NO, I did not just win that huge lottery.
The only thing I like less than casting, is recasting something that
should have come out right the first time.
I often cast and finish 1,000 pieces a week alone in my jewelry shop.
I also cast up to 300 lb single pour ceramic shell bronze molds.
I do not get investment cracking,porosity, inclusions, fire scale or
After 30 years of eyeballing it I learned how to follow directions.
I never have problems making molds due to rubber. I use Costaldo
rubber (pink) have spoken to Micheal Knight, a very knowledgeable
owner of a very good company. If you follow their directions exactly
everything works well, all the time.
I keep their wax injecting guide by my injector at all times. When I
have a problem a quick reference will fix the problem.
I use Ransom and Randolph Ultravest. I keep a stopwatch on my
investment bench and follow their directions to the second.
My water measurements are accurate, investment weighed to the gram.
If you mix investment for the recommended 3 minutes
not only will there be no lumps, but you will see it transform from a
gritty solid to a silky smooth liquid. I burn out for 6 six
hours and hold at casting temp for 1 hour.
These people spend as much time developing their products as we do
making jewelry. I’m all for experimenting,but our suppliers have
spent decades perfecting the use of these products, generally they
are more than happy to answer questions about them. If they say the
wax injects best at 1mm. thickness at 149 temp try it.
I have friends who judge the temperature of bronze by eye. Sure they
might be able to get to within 300 degrees.My used 40
year old $15.00 potentiometer can guess to within 3 degrees.
You may not want to take advice from a guy who reads directions
before assembling a grill or one that stops and asks directions when
However many of the processes we go through are not art but science.
There is a world of things out there to discover
Why waste time trying to figure out how to mix investment, or get
your rubber to vulcanize? Other people have all ready done that.
I know I’m not a better jeweler than the rest of you so maybe reading
and asking directions does help.
Or else I’m just the luckiest jeweler of all.
Sincerely Jeff Kahn