside of an automatic transmission ( that has not had a catastrophic failure or coolant ingestion) is usually spotlessly clean and rust free. ATF makes a great after run oil as long as you don't have an engine with silicone parts (eg: YS). For those engines, I use a synthetic air tool oil.

A quart of ATF can vary from $4 for Walmart brand to $7 for Mobil or Castrol and will last you a very long time.
Hemikiller is offline Find More Posts by Hemikiller
RCG Plus Member
Old Sep 23, 2014, 09:06 PM
Registered User
Joined Jun 2011
1,529 Posts
Quote:
Originally Posted by Chip01 View Post
WD-40 is really a "water dispersant," a solvent. ATF is pretty good stuff. Almost any oil will work as an ARO. There are many preferences. Some is better than none. WD-40 tends to evaporate and has little long term benefits. Mobil 1 is good too but expensive in my mind.

I use a mixture of compressor oils (which tend to have no additives) and ATF. It will all burn off during the first run.

Daily use of Castor does not gum up anything. It takes some time to "gel," like over winter storage. It is a superior lubricant that mixes with both gasoline and alcohol. Not all oils will do that. Synthetic oils have a lower burn temperature and tend to be consumed by combustion in the alcohol engines. Castor's burn temperature is much higher and thus is not consumed but expelled during and after combustion. It also carries away heat, so you engine will run smoother and cooler when there is some Castor oil in the fuel. It basically gets slicker as it gets hotter. Yes, it will discolor the engine after a time due to being baked on so to speak and is a mess to clean up after flying. So it does have its down side but is the best lubricant for our alcohol engines around.
YES, YES, YES. This post is 100% correct.
datsunguy is offline Find More Posts by datsunguy
Reply With Quote
Old Sep 23, 2014, 11:40 PM
Registered User
Joined Dec 2013
136 Posts
I use a 50 / 50 mix of a synthetic ATF and Full synthetic engine oil 5w-40... ATF is hygroscopic (attracts and absorbs moisture) and helps remove any moisture in the crankcase... for short term, all you need is several drops down the plug hole and down the carb or crank breather... for long term storage, I fill the crankcase and put a plastic bag over the engine with a zip tie or rubber band.

John M,
John_M_ is offline Find More Posts by John_M_
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion after run oil? tupeloflyer Fuel Plane Talk 23 Jan 12, 2014 02:56 AM
Sold Synthetic after run oil kylejclaflin Aircraft - Fuel - Engines and Accessories (FS/W) 0 Sep 18, 2013 11:02 AM
After Run Oil rabosr Fuel Plane Talk 22 Aug 11, 2010 10:00 AM
After run oil Mopar92 Engines 14 Feb 14, 2004 05:20 PM