Administered by Hale Sweeny (firstname.lastname@example.org)
This list digest contains the following message subjects:
1. LapDigest News for Issue No. 104 - Tues 1/13/98
2. NEW: Need Pump/Spitters to Retrofit to Old Genie
3. NEW: How Can I Vibro-Polish Lapidary Carvings?
4. NEW: Gemcutter Certification
5. RE: Drilling Holes in Lapidary Items
6. RE: Drilling Holes in Lapidary Items
7. RE: Drilling Holes in Lapidary Items
8. RE: Drilling Holes in Lapidary Items
9. RE: Gluing Doublets and Triplets
10. TIPS: Tumbling Tips
11. SCHOOLS: West Chicago Suburbs
12. BIO: Bill & Betty White
13. FS: Lapis and Kunzite
Subject: LapDigest News for Issue No. 104 - Tues 1/13/98
This is a large issue, with 13 items. When the issues start
getting too large, let me know, and let me know how you think
they may be made shorter.
Let's get right on to reading about lapidary, but before you
do, I want to remind you to please work safely, and be sure
to hug those you love!
Subject: NEW: Need Pump/Spitters to Retrofit to Old Genie
I've contributed a few items to the Digest and now it's my
turn to ask for some help. I do most of my cabbing with an
older Genie (about 1987 or 88) from Diamond Pacific. I'm in
the midst of cutting out a very large parcel of Lightning
Ridge opal and anyone who's cut nobbies knows they make a lot
of mud. I'm very partial to Queensland mud...and what's found
in it. But you have to be able to see it in order to find
it, and there's the problem.
The water delivery spitters on my machine have never been
terribly efficient. I've rebuilt the pump, soaked the
spitters in Lime-Away to counteract our very hard water (I
wonder if it'll cut?), replaced the hoses, etc. Not enough.
I discussed the problem with a Diamond Pacific rep at a show
and while he was generally helpful, his "solution" was to buy
a new machine. Well, that would be nice but everything works
perfectly after 10 or more years (free testimonial, Diamond
Pacific!) except the water system. And apparently pumps from
newer machines can't be retrofitted onto older ones.
Does anyone out there have a solution that avoids plumbing
the machine into the house and setting up a drainage system,
etc.? Is there an after-market spitter that does the job?
Some way to jazz up my pump to get some real water
pressure/volume? Thanks in advance for all input.
Subject: NEW: How Can I Vibro-Polish Lapidary Carvings?
Since I recently got a vibro-tumbler for use in lapidary
(thanks, CJ), I'm wondering how I can use it to sand and
polish gemstone carvings. I'd particularly like to be able to
get into the (deep and sharp) crevices without wearing down
the high spots too much. When one uses a similar machine to
finish metal objects, it is customary to use "ball-cones" or
(American) football-shaped steel shot to accomplish this.
Does anybody know of an analogous medium intended for
lapidary use? I'd especially be interested in diamond-based
media, either plated shaped shot, or a ceramic-diamond alloy,
in various grits.
Failing that, how about a cheap source of diamond powders so
I can make my own- I've heard the Chinese have dropped the
price considerably of late. Even better would be somebody who
is set up to plate diamond onto steel- would it be
prohibitively expensive to plate a few pounds of shot?
It is certainly tedious to sand and polish these little
carvings with five successive grits of diamond paste by hand
- I've got quite a backlog of roughed-out carvings waiting
for me to figure this one out...
Subject: NEW: Gemcutter Certification
In a message dated 98-01-10 18:55:57 EST, you write:
<<I have earned my supreme master gemcutter certification
from the American Society of Gemcutters in 1995. >>
How does one go about obtaining this certification??
Subject: RE: Drilling Holes in Lapidary Items
I am looking for advice for inlay work; I have been looking
for a cutting tool that will cut a core so I can inlay a
small circle in a cabochon.I have been experimenting with
small pieces of tubing and silicon grit to cut a core.
The process is painfully slow, even with soft material.I have
a dremel tool in a drill press setup, and my biggest chuck
will only handle a piece of tubing as big as a refill
cartridge on a ink pen.The metal tube overheats easily and
distorts. I would like to find a diamond core cutter that
will fit my dremel tool.
Subject: RE: Drilling Holes in Lapidary Items
How I Drill Holes In Lapidary Items
There are several instances where you may wish to drill holes
in rocks. First, suppose you've found a perfect little
baroque rock on that last agate hunting trip. It doesn't NEED
polishing to go in that necklace as a piece of "found" art,
so what do you do? Well you could glue a bell cap on it, but
that would cheapen it's natural elegance. Or you could do
what I do and drill a hole in it for stringing. Another
example: a friend of mine made a beautiful little black and
white channel work panda bear, and obviously the panda bear
needed eyes. This was solved by drilling two holes, which
were filled with pieces of silver wire. There are many other
places where drill holes are needed in stone; the way I drill
such holes is described below.
Basic Drilling Setup
I use a Dremel hand tool mounted in a Dremel drill stand and
a set of diamond drills - for small holes, such as in beads,
and a set of core drills - for larger holes. The purpose of
holding the Dremel in a drill stand is to assure that the
drill is rigidly fixed in one up-and-down position. Hand
holding the drill with very small drill bits is inviting
broken drill bits! The important thing is that the drill bit
should be rigidly fixed in one up-and-down position. If you
do it my way, you will also need a big chunk of putty - the
kind that doesn't get hard, and is not water soluble.
With the drill mounted in the drill stand, mount a small
(about 4" x 4" x 1-1/2") block of wood on the drill stand
base. The block of wood should have smooth upper and lower
surfaces. I attach the block to the drill stand base with
double faced carpet tape. Then put a small ball of putty on
the wood block under where the hole will be drilled, and
press the stone into the putty. (The putty gives a firm base
for the stone and allows the stone to be oriented in the
direction you want the hole to be drilled!) Put the drill in
the collet and put it in as far as possible. Only a small bit
of the drill should project past the collet, to reduce the
chance of drill breakage.
Next, build a small dam of putty around the hole-to-be by
taking a small chunk of putty, making it into a small ball
and pressing it right on top of the stone where the hole will
be drilled. Take some small cylindrical object, such as the
eraser end on a pencil, or one end of a small dop stick, and
press it into the putty all the way down to the stone, making
a cavity into which water can be placed. Put water in the
dam - just a little bit - and hold the stone steady when you
drill. Note that an eye dropper is often useful for adding
Set the drill speed according to the values in the chart
given in the Section "Some Added Notes". One hand continually
steadies the stone. With the other hand, lower the drill
slowly, through the water, until it just comes in contact
with the stone, and apply LIGHT pressure till drill bit makes
an entry point... then it is up and down and up and down till
the hole is drilled... Up -to let more water into the drill
hole and to cool the drill, and down - to drill a little
further... till the hole is through. If you want to go all
the way through the rock, then at the end, break through
slowly. You will probably have to extend the drill further
from the collet as you continue to drill... just keep the
amount of exposed drill to a minimum.
To avoid breaking stone out as the drill makes its exit, I
have had some luck with placing a piece of strong shipping
tape on the bottom of the rock where the drill will exit. But
remember that it is very important to make the exit from the
stone very slowly!
If you start drilling on the side of a rock 'hill', the drill
will tend to wander downhill, bending and flexing the drill
with every rotation. For this reason, you should select a
relatively flat place on the stone to drill, as on a slab.
This is exactly the problem when you try to drill a perfectly
spherical bead; you want the drill to enter exactly at the
top of the bead, but the slightest deviation from the top and
the drill is on a hill!! There are special jigs available
which hold the bead, top and bottom, with a hole centered in
the top holder. You clamp the bead in the jig, and drill
through the hole, and the drilled hole will be perfectly
centered. Such jigs are especially useful for drilling
For these reasons, you should lower the drill slowly as you
contact the rock, and use very light pressure to get the
drill hole started. Or you may try a sharp burr to start the
hole; usually a burr shank is much larger than a drill bit,
and is much less flexible.
For drilling very small stones without using a dam , you may
use an eye dropper of water. Hold the stone by hand, and put
a drop of water where the drill hole will be. Then drill down
and up through the water drop, and frequently (as the drill
usually slings the water away) put a new drop of water on the
drill hole and repeat. Now you may think this takes three
hands - it will indeed go faster if you can talk some friend
to add the water, but you can do it alone. When you let the
drill up. let it go all the way up, then take the hand you
were pulling on the drill with and pick up the dropper and
add the water. That's how you can do it alone, but it is
faster with someone else there.
Special Methods for Spherical Beads
You usually shouldn't drill a hole all the way through a bead
in one pass. If you do, you run the risk of some material
spalling as the drill emerges on the far side, disfiguring
the bead. Also, it may be impractical, as the drill may not
be long enough. And finally, you may have started the hole a
little off-set from vertical or not squarely through the
center of the bead. If you drill all the way through, the
hole will be off-center. For all of these reasons, you will
want to be able to drill holes from both sides to meet in
the middle. But they should meet squarely in the middle. If
they are offset in the middle, this can offer a rough place
at the junction of the two holes which may fray the bead
string. The solution is simple and obvious. Get a small nail
or brad as close as but smaller than the size of the drill,
cut the head off and smooth the upper end, chuck it in the
drill and drill a hole in the wood block to get the nail
squarely oriented with the drill. Then carefully hammer the
nail in further.
If you cut a conical-shaped hole in the wood block, and
center the hole directly under the drill, then beads put in
the conical hole will automatically center under the drill
and this is a good way to hold the bead when you start the
After the first hole is drilled in the bead, put some putty
around the nail and put the bead on the nail, pressing it
into the putty. Then drill as above. If you have set the nail
down far enough so that the amount above the block is about
1/3 the diameter of the bead, and if you drill a little more
than half way, both times, you will complete the hole and
will not run the drill into the nail. If the first hole was
off-center, the drill will not be centered properly when you
start the second hole; the nail will usually be smaller than
the hole, and this will allow you to position the bead so
that the second hole will exactly enter the top. You may
smooth the hole with a set of hole reamers to remove all
interior rough spots, or use abrasives on a chord or thong
(this is called "thrumming"). Also use abrasives to smooth
the ends of the drill holes.
Note that in all the above methods, if you drill through the
stone or bead, the water will flow through the bead and onto
your workbench. There is not usually a large amount of water
when drilling this way, but there is a way to prevent any
water spillage. In setting up the drill, first attach a
large pie pan to the base of the drill press, using
double-faced tape, and then put the block of wood in the
pan, attaching it with tape or adhesives. The rest of the
set-up is as before. Any water spillage will flow into the
pan. This will be important for large holes as discussed
Drilling Larger Holes
If you are tired of drilling wimpy little holes for bead
stringing, you CAN drill much larger holes for such uses as
mounting holes for award plaques. These larger holes - 1/4
inch diameter and larger - are made with diamond core drills.
A typical core drill consists of a tube with diamonds bonded
to one end, and a plug in the other end which has a shank for
holding in the drill. A hole in the side wall of the core
drill is available for pressing out the drilled cores.
These diamond core drills work the same way, except that the
dam is made differently. For core drills, I almost always use
dams made from a narrow flat ribbon of putty which is circled
around where the core hole will be drilled; the circle being
slightly larger than the core drill, of course. Water is
added to the dam, and you drill as before. If you have a
small diameter core drill, after you have started drilling
and are down about 1/4 inch, stop and put a small screwdriver
in the slot and pry - the core will pop out, and you can
After the first core has been popped out, the hole serves as
the cavity for holding water and you can remove the dam. A
pie pan under the whole setup will again catch the run-off.
That is all there is to it!!!
Some Added Notes
Diamond drills are usually made from 'music wire', which as I
understand it, is the wire used to string pianos; it is a
very strong, stiff but not brittle wire. Diamond particles,
usually man-made, are then bonded to the bottom and for a
short distance up the sides from the end of the wire.
There are two kinds of diamond drills: sintered and plated.
In sintering, finely divided particles of metal are compacted
into the desired final shape and heated to a high
temperature, the particles fuse together without melting. In
making sintered drills, diamond particles are mixed with the
metal particles and compacted around the wire; thus diamonds
are distributed all the way through the sintered part of the
drill. In plated drills, diamonds only coat the outside of
the drill bit. The plated type drills should only be used
for light duty drilling; continuous drilling or repeated
drilling in very hard materials requires sintered drills.
The drills are quite small. Typical drill sizes start at
3/4mm and go up to 2-1/2mm, and require collets of either
1/32" or 1/16". Typical drill sizes are shown in the table
below, which were taken from Kingsley-North  catalog.
Table of Available Diamond Drill Sizes Available, with
Required Collet Sizes, from Kingsley-North Catalog.
Diam of Drill Appx. Drill Diam. Collet Size needed
(mm) (in.) (in.)
3/4) 0.03 1/32
1 0.04 11/32
1 1/4 0.05 1/16
1 1/2 0.06 1/16
2 0.08 1/16
2 1/2 0.09 1/32
Core drills are essentially tubes onto which diamonds are
either plated or sintered along the bottom edge and for a
short distance up the side.. The upper end of the tube is
plugged and a shaft extends from the center of the plug by
which the core drill is turned. A hole in the side of the
tube allows "cores" to be knocked out of the core drill.
Crystalite Core Drills are listed in the Kingsley North
catalog as ranging from 3-1/2mm OD to 2" OD. The sizes are
[3-1/2mm, 1/4"(1/16")3/4"(1/4")2"], where 1/4(1/16)3/4
means sizes from 1/4 to 3/4 in steps of 1/16. The shanks
range from [1/8"(1/16)3/8"] Thus the smallest core drills
may be held in a Dremel, but as the size increases, they
soon they will require a larger chuck than is available on
According to Sinkankas , the speed of drilling will
depend primarily on the size of the drill bit, as follows:
* small diamond bits: 4500 - 5500 rpm
* small tubular core drills: 2000-3000
* large tubular core drills: <2000rpm
 Sinkankas, John; GEM CUTTING, A Lapidary's Manual
Third Edition p.103-104
 Kingsley-North Co. Phone 1-800-338-9280 for catalog.
Subject: RE: Drilling Holes in Lapidary Items
(In Issue 103, Charles discussed drilling and suggested that
Dapfun-Pac Adhesive was good for holding rocks under water
for drilling. He was asked to tell a little more about it.)
Dapfun-Pac Adhesive can be found at Michaels, Builders
Square, and Home Depot, and at picture framing Galleries, and
most good variety and Fabric stores like cloth world. It has
many uses: it can be used to hang pictures , where you don't
want to damage the wall; faceting judges use it to hold
stones during examination. It will hold the stone securely,
but will release the stone, leaving it clean without marks.
It can be used to hold stones or minerals for display. It is
a green greaseless kind of adhesive that looks like putty.
It comes in a package with 4 or 5 sticks 1/4" thick x 1/2"
wide x about 4" long. and it costs about a buck.-..... That's
about all I can tell you about it.
Charles W. Covill
Subject: RE: Drilling Holes in Lapidary Items
Thanks to all for the info about drilling gems. One thing
occurred to me in reading these, and that is the issue of
safety when using water with electrical equipment. Perhaps
most of you know this but, please be sure that your equipment
is connected to a Ground Fault Interrupter if you are going
to be using it with water. The reason is of course that the
water increases the likelihood of an electrical shock which
could be fatal!!!
Ground Fault Interrupters in my area cost about $8 and simply
replace the normal wall socket. They do not require special
wiring even if the wires coming to them don't have a ground
wire (I got this info directly from a licensed electrician).
If you don't want to change your wall sockets you can buy an
extension cord with a GFI receptacle built into it. I have
one of these cords and I use it whenever I am using
electrical equipment around plumbing or wet conditions. This
special extension cord might be a good idea for when you are
setting up for rock shows.
Take care and be safe.
noncommercial reproduction permission granted
(Ed. Note: My friend Mickey Broadway, a rockhound lapidary
buddy who also is a licensed electrician, says it only takes
5 milliamps to kill you; the GFI measures the current going
out in the black line and the incoming current in the white
line, and shuts off power if the difference is 4 milliamps.
At $9 a socket, it is so cheap that all shop wall sockets
should be GFIs. As he says above, be safe!! USE GFIs!!! hale)
Subject: RE: Gluing Doublets and Triplets
I know the subject of making doublets was discussed awhile
back. I read and learned from the writings, but they dealt
with small size stones, mostly opal. I have made small size
doublets off and on for many years and experienced only
slight difficulty with the mechanics. At the present time I
am making a bunch of doublets using material collected on the
Grasslands from Nebraska N.E. This material tends to be
earthy, with pits and soft spots. Most of what I am grinding
up is 30mm-100mm.
Question to All: Trapped air is my number one problem, I
would appreciate any advice, from any source. I have rigged
up a small vacuum pump and it helps some. However, there
seems to be air trapped in the Epoxy. I am using Epoxy 330.
The pumps removes the air under the bell, but there still
seems to be a tad trapped in the epoxy. I do the following
things: Heat the glue. Place the glued components with cap
down. Place under vacuum bell. Keep level. Have thought about
clamping components but can't think of a good way to do this.
Would love to hear from any one with experience making large
Bill & Betty White
(Ed. Note: Bill, I'd like to suggest that you consider
changing adhesives to Loctite Crystal Clear Glass adhesive. I
feel that no matter how slowly and carefully I mix epoxy, air
seemed to always become entrapped during mixing. Loctite
doesn't require mixing, it is very thin and you should be
able to glue the caps on without bubbles. It's worth a try!
This glue was discussed starting at Issue 86, 4th item.
Let's hear other opinions on the question he raised. hale)
Subject: TIPS: Tumbling Tips
The biggest problem you will have with tumbling rocks is to
get them absolutely clean in between cycles. You don't want
one speck of grit to get into the polish because it will mar
the finish and you will not have bright shiny rocks after
they come out of the tumbling cycle.
The other problem is to keep rocks of basically the same
hardness in the same tumble batch. That saves some of the
softer stones from getting beat up by the harder stones.
Subject: SCHOOLS: West Chicago Suburbs
The West Suburban Lapidary Club and the Elmhurst Park
District of Elmhurst, Illinois will be giving lapidary
classes this winter, in Silversmithing, Basic Wirewrapping,
Cutting and Polishing Stones, and Jewelry (Ages 7-14)
Course descriptions can be found at the WSLC home page:
Subject: BIO: Bill & Betty White
Hello Hale and all the Digest:
My name is Thomas W White, (Bill) my wife's name is Betty. We
have been in this hobby for many years. Betty collects
minerals and show them at many shows My prime interest is
field collecting and general lapidary. I Grind cabochons.
We are active in several clubs, The Independence Gem &
Mineral Club and the Lincoln Nebraska Gem & Mineral club and
the Topeka Gem & Mineral Club, also active in promoting the
Greater Kansas City Gem & Mineral Show held each March. 13th
- 15th, 1998. Betty and I are Special Exhibit chairpersons
for the upcoming Lincoln, Nebraska show to be held March 28th
Bill & Betty White
Subject: Lapis and Kunzite
I just got a parcel in from one supplier of cab material. I
have Lapis and Kunzite for $200 per kilo plus a minor charge
for shipping. I have about 5 kilos of this material.
If you want the entire lot, I will sell all 5.3 kilos for
$1000 and include the shipping. I really don't want to get
into cab rough at this time.
If you are interested in the material, please contact me off
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