Old timer at the hangar told me to stop using anti-seize on spark plugs

Back when I first started at a repair station in Wichita, this grizzled guy named Frank saw me putting anti-seize on every plug I torqued in. He said I was asking for trouble and to knock it off. I figured he was just set in his ways so I kept doing it for about six months. Then I had a cylinder come back with a plug that had backed out halfway during a run-up on a Cessna 172. The threads were all galled up from the compound breaking down at high temps. That was eight years ago and I haven't touched the stuff since. Has anyone else run into problems using anti-seize on aviation plugs or is it just a Continental vs Lycoming thing?

3 comments

3 Comments

rileygarcia1mo ago

The part about the old timer saying you were "asking for trouble" really hits home. Frank was probably right all along, now I'm sitting here wondering how many spark plugs I've accidentally tried to weld into cylinders over the years. Guess some old advice is worth listening to before my engine teaches me the hard way too.

smith.nancy1mo ago

And that metallurgy guy brings up a good point too, I had an old Mustang where the previous owner used anti-seize on everything and the torque specs were all over the place once the engine got hot.

anna4911mo ago

@rileygarcia it's wild how those old timer lessons sneak up on you. I actually heard from a metallurgy guy at a trade show that the real issue is thermal cycling - anti-seize can create a little buffer that messes with the torque spec once things heat up.