LAPIDARY ARTS and FACETERS DIGEST
Issue No. 173 - Thursday July 24, 2003
Moderated by: Thurmond Moore III
Committed to carrying on the fine works of
Hale Sweeny and Jerry Dewbre
POST TO EITHER LINK BELOW:
VISIT OUR WEBSITE TODAY
Good list today but I got very busy today and just about
forgot to do it. (If you can believe that)
Any more bad cutting stories? I know you have them.
You may just not want to remember them.
Keep those post coming.
Index to Today's Digest
01 NEW: Facet Laps
02 RE: Repetitive Motion injuries and faceting
03 RE: Lap Materials.
04 NEW: Worst faceting experience
05 NEW: Azurite Ball .............Mineral Question
06 RE: Copper/Brass?Steel lap
07 NEW: Free Internet Sites Posts
Subject: Facet Laps
Date: Wed, 23 Jul 2003 17:33:49 -0400 (Eastern Standard Time)
From: "Dennis Demerly" <email@example.com>
This is my first time asking for help in try to determine which lap to use
to do what to material on my machine. There are fast laps, copper laps,
lucite laps, corian laps, tin laps , ceramic laps, Batt laps, Etc. I am a
beginner factor and the classes I taken I find that everyone has a
different idea on what to use on what. Is there a book or any other type of
help one could get?
As far as great suppliers of facet rough a company call Lochs is great. You
can find him on E-Bay under Tiny Treasures. The prices match the material.
Thank-you for all your help. The Digest has been a great help.
Subject: Numb Index Finger
Date: Wed, 23 Jul 2003 14:26:48 -0700
From: "Paul Newman" <Vet.Surgeon@verizon.net>
I have been faceting a lot more lately on my Facetron and noticed that my
right index finger tip gets numb. I think it is probably touching the lap
while it is spinning as I hold the stone to the lap with my right hand. Has
anyone encountered this? I am a veterinary surgeon by trade and I need to
have all my senses, especially as they are slightly diminished through
surgical gloves as it is. I bought some "finger cots" at the drug store and
was just wondering if there are other solutions out there. I have been
reading the digest for quite a while and appreciate all the excellent
resources, guidance, and advice from the experienced cutters out there.
Paul Newman, D.V.M.
Alta Loma, CA USA
Subject: Lap Materials.
Date: Wed, 23 Jul 2003 17:46:52 -0400
To: firstname.lastname@example.org (LapidaryArtsDigest)
From: "Jonathan L. Rolfe" <email@example.com>
>Does anyone out there have any comparisons on the performance of copper as a
>lap material compared to brass and red brass. Brass is 67% copper and 33%
>zinc, red brass is 90% copper and 10% zinc. I know that copper has been the
>preferred material for the traditional laps but how does the other materials
>compare to it.
The bronzes have their adherents, but brasses do not do as well as one
would expect. Some reasons are the presence of zinc that toughens the
copper. Zinc is a funny metal for lap use; Some use it with no difficulty,
but many find it "Grabby". Another reason is that brasses vary in
processing and hardening or annealing, and can be unpredictable.
The alpha alloys can be differentiated by a gradual change in color, from
golden yellow to red, as the zinc content is increased up to 35%. Gilding
95%, Commercial Bronze, Jewelry Bronze, Red Brass and Cartridge Brass are
in this category of brasses. These are known for their ease of fabrication
by drawing, high cold worked strength and corrosion resistance. Increasing
the zinc content up to 35 % produces a stronger, more elastic brass alloy
with a moderate decrease in corrosion resistance. Brasses containing
between 32 and 39% zinc have a two phase structure, composed of alpha and
beta phases. Yellow brasses are in this intermediate category of brasses.
Brasses containing more than 39% zinc, such as Muntz metal, have a
predominantly beta structure. The beta phase is harder than the alpha
phase. These materials have high strengths and lower ductility at room
temperature than the alloys containing less zinc. The two phase brasses are
easy to hot work and machine, but cold formability is limited.
The microstructure of brasses containing up to approximately 40% zinc
consists of alpha dendrites with beta surrounding the dendrites. The
wrought materials consist of grains of alpha and beta. Cast alloys with
greater than 40% zinc contain primary dendrites of beta phase. If the
material is fast-cooled, the structure consists entirely of beta phase.
During a slower cool, the alpha precipitates out of solution at the crystal
boundaries, forming a structure of beta dendrites surrounded by alpha. The
wrought, two phase material consists of grains of beta and alpha. Hot
rolling tends to elongate the grains in the rolling direction. This
produces nasty surprises to lap makers, as they watch their laps
preferentially work-harden to deform into "Maltese Cross" Wavy washers
after some use.
Since brasses have a lower Brinell hardness( 55-65 BHN) than unalloyed
copper (80BHN), and these hardness tests use the penetration or indenting
of a steel ball, it would seem that diamond sinks into brass and charges a
brass lap more easily than it would copper- but it does NOT because the
beta phases are not ductile enough to be easily deformed to allow heavy
Since there is little difference in price between ETP copper and brass, and
no real performance benefit, most people do not bother with brass
laps. The bronzes, because of their tin content, do have a lower
coefficient of Friction (Less Grabby) and higher hardnesses (65-80, but
with manganese bronzes, 90-120BHN) than brass but similar to copper .
> For example steel is sometimes used and seems to do quite
Cast Iron used to be a favorite thirty years ago. It still makes a good
lap for sapphire and CZ. But cast iron is unique because of its
porosity. Steels are rather harsh acting. Stainless steels are galling
(Literally) and not successful. Aluminum is used by a few. For a
while. There is little to recommend it except it is ubiquitous and
cheap. It is something every experimenter has to try once, because it is
Over the decades I have tried everything, even bizarre materials like
molybdenum, titanium, and tantalum (Don't bother) and 999 fine silver
(Works as well as copper, therefore, on cost/benefit, silly to do.)
Subject: Worst faceting experience
Date: Wed, 23 Jul 2003 19:49:37 -0400
From: "denney.wilson" <firstname.lastname@example.org>
When I was learning to facet, my instructor gave me a piece of
beautiful peridot. He wanted me to cut it into a full 1.33:1 oval with
maximum brilliance and maximum size from the rough I was given. I
promptly dopped the stone and began cutting, confident that I could do
it as quickly as my instructor wished. However, I had not properly
dopped the stone and it immediately (on the first contact with the lap)
flew off the dop and away from the faceting machine! The rule in the
shop was that if you lost a stone, you had to find it before you could
do any more cutting. Sadly, the carpet (yes, carpet!) in the shop was a
beautiful peridot green! I looked for over 5 hours and could not find
the stone anywhere. Finally, my instructor's assistant volunteered to
help. After 2 hours, she said I should go home and she would keep
looking until the next lesson. After a week, she gave up. My
instructor said he had never permanently lost a stone in his life and
was not going to lose that piece of peridot! He looked for about 10
hours and gave up! Over the years, that shop has been cleaned,
recarpted, and searched and the stone has never been found! I
definitely learned to be far more careful when dopping than I thought
was necessary at the time!
Denney L. Wilson
Thanks for picking up the ball Denny. I have had a similar experience.
I did not lose the stone, however. I just had to remove it from my flesh where
it had poked a large entry hole. It is a scar to remember. LOL
Subject: Azurite Ball .............Mineral Question
Date: Wed, 23 Jul 2003 20:16:22 -0400
To: "LapidaryArtsDigest" <email@example.com>
From: "Peter In Maine" <firstname.lastname@example.org>
Hey , hope the summer is treating everyone well. Actually too hot hot here
Just picked up a killer specimen. It is an azurite ball located on what
looks like crystals of calcite.... Its matrix was carefully drilled around
this specimen to preserve it . Some 30 1/4 inch holes. The matrix is odd
looking and apprears to grey with white chunks of some mineral dispersed
evenly throughout the piece.
The ball is the size of a golf ball and in good shape , no damage done.
I do not know of its origin...
Can send pictures....
Peter...........Humid tonight............79 degrees
Hi Peter, 79 degrees huh? Trade you for my 105 plus. hehehe...
Subject: Copper/Brass?Steel lap
Date: Thu, 24 Jul 2003 09:58:50 +0930
From: Eric <EricWD@bigpond.com>
Any metal can be used as a polish lap with variable success. The softer the metal
the easier it will take up the bort ie. tin/lead. The harder the metal the less
it will take up bort ie steel. A hard lap will still polish but the bort remains
on the surface of the lap and will require constant renewing. a compromise
between a soft lap that will score and a hard lap that will not take up bort is
copper or cast iron in the form of Meehanite iron has proved to be the best until
Batt came along.
For cutting the hardest lap again is the most stable but requires sintering of
the bort into the lap. Softer material can be scored charged and rolled to give a
cutting lap that will last but beware of free bort contamination of finer laps
with that of the coarse Better if you can afford to use commercial sintered
Eric from OZ
Subject: Free Internet Sites Posts
Date: Wed, 23 Jul 2003 20:37:01 -0700
From: "Galarneau's" <email@example.com>
The Faceters Digest is a free for all Internet post site. As in many
free Internet post sites I find many business people advertising their
own self interests at no cost. I disagree with this practice and I
disagree whenever someone cuts off conversation about negative business
comments and post their thoughts as the last word. I see a lot of
buddy-buddy covering for each other and shutting down others comments
all in the line of business relationships.
One of the dangers of the Internet is that people do not post negative
comments for fear of being legally sued. At the same time positive
comments are always allowed to be posted. Someone may have a negative
comment concerning the product or action of the dealer and never post
it. People reading the posts only get one side.
If this site is interested in fairness then no comments should be
allowed about business and no one should be allowed to advertise their
business. That is fair to all and no one gets hurt.
I disagree with anyone who discounts another's experience. Relevance
applies to one persons experience and unless you are that person you
have no business passing judgment. You do have the right to comment on
the actions. Everyone needs to hear all sides of the story and leave
out the finger pointing.
Hi Gerry, If the cutting off of comments refered to my statements yesterday in the
digest let me say that my comment was my opinion and not a directive to stop
the discusssion. It just seemed that the same things were being said over and
over again. If additional comments are needed they are welcome. True enough
I believe some members do belong to various list just to have a place to advertise but
out of nearly 1000 members we have now only about 1% advertise their items on
this one. The cost is mine in time and effort. The payment is satisfaction that I am
providing a vehicle for those who are willing to share, learn and improve their
RESOURCES FOR LAPIDARIES:
PERSONALS: (General Lapidary and Faceting)
Lurking is fine, but participation is better for learning !
Post something from your experiences in gemcutting today!
TODAY'S FUNNY ~
YOU MIGHT BE A FACETER IF:
1- Your children are all named after gemstones.
2- You have at least 2 faceting machines.
3- You keep adjusting to get water dripping perfectly on the lap.
4- You are still a lurker because your 1st stone must be perfect.
5- You have a strong urge to cheat even when playing cards.
6- You can transpose angles but can't remember what 2 + 2 =?
7- You see someone has an eye tic and you immediately think about a lap.
8- You cut a perfect stone just to give it to a pretty somebody down the street.
9- You sit at your machine all day when it's a perfect 70 degree day outside.
10- You subscribed to Grit Magazine thinking it was about faceting abrasives.
11- You always smell like acetone and alcohol.
12- You think a scratched race horse got swarf between the race track and his nose.
13. You scrutinize 5 # of mine run thinking there's a gem in all this manure somewhere.
14- You know it's the expertise of the faceter that cuts a perfect stone, not your machine.
15- You dream about Gem Cad... "With sugar plum gemstone's light rays dancing all thru the night."
16- You see some rough and think... Gee, I need to get some more of that.
17- You always thought Lava Soap and a brush was just to get grease off your hands.
18- You are like a bloodhound always sniffing and howling... for that perfect lap & polish.
19- You are a strong believer in... It works for me!
AND LAST, BUT NOT LEAST....
20- You now have a fish aquarium NOT for windowed stones but because you LOVE fish!!!
"MAY YOUR GIRDLES NEVER ITCH!"
Submitted by: ~ Doug Smith
REFLECTIONS AND TIDBITS:
One day a fisherman was lying on a beautiful beach, with his fishing
pole propped up in the sand and his solitary line cast out into the
sparkling blue surf. He was enjoying the warmth of the afternoon sun
and the prospect of catching a fish.
About that time, a businessman came walking down the beach, trying to
relieve some of the stress of his workday. He noticed the fisherman
sitting on the beach and decided to find out why this fisherman was
fishing instead of working harder to make a living for himself and his
"You aren't going to catch many fish that way," said the businessman
to the fisherman, "you should be working rather than lying on the
The fisherman looked up at the businessman, smiled and replied, "And
what will my reward be?" "Well, you can get bigger nets and catch
more fish!" was the businessman's answer.
"And then what will my reward be?" asked the fisherman, still smiling.
The businessman replied, "You will make money and you'll be able to
buy a boat, which will then result in larger catches of fish!"
"And then what will my reward be?" asked the fisherman again. The
businessman was beginning to get a little irritated with the
fisherman's questions. "You can buy a bigger boat, and hire some
people to work for you!" he said.
"And then what will my reward be?" repeated the fisherman. The
businessman was getting angry. "Don't you understand? You can build
up a fleet of fishing boats, sail all over the world, and let all your
employees catch fish for you!"
Once again the fisherman asked, "And then what will my reward be?"
The businessman was red with rage and shouted at the fisherman, "Don't
you understand that you can become so rich that you will never have to
work for your living again! You can spend all the rest of your days
sitting on this beach, looking at the sunset. You won't have a care
in the world!"
The fisherman, still smiling, looked up and said, "And what do you
think I'm doing right now?"
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