Shellac for transformers

[Nixie]

1. Dewaxed shellac or not?
2. Cheap source of the flakes?
3. What ratio of flakes to methanol?
4. When vacuum impregnating, is it sufficient to have vacuum for only a few minutes? I'm using a water aspirator to create vacuum, and sustaining vacuum for more than a few minutes wastes way too much water (the aspirator is probably on the order of 1500 L/hr).

 

[AndrewT]

Hi,
is shellac the right chemical for a transformer?

 

[Nixie]

I've seen it used before. Various varnishes seem to be used.

 

[Nixie]

Hmm, regular wood varnish seems to work fine. I even had mixed a uretane one with some other type, and diluted the stuff with acetone and methanol so it would flow in the smaller spaces better during the vacuum impregnation.