You wrote:
>
>6 weeks ago I was ready to spend $1200 on a SCT 8" Mead for my kid.
>Tonight I am looking at 2 William & Bell pyrex blanks wondering "What
>have I done?".
Started on a great project, just dive on in....
>My first problem is choosing "which surface is which". I assumed that
>the blanks would have clear surfaces so that I could see if there were
>any underlying faults. Yes I know the breakdown of ass u me. I have
>looked at each surface under a light with some magnification. This
>just seems to makethe surface harder to see past. Would it be wise to
>use a pad sander and wetsand the surfaces so that I can see beneath
>them? These surfaces are ROUGH.
>Am I being overly concerned about possible sub surface flaws? The
>edge on>view offers the best look under the surface. I can tell there
>are no horrendous voids! Please advise. I probably won't start
>actual grindinguntil next week. Still have some things to get into
>place.
Try a little kerosene, or something similar I suppose, dampen the two faces, and shine a flashlite through the disc, you shouldn't see much, hopefully just a couple of small bubbles, but if anything is there, you should be able to see it...
>(actually I plan on letting(making) the kid grind it himself)
Well, I was 14 when a ground my first 6" a la Edmund Sci.
Good luck, you'll find lots of support here if/when you need it.
Bill Marriott Forest Knolls, Ca. USA btk@ix.netcom.com