Hello, I am a twenty four-year old student at GIA; studying
comprehensive wax techniques and casting. My father has been a
jeweler for somewhere in the neighborhood of thirty years and I have
decided to follow in his footsteps and help out in the family
business. I am contacting you because I have been around the jewelry
industry my entire life. During my exposure to this industry I have
been exposed to a phenomenon which exists in the geographic region
where I live. This phenomenon is that of the highly gaurded trade
secret. Jewelers in the area learn through trial and error. There
are certain techniques which just not shared in order to maintain
competitive edge. It is somewhat of a paranoia which may be
understandable in some areas but in others it is plain absurdity.
This leads me to discuss one very problematic area in the workshop:
casting.
Through many years of trial and error we have tried and failed in
the specific procedure of investing for casting. We just seem to get
all of the air bubbles out of the investment; ulitimately leaving
bubbles of gold on the casted piece. What we have come to encounter a
majority of the time during casting cleanup is that when you remove
these bubbles you are left with a pit underneath which must then be
filled. This process of cleanup becomes quite time consuming and in
turn quite costly. It has always been this way sometimes you get
lucky and get less bubbles sometimes more; but almost
invaribly…bubbles. This assures us that the process has something
to with the investment process. We have also been told that when we
are vacuming the air bubbles out of our flasks that because we are at
a high altitude(6,984ft) that our vacum can not physically pull
enough pressure. The most pressure that the gauge on various
machines we have used is 24. We are currently using a vic-9 which is
manufactured by rio grande. Is it possible to get a machine with a
stronger vacuum or is it just not physically possible to achieve a
stronger vacuum than 24lbs at an altitude of nearly 7,000ft?
Please help
Sincerely,
Nicholas Griego