Mollebneum coating on compression nut? Hey folks, would appreciate any info you have to give, advice, opinion etc. All welcome. I am building a rotating racking arm for my plastic conical. I have all my parts, but when I received my 3/4" stainless compression nut, it has a gray coating on it. I think this is a molly coat for high pressure situation but not sure. It seems like some have it and some don't, but the guy at McMaster Carr said that's all he has. My questions are, what is it? Will it leech into my beer? How do I get it off? My goal was to go all stainless with the racking arm, but then I ran into this. Any input is appreciated!