[ATM] Polishing speed

[Mike Lockwood <melockwo@uiuc.edu>]

Mel,

Mel Bartels wrote:
> BTW, 8-10 hours is way too long.  You should be able to polish out a 6 inch
> in an hour, two at most.  
> For more on what might actually happen during polishing (not figuring) and
> why more pressure is better, see
> http://www.bbastrodesigns.com/tm/chemical_mechanical_polishing.html

Could you say more about fast polishing techniques?  I've made many 6" 
mirrors and even with lots of pressure, I have never been able to 
declare them polished in under 6 hours.

And that's not dry polishing - it's plenty wet, and with a fair amount 
of cerium in the solution - not dilute.  Fine grinding was with 5u 
MicroGrit.

Your polishing article mentions that polish rates increase linearly 
with velocity and pressure, and that more cerium particles in the lap 
is good.  Your other articles on mirror making mention slow, 
deliberate polishing strokes.  If the concentration and speed are 
good, this suggests using many times more pressure than I am 
physically capable of applying.

Where's the discrepancy?

	Mike Lockwood


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