RTV molds from TAP Plastics

Jewelry Discussion
1

Hi Mona Great description of The Crucible…makes me wish I lived on
the Left Coast. Oh well…

I had a question about the RTV molds from TAP Plastics you
mentioned. Would you share info on this subject, please? I do use
Bellicold and I do like it, but your statement about tossing it out
piqued my interest. Could you be specific about the process and
about why you prefer it to Bellicold (or any two-part silicone mold
material).

'Preciate your input,
Linda Kaye-Moses

2

Hi Linda- I took your class a while ago and you used a two part
molding product - blue gunk + pink gunk = lovely purple flexible
mold I use all the time. Is this bellicold? I would love to get my
hand on some more of that wonderful molding stuff.

Thanks, Lilly

3

Linda,

I used up half a new supply of Bellicold ($15!!) trying to make
molds of some ancient coin reproductions that didn’t distort the
faces. Each time I pushed the coin into the Bellicold the face in
profile ended up distorted. I have used Bellicold in the past to mold
other things for PMC and haven’t had this problem.

On the advice of the science fiction costumers I met at the
Crucible, I bought a jar of the TAP Silicone RTV system (jar of white
goo that they call “Side A”) and a small jar of TAP Silicone RTV
Catalyst (Blue, Fastcure). Their product bulletin 7B explains how to
use them. I didn’t buy a vacuum pump for the air bubbles, just used
the drip-from-a-shelf-using-a-Dixie-cup method the handout describes,
and it worked well. I put a block of Sculpey in one of TAP’s little
molding containers and pressed the back of the coin into it. The
Sculpey took up room so I didn’t waste molding material and also kept
the molding material from flowing around the back of the coin. The
Sculpey also can serve as a base if you are molding an antique
pin…the pin sticks down into the sculpey and the pin itself isn’t
harmed. The Sculpey allows you to make a one-sided mold of just
about anything, although RTV is designed to mold an entire 3-D
object.

Because the RTV molding material was liquid and dripped onto the
coin, rather than being a cohesive lump like Bellicold, I didn’t get
the same sort of distortion I did with Bellicold. Rather than my
shoving the coin into the molding material and displacing it, it
dripped around and conformed itself to the object, hence the great
detail.

Mona

4

Hi Lilly Cohen,

Bellicold can be purchased from Rio Grande and a similar product
from MicroMark. There are other suppliers out there, too. Happy to
hear from you.

Linda Kaye-Moses