[Amps] Use Caution when using Silicon Dielectric Greases

[Roger (K8RI)]

There are a number of heat conductive and electrically conductive 
compounds available. Do a search on them. There should be some rather 
inexpensive compounds. I believe Beryllium dioxide (BR2) grease should 
work.  It's very expensive in "grease gun cartridges", but it should be 
inexpensive on small quantities.  It's messy and tenacious to use.  Get 
it on your hands and it seems to take on a life of its own.:-D  IIRC Its 
designed for high pressure, low RPM contact, but works well on things 
like rotary inductors.

73, Roger (K8RI)

On 7/6/2018 10:08 AM, Greg Wasik wrote:
> I have a large egde wound Kintronics roller inductor and I'm using it 
> in a remote antenna tuner that I built.
>
> I've been using silver conductive grease on the inductor contacts. 
> (roller)  It is not cheap but you might find a less expensive source....
>
> https://www.amazon.com/gp/product/B005T8QLYM/ref=od_aui_detailpages01?ie=UTF8&psc=1
>
> Greg
> K1YW
>
> On Thu, Jul 5, 2018 at 10:15 PM, Roger (K8RI) <k8ri at rogerhalstead.com 
> <mailto:k8ri at rogerhalstead.com>> wrote:
>
>     Silicone dielectric greases work just fine as long as there is no
>     arcing. If there is an arc in the grease, the grease will break
>     down into its constituent components, one of which is Silicon
>     Dioxide.  This is not a problem as long as the wiper(s) maintain a
>     constant contact. I've used it for years. Even used both DC4 and
>     DC5 in ignition systems with only one exception. After all, these
>     compounds were designed for and used on the ignition systems of B17s.
>
>     However, one distributor cap had a flaw and the grease leaked
>     through to the inside. The rotor wiper was fine, but each
>     connection to the spark plug wires has a tiny gap. Each gap had a
>     "growth" of Silicon Dioxide which eventually grew to the point
>     where the end of the rotor hit it, breaking off mostly small
>     pieces which quickly ground the insides into a mess. The same
>     thing would happen with an RF arc.
>
>     I haven't used a roller inductor in many years, but I used
>     Silicone grease with no problems when I did.
>
>     For those who aren't aware, Silicon Dioxide is Quartz. Fine Quartz
>     is a very tough abrasive!  IIRC it was used for the Space Shuttle
>     windows in its crystal form which were made by decomposing HSiCl3
>     at high temperature. I do not know the process was implemented.
>
>     -- 
>     73, Roger (K8RI)
>
>
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-- 
Roger (K8RI)