Bi metal casting with platinum element in the flask

Jewelry Discussion
1

Hi Everyone,

I am working on a commission piece that is beyond my expertise. I
made several pieces that were a complicated sculptural sterlingpiece
that I then built a wax setting around and cast in 14kt gold. They
came out wonderfully.

One of my friends - a 4th generation watchmaker has requested a
similar piece in platinum (sculptural element) set in 18 kt yellow
gold.

I am outsourcing the platinum casting of the focal element to a
source in LA. I don’t have a shielded gas setup.

I was planning in cleaning up the platinum casting and building the
setting around it…& then casting the 18kt around it.

The flask will be around 1200 - 1250 F.

Do I need to shield, treat, coat, flux or anything to the platinum
piece in the flask? Or, does it behave similar to the
sterlingbimetal casting with an 14kt yellow gold? I had issues with
14 kt gold elements set in wax with the sterling cast around it. The
sterling flashed over the 14kt gold or other issues that were
failures. I was using fresh alloy from the refiner.

Any preventative problem wisdom is appreciated. He’s a great friend,
client and collaborator. I am excited and nervous.

Eileen in LA

2

Wow, I must say that I find you very couragious!

I am a graduate fine jeweller and I am not even doing experiments
like these with the finer metals.

In my studies I learnt to respect the precious metals. Learning that
you had sterling flush over the gold makes my eyes crossed.

You need separated tools to work in Platinum and everything around
the workarea must be cleaned. You will destroy your files if you
were thinking of using your normal tools. Platinum has such a high
melting temperature and slightest dust will melt into the metal and
make pores. That is not considered acceptable when you have Platinum
in your hands.

Be safe and hire a professional!

Saedis Bauer
Fine jeweller