Working on small pieces

[William Smith <wesmith@xxxxxxxxxxxxxx>]

Pamela,

My brother works small stones and metal repousse pieces
using a device called a "pitch bowl" he built himself to
hold them. I believe the idea originates with lapidary
workers and jewelry workers. Small stone pieces should work
too. He wanted to work larger pieces than he thought the
commercial versions would hold, so he built his own. What he
did is cut a bowling ball in half (I am not sure how he did
that though) and bolted and epoxied a cheap frying pan to
the flat side, with the interior of the pan upwards. Then he
bought some pitch, which is like a really solid grease and
melted it and poured it into the frying pan.

The pitch hardens solid, and can be softened with a propane
torch or heat gun. When he wants to hold a piece firmly he
heats the pitch and sets the stone or metal into the pitch
and waits for it too cool. From that point on he can work it
without fear that it will move. He made a base for the
bowling ball to sit in that allows him to rotate and tilt
the whole apparatus so that he can work from different
angles.

Pitch is available in a variety of grades and hardnesses and
melting points.

I don't know how well this would work if one were chiseling
the stone, but working with grinders and files it seems to
work fine. Another question to research would be to see if
the pitch would discolor the stone. I can imagine that
alabaster might discolor, but I really don't know. Also, a
porous stone might take up some pitch into the pore spaces
and be discolored.

That is the only new advice I have on this topic.

Here are commercial sites that show lapidary and engraving
versions of what I am describing.

http://www.bernieslapidary.com/selprod.asp?whichpage=2&pagesize=6&sqlQuery=select+%2A+from+%5BProducts%5D+WHERE+CAT+%3D+%27CHA%27+Order+by+Sort

http://shorinternational.com/ChasingTool.htm

http://www.metalwerx.com/wk-chasing.html

Bill Smith