Hi and thanks to those that responded to my question about
alternatives to Talc (a poreosity causing mineral) for aiding the
evacuation of mold air in the wax injection process. After reading
the responses I am going to experiment with arrowroot and
What would be best would be for you to watch an expert cut a
We own the Rio mold cutting videos which show how to use the choppy
waters technique for ring molds. A good video. Does anyone make a
video that covers bracelet molds?
I have also used the cooking spray called PAM with success on some
For production molds we mostly use vulcanized silicon, today Rio’s
belcone clear, because it is much easier to both fill the mold and
cut, does not need to be sprayed, does not react with the copper in
our masters, and there is less wax sticking at the nozzle, so there
are comparitively less wax slivers getting into the patterns. But I
have noticed that silicon does not vent as easily as natural rubber.
I have ordered some of the new Castaldo VLT 160 F to see how that
works vulcanized on green wax.
Right now I use the teal Kerr wax - what do you like to use?
I am using Rio pink, and Rio carvable, but was thinking of
switching, I will ask for advice on this in a seperate question.
In my experience Talc is best used to separate molds when
vulcanizing.....saves the hassle of cutting the halves apart.
Ditto, I have yet to become an expert at getting the parting lines
where I want them or getting the mold alignment to work as well as
the choppy waters cutting technique. Does anyone have experience
with Castaldo parting cream? I was thinking of trying some for
separating some sections of a mold while cutting other sections to
achieve better parting lines, or to aid in setting up more
complicated spruing systems etc.
if you can't get the detail in your waxes you may either be using
the wrong kind of injection wax
Advice on different waxes welcome.
I would speculate...not venting your mold properly.
I usually start injecting a new mold with as few relief cuts as
possible, starting from the sides at first and then adding cuts as
needed to get complete fills. I at times resort to stabbing through
the bottom of the mold to relive a particularly difficult area. I
was told by one of the experts that this was wrong, but it works for
me and can result to less clean up in the metal. Usually I talc
these cuts with a dull blade. Still I have found that my flat
pieces with deep detail inject the best with excess talc.
After reading the responses to this question I have come up with a
new (to me) technique. I am going to try cutting “through the
backside” vents with a thin ex-acto #4 and then thread the cuts with
thin sewing thread and pull the thread back just out of the cavity.
And maybe build air ducts into the mold with wires, which when cut
to, will increase air expulsion.
Thanks again for the responses,