ATM Fast Figuring

[John Veazey <veazey@ridgecrest.ca.us>]

I'm having a lot of trouble figuring my 8" F8.  Twenty strokes (forward
and back) of a 3/4 dia. W stroke, MOT puts a curve on the glass with
.060 between zones 1 and 7.  With polishing so fast, it's difficult to
control.  Berry says it should take 200 strokes with optical rouge on a
6 in.  Brown says 5 min. for the same mirror.  Texereau says 8 to 10
min. for an 8 in. F8.  I'm using 4:1 mix of red rouge, W-B hard Burgundy
pitch, facets about 3/16 in. thick, 3/4 in. square, 3/16 in. channels. 
The marks from the netting are just visible on the facets.  I have about
5-hours of polishing on the lap and pitch.  The channels close after 2
hours of polishing time and I open them with a soldering iron. It's 70
degrees at 70% humidity.  Any ideas about why the curve forms so fast?

John Veazey
Ridgecrest, CA