Hello Benoit. We have done this before… Sea horses are very brittle
in general and will most likely be damaged in a vulcanized rubber
mold. I don;t think casting the sea horse directly will work as the
structure may not burn out correctly.
The best way to mold this would be to use a liquid RTV rubber that
cures on it’s own with no heat applied in about 16 hours. You have
to fashion a frame to poor the rubber into. What I have always used
is a small piece of PVC pipe… does not matter what color it is…
Make sure the pipe has enough clearance around the item… at least
1/2 inc or better all the way around the interior of the pipe . the
pipe should be at least 2 inches higher than the piece when the sprue
is added to the piece in . or more… Cut the pipe in half , length
wise, , then , tape the pipe back together with electrical tape.
The best way to mount the wax would be by connecting a strong sprue
to the sea horse, then take a flat piece of wood or plastic… weld
the wax to the wood or plastic… then use wax and weld the pipe to
the base… Now it’s ready to pour.
The RTV rubber usually works best if you vaccuum the rubber before
pouring it , then pour it slowly into the pipe… then , you may
need to vacuum the mold again to remove any air bubbles that are
trapped. Now, Let the RTV cure overnight.
Now, Remove the electrical tape from the outside of the pipe and
keep it as this will become your mold holder for the newly made
round mold. You now hand cut the rtv rubber .Your mold is now ready
There are RTV rubbers that you can pour pewter directly into (
Petwer melts at about 450 oF ) and the pewter piece can be used for a
vulcanized mold. Contenti supply has this type of rtv with
instructions at 800-343-3364
This is not the only way to make frames for rtv rubber… but I have
always liked this method because the pipe becomes the mold holder
when you are done
Hope some of you find this useful as it can be used for
many different types of projects.
We do casting,finishing in gold and silver, soldering, assembly
,engraving, cnc model work , enameling and all kinds of other
services for designers, stores and people in the trade.