Jeff Liebermann wrote:
On Wed, 19 Aug 2015 01:20:09 -0700 (PDT), whit3rd
wrote:

Yeah, there's a high information cost... and there's more boosterism than
chemical physics in the sales lit. As to 'how conductive', the L260 variant
that I used doesn't have conductive particles, so it only conducts in thin films,
like rubbing parts would have around contact points. Because it is nonlinear,
'conductivity' is undefined (and the rubbing of bumpy surfaces mean
the film thickness is likewise indefinite). Variants on this lubricant
are recommended for slide potentiometers, I see.

The admixture of conductive particles would make a grease conduct electricity,
but that would be unsafe in electrical panels (and the intended uses include busbars).
It would decalibrate potentiometers, too. Because metallic particles would
constitute dissimilar metals in my mechanism, I didn't want to use such a grease.

If the stuff works as you describe, then it should change conductivity
from a bad insulator to a marginal conductor when pressure is applied.
That got my interest because I have an application for a cheap
pressure sensing system, that will work with rollers and gears. In
theory, I could monitor the conductivity between meshed gears, which
would give me an indication of the applied pressure or changes in
pressure.

However, I don't think it works the way you suggest[1]. The grease
simply prevents surface oxidation and displaces electrolytes to reduce
galavanic corrosion if the mating surfaces are dissimilar meatals.
Doping it with conductive particles also helps reduce galvanic
corrosion. When I read the vague and misleading promotional
literature from that point of view, the claims seems to make sense.

On the other foot, there are specialized greases that allegedly work
the way you describe. I found a hint at:
https://www.linkedin.com/grp/post/1786018-215513373
but could not find any specifics. I'll dig more later. I also
haven't had time to read through the patents yet but I'll get to it
this weekend.


[1] increased pressure = thin film = increased conductivity

I still have cramolin copper grease. I never used it on anything. Seems
like it had little conductivity with test leads.

Greg