Pink & Yellow mold rubber

Jewelry Discussion
1

at my store we use a middle layer of no shrink pink around the actual
piece of jewelery being molded, and then fill in the rest of the mold
frame with regular rubber.

I’ve heard that the pink requires more strict temp. and time while in
the vulcanizer. Are there any special instructions or tips for
combining pink and yellow mold rubber? Thanks

2

We spent a lot of time working with No Shrink Pink (months, years)
and found it to be erratic and unreliable. We called it Usually
Shrinks Pink. I called the manufacturer several times to try to pin
down parameters that would give us consistent “No Shrink” results and
they couldn’t. They said it all depends, you have to play with it to
find the correct temperature/time. I had three different people try
it using a record book to record times and temperatures. We gave up,
now we us Castaldo Quick-Sil for molding items we don’t want to
shrink. I don’t love it, but it works. The molds are a bit stiff and
can tear. But it you just need a couple of quick waxes it does the
trick. Mark

3 
        at my store we use a middle layer of no shrink pink around
the actual piece of jewelery being molded, and then fill in the rest
of the mold frame with regular rubber. I've heard that the pink
requires more strict temp. and time while in the vulcanizer.  Are
there any special instructions or tips for combining pink and yellow
mold rubber? Thanks

Hi, this is Michael Knight at CASTALDO.

No, there are no special requirements or procedures for combining
Gold Label and No Shrink Pink EXCEPT to vulcanize the entire sandwich
as if it were 100% No Shrink Pink. Otherwise, nothing special.

Best Regards
F.E. Knight, Inc.
120 Constitution Blvd.
Franklin, MA 02038
United States of America
Voice: 508-520-1666
Fax: 508-520-2402
E-mail: FEKnight@ziplink.net

4

hello!

at our store, we use yellow and no-shrink pink together. we fill the
mold the same as you do, but we calculate 7 minutes for every layer of
pink, including rubber rolled up and fitted into hollow parts, and
five minutes for every layer of yellow. we make no allowance for
altitude (we’re at 7,580ft above sea level), so if this affects the
vulcanization process, you might want to consider that in your
calculations.

generally, after the first ten minutes of vulcanizing, we tighten the
squeeze a little more.

of course, there are times where we forget about the mold altogether.
:wink: however, when this has happened, it has not affected the mold
noticeably.

hope this helps,
susannah