Hi Ed,
I'm not sure where to get the compound used say in NST's, but there
are vast resources of manufacturers that manufacturer electronic grade
potting compounds. Thermal conductivity, hardness, and flammability,
are a few parameters to consider. They also make compounds for HV use
(I think a silicone base). Here is a site that does pretty well at
explaining the various compounds available. Problem #1 is cost.
http://www.pottingsolutions.com/
At work, we had issues with corrosion in an electronic box used on
city buses in a particular model where the box was subjected to
"massive moisture". I redesigned the board with vertical fuse towers
(1.75" ht) and used an electronic grade potting compound with a low
hardness (like a soft rubber). It is simply a 2 part epoxy poored in
the box to 1/4" below the top of the fuse towers. In this case, I used
a low hardness epoxy to prevent surface mount components from ripping
off the board during cure and shrinkage. In a transformer potting
application, that would be going overboard.
Anyway, it is a good idea to call and talk with the experts if you are
really seeking a potting compound. They could give the best advice
about this.
Take care,
Bart
Ed Phillips wrote:
Does anyone know where to get the type of black "tar" used to pot
transformers? Does anyone know the actual temperature at which it's
poured into the transformers? Did a web search but got nowhere and
suspect that roofing tar or pitch probably isn't suitable. I want to
pot a couple of GMHEI transformers in a cylinder to simulate the
secondary of a "spark coil" and don't want to mess with oil or the
like. Paraffin wax doesn't work, at least for me, because of too
many bubbles - I've tried pretty hard to get rid of them [with the
exception of vacuum] without much luck.
Ed
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla