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This list digest contains the following message subjects:

1. LapDigest News for Issue No. 119 - Fri 2/27/98
2. RE: Electroforming (Metal Plating) On Lapidary
3. RE: Criterion or Gemking Saw Blades
4. RE: Dopping Opals
5. RE: Dopping Opals
6. RE: Dopping Opals
7. BIO: Sandy Chownyk


Subject: LapDigest News for Issue No. 119 - Fri 2/27/98

I know I said that the next issue would probably come out on
next Wednesday, but the morning we were ready to leave for
the trip, my wife awoke with latent tummy bug, which
worsened during the day. So we finally canceled the trip,
we are at home and here is Issue 119!

Have a super weekend!


Subject: RE: Electroforming (Metal Plating) On Lapidary


A couple of points in terminology

1) "Grounded" and "Earthed" are the same term.

2) Although the idea of using a domestic light dimmer
will work with most old type chargers, nearly all new
chargers have some sort of internal semiconductor regulator.
Using a dimmer with these may cause the whole thing to fail.

3) NEVER use a non-isolating system to drive a plating
bath. This is an auto transformer or variable transformer or
Variac. On either 110 or 240V this could be fatal! There must
be an isolating transformer as well.

There are some cheap(ish) high current supplies (made by
Altai and others) for about £ 80-100 ($170??) that give
15-20A and can be adjusted to low voltages.

Note plating current can change significantly with
temperature and time so practice is needed to get all the
factors right.

Many thanks to the previous authors for the information.

Geoff Hockley

Subject: RE: Criterion or Gemking Saw Blades

Both blades are manufactured by MK Diamond Products, a world
leader. Both are notched rim blades meaning that notches in
the blade are filled with sintered diamond. Why the price
difference? The amount of diamond in the blade. You get what
you pay for.

As far as the advice on rim thickness, let me put it this way.
THOUSANDS of these blades have cut many more thousands of
slabs and have done it economically. If your saw is aligned,
the power feed is at the correct speed and is powered with the
right horsepower motor, the .075 blade will be fine. Going to
a thicker blade costs more (more diamond) and requires more

Your last question:
<<Can anyone recommend a good 24" saw blade that is not too
You will not get a more value packed blade than the Gemking!

Peter Erdo
Graves Company

non-commercial republish permission granted

Subject: RE: Dopping Opals

This may sound a bit off to some of you folks, but for
years I've been taking matchbook covers, coating them with
super glue, drawing my pattern on them, and then using them,
once again with super glue, to place between my opal and my
dop. After I'm done cutting I simply take a razor blade
(single edge for me) and split the matchbook cover off of the
dop. I did manage to chip one opal about 10 or 12 years ago
so try the first few on some common stuff. Its well worth
giving a try and really beats heating up your stone.

C Nielson

Subject: RE: Dopping Opals

Hale , I am surprised that no one has mentioned water glass
for dopping opal.

Use a wooden dop and when cab is finished, drop cab and dop
into water. The cab will come off clean. If you are worried
about water breaking the bond during the cab grinding and
polishing, cover the connection with fingernail polish, and
remove polish with file when finished. It works for me.

Charles in Austin

Non Commercial permission to republish granted

Subject: RE: Dopping Opals

Added comment on dopping opal...I too use super glue...small
drop on flat nail head. When I remove the stone...I use a
debonder squirted around the edge of the nail head. Also
apply some heat with minitorch to nail, away from the opal.
Might have to do it two or three times...but it comes off.
Haven't damaged an opal yet...(knocking on wood).

(I asked Beth to amplify a bit on this, and in particular to
tell us what brands she used. This is her reply:)

Have been using Zap a Gap super glue that Kingsley North sells
through their catalog. They also used to sell the debonder..
.but I don't think they do anymore. The other day I bought
a tube of debonder at seems to work OK on my
faceted stones...haven't tried with the opal yet. It's Duro
Super Glue remover. It removed the Zap a Gap OK on a
citrine I had cut. The debonder that Kingsley North sold
was EZ7, I think. I threw the bottle away the other day. It
is no longer in their catalog.


Subject: BIO: Sandy Chownyk

Hello Everyone:

My name is Sandy Chownyk from Michigan. I am a member of the
Mt. Clemens Gem and Lapidary Society. Although we are
relatively new members (only 3 years) - my family and I are
very involved. I am the editor of the newsletter, "The
Crystal Gazer", my 13 year old daughter, Jennie, is in charge
of monthly displays and my husband takes care of the annual
swap. We also help at the annual show.

My husband and I recently took a lapidary class through our
group and are very new to this. The machines we use are
whatever the club has in the lapidary room! My husband hopes
to build his own machines some day - but right now all we
have is a couple of rock tumblers we had when we were kids
and hundreds of pounds of rocks from field trips.

At a recent silent auction I bought a lot of slabs including
snowflake obsidian, montana agate, botswana? agate and a nice
chunk of sodalite. I hope to start making cabs with these

I have enjoyed the digest and hope to publish some of the
things I have read in my newsletter!!

Thanx for this service

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