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Hi Keith,

I'm not an AP owner ... so my info on this subject comes 2nd hand.? If you are in that forum you may have a better finger on the pulse of this riddle.??

My research on this topic showed some strong concerns by a website catering to old industrial machines (lathes, motors, where things get very hot) that were concerned about MolyD lubes deteriorating "brass" components.? Yet the McMaster-Carr company website highly recommends MolyD lubes for all metals.? It is a puzzle....is this a serious concern or a chicken-little story???

My friends, either profs who teach materials science, or head metallurgy industrial departments, were also concerned about sulphur reacting with brass (any copper alloys).? That in theory could be a corrosion concern.? But no one knows the kinetics or time dependence at room temperature, so I started a simple reaction test to see for myself.? So far...nothing is happening and I'm still exposing my test strip.? If this were a test on lemon juice I think I'd see a reaction already.? Of course all copper alloys deteriorate in air through oxidation, slowly, as the copper goes through its oxidation states Cu2O, CuO, CuO2.??

However, the MolyD in the CRC grease is diluted and anyway is not pure sulfur. The sulfur in bound up in the slippery crystal mineral crystal MoS2.? The reason that is a lubricant is that the flat layers of MoS2 slide on each other....like why graphite is slippery.??

That's why modern expensive gasolines are low sulfur too... when they burn in a car engine, the combined sulfur and water form a sulfuric acid that eats away at metals. (and pre 2001 Jaguar engines had a "Nikisil " high strength coating from BMW motorcycles...and high sulfur gasolinesxin Europe ate that coating away...bye bye engine cylinders.? US gasolines don't have the sulfur so they don't get this problem...)

It's also why I like astronomy as a hobby.? It has so many challenges!!!? (Fred the expert punster would tell me it's a slippery subject.)

All the best,

Michael