anti seize on spark plugs

[Trav]

I have been using it on plugs for almost 50 years and not once had an issue removing any I installed, using too much and using one of these without taking the anti seize into consideration are the biggest culprits in having difficulties removing them.

 

[Astro14]

Depends where you’re measuring voltage (potential).

Across a big R - there will be a big V. Whether that R come from air gap, or internal resistance, or whatever, impeding the flow.

So, across a plug? High.

Across a length of conductor/wire it should be zero.

So, if you’re measuring voltage along a length of wire, even as current flows through it, voltage is basically zero.

Same expectation along the ground electrode path. Electrode, to threads, through threads to head, through metal of engine to ground.

Basically zero voltage along that entire path as the current flows without resistance.

You can prove this to yourself using a voltmeter, a battery, some wire, and some load like a lightbulb. Measure the voltage between the positive terminal of the battery, and the input to the lightbulb. Zero. Across the bulb? Battery voltage. Output from bulb to negative terminal. Zero.

 

[4WD]

I buy the cheap packs of artist style paint brushes. Great for light and controlled applications like this discussion entails …

 

[KrisZ]

Can you explain that. Before the arc there is no circuit. It takes a high voltage to arc, but once the arc is complete the ionizing of the A/F cause resistance and voltage drop near instantly - is my understanding?

Yes, once the arc is struck, the voltage and resistance go to near 0 and the current spikes extremely high, in theory to infinity if my memory serves me correctly.

Astro above explained it really well.

 

[SHOZ]

Once the spark jumps the gap to ground there is 0 voltage as there is no potential. This being DC current and the block as the main ground from the alternator. You should be able to see some millivolts, when the engine is running, from the head near the spark plug and the alternator body. That is dependent on the resistance of the heads, head bolts and block/alternator mating surface.

 

[JeffKeryk]

I have been using it on plugs for almost 50 years and not once had an issue removing any I installed, using too much and using one of these without taking the anti seize into consideration are the biggest culprits in having difficulties removing them.


View attachment 231949

This. Wrong is wrong. As @Astro14 points out using anti seize incorrectly can cause trouble as well.
Just a little around the bottom threads and torque to the lower end of the range.

 

[BurrWinder]

Never seize - even the regular stuff - is not di-electric. However so as not to re-ignite that discussion - as pointed out, between the torque of thread contacts, the extremely thin film, and the fact your dealing with 20KV minimum, your unlikely to have any issues either way.

My big issue with di-electric is people start using it on other places, where there at 12V, and then it does matter. So I suggest di-electric doesn't really belong on a car. Its intended to seal electrical joints after termination in areas that they may get wet. It does work really well on battery terminals, but honestly given there is no real likelyhood of arc there anyway, so does almost any grease.

The plug OEM's don't want you using it due to the potential to over torque. As long as you compensate for that your fairly unlikely to have an issue.

This is the answer here. Anyone that has been a tech for any length of time is aware that the threads can gall or corrode for various reasons and a thin layer of anti seize that is applied carefully ( not close to the plug base ) is the answer to preventing this. I think part of the reason this is an issue is too many people put it on a plug like putting teflon on a pipe - that is way too much !
It should be just a small amount ( like a mens wedding ring size or A bit more so ) not gooped up and heavy on the entire threads. Because of this logic, of too many people apply it like this - ( and the anti seize that shorts out the plug strap or contaminates a cylinder ) is why THEY don't recommend it be used. Many newer plugs are not raw metal ( anodized or treated threads, etc. ) but over time can have carbon buildup or corrosion that can make them a bear or cause damage when removing them. Either way a small amount will prevent this issue on either plug. Dielectric can go on the other end to try to ease boot removal next time and to try to prevent more spark flashover down the ceramic insulator.

 

[Astro14]

This. Wrong is wrong. As @Astro14 points out using anti seize incorrectly can cause trouble as well.
Just a little around the bottom threads and torque to the lower end of the range.

However, I suspect that @Trav is using it correctly - with 50+ years of experience, when he speaks, I listen.

 

[Mackelroy]

Dielectric grease is an insulator, so that’s a very, very, terrible, horrendous idea.

Not using enough on there to even make a difference(only a tiny unseen film on couple of threads as a lube, like lubing a Bullet shell case, its not seen), and there are no metal compounds in it. Where as antiseize is full of metal compounds. Any clumps of that drop into the cylinder, not good.

 

[Mackelroy]

How many BITOG threads does it take to put antiseize on a spark plug?

This much…

View attachment 231802

Yeah that picture looks like you average idjit LOL!

 

[TomYoung]

Not using enough on there to even make a difference(only a tiny unseen film on couple of threads as a lube, like lubing a Bullet shell case, its not seen), and there are no metal compounds in it. Where as antiseize is full of metal compounds. Any clumps of that drop into the cylinder, not good.

Are you pro or con?

 

[kschachn]

Not using enough on there to even make a difference(only a tiny unseen film on couple of threads as a lube, like lubing a Bullet shell case, its not seen), and there are no metal compounds in it. Where as antiseize is full of metal compounds. Any clumps of that drop into the cylinder, not good.

But it’s the metal in it that makes it anti-seize.

 

[Mackelroy]

But it’s the metal in it that makes it anti-seize.

Some plugs like ngk use a coated plating on the threads, so unlikey to seize anyway.

Ive never had a plug seizing issue, might happen more in some areas of the country.

If you put antiseize on spark threads, even if you manage to install with nothing going into the cylinder, the next time you removed the plug, antiseize debri will be falling into the cylinder.

I have absolutely no use for antiseize on a spark plug thread, and if I did, there are better alternatives.

now 02 sensors, tend to use antiseize, but that is past the combustion chamber.

 

[Mackelroy]

Are you pro or con?

Well, i dont use antiseize on spark plug threads, if thats what you are asking.

 

[grampi]

Why not use it? I hurts absolutely nothing, and adding a little insurance to making them easier to remove is a good thing...you don't want to strip out threads in an aluminum head...

 

[A_User55555]

When I changed the spark plugs on my DTS at 100K, some of them required a breaker bar to remove. When I saw the threads, there was some brown rust residue on it

So for the new plugs, I put a smidge of anti-size on the first few threads. Put them back and just tightened them with my 3/8ths ratchet.

5 years later and almost 92K miles after, I have no issues.

 

[Exhaustgases]

Why not use it? I hurts absolutely nothing, and adding a little insurance to making them easier to remove is a good thing...you don't want to strip out threads in an aluminum head...

Because high heat drys it out, and then the concrete seizes the plug into the head.

 

[vavavroom]

It does not make the current move through the plug. Someone else said it is all about allowing eventual release of the spark plug boot.

That's what I have noticed. Ungreased boots can get stuck really good on the ceramic spark plug insulator. With the insulator having a film of dielectric grease on it, the boot comes off smoothly and goes on easily. The addition of a thin film of grease will certainly make for a better seal against moisture ingress than the boot alone.

 

[TomYoung]

That's what I have noticed. Ungreased boots can get stuck really good on the ceramic spark plug insulator. With the insulator having a film of dielectric grease on it, the boot comes off smoothly and goes on easily. The addition of a thin film of grease will certainly make for a better seal against moisture ingress than the boot alone.

If any remains eight years down the road when its spark plug time.

 

[vavavroom]

If any remains eight years down the road when its spark plug time.

That's not a problem for me. I replace the spark plugs about every 60k miles so every 2-3 years. I actually pull them about every 20k miles because I don't want to wait until there are noticeable performance issues. It Also prevents the threads from seizing. I'd consider leaving spark plugs in for 8 years with intermittent revmoval negligent maintenance.