ATM pitch lap question

[Alvaro Cortizo <alvaro@netpandora.com>]

Hello List,
After  a  2 weeks vacations with some time dedicated to the grindiding
to my 200mm mirror, and after the #80, #120, #220 and #500 grinding, i
made  the  pitch  lap  with  dental stone and pitch, as is explaied on
www.stellafane.com.
The problem is: the entire central square, and some edges of the pitch
are  not  in  entire  contact  with  the  glass,  even after 1 hour of
polishing  with  CeO the central part of the mirror is grey, (the rest
is pretty transparent by now).
Always with the mirror on top (im a little long with the RoC).
I  tryed  with hot water, putting the pitch lap in the Microwave oven,
etc,  and  after  that  putting  on  weight of 10Kg (~20 pounds) for a
couple of hours... the width channels (~10 mm width) almost close, but
no  luck...  still  no  deep contact on the centre... i will try later
with  an  hot  air  pistol  heater,  but i dont know if that is a good
solution.
Anyone knows why this happens?... if i continue with the polishing, im
pretty  sure i will ruin the figure, making it with even a longer RoC,
or whorse, with TDE.
  

-- 
Best regards,
 Alvaro                          mailto:alvaro@netpandora.com