"N_Cook" wrote in message
...
On 05/03/2016 17:14, DaveC wrote:
Cleaning up an old rotary mode switch used for 5v logic levels. It has
some
kind of grease in it.


€¦which has always confused me: grease is an insulator (well, the grease
in
this switch is€”just tested and its infinite ohms).

I read that dielectric grease is good to keep contacts sealed against the
elements that have high physical pressure (which overcomes any separation
provided by the grease) but that signal and other low voltages grease is
contra-indicated.

What say yall?

Thanks.


Can we summarise this thread by saying -
Any grease is better than no grease,

Some mechanical engineering greases contain a significant proportion of
water.

Not certain - but that may open the possibility of corrosive decomposition
products.

Many greases are lithium based, its probably bound up in stable compounds,
but very reactive if it gets loose.

Molybdenum grease is probably OK except in high voltage or high impedance
work - graphite grease is probably not OK for anything electrical. Graphite
is the lubricant of choice for brass, such as locks etc.

PTFE penetrating oil works well on contacts, as for grease the one I know of
is Finish-line PTFE fortified bicycle grease. It works OK on heavy contacts,
but may isolate the wiper on light duty switchgear.

Silicone grease is exactly opposite to hygroscopic - it repels water.