What is epoxy of mylar cap made from?

Can I guess? It is made of epoxy resin with red paint... apparently. But be careful, the wires are probably magnetic and will upset your coil and Q-factor.

Dear Ban,

That is right, I really want to know expoxy resin of mylar capacitor. Additionally, I will not use the wire of mylar capacitor, but need epoxy resin.

Thanks,

You do know that mylar is one sort of plastic, and epoxy is another? Mylar is a trademark of Dupont (IIRC), for Poly Ethylene Tetraphalate. Wikipedia should tell you more.

Are you just needing a compound to dip your own wound coils in to encase them against damage and maintain the coil spacing? Or just curious about what the epoxy compound is?

Yes, It is going to be used to mold coil and EMI shield to maintain its own frequency characteristics. It is secondary part of coreless transformer for contactless things.

On 10 Apr 2006 13:01:38 GMT, Ian Stirling Gave us:

The mylar is the film used as the dielectric for the cap. The epoxy ia the encapsulant, and is usually not painted.

A similar epoxy material for the electronics industry that he can find and buy is called "Stycast".

It can be made highly thermally conductive as well. Silica powder added to it works, but they actually sell one already done up. It is bright blue.

On 10 Apr 2006 16:26:46 -0700, "Bob J." Gave us:

You probably do NOT want a hard epoxy then. It can shear wires from the thermal expansions. There are transformer encapsulants out there for the purpose. Things have to have a small degree of flexure.

One is called Dolph's AC 43 impregnation varnish (top of the line). They are a decades old company that has been doing it for years.

If you are worried about voltage arcing, you should vacuum impregnate it, or reduced pressure at least. The AC43 has a 2000V per mil breakdown strength.

It can be baked for faster cure at up to 275 F (135C). That is usually not too hot for most plastic coil forms.