Insulation Material for Homemade HV Transformer

[ice595]

So long story short, I found my long lost homemade HV transformer that I made 9 years ago and decided to have some fun with it once again.
I still remember skipping class in high school just to come home early and wind this sucker.
The secondary must have been at least 1000+ turns, to be fair I lost count after the first couple hundred turns.
Standard printer paper was used as insulation for each layer of winding and the whole thing was submerged in cooking oil.
It was a lot of fun drawing 4 inch arcs when driven with a ZVS driver circuit with 46V input. Then I cranked up the input to 56V, I was able to draw 5 inch THICK arcs and the secondary shorted out shortly after.
Well I suppose it was fun while it lasted. Video of me drawing arcs here:
Now im itching to wind another one but with better insulation this time around.
What commonly available insulation material is suitable for HV transformers?
Is Kapton tape better than standard 0.1mm thick printer paper?

[james_s]

IIRC the most common material used for transformer layers is polyester. HV transformers are hard though, especially HV high frequency transformers, it's very difficult to prevent arcs and virtually all commercially made HV high frequency transformers are vacuum impregnated in epoxy. Typically they also are made on a sectioned bobbin so that it is effectively multiple smaller windings end to end in series. While messy, for a home made thing it's hard to beat mineral oil.

[ice595]

Typically they also are made on a sectioned bobbin so that it is effectively multiple smaller windings end to end in series. While messy, for a home made thing it's hard to beat mineral oil.

Good idea, I can 3D print a bobbin this time around. Might be difficult to add insulation layer in between windings though.
I do have a fridge compressor that can act as a vacuum pump to suck out any air then pressurize it fill any voids left behind.

[james_s]

You don't need much of a vacuum, even one of those hand pumped ones for testing automotive vacuum actuators will work. Fridge compressor will work fine too.