Machining graphite block

Jewelry Discussion
1

I just acquired several blocks of machineable/drillable graphite
that I wish to turn into ingot molds. Frankly, I don’t have a clue
what I am doing…lol.

Does anyone on this list have experience using this material for
this purpose, and how do I machine this stuff without turning my shop
into what looks like the inside of a pencil sharpener–just handling
this stuff turns my hands black.

Edward

2

A simple drill press will work well to mill out insets for ingot
molds.

Most graphite mills have strong a strong vacuum at the spindle, and
are usually enclosed. Maybe if you just set up a shop vac with duct
tape that will work! :slight_smile:

Jeffrey

3

Steve: I have been using grafite blocks for about 20 years for ingot
molds for sterling silver. I drilled a series of holes in the blocks
with a 3/8 " Di.steel drill bit and some os a 1/2" di. about 1" and
` 1/4" deep/ It works great for my Thermidor I 3 casting machine.
yours Billy S. Bates

4 
   I just acquired several blocks of machineable/drillable
graphite that I wish to turn into ingot molds. Frankly, I don't
have a clue what I am doing...lol.

Hi Edward; I used to make and use graphite molds for pewter, and I’ve
helped my father make glassblowers tools from it. It’s very easy to
machine (self lubricating too). And yes, it’s messy. You can use
just about any file, drill, saw, whether designed for metal or wood.
I’d get a shop vac, turn it on and put the hose end right up to where
the tool is cutting. I’d wear a dust mask too, and ear plugs to
block the noise of the vac. Graphite is quite a heat sink, I’ve not
tried it for pouring gold or silver into, but I can’t see why it
wouldn’t work. You could always pre-heat it if the metal were
chilling before it filled the mold.

David L. Huffman

5 
Steve: I have been using grafite blocks for about 20 years for
ingot molds for sterling silver. I drilled a series of holes in the
blocks with a 3/8 "  Di.steel drill bit and some os a 1/2" di.
about 1" and ` 1/4" deep/ It works great for my Thermidor I 3
casting machine. yours Billy S. Bates

Heh, it’s good to hear of someone else (besides me) who uses a
Thermotrol casting machine. Mine is about 35 years old, it’s mostly
manual, not one of the newer microchip designs, and takes up to a
5"x7" flask. I only use it when necessary because most of my casting
is done on a vacuum machine.

Jeffrey Everett