I took in a job the other day that required me to duplicate a ring
in platinum. It had some tricky freeform curves that wax carving
wasn’t getting for me, especially du to the fact it’s not easy for
me to “over polish” them metal to achieve the rounded flowing look.
Anyway, I decided to try the no shrink pink rubber to get the 0%
shrinkage. I don’t use a vulcanizer but an oven and I use C clamps
to hold the plates together. It’s worked fine for me for years. I
calibrated my oven with my digital pyrometer from my casting oven
and set the temp at 315 according to customer service at Castaldo.
The oven was cycling between 306 - 325. I baked it for 45 minutes
(5 sheets 1/8 thick) and it came out with tiny bubbles everywhere
and REAL soft. Tried again at 310 (cycling between 298 - 317) and
no bubbles. The only problem was when I started to cut it, it was
like chewing gum. REAL soft and pliable. I got pissed off and
ripped it apart with my hands to get the model out and went back to
my silicone. It had a little shrinkage, but my friendly wax pen
helped build up the thin spots. Anybody have an idea what went wrong
with my pink mold? Do I have a bad batch? Is this normal? I did
notice that after the mold (or what is now a lump of pink rubber) is
harder than what it was when it was warm. Not sure if it has to
cure a bit longer to gain it’s composure. Please let me know your
thoughts before I return this stuff back to RIO.