Re: [ATM] First Timer Polishing Questions

["Meeks Robert-PT1784" <bob.meeks@motorola.com>]

Thanks to all for your input.  A couple of follow-ups below:

<Bob May Wrote>
"The thing that you have to remember is that the glass surface
will reflect about 4% of the light from the pointer."

Hi Bob - I've read your past posts regarding the 4% but I have been
confused on this point.  I don't know if this will come across, but let
me try a little text "drawing" to illustrate my question.  

 A   B   C      D
  \     /
   \   /
    \ /
 ---------------
      \
       \
        E

If the laser is at point A, and the mirror surface is the horizontal
line, then some amount of light passes through to point E and some
amount of light is reflected up to point C.  Are you saying that on a
perfectly polished surface, 96% of the light passes through to point E
and 4% is reflected to point C?  If yes, then I would expect to see NO
reflection at points B or D.  If no, then you are indicating that points
C and E together represent 96% of the light, and 4% of light is
scattered around, such as to points B and D.  In that case, I would
always expect to see some small disk on the surface of mirror.

What's confusing is that the Stellafane site indicates pretty adamently
that you will see no scatter of light at points B or D, but I've tried
this test on eyeglass lenses and my wife's crystal wine glasses when she
wasn't looking and I always see a little red dot on the surface of glass
from different positions, even though most of the light either passes
through or is reflected at the appropriate angle.  Hence, my confusion.
Thanks for you time to help clear this up for me.  Interesting website,
BTW.

<Guy Brandenburg Wrote>
"I think we've finally found a *reliable* way to tell if a mirror is
truly polished out. Radio Shack sells (or at least they did) little
inexpensive, hand-held microscopes that go up to 30 X"

I just ran out to my local Radio Shack and these have been discontinued,
but they had two left on clearance for $7.99.  Might be a different
model; mine goes from 60X to 100X but does have the oblique light.  I'll
give it a shot tonight.

<Several people asked>
"Do you wash with soap?" <referring to the mirror, not me>

No, just water.  But I did try some lens cleaner and lens cleaner tissue
on a small spot with similar results.  Actually brought the reflection
back in an area I had wiped off with my thumb.  That said, I'll use a
little liquid soap to see what that does.

<Mark Holm Wrote>
"I'm not so keen on the lap in the freezer method. "

<and several others indicated nominal pressure required>

The input I received back seemed to indicate that excess pressure was
not really a necessity for polishing, so I can live with a softer pitch
(without the freezer part, though frozen pitch-on-a-stick could be the
next big thing.  Pitchsicles; refreshingly cold yet chewy) especially if
all indications are that I really am in a polished state at this point.
I work in my garage here in San Diego, so it's a pretty comfy
temperature (around 70 give or take).

Thanks again for everyone's input and help.  I read about doing this as
a kid, ordered my blanks/grit 12 years ago at age 30; put it on the
shelf when I got side-tracked with a work project, tried building a
Focault tester twice without much luck, had somewhat written off the
entire thing, and then a couple of months ago my son asked me to come
give a talk to his 5th grade class about telescopes.  Decided to take
another stab at it, built a successful tester this time, and can see the
end in site.  Only 30 years in the making!  At any rate, I'm glad to be
back finishing this.  Enjoying it immensely.

Regards,
Bob
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