CVD thick teflon

You dissolve Teflon powder in Fluorinert, coat, then bake off the Fluorinert. Several of the attempts to make substrates for moving droplets around (for microchemistry) have used this approach to make a hydrophobic surface.
There are several different Fluorinerts. You'll probably need the lightest one to stay below 100C.

I thought of that (did not tried though) but would the coating be non- porous. I guess I still will have some kind of powder dispertion? Porosity/pinhole would kill the dielectric strength. Can you confirm/ deny? Thanks anyway

Can the very near surface get hotter than 100C? Some PTFE and ETFE coatings can be flame sprayed, but I do not know if a flame spray will give you the type of coating that you need.
The very surface of your substrate will get hotter than 100 C, but the vast majority will be much cooler. I've applied Al2O3 to a styrofoam cup using a plasma gun and the cup held up - it doesn't get much rougher than that ;-)
Gregg

snipped-for-privacy@gmail.com wrote in news:1181289422.978674.106840 @w5g2000hsg.googlegroups.com:
What are your performance requirements for the coating, post-application?
If it cannot be porous, and you need 2 mils, does it have to be CVD? I've got a polyamide/imide urethane diacrylate resin with a dielectric constant of 3.4 (and outstanding adhesion to Kapton), a silicone urethane diacrylate with "E" of 2.3, and a polyBD urethane diacrylate with "E" of 1.8, each of which can be further diluted in acrylate monomers, add some PI, and UV cure, which'll keep your substrate cool as a cucumber (30 to 35 degC, max).
Regards, R. David Zopf snipped-for-privacy@bomarspecialties.com

I don't see why it would be porous. If it is, you can always apply another coat, if the solution is at saturation.
It won't have powder in it. The powder will dissolve. You can filter out any undissolved powder.

- The key for me is dielectic strength. I need to hold several kV. Up to 15kV if possible. Thanks for your help.