[ATM] Updated pictures of 8"f6 mirror............

[Mike Lockwood]

Jerry,

Jerry wrote:
> My reply: You may be guessing, but I am not. There are the results
>  to give us an idea.

I like to gather a bit more information before I start trying to
figure out what's happenning.  I've seen enough results from others to
know I can't come close to making a recommendation until I have
certain bits of information.

> My Reply: Why do you think his pitch is too hard? Could it be too
> soft? Could it be just right?

I never made a judgement either way until he answered my question 
about channel closing time.  The example was just to indicate how much 
climate change was necessary to alter the pitch characteristics.  I 
could just as easily have spoke of cooling things down by 10F.

> My reply: "Keeping" might be a problem. John's work area is.... I 
> believe he said a garden shed.....  The work temperature will be
> varying.... lets say "wildly".

I wasn't talking just to John, I was making a point to anyone on the 
list that might have issues with the temperature of their work area. 
Maybe John will decide to work indoors in the future.

> My reply: Obviously I do not think it is the best we can do. I 
> agree most will not make a pitch tester. Ruling out the pitch 
> tester, channel close time is not the best.   I'm not saying CCT is
> of no interest at all. You seem to imply that if the mirror results
> are excellent but the channels closed "too fast" or "too slow" a 
> new lap of different hardness is needed.

I'm not sure how you got that out of it - I'm just trying to help 
someone judge how their pitch is acting, and the results thus far are 
clearly NOT excellent yet, because there is TDE and surface roughness 
(or at least there was on the last set of photos I saw).

> And here we see the vagueness of CCT.  His answer is as
> specific as can be expected. Yet if he had said 3 hours you would
> be no more certain of the lap condition than if he had said 5 or 6
> hours.

I use Gugolz pitch daily, and 3 hours is definitely different than 6 
hours.  Big difference.

I am curious - what is your mirror making experience, Jerry?

Mike Lockwood
http://bi-staff.beckman.uiuc.edu/~melockwo/index.html