Jacko wrote:
From Lycoming Service Instruction No. 1042AC: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.
Thank you for this! Very enlightening.
That Lycoming instruction is outdated. The spark plug anti-seize compound is much better. I do not know shops that still use engine oil. Not recommended.
Does anyone know the composition of the modern anti-seize compound? It is likely to be a common industrial product relabelled and sold at an obscene profit.
I don’t know why Lycoming forbids graphite thread lube. Maybe a metallurgical thing. However, the Autolite stuff definitely contains graphite and is commonly sold to and used by aircraft technicians. What about the Champion anti-seize compound, does anyone know what that consist of?
Jacko wrote:
I don’t know why Lycoming forbids graphite thread lube
Nothing corrodes aluminium more than graphite (galvanic corrosion). Can’t imagine copper paste being too good either though. At least engine oil won’t do any harm in this respect.
Specifically for the brake caliper job Cleveland specifies in the manual that the torque settings are dry and anti-seize should not be applied to the back plate tie bolts.
See here
See Appendix A3 for torquing instructions and the torque table.
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