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


I am fairly sure the pitch has lost some of the volatiles and is now on the
too-hard side.  Try it as-is with higher pressing temps, but if it gives
poor performance (rough surface, ripple, grabbing/sticking, weird figuring
results), you will want to remelt it and replace the volatiles with some
turpentine.  one teaspoon will make a difference.

Maybe time to buy some more pitch.  This won't be your only scope, ya know.

Colin

-----Original Message-----
From: owner-atm{at}shore.net [mailto:owner-atm{at}shore.net]On Behalf Of Rich
Ball
Sent: Sunday, June 29, 2003 7:20 PM To: ATM
Subject: ATM Old tool



Mentors - I need help again.

My 8" mirror project has been dormant for more than two years.  My
tool (pitch lap) has been stored pitch up in a covered tray.  Today I set
myself to figuring after finally making sense out of Mr. Foucault.

I warmed the tool to about 80 degrees and pressed it with a mesh and cerium
oxide for about 1 hour with a 30 pound weight.

But even after so severe a pressing the mesh was not taken up in the pitch
and I fear the pitch is too hard to take the pressing.  What should I do?
More heat?  New pitch?

--Rich Ball

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