material inside tranny bell covers?

[Dave H]

Donīt know the common English name, we literally call it "buttered paper" (papel manteca) and you can get it at local Supermarket

It's called greaseproof paper in the UK.

[Mick Bailey]

An insulating material I use time and time again is the stiff but flexible plastic from office folders, file index spacers or those thin ring binder files. It has excellent insulating properties, good mechanical strength and can by cut and folded easily. It also has a consistent thickness and fair thermal properties.

[bob p]

+1 on the milk jug. I've used it for all sorts of things, even to fabricate rim protectors for changing motorcycle tires. You can warm it in an oven and re-shape it.

[Randall]

I went with folding down wax paper to get it 8 sheets thick. Seems like that should do the trick.

[cjenrick]

Nomex is good for 1000 volts per mil, so #5 Nomex = 5000 volts,

good stuff, a bit pricey but worth it, very heat proof, used in quality transformers, good substitute for fish paper, cheaper for 24 by 36 inch rolls,