Edited and Published by Hale Sweeny
Web Site:
Associate Editors: Geo. Butts, JR Shroeder, Steve Henegar
and Margaret Malm

This list digest contains the following message subjects:

1. LapDigest News for Issue No 267 - Sun 3/19/2000
2. NEW: Power Feed Rates on a 18" Slab Saw.
3. NEW: Soft Stone Carving
4. NEW: Undercutting with a Vibratory Flatlap
5. NEW: Another Way to Clean Saw Oil
6. RE: Another Way to Clean Saw Oil
7. RE: Expanding Drum Problem
8. RE: Expanding Drum Problem
9. RE: Expanding Drum Problem
10. RE: Mineral Oil as a Cutting Lubricant
11. RE: Mineral Oil as a Cutting Lubricant
12. RE: Zebra Marble
13. BIO: Dennis Marinac
14. BIO: Judy Turner
15. SHOW: Minnesota Mineral Club in Minneapolis
16. FS: Expandable Drums and Belts
17. FS: Frantom 20" Slab Saw


Subject: LapDigest News for Issue No 267 - Sun 3/19/2000

In case you haven't seen it, take a look at the website:
It focuses on faceting, and also on Gerald Wykoff.

I'm sorry if you got two (or maybe even more) copies of the
past two Digests. My list management program has a problem
that I am working on! Hopefully no more duplicates!

Thanks all of you who have written listing your expandable
drums and describing your experiences with them. If you
have not done this yet, please send me a note telling me
what drums you have (makes, sizes) and their ages. Thanks,

Here is an idea... tell me what you think. Newcomers need
someone - as mentor - they can turn to with questions and
get expert answers. We have lots of experts on this list
who might volunteer to help beginners. We can post a list
of such volunteer mentors in their specialties: polishing,
intarsia, channel work, carving are examples of such
specialties. Is this a good idea? Would you be willing to
volunteer to be a mentor (if so, write and tell me which
areas you would feel comfortable helping out in.) Would you
like to see us develop such a mentor list?

Spring is such a beautiful time of the year. In NC, our
dogwoods' blooms make the whole area a carpet of white.
Makes you just feel good to be alive! Take advantage of
this. Teach your children to enjoy and appreciate all this
beauty; take them on walks in gardens and areas where spring
is bursting. The time will be repaid many times over.

And while you are at it, be sure you all have fun together.


Subject: NEW: Power Feed Rates on a 18" Slab Saw.

Hi Hale & fellow list members,

I'm building an 18" slab saw and am ready to build the
power feed. I need help on determining the correct feed
rate for the power feed. Does anyone have any info on feed
rates needed for various materials?


Noel: When you are finished (and if it works OK (smile)),
please share the plans you are using and let's put them on
the website so others will have some idea to go by. Will
you do this? hale

Subject: NEW: Soft Stone Carving

Hi Hale -

I do a little soft stone work; my first was some catlinite
which my grandfather brought me in 1956. My favorite is a
gemmy serpentine I've collected from the Thurman-Athol, NY
asbestos mines near Lake George, NY. This material can be
worked either as a soft stone (it responds to files and
hacksaws) or as a hard lapidary stone because it is fully 4
in hardness.

The best book I've found is now (I believe) out-of-print.
Here are the specifics: SOFT STONE CARVING by Carson I.A.
Ritchie. A SCOPAS Handbook published originally in Great
Britain. US edition 1973 by St. Martin's Press NYC

This is a nice little book (86 pages) which includes a
number of unlikely carving materials, like Blue John
fluorite. It has a variety of techniques described, along
with much of their historical derivation. The book is
distinctly British/European in background and description.

Jim Small
Thanks, Jim. I ordered the book from a used bookstore in
England and it will be here in several weeks. hale

Subject: NEW: Undercutting with a Vibratory Flatlap

Hello All:

I am having some problems with unakite blocks in my flat
lap. I am using a Lortone 15" vibratory flat lap and
blocks of unakite collected at a gravel quarry near
Richmond, VA.

The material is typical of unakite, consisting of a compact
granitic aggregate mostly of epidote, quartz, and feldspar.
Chunks are about 1" thick and around 18^2(sq.) inches in
mostly rectangular, but irregular edged, pieces.

I started with 2 pieces of unakite, and 2 matching sized
pieces of red granite from the same location. First
charge was with a course tumbler grit. My local lapidary
was out of stock in graded grit, so I opted for the
tumbler charges. This gave me a uniform surface, with no
saw marks to start out with, and only took about 4 hours to
complete. I then moved to a graded 400 grit, and allowed
to run until smooth to hand and eye, required about a day.
Next came a graded 700 grit, ran for 1.5 days, until surface
was glassy when damp, and clear of surfaces changes.

To this point, all is well, at least everything eye and
feel inspected well. The surface of both the granite and
the unakite are doing great and life is good. So I switch
to a polish pan, with a thin pad in the bottom (as provided
by Lortone). I charged this first with Raybrite A (my
default polish) and let her run for a day. Came back to
find the granite looked great, but the unakite showed a
very ugly pattern of unpolished, and pitted areas, and
polished areas. A molted look say, and not at all
attractive. But the granite is perfect. Both piece of
granite started life on the lap with cracks going through
them, and I felt for sure grit would tear those open, but
instead they simply came out perfect. The unakite looked
better on the saw side then the polish side.

I am currently rerunning the polish in a clean pan with TL,
to see if the Raybrite was the culprit. I have made sure
my pans are always purged and brushed between grits, etc.,
as well. As far as I know, the granite and unakite are
basically the same type of aggregate, from the same types
of base minerals.

Any help, ideas, recommendations on how to best drive a
flatlap, save me from this problem of undercutting, grit
recommendations, charging methods, how much water to use,
etc., would be greatly appreciated. Please email to me
directly. I will consolidate the various suggestions into
a single flatlap FAQ and send back to the list for

Whoa, Jim!!! Before you go off doing that, please go to
the Archives and search for stuff already there. We had a
lot of items in Digests #25 - 150 (and also outside this
range.). Search Alta Vista on 'vibratory lap' or on
the two keywords:( +vibra +lap). Lots of items there,
and you would just be duplicating what is already there.
Don't remember anything about undercutting, but I do have
CRS, so you had better check! hale

Subject: NEW: Another Way to Clean Saw Oil

Just a thought...

I've gotten recently a nice Rock Rascal 6" saw, and so don't
use a lot of oil at once... but I still want to reclaim it.

I bought:

1) A jar of pickles (ate the pickles, cleaned the jar)
2) A 99 cent plastic funnel
3) 6" round HEPA filters (it was 3.79 for 100 at Home Depot
or another Do-It-Yourself type place)

Total cost: five bucks and change.

Take a hepa filter, fold it in half. Then fold it in half
again. Open it up and you will have a cone shape. Put it
in the funnel and put the funnel atop the jar so it's lip
rests against the lip of the jar, or in any case so it's
business end is in the jar, and the jar's holding it up.

Pour your used oil into the funnel.

Repeat as necessary.

Like I said, I don't have a lot of oil to reclaim, but HEPA
is certified against bacteria, so suspended particulate
should be caught easy enough. After one or two funnels
full, the filter needs to be changed, but they're basically
free when you look at their unit cost. I like this method
because it's cheap, efficient, clean, and requires the
brain power of a flea to set up.

Ryan Kolter

Subject: RE: Another Way to Clean Saw Oil

I also recently changed from Pella oil to mineral oil. (I
paid 99c/14 oz at the local 99c store (that’s $9.14/gal).
They thought it was baby oil.) I was amazed at how much
more pleasant it was cutting without the mist, and the slabs
don't stink. I too found the slower sedimentation to be a
problem. Having only used Pella oil, I was accustomed to
rapid filtering through the paper bags with a pretty hard
paste, but the mineral oil never seemed to finish. It
remained jelly-like for weeks. (I was cutting hard stuff

The reason I am writing is to share some bag-filtering tips
that I read in an old LJ (sorry, no reference). The first
couple of tricks are pretty simple - look inside the bag
for holes before you start, and trim off excess paper from
the top to save a smidgen of oil. The main tip is to wait
until the filtering has stopped, fold the top of the bag
down to close it, and put a weight on top. The author used
old bags as weights on top of new bags, making a big stack
of bags to squeeze out every drop.

It was a longish, humorous article and probably had more
tips, but those are the ones I use. I'm still at the
big-rock-on-top stage though.

Flint Smith (though not for long. I'm moving to FREE internet)

Subject: RE: Expanding Drum Problem

Hale -

Over the years I've used a variety of 8" diam. expandable
and locking sanding drums. I've pretty much settled on the
Raytech expandable drums as being the best, and currently
use three of them; two on a Poly arbor, and the third as
the end drum on a Beacon Star unit.

I have always purchased generic SiC belts for 8" drums, and
never had any difficulty mounting the belts. Nor have I had
any problems with slippage while the units were running.
The three inch wide leather belts for polishing also work
very easily. Interestingly, I have had trouble mounting the
diamond-chargeable resin belts from Raytech. This hasn't
been too much hassle, because one belt lasts over a year
with careful use, and I leave it mounted.

I have had only good experiences those few times I used 6"
Raytech expandable drums. My only complaint about any 6"
wheel is it is too small to be effective in a commercial

Jim Small

Subject: RE: Expanding Drum Problem


Yes, I have plenty of experience and almost daily use of
lapidary machines equipped with drums and belts. Ten years
ago I used the 'take apart' drums which had to be removed
from the shaft in order to change belts. We have come a
long way with the expanding drums which allow changing of
belts without removing drums from the shaft.

In my business, I have two custom retro-fitted Lortone
arbor machines with dual drums on each side that have a
total of eight (8) molded rubber drums which get heavy use
daily. I will respond following the number order of your

1) These drums are 6" x 2-1/2" molded rubber.

2) Manufacturer: Scott-Murray Censpan HY-POL drums (sold
though Lortone to dealers.)

3) My business equipment, drums, and Silicon Carbide belts
were purchased from Alamo Rock Shop, #27642 Interstate
10-West, Boerne, Texas 78006 Phone (210) 698-2666.

4) Drum type: molded rubber on the rim with 45 degree
slots in rubber.

5) Eight Drums in use from 6 months to over 3 years old.

6) Any trouble fitting a belt over the drum, either too
tight or too loose?

Yes, both problems. I experienced very loose belts on one
wheel and it had to be replaced to fix the problem. Usually,
most belts fit snug to tight and I am told are made that
way. My procedure in changing a belt is to use both hands
to manually rotate the arbor slowly, maybe 10 times or so.
By using a push and pulling motion, the belt will slip off
the drum. It is easier when the wheels are wet. New belts
slip on much easier, but I use the same procedure of slowly
rotating the arbor and wheels and hand 'inching belt onto
the drum.' The process is much easier than it sounds as I
have described it.

If the machine is not used for a couple weeks, belts can dry
up and be very tight on drums. I have resorted to slipping
a knife under a belt to slice it off. Be careful not to cut
the rubber.

Other comments:

Usage: Main machine in shop is used an average of 4 hours
daily and 3-4 days per week. My second machine is on a
portable table on wheels and is used weekends at shows. It
runs almost constantly for 6-8 hours. All four belts are
frequently changed one or two times per show. I am hard on
drums, but have only replaced one three-year-old wheel that
shrank from extended use. I rotate drums on the arbor and
reverse rotation direction for the 400 and 600 grits. They
last longer (much like your car tires.)

Note: My old drum was recycled by an auto mechanic who is
using it with a polishing compound to clean metal parts.

I hope this information helps and keep up the good work.

Ron Day, Bryan/College Station, Texas

Subject: RE: Expanding Drum Problem


It has been a while since I switched from expanding drums
to diamond wheels, but my comments are as follows:

I purchased expanding drums and the belts from Rio Grande
Gems and Findings. Everything was perfect for a while,
then it got harder and harder to put on the belts as time
went on. I think, although I don't know for sure, that the
drum loses some of it's elasticity from extended use at
high RPM's and doesn't contract as much when the power is
off, thus making the drum "grow" over time.

Just a thought.

Greg Peters
Greg: I hypothesized the same thing when we were setting up
this project, and plan to collect data which may prove or
disprove this. It is a good thought .. Thanks. Hale

Subject: RE: Mineral Oil as a Cutting Lubricant

If you want Shell Pella cutting oil, in your Yellow Pages
look under oil distributors. I just purchased a 5 gallon
bucket for $29.87. In my 10" trim saw I used to use
un-scented KEROSENE, now just plain water. I drain and
clean and spray with WD-40. I've been doing it this way for
16 years; the saw is a Lortone purchased in 1975. It is a
little more work this way, but, if I'm cutting inside the
garage or on the porch there is no oily mist to contend
with. I use the Pella in my 24". Can't find the un-scented
KEROSENE since we moved to the central coast of California.



Subject: RE: Mineral Oil as a Cutting Lubricant


I just want to say your note on LD-266, msg-8 was right on
target. It’s not worth a new message but, FYI, I buy mineral
oil saw oil for 12.00/gal in 4 gal units from Kingsley North.
They call it "Lubri-Kool" and their catalog number is 7-0370.
They also sell it in a 5-gal pail for $11.00/gal. Kingsley
North is an excellent vendor and this oil is as good as it
gets. I use it in my own 14" and the club's 18" saw without
a complaint. I pay the $1/gallon extra in order to get it
in plastic bottles.

I clean the oil in our club just as you described (except I
only use 1 grocery bag) and bottle off the drainage after a
week or so back into the empty bottles. It's easier to
handle as well as to watch the inventory when it's stored in
plastic. When I clean again several months later, I get the
remaining drainage. The oily dregs never drain "dry" and
someone suggested mixing water with the filtered gunk which
should "force" the oil free to rise away from the rock dust
and water. I just never needed that last bit that much.

While I'm on this subject, head anyone off at the pass if
the suggestion of Propylene Glycol (mobile home anti-freeze
type) ever comes up again. It turns out that MOST of that
liquid is water and, while it doesn't rust under the liquid
surface, it'll do a number on your bearings, screw threads
and rock vise! Every iron surface in the vapor head space
will corrode to beat the band.



Subject: RE: Zebra Marble

Zebra Marble does indeed come from Utah. I was fortunate
to meet the quarry owner while sitting in a traffic jam in
Nevada. He supplies hundreds of tons per year of the Zebra
Marble to the aquarium trade. So a good source for this is
your local pet store. The more fish the store carries, the
more likely they will have a big box of it. It sells for
$1.50 to $3.00 per pound. Usually there is a tag either on
the rock or the box. Sometimes it is the wholesaler's tag,
many times it is the suppliers tag. If the address is
Utah, most likely that is the source. The owners are
rockhounds and are very friendly people.

They might sell direct if you contact them.

Steve Henegar

Subject: BIO: Dennis Marinac

Hello my name is Dennis Marinac, I am new to this discussion
group and would like to introduce myself by giving you a
brief background for the record.

I began my lapidarian skills during my senior year at Royal
High School in So. California. Working with lunch money as
my budget, getting materials was mainly from rock hounding
at the beach or in the backyard. Oh one last place for
hounding was in the classroom where I got a real kick out
of making cabochons from material mainly generated from the
adult ed class and left in the scrap bucket. I would find
the coolest cutoffs, scraps and abandoned cuttings to work
with. I had a fun time being able to make really nice cabs
from someone’s junk (junk to gems as I call it).

I liked this class so much my first goal was to complete
the requirements of cutting cabochons to fit each shape of
the templates, the dome, borders, and polish had to be near
perfect before Mr. Neilsen would put a grade on it. With
all my cabs completed I was free to go any direction and I
tried my hand at silversmithing, cutting freeform cabs,
and creating my version of modern day arrowheads (cut, not
knapped). Not many of us sludge making students aced the
class, but we all did learn that there is no end to what
can be created with a bucket of rocks. I often think how
privileged I was to have a lapidary class in a public high

I now live in Auburn California, Gold Country. I am 38, have
2 mining claims (Gold) on the American River below French
Meadows Reservoir. Some of the things I enjoy most are
lapidary, opalholism, gold dredging in the Sierras,
silversmithing and my work as a School Construction
Inspector. I am resourceful, innovative, and open minded.

It was a pleasure to find Hale's website. Thank you for
your time and for sharing your wealth of information.

Dennis Marinac

Subject: BIO: Judy Turner

Hello. I'm a 45 year old mother of a teenager, and I have
a pile of rocks in my basement. Agates from the beach in
Oregon, thundereggs from Jackson's Ranch, rocks ready to be
tumbled accumulated from various rock shops, North Carolina
rubies and sapphires sluiced from Jacob's Mine (along with
the gravel it came from), polished chatoyant malachite,
Sugilite, pietersite, and others. I especially like
working with stones I have found myself.

I started craftwork by making collages, using Envirotec (a
clear polymer coating that gives decoupage-like results) to
finish coat. Envirotec is thick enough that I can have some
texture in the collages, such as small tumbled stones. The
weight of the collages led to finished products like trivets
and table tops. The need to edge the products led to metal
work, and I've taken a number of jewelry-making courses in
the past couple of years. I love making jewelry that shows
the individuality of a stone. And I like stones that are
finished enough to show themselves off, but not necessarily
regularly shaped. I'd like to be able to cut the shape I
want from rough.

I've experimented with tumble polishing using a Lortone
tumbler with three small containers, a Vibra-Tek vibrating
tumbler (with poor results) and a Raytheon vibrating
tumbler. Mixed results, probably because so many of my
rocks are mixed.

I've pored through catalogs looking at lap equipment, and
may be willing to make some investment in it, but need to
know more about what I'm buying, what it can and can't do,
and what minimum levels of equipment I need. I've also
invested in some diamond burs for my Foredom flexshaft, make
an acrylic stand to hold the #30 handle, and have a tubing
setup so that I can drip water onto the blade, but I'm not
clear how much water I need to drip. I toasted one diamond
bur, and have paused to get more information.

I'm looking forward to "listening in" on what's going on
here, and maybe someday I'll have something to contribute.



Subject: SHOW: Minnesota Mineral Club in Minneapolis

The Minnesota Mineral Club will be holding their annual
silent auction on Saturday, April 8 Anyone who will be in
the Twin Cities area is welcome to come.

Also on April 14th we will be hosting delegates from the
Midwest Federation at a show in Har Mar Mall in St. Paul.
For details and further information, e-mail Giovanna Fregni


Subject: FS: Expandable Drums and Belts

Hale, I know that I wrote you a couple of messages about
expandable drums. I have used one for years and have never
had trouble getting the belts on or off. We sell both the
drum and the belts and we get both from Lortone. At least I
know that the Lortone belts do what they are suppose to (go
on & off easily).

If any of your readers would like to purchase some of these
belts they can visit our web site.

Russ & Betty Nation
1 (800) 820-3612

Subject: FS: Frantom 20" Slab Saw

For Sale 20 inch Frantom slab saw. I have a new 1/2 horse
motor in box plus motor on saw. I have all the pulley's and
belts. They only thing non standard on the saw is the
front part of the vice which is from a Highland Park saw.
It does fit and work. I have 5 saws and 2 of these are 20
inchers. I am selling the one I use the least. Asking
$1500 and will deliver within 200 miles of Atlanta.


Tim Vogle
To unsubscribe from the Lapidary Digest, send a message to, with the word UNSUBSCRIBE DIGEST as
the subject of the message. Other commands you may use are:
SUBSCRIBE DIGEST to join, 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.