[Amps] Tufnol rod

[rlm]

>I have acquired various lengths and diameters from ¼" to 1" Tufnol rod. I
>plan on using it to wind my anode choke and at HV stand-off points.
>
> 
>
>Although I see a number of articles (here in Europe) suggesting PTFE or
>Tufnol maybe used in the applications mentioned, I rarely see anyone using
>Tufnol.
>
€   I use g-10 or g-11 fiberglass tubing for HV-RFCs because Teflon has 
the problem of cold-flowing.
> 
>
>In order to "get wise" on the pros & cons of both materials I did a web
>search and found VERY little information on Tufnol rod in general. I asked a
>friend in the USA who builds amps and he said he had never heard of the
>stuff.
>
> 
>
>My question is:
>
> 
>
>(1)     Is Tufnol a European "thing"?
>
>(2)     Is one "better" than the other?
>
> 
>
>I also heard  one way to test coil former material is to check its heating
>properties by placing it in a microwave oven with a cup of water (Not in the
>water, this just acts as a dummy load (Food) to protect the oven). If it
>stays cold then it has very little or no loss effects at RF, the web page
>was for trap making ides.
>
€  this is what I would do to evaluate the D-factor,