Silicone mold rubber question

I’m trying to find something easier to use with powder separated
mold making than Gold Label rubber. I’ve done some things that way
with the Gold Label, but I think the silicone mold rubber would work
better. I’m confused about various silicone rubber products.

What’s the difference between the Castaldo Econosil and the Castaldo
Gelato Super High Strength silicone mold rubber? Which would be
better for general use? And with the Gelato, is there any difference
in the product between the different colors? Is one color better than
another for specific uses?

–Kathy Johnson
Feathered Gems Pet Motif Jewelry

The Castaldo Gelato is also Super High Strength, just like the same
product in the mustard color. I’ve been using the Gelato, and I
really like it. Progress carries it, and Gesswein told me it would be
in the new catalog.

Here’s what it says on the Castaldo website:

Castaldo Econosil Jewelry Molding Rubber is a harder, firmer version
of our Castaldo Super High Strength jewelry molding rubber at a lower

Just like our Castaldo Super High Strength jewelry molding rubber,
Econosil is a putty-like material that makes strong, tough,
production rubber molds.

Molds made of Castaldo Econosil cut like butter, give waxes with a
high shine finish and require no messy sprays or powders. Waxes
self-release easily.

Castaldo Econosil a brick-red/brown color and is lined with special
release paper on both sides.

Castaldo Econosil Jewelry Molding Rubbers is available in strips 18"
x 2 7/8" x approximately 3/8" / 45.7 cm x 7.3 cm x approximately 6
mm. Special sizes are available on request.

Elaine Luther
Chicago area, Illinois, USA
Metalsmith, Certified PMC Instructor
Studio 925; established 1992

Dear Kathy,

This is Michael Knight at CASTALDO.

Yes, you can make powder separation molds with our silicone
vulcanizing rubbers. The process is the same as that with Gold
Label, but much easier because of the rubber’s clay-like

Econosil, as the name suggests, is our economy brand. It is not as
tough, not as strong and not as elastic as our Super High Strength
Silicone Molding Rubber. But it’s still strong, elastic, etc enough
for most uses. And it is harder.

For many decades we made our Super High Strength Silicone Molding
Rubber only in tan color. Then we began making it in the new Gelato
rainbow of colors. It’s all the same rubber – only the colors are
different. For some people it’s merely a matter of personal
preference. Other people find that they can color code their molds
– pink for customer A, blue for customer B or pink for earrings,
green for rings, etc.

Let me know if you need more info.

Do you want a small sample to experiments with? Does anyone else out
there? If so, please let me have your shipping address (not a P.O.

Michael Knight

Products Mfg. Corp. & F.E. Knight Inc.
120 Constitution Blvd.Franklin, MA 02038 U.S.A.
Voice: 508-520-1666
Fax: 508-520-2402