>For those concerned about going into polishing with a TDE, here is a simple
>test. This should be done only with the final abrasive before polishing. Clean
>and dry the mirror and tool. With a waterproof marker, make a tic tac toe like
>pattern on the mirror, going all the way to the edge. Then do a short wet,
>maybe 30 seconds or a minute with at least a full rotation of mirror and too.
>Check the wear of the pattern. If it is wearing away gradually all around, all
>is well. If everything is wearing except the edge, you have TDE. If the center
>isn't wearing, the mirror has a hole in the center. Either condition should be
>corrected before proceeding to polishing. This was shown to me as "The Pencil
>Test", since a pencil works as well as a permanent marker. Hope this is
>helpful. RICH
Actually, if everything is spherical, then you should not have to rotate the mirror.
I would also do the test at the end of a wet, where the abrasive is well worn.
Bill