Hello,
I am thinking of casting brass and bronze bracelets and in lost wax
casting, my question is: how to produce a quality model using
elastomer mold (cold-vulcanizing) - the cost of molding is
relatively expensive considering the number of models i need to make…
second question: to thin down my blue injection wax (or turquoise)
can I add a little paraffin ? what will be the possible implication
on the mold ?
I have been making molds for sculptural figures as well as jewelry
for decades. There are a couple of different ways to make a mold,
pour it then cut it, use clay dams to get the mold separations where
you want them being the basic ways. I do both but more of the clay
damed molds than the cut molds. I have used many of the different
molding materials but I pretty much stick with silicon materials
these days. With silicon, you have tin or platinum cured materials,
tine is cheaper but has a mold life of about 10 years then starts to
get “brittle” or break/tear easily. Platinum gives a mold that has a
VERY LONG life. It is somewhat difficult to use both in the studio
as tin “contaminated” items, if used with a platinum mold rubber,
will cause all sorts of problems with proper cure so use one or the
other but do not mix use in the same room with "shared"
mixing/molding equipment.
There are a number of RTV mold material makers, I tend to use
Smooth-on products as a very good, long time friend owns Douglas and
Sturgess in the San Francisco Bay area (Artie Cordisco) and if I
have any problems or question I know that Artie or one of the "crew"
will be able to help me out. Smooth-on has a LOT of videos on line
to help get one a bit knowledgeable as to how their products can be
used.
If I can be of help, I would be happy to do what I can do for you. I
feel the absolutely BEST way to learn mold making is to bite the
bullet and take a class somewhere, a 1 to 4 day class, not a whole
semester as offered in schools. A person needs to get some basics
(the class) so that they can hone these basic skills and be able to
make really fine molds. With the internet, “on line classes” could
be done but an in person and on site class is best. Also there are
many ways to make a mold, , give 5 mold makers an item to mold,
and you will get 5 different ways to make a mold, so any class is
just to get the basic ideas and then it is up to you to make it work
for you and your situation and needs.
There are all sorts of “little” things that can make HUGE
differences in making molds easily. Releases, dam material, mother
materials, alignment methods systems, getting/keeping bubbles out,
and on and on. Another place that a “class” can make all the
difference in the world, just to show you all the differences and
materials. Some “teachers” teach how they make molds, ,
period. I try to show different ways, different materials so a
person can make modifications in the process to suit their needs,
methods and way they work.
Good luck and if I can be of any help, let me know. I live about 1.5
house West of Seattle WA in a little town of Sequim. I do give
workshops for small groups or individuals. I work in jewelry size to
sculptural size. I also "teach TIG, MIG and plasma work, patination
(“real” and faux), I love to cook and fish.
Best of luck and I hope this helps a bit.
john dach
Injection wax type, temperature, air pressure or psi, and amount of
frame pressure are all of the variables that need to be perfected
through trial and error. It a case by case per style of bracelet
mass.