From: "Herb Kasler" 
To: "Scott Berfield" , 
Reply-To: "Herb Kasler" 


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Scott,


You say you've been polishing only a few hours? If you made a mistake, = it
was only that you let yourself get psyched out by a weird Ronchi = image on
an incompletely polished piece of glass. What you have is a = classic
picture of an incompletely polished-out surface. You are = probably doing
mostly MOT. If you look at your surface, I bet you'll see = more pits near
the edge than in the middle. This is perfectly normal. = The edge zones
just haven't come into full contact with the tool yet. = You can hasten the
process by either switching to TOT for a while or = maybe by giving your
tool a really good long pressing, and then = lengthening your strokes just
a bit. Either way, you should polish until = you can't see any more pits
before you worry about anything you see on = the test stand. What I see is
that inside of the zone of good contact, = what you have looks like a
perfect sphere. Keep polishing a few more = hours, and the whole mirror
will probably look that way.

Good luck,

Herb.
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Scott,
 
 
You say you've been polishing only a =
few hours? If=20
you made a mistake, it was only that you let yourself get psyched out by = a weird=20
Ronchi image on an incompletely polished piece of glass. What you have =
is a=20
classic picture of an incompletely polished-out surface. You are = probably doing=20
mostly MOT. If you look at your surface, I bet you'll see more pits near = the=20
edge than in the middle. This is perfectly normal. The edge zones just = haven't=20
come into full contact with the tool yet. You can hasten the process by = either=20
switching to TOT for a while or maybe by giving your tool a really good = long=20
pressing, and then lengthening your strokes just a bit. Either way, you = should=20
polish until you can't see any more pits before you worry about anything = you see=20
on the test stand. What I see is that inside of the zone of good = contact, what=20
you have looks like a perfect sphere. Keep polishing a few more hours, = and the=20
whole mirror will probably look that way.
 
Good luck,
 
Herb.

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