After run oils

What a lot of people don't understand is that WD-40 isn't a necessarily a lubricant, and definitely not a preserver. It's a penetrating solvent meant to break down oils and reduce friction between metals in the short term. With that said, I have used it to successfully free a couple seized engines by letting some sit in the cylinder overnight, but it was thoroughly flushed with alcohol afterwards. I never have understood 3 in 1. It's marketed as an all-purpose lubricant but as Ken said, gradually congeals and solidifies. Unlike Castor, it thickens up when heated which can be problematic while starting engines out of storage.

For lubrication I have used air tool oil as well as Norvey "turbine" oil in the convenient Zoom Spout bottle. The engines I lubed two years ago are still completely free. Sealing them from oxygen in a ziploc bag is a good idea.

I have been using 10w hydraulic oil like for my log splitter , has been working fine for me if anything I have seen it dry up some what after a yr. or two , but not gum up. That castor oil sounds good as I use that in my truck engine. Next oil change in the Farmall 140 will be castor . Eric

I am using this from COX Int'l and have no reasons to complain...

http://coxengines.ca/coxlube-after-run-oil.html

I've used both air tool oil, and light sewing machine oil. Both worked great for me.

The Oily Mark

Yes, 3in1 was probably not the best choice, but it was handy and I just wanted it for short term storage and wear protection. I do have air tool oil but never thought to use it.

When My bottle of Prather is gone I will look to CI for replacement.

In my opinion, if you are regularly flying, say weekly, after run oil is extra expense that is not necessary, particularly with bushed engines. There is enough protection from the oil in the fuel for much longer than a week even. Eventually the castor will start congealing because it is an organic oil and is an organic oil that has been cooked.

Now, if you fly less frequently, or are putting things up for the off season then some suitable, persistent, low viscosity oil that will displace much of the castor, partially burnt fuel and oil, and moisture will be beneficial. Prevention of rust and prevention of gum is important. After a few months, or years, a properly stored engine will be as ready to run as it was when put away.

Phil

I agree with Phil, I don't bother with after run. The only ones that get that treatment are the ones in storage.

I got a quart of airtool oil at the auto parts store for 5 or 6 bucks. I have a small container of Singer sewing machine oil in my flight box for field use. I used to rotate my planes from hanging with a rope by the spinner backplate to the tail, just to move the oil around. But after finding some profile fuselages' stabs slightly out of line with the wing TE, I quit hanging them by the tail.
Rusty

One more opinion: How much you need after-run oil somewhat depends on what you are flying.
If you fly CL or FF you generally run the engine dry. At the end of a flying session, I like to connect the booster and flip the engine and run off any residual fuel in the crankcase.
If you fly RC and throttle back at the end of a flight you may still have fuel in the crankcase. Make sure you run off any fuel in the crankcase here also.
Glow fuel left in the crankcase can cause rust quickly. Unburned alcohol will gather moisture and unburned nitro can form nitric acid.
The WD in WD-40 means "water displacement" so lubrication is not its strong suit. It will provide short term after-run protection, however.
I prefer Air tool oil or Rislone for storage. BTW, a Marvel rep replied online once that Marvel Air Tool Oil is MMO with additional rust inhibitors.
My personal experience with 3-in-1 is that it disappears over time...don't know why.
And again, these are my opinions. Individual results may vary. :-)

George

Hi Guys,
The Prather after run oil is excellent but inefficiant cost wise, once you know what's in it.
Henry Nelson recommends using ATF (Auto Transmission Fluid) (much better cost wise effecient)

The multi-time AMA Nats speed champ & multi AMA speed record holder Gerry Rocha uses Mobil Jet II in his engines AND TANKS. He says it great.
Working in the Industtry, Mobil Jet II is the preferred turbine oil for many airlines for use in all their engines, starters & aux. power units. Perhaps there's a reason for that...
Notable former 1/2A record holder Greg Settle has found 1/2 of 1 % MJ-II added to his glow fuel reduces cylinder head temp by 50 degrees...
The NEGATIVE w/ MJ-II is that it contains a toxic additive ( Tricresyl Phosphate) which stains paint & is not advised to be handled with hands.

I ran out of Prather oil a year ago & now I personally use ATF. I expect my quart to last indefinatly... Food for thought.

Cheers, Paul