From: "CSC" 
To: "Atm" 
Reply-To: "CSC" 


The grooves allow circulation of the polishing slurry and the fact that
they close up means they are allowing the mirror to mate to the pitch in
real time, constantly fitting the curve.  Make them wide enough
(1/4-3/8)and often enough to make sure they don't close in completely, as
it's easier to shave the sides of the facets than to try and carve out a
new groove in a flat layer of pitch.

Believe me.

Just take a razor blade or sharp knife and skim it down the length of a row
of facets a few times, then the next.

Scrub the lap well with a stiff brush to break up the glazing that happens
to the lap.  warm slightly under warm water, press and go.

It becomes a ritual that keeps you out of trouble.

Colin





-----Original Message-----
From: owner-atm{at}shore.net [mailto:owner-atm{at}shore.net]On Behalf Of
Robert Fifarek
Sent: Thursday, August 07, 2003 11:57 PM To: atm{at}shore.net
Subject: ATM Grooving on Pitch Laps



I am wondering whether the need to have wide and deep grooves in the pitch
polishing tool is really necessary? I am polishing out an f4, 16"
plate glass mirror. The gugolz pitch is working well, but the grooves are
starting to close up. I can clearly see the grooves through the back of the
mirror when I am  MOT, and the polishing mixture flows through the grooves.
So when and how deep should they be to continue? Also, I do not receive any
email from the list anymore, and do not know why. Could someone please
respond to this email if for nothing else, just to see if it works for me?
Thanks.
Rob in Ramona

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