Dear Stephanie & Peter Sloan,
Yes, it's quite a major question you've asked. One could write
not one but several books on the subjects you asked. But no one
will because it’s too time consuming.
I can offer you some answers, however.
For the differences between different mold rubbers, please
check out our web site at: http://www.castaldorubber.com It’s an
exhaustive treatment of the subject with 100’s of pages,
technical articles, descriptions, etc.
Why do your silicone rubber molds lose flexibility? Perhaps you
need a better silicone mold rubber. Please send me your shipping
address and I’ll send you a free sample of a really good
silicone mold rubber. You’ll like it.
As for powder and silicone spray, well, you are not alone in
The silicone spray is used to release the wax casting from the
rubber. It should be sprayed into the mold cavity as needed, but
sparingly and infrequently. (Not needed for silicone rubbers, as
these are self-releasing.)
Powder is not used for release of the wax. If it is used for
this purpose it will need to be re-applied frequently, will gunk
up the mold, and will degrade the surface finish and reproduction
of details. So don’t do it. Powder is used solely to keep the air
release vents in the mold open to help the wax fill the mold.
(Neither air release vents nor powder are needed if you are using
a vacuum wax injector.)
Flask size is entirely dependent on the size of what you put
into it. There is no " most successful " size. I’m no expert
here- you need to talk to an experienced caster. Or your
Hope I’ve been helpful
F.E. Knight, Inc., 120 Constitution Blvd., Franklin, MA 02038 |
508/520-1666 FEKnight@ziplink.net |