[time-nuts] Re: Potting compound advice needed

[Lux, Jim]

On 11/11/21 4:00 PM, djl wrote:
> I've used, wait for it, beeswax as a potting compound. Gouda cheese 
> comes coated with it (some has paraffin, get the best,) in a lovely 
> red. I also found out some years ago that Catholic churches use pure 
> beeswax for large (not votive) candles and may give you the stubs. 
> Nice, clean white.  Or, dear ol' Amazon has a huge assortment for 
> around $1.00 / oz, in various stages of "purification". For expensive 
> beeswax with some unknown sticky additives, use toilet mounting 
> rings... (good also for preserving dry milsurp gunstocks, according to 
> Anvil.)
> 73, Don 


Beeswax, if perfectly dry, and no carbon residue, is pretty good RF wise 
- at 1 MHz, epsilon is around 2.5, tan d is around 0.01 which is ok, but 
not great. You could mix it with microballoons to lower epsilon and 
dissipation.

It does shrink and, of course, it's pretty soft.


Pointing back to a previous suggestion 3M DP270 - that's 3.5 epsilon and 
0.018 tan d, but at 1kHz.  The graph in the datasheet does show pretty 
constant 0.020 up to 1 MHz.

http://www.emesystems.com/pdfs/parts/DP270.pdf

At least it's available in less than a gallon quantities.