[TowerTalk] aluminum protecting compound.

[D D]

I have a serious problem with a Cushcraft C8 antenna. There seems to be a dark non-conductive oxide that formes between some of the aluminum sections, which resultes in the antenna not working on some of the bands. 
My question is , does anyone know of a protective conductive "grease"  that will prevent this oxidation from forming ?
 And of course,  where can I get it ?
thanks,
Dan Donnelly kc7vda