Anti-seize on spark plug threads

It took a heli-coil to repair the damage.
That is not a easy repair in aircraft cylinders, most times the heli-coil is damaged beyond the repair limits. so a case saver is installed, this requires special tools, which required machining a new hole, and installing a special bushing.
I'm all my years I have never seen a spark plug stuck when the nickel anti-seize is used.
it will happen when copper anti-seize over temped.
 
Much of the argument here arise between pilot/owners who want to know stuff, and mechanics who do know the stuff. Some owners will dispute the aviation standard practices. Some mechanics will disagree with each other over stuff they've "always done that way." Some mechanics will keep using procedures that were obsoleted a long time ago by service bulletins, service letters or maintenance manual revisions. Some owners will insist that their way is the right way because they do it that way on their cars.

There is latitude in a lot of things. Some guys tighten sparkplugs for 40 years without a torque wrench and get away with it, while others will do that and overtorque the plugs repeatedly until the threads tear out of the head. Rare, but it happens. Sparkplug threads are big and somewhat forgiving. If they tighten 1/4" bolts and nuts without a wrench, overtorquing is far more likely, and bolts break. I've seen stretched and broken AN4 bolts on brake calipers. Had to very carefully remove a broken AN4 bolt out of the retract actuators in a 182RG. The threaded end was broken off below flush in the airframe casting, and if I couldn't get it out, half the airplane would have had to come apart to get that casting out. The airframe is built around it.

When it comes right down to it, a lot of pilots and owners just don't know how much there is to know when a mechanic studies and apprenctices for his ticket. It's like this:

View attachment 90938

I got my PPL in a few hours of study and flight, totalling maybe 100 hours. It took me a bit longer to get the commercial. The IFR and Instructor ratings took a while, too. Altogether there was less than maybe 15 months work. My Aircraft Maintenance Engineer ticket (Canadian A&P-IA) took me four years (7200 hours minimum) of apprenticeship and the equivalent of two years of study. A student pilot in Canada can solo at 14 years of age, hold the PPL at 17, Commercial at 18, but that AME ticket only goes to someone 21 or older. All that says something about the time it takes to acquire the skills and knowledge to be a mechanic.

Aviation is rewarding but terribly unforgiving. There is no place for flippancy in it, whether in flying or maintaining. It will kill you.

And with all of that, we get new better products all the time.
 
Since Lycoming says anti-seize or engine oil, which engine oil do you experts think works best?

That should keep you busy for awhile. :)
 
Since Lycoming says anti-seize or engine oil, which engine oil do you experts think works best?

That should keep you busy for awhile. :)
My opinion won't sway yours or Lycoming's, but I have found engine-oiled plugs hard to get out after they've been in there for too long in too much heat. Oil turns to a sticky varnish after a while and can make a plug harder to remove if the varnish gets hard enough. But that's just my opinion.
 
That is not a easy repair in aircraft cylinders, most times the heli-coil is damaged beyond the repair limits. so a case saver is installed, this requires special tools, which required machining a new hole, and installing a special bushing.
I'm all my years I have never seen a spark plug stuck when the nickel anti-seize is used.
it will happen when copper anti-seize over temped.
If the cylinder head gets so hot that the copper anti-seize is over temped, that engine has bigger problems than a spark plug change. Copper anti-seize is good to 1800 °F ;)

No reason not to follow the engine manufacturer's instructions.
 
Not too long ago I had a 1992 Nissan 240SX. I changed out the spark plugs and did not torque them. This was before I owned an airplane and a proper torque wrench--I did have a torsion bar torque wrench.

I started the car in the underground parking garage of where I was working. I heard a rhythmic psst-psst-psst, and while I was wondering WTF ... BANG! A pimple appeared in the hood. The engine starting shaking and shimmying like a twerking female popstar, and I shut her down. Popping the newly customized hood I found one of the spark plugs, laying loose, plug wire still attached, laying atop the engine.

It took a heli-coil to repair the damage.
I suspect the plug was probably just barely inserted and maybe engaged by one thread. Very unlikely that a merely un-torqued but fully screwed in plug would unscrew itself with the ignition wire still attached. Try it. I have seen plugs that were never wrench tightened at all and nothing much happened
 
Much of the argument here arise between pilot/owners who want to know stuff, and mechanics who do know the stuff. Some owners will dispute the aviation standard practices. Some mechanics will disagree with each other over stuff they've "always done that way." Some mechanics will keep using procedures that were obsoleted a long time ago by service bulletins, service letters or maintenance manual revisions. Some owners will insist that their way is the right way because they do it that way on their cars.

There is latitude in a lot of things. Some guys tighten sparkplugs for 40 years without a torque wrench and get away with it, while others will do that and overtorque the plugs repeatedly until the threads tear out of the head. Rare, but it happens. Sparkplug threads are big and somewhat forgiving. If they tighten 1/4" bolts and nuts without a wrench, overtorquing is far more likely, and bolts break. I've seen stretched and broken AN4 bolts on brake calipers. Had to very carefully remove a broken AN4 bolt out of the retract actuators in a 182RG. The threaded end was broken off below flush in the airframe casting, and if I couldn't get it out, half the airplane would have had to come apart to get that casting out. The airframe is built around it.

When it comes right down to it, a lot of pilots and owners just don't know how much there is to know when a mechanic studies and apprenctices for his ticket. It's like this:

View attachment 90938

I got my PPL in a few hours of study and flight, totalling maybe 100 hours. It took me a bit longer to get the commercial. The IFR and Instructor ratings took a while, too. Altogether there was less than maybe 15 months work. My Aircraft Maintenance Engineer ticket (Canadian A&P-IA) took me four years (7200 hours minimum) of apprenticeship and the equivalent of two years of study. A student pilot in Canada can solo at 14 years of age, hold the PPL at 17, Commercial at 18, but that AME ticket only goes to someone 21 or older. All that says something about the time it takes to acquire the skills and knowledge to be a mechanic.

Aviation is rewarding but terribly unforgiving. There is no place for flippancy in it, whether in flying or maintaining. It will kill you.
I prefer the onion layers description of knowledge. Each time you expand your knowledge to a larger ring, it takes more to expand it further, and you are aware of more of the gaps in your knowledge (the next ring)
 
I suspect the plug was probably just barely inserted and maybe engaged by one thread. Very unlikely that a merely un-torqued but fully screwed in plug would unscrew itself with the ignition wire still attached. Try it. I have seen plugs that were never wrench tightened at all and nothing much happened
The plug didn't unscrew itself. Read the post again. It took a helicoil to repair it because the aluminum threads were torn out by the plug as it was blown out. Overtorquing weakens the threads.
 
Did you simply forget to torque them, or did you not know you were supposed to torque them?
I never torqued my automobile spark plugs until I bought an airplane and bought a Snap-On torque wrench.
I suspect the plug was probably just barely inserted and maybe engaged by one thread. Very unlikely that a merely un-torqued but fully screwed in plug would unscrew itself with the ignition wire still attached. Try it. I have seen plugs that were never wrench tightened at all and nothing much happened
The plug didn't unscrew itself. Read the post again. It took a helicoil to repair it because the aluminum threads were torn out by the plug as it was blown out. Overtorquing weakens the threads.
The plug was fully screwed into the head. It may have only been finger tight or it was wrench tight but not torqued. The Nissan KA24DE engine is a dual overhead cam engine. As such the plugs are inserted vertically into a long tunnel in the valve/cam cover. My automotive SOP is to hold the plug in a spark plug socket with foam insert on an extension, and screw finger tight, then wrench tighten. I may have forgotten to wrench tighten. After the blowout, the head threads had play. I took that as a result of the loose plug vibrating against the aluminum thread and wearing them away.

The heli-coil was professionally installed.

On the plane I have ALWAYS torqued to spec and *GASP* used nickel-based anti-seize.
 
Overtorquing weakens the threads.
It's funny, some worry about a couple foot pounds of torque, when I'll wager that 90% of the torque wrenches never get calibrated.

or worry about the quality of the tools they use.

Yet there are those who are that anal retentive :)

Hmmmmm. When I install critical parts, I am very anal. Prop bolts, wing attach hardware, internal engine bolts. Spark plugs is one of them.
 
Hmmmmm. When I install critical parts, I am very anal. Prop bolts, wing attach hardware, internal engine bolts. Spark plugs is one of them.
Sometimes the margin between undertorqued and overtorqued is narrow. Too much torque and you crush the structure and/or overstress the fastener. Too little and the fastener will let the parts move relative to one another and cause damage. One of the bad places is the Cessna 180/185 and old 182 horizontal stab pivots under the stab's aft spar. Some mechanics think it's supposed to pivot on the bolt so they leave it a little loose. It's actually supposed to pivot on the bushing that the bolt is supposed to clamp between the structural bracketry. Leaving it loose lets the stab move the bolts and wallow out their holes in an area where there is no margin for any repair, so major, very expensive replacements result. Cessna has a torque spec right on the diagram in the manual.
 
So how bad is it if I installed my spark plugs on my O-200 with just measly Permatex Aluminum anti-seize (which contains aluminum and copper)? It is only good to 1600 degrees. But if my little engine ever gets close to that, I would be surprised.
 
So how bad is it if I installed my spark plugs on my O-200 with just measly Permatex Aluminum anti-seize (which contains aluminum and copper)? It is only good to 1600 degrees. But if my little engine ever gets close to that, I would be surprised.
I'm pretty sure that if you fly over a school for the handicapped children of personal injury attorneys your airplane will automatically go into a nose dive right into it.
 
I'm pretty sure that if you fly over a school for the handicapped children of personal injury attorneys your airplane will automatically go into a nose dive right into it.
That must be why the departure procedure for the airport where my mechanic is located says not to fly over the school just off the end of the runway. They must have heard that I was using sub-standard anti seize.
 
So how bad is it if I installed my spark plugs on my O-200 with just measly Permatex Aluminum anti-seize (which contains aluminum and copper)? It is only good to 1600 degrees. But if my little engine ever gets close to that, I would be surprised.

Like to live on the edge, don't you. :eek:
 
Hmmmmm. When I install critical parts, I am very anal. Prop bolts, wing attach hardware, internal engine bolts. Spark plugs is one of them.
That's you,, not every one is that way.
I see owners that are having trouble, not those who are not.
 
Some us are lucky and use auto spark plugs. We install reducing adapters into the heads and then spark plugs into the adapters. We torque the plugs to 18 lb/ft and the adapter is torqued by the spark plug. We never torque the adapters separately. Anti Seize is important.
 
That's you,, not every one is that way.
I see owners that are having trouble, not those who
Sacramento Skyranch Engineering Manual is a great resource to read up on the subject of torque.
 
"Dan Thomas said:
Torques specified for sparkplugs by Continental and Lycoming will be based on the presence of the anti-seize they specify."

YGTBSM, do you really think it makes a difference ?

No difference at all. It's the same with engine oil, it does not really lubricate (a fantasy of the over educated) and it's main purpose is cooling. I just use water, which cools better, in engines and save a bundle.

Usually the engines make a more exciting roaring sound than they do with oil in them which is an added benefit.
 
Sacramento Skyranch Engineering Manual is a great resource to read up on the subject of torque.
Right. but you haven't said how much different it makes between the two types of anti-seize

Real mechanics want to know :)
 
Right. but you haven't said how much different it makes between the two types of anti-seize

Real mechanics want to know :)

Sorry, Tom, I don't know.

But I do know that real mechanics are supposed to follow manufacturer's recommendations. Pretty sure I read that somewhere. When substitutions are made, you better be willing to back it up with more than fluffed up feathers and bs.

PS I do use nickle anti seize vs the copper. Meets the same mil spec. I also use a calibrated torque wrench. I re-use gaskets that are annealed (industry practice). Don't really care if the bevel is up or down as I haven't seen anything in print about that. I also test new plugs before install (seen a couple that failed at install, so a personal practice that is not contrary to recommendations).
 
Consider that anti seize specifications may not just be about temperature. They may also be about galvanic corrosion potential.
 
Consider that anti seize specifications may not just be about temperature. They may also be about galvanic corrosion potential.
If the spark plug is corroded in, there is some thing matter with your maintenance practices.
 
Not too long ago I had a 1992 Nissan 240SX. I changed out the spark plugs and did not torque them. This was before I owned an airplane and a proper torque wrench--I did have a torsion bar torque wrench.

I started the car in the underground parking garage of where I was working. I heard a rhythmic psst-psst-psst, and while I was wondering WTF ... BANG! A pimple appeared in the hood. The engine starting shaking and shimmying like a twerking female popstar, and I shut her down. Popping the newly customized hood I found one of the spark plugs, laying loose, plug wire still attached, laying atop the engine.

It took a heli-coil to repair the damage.
Clearly you had the gasket on backwards. Amateur.
 
Consider that anti seize specifications may not just be about temperature. They may also be about galvanic corrosion potential.
Like using the wrong anti-seize? :eek:
So how come nobody has complained about me just using the cheap aluminum Permatex anti seize yet? Can’t be worse for galvanic reaction than the copper (contains aluminum and copper, but less copper). I guess I am just so far off the deep end that it is a lost cause. I’ll let everyone know when my plugs all back out in flight.
 
I suppose the graphite spark plug thread lubricant marketed by Tempest is a no no..:)
 
I suppose the graphite spark plug thread lubricant marketed by Tempest is a no no..:)
I was just looking at something else that stated never to use graphite pencils on aluminum due to galvanic corrosion. So that is interesting as it seems that would go against that what I had recently read.
Here is an article that shows that graphite and aluminum do cause corrosion, but what exactly it means to airplanes, I have no idea.
http://www.electrochemsci.org/papers/vol6/6041085.pdf
 
Steel and aluminum are both anodic dissimilar metals which is a good reason to coat the threads with a barrier like copper or nickel. Copper is least anodic.
We used the graphite based anti seize for years until we switched to copper or nickel. I never had any issues that I recall.
 
Steel and aluminum are both anodic dissimilar metals which is a good reason to coat the threads with a barrier like copper or nickel. Copper is least anodic.
We used the graphite based anti seize for years until we switched to copper or nickel. I never had any issues that I recall.
So looking at this galvanic chart, steel and aluminum are very close to each other, while copper and aluminum are much farther away, with graphite being at the extreme far end from aluminum. What am I missing here? Copper and aluminum together will result in aluminum corroding. Graphite and aluminum is the worst combination possible.

https://images.app.goo.gl/D4CLXfB1pDtdL8BE8
 
So looking at this galvanic chart, steel and aluminum are very close to each other, while copper and aluminum are much farther away, with graphite being at the extreme far end from aluminum. What am I missing here? Copper and aluminum together will result in aluminum corroding. Graphite and aluminum is the worst combination possible.

https://images.app.goo.gl/D4CLXfB1pDtdL8BE8
Probably missing that the stuff is in some sort of grease, so there is nothing to carry the ions/electrons to close the electrical circuit. There shouldn't be much water from combustion getting up there.
 
Probably missing that the stuff is in some sort of grease, so there is nothing to carry the ions/electrons to close the electrical circuit. There shouldn't be much water from combustion getting up there.
Sure, just responding to @Doug Reid who stated that it was somehow better to coat the aluminum in copper to prevent corrosion from steel when in fact the copper would promote more corrosion than the steel itself.
 
Anyone seeing corrosion at spark
Plug threads from mfgr-recommended copper based anti seize? Yah, me either. The purists could use food grade anti seize. Parts of my Lycoming manual recommend it, but not for spark plugs.
 
Anyone seeing corrosion at spark
Plug threads from mfgr-recommended copper based anti seize? Yah, me either. The purists could use food grade anti seize. Parts of my Lycoming manual recommend it, but not for spark plugs.
My plugs that I just replaced were so old that they were super rusted just above the threads. Like not just surface rust but solid pitting 1/16” deep all over. Serious material loss on the spark plug body. The threads? No rust.
 
I always hesitate to post here on POA ... Ever heard of 2024 aluminum alloy ?..
Ok, so the copper won't corrode, the aluminum will. How does that help either the cylinder or your claim that copper works better? Please explain to me in more than one sentence why coating aluminum in copper would help prevent corrosion. We have already established that the anti seize is mainly protecting because of its oil-base. But you said that the copper would prevent corrosion - how?

http://www.electrochemsci.org/papers/vol6/6105052.pdf
Galvanic Corrosion of Aluminum Alloy (Al2024) and Copper in 1.0 M Nitric Acid
"ZRA result shows that aluminum is the sacrificial anode when coupled with copper in 1.0 M nitric acid solution."

Yes, this is in nitric acid, but often that is used to accelerate corrosion for the purpose of speed. If someone knows why nitric acid is not a good test, then I am happy to hear it.
 
I think you missed my entire point....I was pointing out that using antiseize was a good practice and that even when we used graphite based products, we never had issues . Most seem to prefer copper based...I use nickel or copper. ACS still sells graphite antiseize from Tempest.
 
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