Secondary wire size concerns

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Nathan Morris by way of Terry Fritz <twftesla-at-uswest-dot-net>" <themfam-at-home-dot-com>

Hello list,
Last night I finished some planning on my first coil.  The secondary will be 12
inches high, 3 inches in diameter and will need to be wound with 31 AWG.  That
is .0089 inches in diameter (not including the insulation).  In theory (if
wound perfectly) this would allow me to get 87.7 turns per inch for a total of
1053 turns (insulation included).  Is this a common wire size used on
secondary?  My transformer is a NST 7.5kv 20ma.  Should my secondary be taller
and my wire size be larger?  If this set up sounds ok, how much taller should I
make my secondary to account for the 'winding slop' that will inevitably occur
on my first wrap job?
TIA
--Green Horn