[ATM] Stuck 20" lap on 30" mirror

[Bill Prewitt <bprewitt@neo.rr.com>]

I've been traveling a lot lately, and have only been able to work on 
this figuring project for a few days every month or so. Last month, I 
poured a fresh layer of Gugolz 55 on a 20" lap, and left it to cold 
press till I came back.

Big mistake... It was stuck tight.

To dislodge the lap, I tried bar clamps, tubular webbing with a wood 
lever, then plastic-sheathed steel cable with a metal lever for several 
days of sustained force, but nothing worked.

So yesterday I bought 10 pounds of dry ice, layered it on top of the 
lap, and covered everything with towels and blankets. After 24 hours of 
chilling under tension, the lap separated easily from the mirror.

The lap surface was shiny & black.
I had forgotten to coat the face with CeO before pressing.

      Bill Prewitt
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          www.astrocaver.com
  webpage of telescope making and caving
      My hobbies keep me in the dark
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