[Amps] Forms for air wound coils

[k7fm]

"Other than ceramic, can anything else be used as a coil form?"

I just built a TNT transmitter (Tuned plate Not Tuned grid), using a type 10 
tube.  The coil form is 3 oak dowels I turned on my lathe.  The old method 
of making these rf proof was to "boil" them in paraffin, but I cheated and 
used spar varnish.  I have seen similar forme made using glass.  Cut up a 
wine bottle and use that as a coil form.  It will add class to the rig.

73,  Colin  K7FM