Aileron Lube

brien23

brien23

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Brien
What is the best Aileron, Elevator or Rudder lube. What sticks best and does not wash off the first rain that gets on it. Marine grade oil, chain saw bar lube, thick oil, anybody got a good lube that might last more than a day.
 
The maintenance manual will specify what the manufacturer wants. Cessna wants a MIL-spec oil in some, and dry graphite in the aileron hinges (piano-hinge type hinge). I frequently encounter worn aileron hinges that have been faithfully oiled so that dust gets in there and sticks and grinds that thin aluminum hinge all to bits. The elevator and rudder bearings get greased on assembly, and a bit of the MIL-spec oil in them (one drop or maybe two) will keep them free.

Getting dry graphite into a piano hinge is fun. I mix some with a bit of brake cleaner fluid and drop it on with a syringe. It wicks in, the brake cleaner dries up, and the graphite is where it needs to be.

Some guys spritz everything with LPS. The problem with spray cans is that they shoot about 20 times as much lube as is needed, and most of it goes onto everything but where it needs to be, and it just gums up and makes a mess. Flap rollers are a prime example. And flap microswitches suffer from being polluted with it, too. Cheap syringes from the druggist are handy for precision lubrication. Stick an old LPS or WD-40 plastic tube in the syringe to get into tiny places.
 
Dan Thomas said:
Getting dry graphite into a piano hinge is fun. I mix some with a bit of brake cleaner fluid and drop it on with a syringe. It wicks in, the brake cleaner dries up, and the graphite is where it needs to be.
Click to expand...

Great idea, I will try that.
 
brien23 said:
What is the best Aileron, Elevator or Rudder lube. What sticks best and does not wash off the first rain that gets on it. Marine grade oil, chain saw bar lube, thick oil, anybody got a good lube that might last more than a day.
Click to expand...
brien:
Another option is LPS 3. It's marketed as a corrosion inhibitor but we used it as a lubricant in similar areas on helicopters. It's basically a wax-based mineral oil that sticks and lasts. We had tried graphite, silicon, anti-seize, etc but these washed out between inspections. LPS 3 made it to each inspection and normally didn't need retouch unless it was in an area that was washed daily to remove salt residue from the airframe.
 
Dan Thomas said:
The problem with spray cans is that they shoot about 20 times as much lube as is needed, and most of it goes onto everything but where it needs to be, and it just gums up and makes a mess.
Click to expand...

That is just operator error. Spray cans are, by far, the best method.
 
GlennAB1 said:
Warming your piano hinge pin decreases clearances and increases friction.
Click to expand...

Depending on how worn the “hinge” is where the “pin” is going, he might consider that a plus...

Wait, are we still talking about airplanes?
 
Why do you believe Cessna used a bronze bushing as a bearing in these hinges?
 
I have always wondered about that section in AC43.13-1B which states graphite, esp dry "graphite should never be used as a lubricant for any component", `then discusses galvanic corrosion in the presence of any moisture. I think even one Cessna Svc Manual contradicts that. (I am not asking which document is controlling, I am wondering why the FAA could be so adamant about it, then a manufacturer says it's ok)
 
Bell206 said:
brien:
Another option is LPS 3. It's marketed as a corrosion inhibitor but we used it as a lubricant in similar areas on helicopters. It's basically a wax-based mineral oil that sticks and lasts. We had tried graphite, silicon, anti-seize, etc but these washed out between inspections. LPS 3 made it to each inspection and normally didn't need retouch unless it was in an area that was washed daily to remove salt residue from the airframe.
Click to expand...
Big fan of LPS products.
 
Let'sgoflying! said:
I have always wondered about that section in AC43.13-1B which states graphite, esp dry "graphite should never be used as a lubricant for any component", `then discusses galvanic corrosion in the presence of any moisture. I think even one Cessna Svc Manual contradicts that. (I am not asking which document is controlling, I am wondering why the FAA could be so adamant about it, then a manufacturer says it's ok)
Click to expand...
Let's:
The main reason for the AC note on graphite is that it is a great electrical conductor when mixed with water and provides an excellent path for the dissimilar metal corrosion. As I was told, back in the day graphite was the go to dry lube, but was often field substituted as it was cheaper than grease and oil. Thus more corrosion. Moly coat products have basically replaced straight graphite products, but graphite still has it's uses which is why you see OEMs still use it. There are even moly coat compounds that include graphite.
 
So it's still a good idea to avoid graphite powder on exposed hinges like aileron hinges because of the corrosion potential?
 
Let'sgoflying! said:
So it's still a good idea to avoid graphite powder on exposed hinges like aileron hinges because of the corrosion potential?
Click to expand...

Personally, I wouldn't use graphite as a lubricant unless it was a choice of last resort or specifically required due to system contamination issues. The selection of todays lubricants excel beyond graphite especially on the dry side. Molybdenum disulfide (MoS2) would be my choice to replace graphite or if you want to go top self Tungsten Disulfide (WS2) which I believe is the slickest sh*t out there. So my answer to your question would be no, but not for corrosion issues rather performance issues. I would use a LPS product on all hinges.
 
Tom-D said:
Simply follow the 25 hour inspection routine in the Cessna 100 maintenance manual.
Click to expand...

"Simply"?

Even though the SM specifically calls out powdered graphite for aileron hinges (fig 2-4 in your link); in direct contradiction to what AC43.13-1B Ch6 says?

Remember, we are not discussing which document is controlling here nor any legal aspect of it. This is about "is powdered graphite truly a good idea on exposed hinges or is it actually going to cause corrosion".
 
Let'sgoflying! said:
This is about "is powdered graphite truly a good idea on exposed hinges or is it actually going to cause corrosion".
Click to expand...
Really? in all the years this manual has been out why haven't we seen an update, if corrosion has been a problem? (or was that the question)

Aileron hinge-- simple piano hinge stainless pin and cast aluminum hinge.
How would you get powdered graphite in where it could lubricate?
 
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Let'sgoflying! said:
"Simply"?

Even though the SM specifically calls out powdered graphite for aileron hinges (fig 2-4 in your link); in direct contradiction to what AC43.13-1B Ch6 says?

Remember, we are not discussing which document is controlling here nor any legal aspect of it. This is about "is powdered graphite truly a good idea on exposed hinges or is it actually going to cause corrosion".
Click to expand...

While the science says graphite will cause corrosion, in your specific example, I doubt it as the water/graphite mix wouldn't stay in the hinge long enough to corrode since graphite has no useful adhesive qualities. Which is why Cessna probably didn't see a problem with it, especially if it is on a 25hr lube schedule. For galvanic/dissimilar metal corrosion to set in it can take considerable time with basically undisturbed conditions which your hinge environment does not provide.
 
Let'sgoflying! said:
I have always wondered about that section in AC43.13-1B which states graphite, esp dry "graphite should never be used as a lubricant for any component", `then discusses galvanic corrosion in the presence of any moisture. I think even one Cessna Svc Manual contradicts that. (I am not asking which document is controlling, I am wondering why the FAA could be so adamant about it, then a manufacturer says it's ok)
Click to expand...

Read Paragraphs 1 and 3 of the AC, see how adamant the FAA is about the use of the AC when it conflicts with the manufacturers data.
 
Bell206 said:
While the science says graphite will cause corrosion, in your specific example, I doubt it as the water/graphite mix wouldn't stay in the hinge long enough to corrode since graphite has no useful adhesive qualities. Which is why Cessna probably didn't see a problem with it, especially if it is on a 25hr lube schedule. For galvanic/dissimilar metal corrosion to set in it can take considerable time with basically undisturbed conditions which your hinge environment does not provide.
Click to expand...
This is a syndrome that is good in theory but not in reality. because it is so seldom used.

the only part of a aileron hinge I see corroded is the cheap little $.03c cotter key thru the end of the hinge pin.
 
Tom-D said:
This is a syndrome that is good in theory but not in reality. because it is so seldom used.
Click to expand...

I agree. But I guess way back graphite was used a lot on the cheap, in places it shouldn't have been. Years ago we took apart 4 Stearman frames that had been dusters: metalized sides; stainless fittings and mounts, etc. Every bolt had to be cut off. I figured it was from the chemical salts except a couple of the old timers pointed out it was from using graphite on the hardware. I guess it worked fine pulling the bolts yearly but not after 40 years sitting on their firewalls under a leaky roof.
 
Tom-D said:
This is a syndrome that is good in theory but not in reality. because it is so seldom used.

the only part of a aileron hinge I see corroded is the cheap little $.03c cotter key thru the end of the hinge pin.
Click to expand...
And if you used a $.10 it wouldn't be corroded.

DGF is call out for by manufacturers of commercial jets and jet engines. 757 engine fan blades are routinely removed, "lubricated" with DGF, and reinstalled.
 
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Bell206 said:
Personally, I wouldn't use graphite as a lubricant unless it was a choice of last resort or specifically required due to system contamination issues. The selection of todays lubricants excel beyond graphite especially on the dry side. Molybdenum disulfide (MoS2) would be my choice to replace graphite or if you want to go top self Tungsten Disulfide (WS2) which I believe is the slickest sh*t out there. So my answer to your question would be no, but not for corrosion issues rather performance issues. I would use a LPS product on all hinges.
Click to expand...
I think this is the definitive answer to the OP. Consider also that the Cessna or Piper engineers back many decades ago did not have access to the quality of synthetic products that we have today. Likely they were also part of a "group think" environment - if the engineering manager had an idea about the best lubrication method based on his experience in 1940, that became the standard. I have been a long time user of LPS products - they are proven products based on years of use in my shop.
 
Dan Thomas said:
The maintenance manual will specify what the manufacturer wants. Cessna wants a MIL-spec oil in some, and dry graphite in the aileron hinges (piano-hinge type hinge). I frequently encounter worn aileron hinges that have been faithfully oiled so that dust gets in there and sticks and grinds that thin aluminum hinge all to bits. The elevator and rudder bearings get greased on assembly, and a bit of the MIL-spec oil in them (one drop or maybe two) will keep them free.

Getting dry graphite into a piano hinge is fun. I mix some with a bit of brake cleaner fluid and drop it on with a syringe. It wicks in, the brake cleaner dries up, and the graphite is where it needs to be.

Some guys spritz everything with LPS. The problem with spray cans is that they shoot about 20 times as much lube as is needed, and most of it goes onto everything but where it needs to be, and it just gums up and makes a mess. Flap rollers are a prime example. And flap microswitches suffer from being polluted with it, too. Cheap syringes from the druggist are handy for precision lubrication. Stick an old LPS or WD-40 plastic tube in the syringe to get into tiny places.
Click to expand...

Yes, this is what I do every week. A syringe filled with 7870/aeroshell 3 with a spray straw inserted in the end. Directs the proper lube towards the proper spot without the shot gun spray approach. If a plane is washed often or is outside in the rain lots, an extra bit of lubingisn't a bad thing.
 
GlennAB1 said:
And if you used a $.10 it wouldn't be corroded.

DGF is call out for by manufacturers of commercial jets and jet engines. 757 engine fan blades are routinely removed, "lubricated" with DGF, and reinstalled.
Click to expand...

DGF is what?

Aren't those Rolls Royce engines? The brits have some interesting items in their manuals. "Offer the prop to the engine!"!!
 
Dry Graphite Film

757's come with Rolls or Pratt.

Yes they do.

Offer the prop up to the engine :(

Rod end twizzle.
 
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I avoided this thread for a long time. Couldn’t bring myself to open any thread about lube on PoA. Haha.

Wasn’t quite as bad as I thought.
 
Rob58 said:
I think this is the definitive answer to the OP. Consider also that the Cessna or Piper engineers back many decades ago did not have access to the quality of synthetic products that we have today. Likely they were also part of a "group think" environment - if the engineering manager had an idea about the best lubrication method based on his experience in 1940, that became the standard. I have been a long time user of LPS products - they are proven products based on years of use in my shop.
Click to expand...

Got to work this morning. Fired up the Cessna maintenance manuals, online versions, constantly updated. And for the '96 and on singles, right up to the present, they specify dry graphite for aileron piano hinges.

Cessna is pretty thorough about demanding changes in maintenance when they see a need for it. Lawsuits tend to do that. They have a long list of SIDs to prove it. If dry graphite, or "powdered graphite," as they call it, was inferior or causing corrosion, we'd have seen changes by now. I see them regularly in other areas.
 
JAWS said:
Aren't those Rolls Royce engines? The brits have some interesting items in their manuals. "Offer the prop to the engine!"!!
Click to expand...
And they know what "SWARF" is.
 
the only part of a aileron hinge I see corroded is the cheap little $.03c cotter key thru the end of the hinge pin.
Click to expand...
INTERESTING- I bet the cotter pin's plating is acting as a sacrificial anode.

BTW, I used to love LPS-3 for the superior corrosion protection it provided for bare steel parts; however the spray cans kept clogging and I was throwing away half filled cans. LPS-2 is somewhat thinner and works nearly as well without problems. OR you can buy gallon jugs of LPS-3, but...
 
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