Re: ATM polishing 24" taking a long time

[Anthony Stillman <atmer@flash.net>]

>How long does a 24" take typically?


David,

To first order polishing rates are dictated by surface area in contact,
relative speed and the pressure between the tool and the glass.  All things
being equal, the amount of time needed to polish out a 4" or 40" with a
full sized tool should be the same.  Alas, things are far from equal.  Most
notable, I think, is the difference in pounds per square inch(1) applied
during polish.  If I put my back into a 4" I can polish it out in under
three hours.  I tried putting my back into polising out my 16" and it did
squat.  That's when I got the bright idea of putting one of the five gallon
plastic jugs of earthquake water on the tool.  It still didn't come close
to the pressure a 4"er sees and ten hours later the 16" blank was polished
out.  A less than accurate rule of thumb is an hour an inch, but Frank
could be right, you might only be five hours from done.

Anthony



1) Or fig newtons per centimeter mouth.