I am having a problem getting the wax out of a mold made with
Castaldo gold rubber. The wax I am using is Kerr NYC pink.
The mold is a three piece mold, the piece is about 2" long and
thin and has a fair undercut to it. I can not seem to get the
thin piece to snap out of the rubber with out breaking it.
I have tried Spirits general purpose mold release AE, Vaseline mixed
with alcohol, talc and Ivory dish detergent straight. The ivory
seemed to work the best but produced some soap bubbles which ruined
the piece. If I leave the Ivory dry by sitting 15 to 20 minutes
will this still suds up? Any other ideas, such as deleting the
Ivory or straight Vaseline?
All ideas and help is appreciated.
Dear Jim, Usually the problem of wax sticking to rubber is caused by
the wax being quite a bit too hot. Are you sure you dial setting
reflects the actually injection temperature? The way to check is to
suspend a thermometer in the molten wax – don’t let it touch the
sides or bottom – and see what the temperature really is.
Silicone mold release spray is usually all that's needed. Anything
more indicates an unusual problem.
HI Jim, If you’re looking for the best silicon spray, try the
Castaldo brand. It is the best spray I’ve found. I use a lot of
Castaldo rubber (about 200 lbs a year) and have tried EVERY injection
wax on the market. I have also molded some pretty wild things! To me,
it sounds like a mold cutting issue. You may be able to cut a plug in
the mold which is removeable before the mold is opened and the wax is
pulled. Sometimes a severe undercut that cannot be supported will
give a moldmaker fits. In some cases I have fashioned a hard plug of
metal or even heat resistant plastic so the undercut is well
supported and sufficient pressure for injection can be achieved.
There are a few waxes that will give you greater strength and aid wax
pattern removal from your mold, however in my experience, when you
swap waxes you gain one property and give up another. The search goes
on for the perfect all-around one-does-everything wax. For a lot of
shops the solution here is to have two or more wax pots to give you
the injection properties you require for any given mold. John,
J.A.Henkel Co., Inc., Moldmaking Casting Finshing, Producing Solutions
For Jewelry Artists.
My experience has been that if the wax is too hot, it will stick to
the rubber no matter how much you try to grease it up.
Bruce D. Holmgrain