In a message dated 96-07-29 01:19:44 EDT, you write:
>I use something called OXGARD. I think/hope it's the same stuff. I put a
>smear of it on a non-metallic flat surface yesterday so I could see how
>conductive it was. I was surprised to see no deflection at all in my VOM
>when I stuck the two probes into it. It looks like it's impregnated with
>zinc or some metal so what gives? The joints I've used it on show good
>electrical connections so I'm relieved to see that it's not the perfect
>insulator that it appears to be when not in contact with metal.
Hi, Matt --
Surprise! Yes, your observation is correct. The reason is that the
vehicle material is non-conductive with metal particles held in suspension.
What happens is that as the joint is tightened (element pieces, ground lug,
etc.), the particles penetrate the outer oxidized layer of the material and
thus provides the 'permanent' connection through the oxidation. The carrier
material keeps oxygen out (OXI-dation, remember) preventing additional
corrosion. The different brands are different formulations of vehicle
(molybdenum, petroleum, etc.) and particles (zinc, copper, graphite, etc.).
Also, Permatex Anti-Seize Lubricant can be used on the threads of
U-bolts to prevent "seizing, galling and corrosion." It aids in the
disassembly of the antenna's hardware. Not for use on electrical
connections. (This is a quote from an interesting table of anti-oxidant
products available from the ARRL lab and compiled by Mike Gruber, WA1SVF.)
73, Steve K7LXC
TOWER TECH -- professional tower supplies and services for amateurs