Subject: Grinding Wheel for Glass?

From: [email-masked] (Bob Neidorff)
Date: Sat, 24 Dec 1994 22:06:16 GMT

A friend asked me to locate a grinding wheel of sorts for
a glass polishing machine.  Can you help?  Let me describe
it.

The grinder has a 5/16" diameter vertical shaft.  The wheel
is really a diamond grit coated drum which slides over the
shaft and stays in place via a set screw.  The shaft which
my friend uses now is 3/4" diameter and 1.25" high.  Only
the middle 1/2" of the shaft is coated by grit.

My friend uses the grinder to finish glass edges in stained
glass work.  The local stained glass supplier wants $50 for
a replacement drum, which seems very high.  Any ideas?

Thanks for your suggestions.  If possible, please reply
directly.

--
Bob Neidorff; Unitrode I. C. Corp.  |  Internet: [email-masked]
7 Continental Blvd.                 |  Voice   : (US) 603-429-8541
Merrimack, NH  03054-0399 USA       |  FAX     : (US) 603-424-3460

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From: [email-masked] (Mark G. Forbes)
Date: Tue, 27 Dec 94 10:28:34 PST

>a replacement drum, which seems very high.  Any ideas?

Yep, that's what they cost. Either 1) Your friend's gotten
a lot of mileage out of that stone, or 2) Your friend toasted
it by running without water. I looked in my jewelry supply
catalogs that have diamond grinding wheels, etc, and the
prices are even higher. 

Yes, $50 is not cheap, but it's a long-term investment. Think
of what *time* is worth if you're doing this stuff by hand!
*I* would spend the $50, rather than grozzing with pliers
for the rest of my life...

[email-masked]
Mark G. Forbes

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From: Sandra J. Grossmann <[email-masked]>
Date: 28 Dec 1994 19:20:14 GMT

In article <[email-masked]> Bob Neidorff, [email-masked] writes:
> a glass polishing machine.  Can you help?  

Well, no, I can't--sorry-- but whatever grinding wheel he/she winds up
with for this, please remember that glass "dust" is truly nasty stuff. 
If your friend can't put a vacuum shield on this grinder, then your
friend should maybe reconsider doing this at all.  And no matter what,
your friend should use HEPA respiratory protection.   

Anyway, good luck and good health...

SJG

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From: [email-masked] (Russ Kepler)
Date: Wed, 28 Dec 1994 23:17:40 GMT

In article <[email-masked]>,
>your friend should use HEPA respiratory protection.   

Not if they're grinding this with a wet grinder, as most of these
glass grinders are designed.  As to the suggestion the they use a HEPA
filter "no matter what" I'd suggest that you go back to class on that
- silicosis is a *long* term disease and I'd suggest that their
childhood playground exposure to silica likely exceeds the exposure in
grinding for a few glass windows.  I suspect that you're confusing
chronic exposure in a work environment with the occasional home
hobbyist exposure.

-- 
Russ Kepler posting from home  [email-masked]

                      Please don't feed the Engineers

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From: [email-masked] (Ncretc)
Date: 30 Dec 1994 08:36:59 -0500

Try Starret (I think)  Tool supplier (could be Starrett). It's not going
to be cheap but it should last forever.

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From: [email-masked] (Steve Rayner)
Date: Fri, 30 Dec 1994 12:50:24 GMT

>Anyway, good luck and good health...
I know of a person who used a diamond impregnated grinding wheel to hog out
a 12 inch telescope mirror. A flow of water over the work will eliminate any
glass dust.  A local glass co. uses a large vertical belt sander to smoot
the edge of glass after cutting.  It has an automatic water supply that
turns pon with the machine. The water is introduced at the top of the
sanding belt and exits via a trough at the bottom. 
As the maker of a couple of telescope mirrors I can tell you that a grinding
wheel will not polish glass.  It must be fine ground with at least 600 grit
carborundum, then followed with aluminum oxide powder (optional, but saves
work later). It is then polished with cerium oxide and a pitch lap.
All grinding and polishing compounds are mixed to a slurry with water.
 
-- 
                                Steve Rayner.