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Rusty Dip Stick

Paris12Man

Paris12Man

Well Known Member
No pun intended:D......but I was very surprised to find a rusty dip stick today:mad:. I thought these would have been made from stainless steel. I've included a picture below and unfortunately I kind of cleaned it up a bit with my thumb. Have others experienced this. Steve

Rustydipstick002.jpg
 
Hey Steve - -

This is on a flying plane ? Was it rusty when installed ?

Condensation can come from your environment, or the oil not getting warm enough if a flying plane. ( I would assume this one ? ? )

John Bender
 
Muractic acid will do that...just the fumes in the area. Like if you were trying to etch a concrete floor...all the uncovered tools would rust. Should not have arrived like that...no.
 
A cause and a prevention

1. Cause. It's not that you don't get the engine warm enough, although that can contribute. Any time you operate an engine, a normal result of combustion is water vapor. You are oxidizing hydrogen. H2O. Some of that vapor blows past the rings and enters the crank case. There is always hot, humid air in the crankcase of a running IC 4-stroke engine. When the engine cools the air cools. When hot, humid air cools there is condensation. Getting the engine fully warmed up in operation does not and cannot prevent this.

2. Prevention. Get a dryer or build one yourself. There are various models and approaches that have been discussed in this forum. I suggest searching on dehydrator. Some, perhaps all, are highly effective. Aviation Consumer also did an article on them within the last two years, I think.
 
Your dip stick will get rusty if not used. :rolleyes:


Rotax "requires" having the oil temps reach 200F at least once a flight day. This is why the oil thermostat is so important ...... and now recommended by Rotax.

PM, look at the underside of your oil canister cap.
 
Stainless stick

This is not a flying airplane yet. I have only started the engine twice and warmed up the oil to around 140 degrees. If this issue is caused by condensation, why not build a dip stick out of stainless? That would be easy to do and remove the possibility of a rusty stick. The oil cap might still be an issue. Maybe chroming the cap?
 
Hey Steve - -

1. Was the stick rusty before first startup ?

2. Getting the oil up to 200 degrees or more takes the condensation out of the tank.

If answer one is no, you likely just had condensation from not getting it warm enough. In cool, or colder climates, you need a therm to help get the oil warm enough to take the condensation out.

John Bender
 
Clean

John, the dip stick was brand new and didn't have rust on it. I guess it was caused from my low temperatures and short engine runs. I think I will go ahead and make a dip stick out of stainless. Your thoughts?
 
Paris12Man said:
John, the dip stick was brand new and didn't have rust on it. I guess it was caused from my low temperatures and short engine runs. I think I will go ahead and make a dip stick out of stainless. Your thoughts?
Click to expand...

I am not John, but I drive by a Hoiliday Inn Express yesterday, and I am much better looking. ;)

The dip stick can be cleaned up with no problems, but that is really not the issue. The rust is a symptom of a bigger problem. The engine is not getting to recommended operating temps. The dip stick is like a canary in a mine. If you are getting enough mositure accumulating in the oil tank then you may have alot of moisture accumulating in the crank case. Getting the oil temps to the recommended 200F every flight day helps remove excess water. I have never had rust on the dip stick on any of the 912s I have owned because I follow the 200F rule.
 
Last edited:
hevansrv7a said:
1. Cause. It's not that you don't get the engine warm enough, although that can contribute. Any time you operate an engine, a normal result of combustion is water vapor. You are oxidizing hydrogen. H2O. Some of that vapor blows past the rings and enters the crank case. There is always hot, humid air in the crankcase of a running IC 4-stroke engine. When the engine cools the air cools. When hot, humid air cools there is condensation. Getting the engine fully warmed up in operation does not and cannot prevent this.

2. Prevention. Get a dryer or build one yourself. There are various models and approaches that have been discussed in this forum. I suggest searching on dehydrator. Some, perhaps all, are highly effective. Aviation Consumer also did an article on them within the last two years, I think.
Click to expand...

I was stunned to find out that a gallon of gasoline burned in an engine produces over a gallon of water. Pretty amazing to me anyway.
 
Geico266 said:
I was stunned to find out that a gallon of gasoline burned in an engine produces over a gallon of water. Pretty amazing to me anyway.
Click to expand...

It seems counter-intuitive at first, but it makes a lot of sense when you think about it. The water is produced via combustion by combining Oxygen from the atmosphere with Hydrogen from the fuel! So, of the gallon of water, only 2/18ths (by mass) actually came from the fuel! The rest came from the atmosphere.
 
200 degree rule

Thanks guys, I will try to follow the 200 degree rule in the future. Unfortunately, the last engine run I developed a serious fuel leak from the carburetor and the engine test was cut short. That was about two weeks ago and I haven't been able to run it since. Thanks for all the info....:)
 
Hey Steve - -

GEICO

I am not John, but I drive by a Hoiliday Inn Express yesterday, and I am much better looking.

-----------------------------------------------------------------------

Steve - his wife's opinion varies a tich ! ! ! ! Larry's statements are at least as good as a politician's ! ! ! ( don't worry - I'll pay ! ! ) H A !

John Bender
 
If you do a short ground run on the Rotax motor and then after shutdown lift off the oil tank cap you will find water droplets on the inside of the cap and on the dipstick. I would wipe this all dry and then either replace the cap or leave it off so water vapor in the top of the tank can evaporate. I also have had air cooled Porsches which have an oil tank feeding a dry sump (12 quart!) lubrication system. I find condensed water in the top of the Porsche tank similar to what occurs in the Rotax tank. In winter it is very difficult to get a Porsche up to 200° unless you want to be incarcerated. The nice thing about the airplane engine is that you can run it as hard as you want without risk of being arrested and even in cold weather a full power climb will get the oil temperature up high enough to dry out the water vapor.
I have found flying the 12 here in WA even in the winter that the oil tank will be devoid of any condensation when I remove the cap after a flight. The only ground runs I do now are if it is necessary to sync the carbs or some other maintenance reason. Then I find condensed water in the top of the tank. I wipe this out with a paper towel and have not had any rust form on the cap or dipstick. Or better yet, after a ground run, go for a ride :D

Tony
 
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