View Single Post
  #9   Report Post  
Posted to rec.crafts.metalworking
Frank J Warner Frank J Warner is offline
external usenet poster
 
Posts: 47
Default Melting Dental Gold

In article , Frank J
Warner wrote:

To make a long story short, a customer wants a very special knife,
which is mostly built. But he wants embellishments on the knife that
I've never attempted before, so I'm seeking advice from the good and
knowledgeable people in this group.

He wants a solid gold thumb stud, and he sent me the gold. It is, for
the unsqueamish, a dental bridge and a couple of gold crowns,
apparently harvested from his own mouth a few years ago when he plowed
into a bridge abutment and ate the steering wheel. The doctors had to
reconstruct his face, but they saved his gold teeth, which he sent to
me for this project.

Yeah. He sent me his teeth. You can stop gaping now. Metal content
ensues:

I've looked online and found that dental gold can contain lots of other
metals, including platinum, palladium, silver and even chromium, copper
and zinc. No way to tell what's in this guy's teeth. The fittings don't
look like gold. They look like untarnished copper. They don't have the
look of a 24 karat grille, but they are 40 years old.

I've melted and cast small gold parts before, but only from gold that
was 100% identifiable in terms of alloy. This is a different situation.
I have no way to know what's in this amalgam. I'm afraid to put a torch
to it.

My tooling includes a heat-treating oven that can reach 2200° F, a
propane torch and an AO rig. I have crucibles for precious metal
melting.

How can I make this guy's thumb stud?

-Frank


Replying to my own post, I melted one of the small crowns not attached
to the main bridge piece with a propane torch this afternoon. It melted
just like one of those old dimes I used to melt with my daddy's propane
torch back in the 60s; the real silver lady liberty dimes.

The resulting lump was more silver than gold in color, so I suspect
this amalgam is heavy with silver.

The bottom line is that it melted in a familiar way, so I'm probably
able to melt and cast the remainder into a piece I can machine for a
thumb stud.

The color will be slightly off. This knife uses pre-ban elephant ivory
for the scales, and I'm using gold-plated screws to hold it all
together. The thumb stud will be halfway between the color of the blade
and the color of the screws.

-Frank

--
Here's some of my work:
http://www.franksknives.com