Spark plug anti seize question.

Gary Ward

Gary Ward

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Is the black liquid anti seize the best lube to use on plugs? Is there anything else that can be used to offer a little more lube. Every time I remove plugs I think they could use a little more lube. They are very dry and even a little rusty I think when I take them out. I used the black aviation anti seize and nothing else when I put them in.
I am so tempted to add a drop of oil but wanted to get some opinions on what is best.
I read the bottle and it says to shake well and that there is ball inside to assist in mixing it but I don't think there is a ball inside mine? It is so thin and it just don't seem to offer much lube. Maybe lube is not what we need? I do understand we want good electrical contact.

Got some hrs on these plugs, 122 since last time I cleaned them. One or 2 almost seemed like the threads were rusty. I checked the gaps on all of them and they are over 22 on a couple of them. So I am glad I swapped them as they were running good with no issues but I knew they were over a 100 hrs since last cleaning and re-gapping.
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I use the silver automotive stuff and all my A&P said was to use it sparingly. It’s nice and greasy. I get it everywhere no matter how careful I am, lol.

Do you have a picture of the stuff you use? Am I doing it wrong? Is my A&P a bad dude? o_O
 
455 Bravo Uniform said:
I use the silver automotive stuff and all my A&P said was to use it sparingly. It’s nice and greasy. I get it everywhere no matter how careful I am, lol.

Do you have a picture of the stuff you use? Am I doing it wrong? Is my A&P a bad dude? o_O
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I also use the Permatex anti-seize that comes in the tube, based on the recommendation of my A&P/IA. I am careful to keep it away from the electrode end of the spark plug - none applied to the last thread, and use it sparingly. I haven't had any issues in 23 years using it this way.
 
Lon Stratton said:
I used to use that same stuff until my mechanic mentioned how much he hated it. He uses this stuff....

View attachment 126962
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That is what I used on race car plugs that used a magneto for an ignition. I also use it on the slip joints on my exhaust. Like said use it sparingly on plugs.
I was under the impression only the black stuff should be used in aviation? It is in my picture above. I have 2 bottles of it with different names on the bottle and both are the same stuff. Watery black stuff.
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My bottles said "Champion". Same stuff. Notice it also says "Do not freeze" on the black stuff bottles.
 
Lon Stratton said:
My bottles said "Champion". Same stuff. Notice it also says "Do not freeze" on the black stuff bottles.
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Yes I did, what happens if it freezes?
I think one of mine might have froze a couple years ago? Now I keep it in this hot box during the winter.
IMG_4114.JPG
 
Gary Ward said:
That is what I used on race car plugs that used a magneto for an ignition. I also use it on the slip joints on my exhaust. Like said use it sparingly. I was under the impression only the black stuff should be used in aviation? It is in my picture above. I have 2 bottles of it with different names on the bottle and both are the same stuff. Watery black stuff.
IMG_4111.JPG
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I’ve used that for years with no issues. I paint it on the threads sparingly all the way around.
 
Lycoming moved away from the graphite based (the black stuff) and now wants the copper based anti-seize. “Use a copper-based anti-seize compound or engine oil on spark plug threads starting two full threads from the electrode, but DO NOT use a graphite-based compound.” See SI 1042AH. Continental says to use the plug manufacturers recommended anti-seize.
 
Ryan Klems said:
Lycoming moved away from the graphite based (the black stuff) and now wants the copper based anti-seize. “Use a copper-based anti-seize compound or engine oil on spark plug threads starting two full threads from the electrode, but DO NOT use a graphite-based compound.” See SI 1042AH. Continental says to use the plug manufacturers recommended anti-seize.
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Thanks for the link and education. Very valuable Thanks again..Glad I asked before sticking these next 8 plugs in.
I will start using the copper anti seize, like meeting an old friend again as I replaced 16 plugs every run in a dual plug hemi in the early days.
 
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Would the graphite based spark plug anti seize be good to use on aileron hinges on a cessna?
 
I use the Nickel...and very sparingly.
But had a mechanic just tell me last month to quit using any altogether. He gave a reason or two, but I don't remember exactly what he said, other than if you take the plugs out fairly regularly, which you should be doing, you won't have any issues.
Now I have mixed thoughts.

I think..
 
Gary Ward said:
Would the graphite based spark plug anti seize be good to use on aileron hinges on a cessna?
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Graphite based lubricants have a problem in unconditioned air. They will absorb slight amounts of water, tend to clump and will hold any dirt that gets to them. Additionally, under the right conditions and against the right materials, graphite acts as an abrasive. On the F-16, the only thing that gets a lube that contains graphite is the ground power plug. The pins get a very light dusting of graphite powder.

Copper or nickle anti-seize works for spark plugs. Lightly apply to the 2nd or 3rd thread from the electrode end and thread them in. You should only need to reapply if you chemically wash the plug, or after pulling them 3-4 times. Remember to torque according to the engine books. IF the book specifies a dry torque, you need to go lower with anti-seize applied.
 
I've tried the thin, liquid black stuff and the silver paste in the tube. Tossed the black stuff and for decades have exclusively used the silver paste.
 
I fly an experimental. When I used the stock auto plugs in my engine I would sometimes get rust on the plugs. I now use iridium spark plugs and they have a nickel plating to prevent corrosion. I still use a light touch of Permatex anti-seize on the threads (keeping away from the electrode end). Available at AS:

1711031788239.png
 
Skyrys62 said:
I use the Nickel...and very sparingly.
But had a mechanic just tell me last month to quit using any altogether. He gave a reason or two, but I don't remember exactly what he said, other than if you take the plugs out fairly regularly, which you should be doing, you won't have any issues.
Now I have mixed thoughts.

I think..
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There was an article in the EAA magazine a few years ago that advocated not using anti-seize, stating that it interferes with heat transfer from the spark plug body to the cylinder head. IIRC, the author was a Rotax specialist and was referring to that line of engines in particular.

If Lycoming and Continental recommend anti-seize, I’d go with what they say. They wouldn’t have put it in there without a reason, or if it caused problems.
 
As usual, lots of opinions here. Champion's sparkplug manuals used to tell you not to use graphite compounds on those threads, and at the same time they were selling you that black stuff that is, according to the MSDS, between 10 and 30% graphite:
1711039411940.png

So, based on their warning not to use graphite, many mechanics use Permatex Anti-Seize, which contains aluminum, and the MSDS for that says:
1711039481064.png
And some use Copper anti-seize:
1711039641624.png
And others use Nickel anti-seize, which has no graphite:
1711039736102.png

I have used them all, but prefer the Champion stuff. It doesn't have the metals and minerals that tend to accumulate in the port threads in the head after repeated removals and reinstallations.

I could always tell when some mechanic was using oil instead of any anti-seize. Those plugs were tough to get out. The oil turns to a hardened gum and acts like a threadlocker. That head gets awfully hot. Don't do that.
 
Were they not pushing the black liquid because they knew you'd knock it over at some point, (spilling that hard-to-remove octopus ink everywhere), then have to buy more - which was good for sales?
The switch to paste-type is a bad marketing move.
 
Dan Thomas said:
As usual, lots of opinions here. Champion's sparkplug manuals used to tell you not to use graphite compounds on those threads, and at the same time they were selling you that black stuff that is, according to the MSDS, between 10 and 30% graphite:
View attachment 126977

So, based on their warning not to use graphite, many mechanics use Permatex Anti-Seize, which contains aluminum, and the MSDS for that says:
View attachment 126978
And some use Copper anti-seize:
View attachment 126979
And others use Nickel anti-seize, which has no graphite:
View attachment 126980
O
I have used them all, but prefer the Champion stuff. It doesn't have the metals and minerals that tend to accumulate in the port threads in the head after repeated removals and reinstallations.

I could always tell when some mechanic was using oil instead of any anti-seize. Those plugs were tough to get out. The oil turns to a hardened gum and acts like a threadlocker. That head gets awfully hot. Don't do that.
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So you mean the Champion black stuff like I have been using?

When I was racing MSD ignition warned us not to use aluminum silver anti seize on our spark plug because it acted as an insulator and you want good electrical contact.We were running huge magnetos.
So they advised to use very little copper anti seize I guess because it conducts electricity a little better?

So you would keep using the black stuff? TIA
 
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Let'sgoflying! said:
Were they not pushing the black liquid because they knew you'd knock it over at some point, (spilling that hard-to-remove octopus ink everywhere), then have to buy more - which was good for sales?
The switch to paste-type is a bad marketing move.
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lol I think this is why I have 2 bottles, one was spilled! lol
 
I need 2 spark plug racks, wasn’t gonna buy another. Found a 4x4 in my buddy’s hangar last night and cut off 8” of it.
Today it is a spark plug rack.

IMG_4149.jpegIMG_4150.jpeg
Not the first one I made…

IMG_4151.jpeg
 
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Gary Ward said:
So you would keep using the black stuff? TIA
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Yup. The plug grounds through the gasket and plug flange anyway. They must not be lubed with anti seize, or the plug is easily over tightened or could come loose more easily.

A spark is measured in microamps. It takes plenty of resistance to foul it up. After all, the plug's internal resistance can be as high as 5000 ohms and still be serviceable.
 
Dan Thomas said:
Yup. The plug grounds through the gasket and plug flange anyway. They must not be lubed with anti seize, or the plug is easily over tightened or could come loose more easily.

A spark is measured in microamps. It takes plenty of resistance to foul it up. After all, the plug's internal resistance can be as high as 5000 ohms and still be serviceable.
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Thanks I trust your judgment and will stick to my original game plan using the black stuff.
Thanks for responding because I just got to the hangar and plan to put the fresh plugs back in in a few minutes so I can fly tonight.
First day in 5 days that the wind has settled down. I was driving out here thinking I got to make a decision soon.

Remember that the sm says to use graphite on the aileron hinges?
Think that black stuff would be good for that?
 
Gary Ward said:
Remember that the sm says to use graphite on the aileron hinges?
Think that black stuff would be good for that?
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Not really. Not runny enough. I used to mix dry graphite powder with some non-chlorinated brake cleaner, and using a disposable syringe, wicked it into the hinges. It goes way in there and the brake cleaner dries and leaves it there.
 
Dan Thomas said:
Not really. Not runny enough. I used to mix dry graphite powder with some non-chlorinated brake cleaner, and using a disposable syringe, wicked it into the hinges. It goes way in there and the brake cleaner dries and leaves it there.
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Thanks
Just finished putting the plugs in and cowls on, time to fly.
I do appreciate everyone’s thoughts on this, thanks for posting.
 
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I haven’t used any for years? Works just fine for 1000’s of hours.
 
Dan Thomas said:
A spark is measured in microamps.
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How do you figure that? My simplistic calculation: If primary current is two amps and coil turns ratio is 100, then secondary current would be 2/100 amps or 20 milliamps.
 
flyingbrit said:
How do you figure that? My simplistic calculation: If primary current is two amps and coil turns ratio is 100, then secondary current would be 2/100 amps or 20 milliamps.
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If, in a car, the coil ratio was 100:1 and the voltage was 14 volts, we'd get a 1400-volt spark, which would do nothing at all for ignition. We need 20,000 volts or so.

The magneto will put out maybe 12K volts when starting, maybe 20K running. From the Slick L-1363J magneto manual:
1711121375944.png

Again, from the Slick mag manual:

1711121302831.png

From those resistances we can get an idea of the ratio between the primary and secondary:

13,000/0.50 = 26000:1
20,500/1.2 = 17083:1

If we took the extreme, with 20,500/.5, we'd get 41,000:1.

You can see that it's far, far beyond 100:1. If we took your 2-amp guess, and used the middle-range 26,000:1 number, we'd end up with 2/26000 = .000077 amps. That's 77 microamps. Now, the current in the mag is likely higher than two amps, but even if it was, say, 7 amps, we'd still only see .00027 amps, or 270 microamps, much less than a milliamp.

The ratio is not the only dynamic here. The rapidity with which we can get the primary's field to collapse through the secondary winding is paramount, along with minimal points resistance when charging the coil. That capacitor (condenser) has to be in good shape, too, which is why its capacitance has that narrow tolerance of 10%. Too low, and the current starts arcing across the points, representing a slow decrease in the primary flux. Too high, and it will let the primary flux down too far before it fills and stops the current to get the collapse.

Too much current and we'd see very rapid erosion of the sparkplugs, like the burning up of a welding rod. We don't need large currents to light off the mixture, just adequate current and lots of voltage to make a hot spark so that it continues sparking under high cylinder compression pressures.
 
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Dan Thomas said:
If, in a car, the coil ratio was 100:1 and the voltage was 14 volts, we'd get a 1400-volt spark, which would do nothing at all for ignition. We need 20,000 volts or so.
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The peak voltage in the primary winding is much higher than 14V because of the "inductive spike" generated when the points open (or the transistor turns off). 100-200V typically. Same deal with magnetos.
Dan Thomas said:
View attachment 127008

From those resistances we can get an idea of the ratio between the primary and secondary:

13,000/0.50 = 26000:1
20,500/1.2 = 17083:1
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That is NOT how you measure the turns ratio in a transformer. A common method is to apply a known AC voltage to one winding and measure the open circuit voltage of the other winding(s). Your DC resistance method is woefully inaccurate because the secondary of an ignition coil is wound with much finer wire than the primary and so has much higher resistance per turn. The finer wire is used because a) it takes up less space and b) the lower current in the secondary allows this without overheating.

Here is a scholarly article on magneto theory:


P. 11 lists a turns ratio of 57:1. P.15 lists an average spark current of .033A (33mA). Both of these numbers reasonably close to my example.
 
I prefer copper for the airplane and zinc when some bag wants to play stupid games. Real hard to see silver goop on top of that welding tank.
 
Daleandee said:
I fly an experimental. When I used the stock auto plugs in my engine I would sometimes get rust on the plugs. I now use iridium spark plugs and they have a nickel plating to prevent corrosion. I still use a light touch of Permatex anti-seize on the threads (keeping away from the electrode end). Available at AS:

View attachment 126969
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If you own an 8 oz bottle of the stuff, it needs to be included in your will. It'll last at least five more generations after you're gone.

:biggrin:
 
3393RP said:
If you own an 8 oz bottle of the stuff, it needs to be included in your will. It'll last at least five more generations after you're gone.

:biggrin:
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You speak truth! After twenty years I'm still taking little dabs out of the cap ...
 
Gary Ward said:
I need 2 spark plug racks, wasn’t gonna buy another. Found a 4x4 in my buddy’s hangar last night and cut off 8” of it.
Today it is a spark plug rack.
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Yup, my spark plug rack is made from a 2x4. Why spend $36?
3393RP said:
If you own an 8 oz bottle of the stuff, it needs to be included in your will. It'll last at least five more generations after you're gone.

:biggrin:
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I have a tube of nickel antiseize that I got as a free bingo card sample sometime in the early 1980s. My policy is any bolt that breaks my balls getting it loose gets antiseize before going back in. About a year ago I bought some more because it was getting hard to squeeze the tube, but the tube still isn't empty...

I actually prefer the thin black stuff for spark plugs though, it's so thin it wicks around so you only need a tiny bit. The paste tends to be messier, and easier to get where you don't want it.
 
It will do the job nicely, 7/8 diameter holes. Should have made the first one. It actually is a little easier to carry around the shop.
IMG_4153.jpeg
I have found my old anti seize drys up before I can use all of it. You know the drill, digging out the bottom of the bottle with a screwdriver to find it dried up. What do you cut that stuff with if wanted to add moisture ?
I do use lots of it at work to keep wheels from seizing on the hub.
 
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The way to being always easy to remove plugs next time without damaging the helicoil, was to carefully wire brush the threads in the cylinders with a small rotating wire brush in a drill to remove the crud. Doesn't anyone else do this? Reinstall w anti seize of course.
 
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