LAPIDARY DIGEST
Administered by Hale Sweeny (hale2@mindspring.com)
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This list digest contains the following message subjects:

1. LapDigest News for Issue No. 154 - Wed 7/8/98
2. NEW: How to Access the Archives, Part 2
3. NEW: Using Opticon on Malachite in Carving
4. RE: Supplying Coolant to Lapidary Grinding Wheels
5. RE: Supplying Coolant to Lapidary Grinding Wheels
6. RE: Reconstituted Black Onyx
7. RE: Hydrofluoric Acid
8. WTB: Looking for Turquoise


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<MSG1>

Subject: LapDigest News for Issue No. 154 - Wed 7/8/98

The LapDigest computer has really been busy sending out files
this past week.. It has sent 92 of them! I went through the
requests and noted all reasons files were not sent, and, based
on these, further instructions for accessing archives are
given below.

Take care, and stay cool and safe.

..And above all, relax and have fun!!

hale
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<MSG2>

Subject: NEW: How to Access the Archives, Part 2

The description of 'How to Access the Archives' in the last
issue must have stirred up a lot of interest, for the
LapDigest computer has had 92 hits (92 requests for files)
on the Archives since that information was sent out.
Unfortunately, the information must not have been clear
enough, as there were a lot of errors in the requests which
were sent. I would like to add some more to those instructions.

First, the only thing in the Archives are files. These files
each have file names and a file extension. There is one
extension used for all files, and that is: 'txt'. You must
first learn the names of the files available in the Archives
before you can request them. I suggest you do this by sending
a message to 'lapidary@mindspring.com' with the single word
DIR on the Subject Line. You will receive a listing of all of
the available file names, along with a date and a file size.
I have tried to give these files very descriptive titles, so
you can guess the content from the file names.

Remember, to get the listing, send a message to
lapidary@mindspring.com with the single word: DIR on the
Subject line.

After you know the file names, you can get the file you want
by sending a message to the same address with the word GET,
followed by a space, and then the file name, all on the
subject line of the message. For example, to get the file:
Digest85.txt (which is a copy of the 85th issue of the
Digest), send a message to lapidary@mindspring.com with the
following on the subject line:

GET Digest85.txt

Don't forget the space; it won't work without it!

There is a file in the Archives named

LapidarySiCGrindingWheels.txt

This file contains information on Silicon Carbide Abrasive
wheels which formerly were the main lapidary wheels used. To
get a copy of this file, send a message with the words

GET LapidarySiCGrindingWheels.txt

on the SUBJECT line of the message. The computer reads ONLY
the subject line, sees the word GET and knows it is a
command message, and then ignores everything in the body of
the message.

Some errors in messages, and the reasons they were errors,
are given below:

..GETlapidary100.txt (no space between GET and filename)

..GET DIR (DIR is not a file name; only use 'DIR')

..GET ARCHIVIE.TXT (No such file; possibly misspelled)

..GET AUTOMATICCABGRINDINGEQUIPMENT.TXT (ditto)

..GET ARCHIVE1.TEX (Extension should have been: TXT)

..GET LAPIDARYGLUEANDCEMENTS.TXT (Should have been GLUES)

..GET INDEXTO100PART1.TXT (This file was renamed INDEX1.txt
some time ago; this points up the need to get new copies of
DIR periodically)

Finally, if all else fails, and you still can't get that file,
write me and I will try to help.

hale
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<MSG3>

Subject: NEW: Using Opticon on Malachite in Carving


I am looking for information on Opticon 224 use on large
stones, malachite in particular. I am wondering about
whether to use Opticon before carving or after for the best
results.

Look forward to hearing from you.

Thomas H. Louthen III
<louthen@mail.bright.net>
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<MSG4>

Subject: RE: Supplying Coolant to Lapidary Grinding Wheels


Hi all

OK so maybe I'm not the brightest person in the world here.
What keeps a bubbler type water unit from contaminating the
water? When you go from a 100 grit wheel to a 360 grit for
example, what keeps the 100 grit size chips in the water pan
from sucking back up through the system and flowing between
your stone and your wheel? What happens if your changing from
a hard stone to a soft stone? Do you have to scrub down the
pan and the tubing system between grits?

Sorry to be so dense, but I have always used a flow through
type system and have never understood how a recirculating
system could not contaminate your work.
TIA

Craig Nielson
cnielson@webtv.net
-------------------------------------------------------------
The contamination occurs when silicon carbide wheels are used
as the SiC abrasive grains really slough off those wheels and
would be carried by the coolant back to the work. But it does
not happen with diamond wheels, for some reason. Perhaps some
member can explain why. hale
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<MSG5>

Subject: RE: Supplying Coolant to Lapidary Grinding Wheels


I have set up my cab unit in the backyard where I can enjoy
the summer days here in S. California. I purchased this old
Raytech machine from a friend that was moving, as he did not
want it anymore. Unfortunately, it did not come with any of
the plumbing for supplying water to the grinding wheels.

So, here is what I did: went down to the hardware store,
and bought some drip irrigation components. The first was a
"manifold" that connects to your hose, and to which six
standard drip lines can be attached. I then purchased enough
drip hose to run from the manifold (which I fastened to the
side of the machine) to each one of the wheels. Above each
wheel, I drilled a hole, and inserted a drip line. All that
was required then is to attach my garden hose to the machine,
and turn it on just a little bit. This has worked quite well,
and cost less than $10. The water delivery from these lines
are much more substantial than traditional fittings/pumps.

Paul
<gemking@inland.net>
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<MSG6>

Subject: RE: Reconstituted Black Onyx

There are several sources for black onyx (dyed agate) which
is what most black onyx is. I am away from my catalogs at
the moment but the Lapidary Journal will have multiple
listings for black onyx in the classifieds. New Era Gems has
black onyx slabs for a reasonable price and GoodNews Lapidary
in Vermont has black onyx and even black onyx druzy for
reasonable prices.

THL III
louthen@mail.bright.net
-------------------------------------------------------------
The original question was about the stability of reconstituted
black onyx. Does anyone know of a reason this reconstituted
material would not be durable when used in doublets? hale
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<MSG7>

Subject: RE: Hydrofluoric Acid
RE:

On the subject of Hydrofluoric Acid aka HF, I missed the
original post but want to re-emphasize the very hazardous
nature of HF. This material is so hazardous that bottles
often come with a telltale label or strip that changes color
if the acid drips on it. This acts as a warning to the
knowledgeable to not pick up the bottle. Bottles also have a
special drip-resistant spout. If you use this material get
the MSDS and carefully study it before you handle it.

The MSDS is available from:

http://www.uos.harvard.edu/ehs/safety_alerts/
alert_hydrofluoric_acid.html
and:

http://www.chem.utah.edu/MSDS/H/HYDROFLUORIC_ACID

You must wear gloves that are resistant to HF, most gloves
are NOT resistant, a proper pair may cost up to $50. You
also need a full chemical face shield, NOT the type you may
pick up at the hardware store. And a chemical apron. A
respirator is also required since expose to 50 ppm may be
fatal. Burns are often not painful and thus treatment which
is very specific may delayed until its too late. A special
first aid kit should be available. Operations should be
conducted under a fume hood.

J Bryan Kramer
<jbryankramer@e-mail.msn.com>

"non-commercial republish permission granted"
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<MSG8>

Subject: WTB: Looking for Turquoise


Hi Folks -

I need a small slab of turquoise for a silver belt buckle a
friend is making at my workbench. When he sawed out the
design holes that the turquoise was to go into he discovered
that my pieces were too small to fill the two largest spaces.

What I'm looking for is a slab not smaller than
1 3/4" x 1 3/4" (and preferably not much bigger either), at
least 1/8" thick and not more than about 3/16" thick.

I'm posting this request to the list because there isn't
anywhere I know of within 500 miles of where I live where I
could get such a thing. If you have a slab of the proper
size that you'd be prepared to sell or to trade, please e-mail
me privately.

Cheers & thanks
Hans Durstling
Moncton, New Brunswick
Canada
e-mail <sinico@nbnet.nb.ca>
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To subscribe to the Lapidary Digest, send a message to
Lapidary@mindspring.com, with the word SUBSCRIBE DIGEST as
the subject of the message. Other commands you may use are:
UNSUBSCRIBE DIGEST to quit, HELP to receive a page of help
instructions on the use of the list, and DIR to receive a
list of names of all files in the Archives.

The command <GET filename> may be used on the subject line
(without brackets, of course) to obtain a copy of the file
named "filename". Type filename exactly as it appears in the
directory, including the extension txt. Do not cut-and-paste
filenames into the subject line.

Each author is requested to write the words
"non-commercial republish permission granted" at the end of
every item submitted. This gives permission for others to use
your item for non-commercial purposes. Please use those four
words at the end of each item you submit.
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