Grant Erwin wrote:

Ask your dentist. They're pretty good at inlaying metals.

The way this works, I believe, is gold leaf, in one method. Noble
metals self-weld. The area must be spotlessly clean and dry. These
metals self-weld readily because the oxide layer is just not there;
they don't react; they are noble. The dentist packs the gold leaf into
the cavity, right?

Now, you'll need a lot of gold leaf to fill a cavity like a readable
letter, but the principle is the same. Something thicker than leaf and
a burnishing/planishing tool (a very smooth tool) might do it.

I've never done this, but planned a PATC brick for the cabin my aunt
and her PATC friends built in the woods. Mill out the letters into a
brick with a carbide bit, dovetail with carbide, and pour some alloy,
low melting most likely. Then mill flush with the carbide face mill.

I wonder which method would take longer?

Yours,

Doug Goncz
Replikon Research
Seven Corners, VA 22044-0394