hi reptiles,
from your question i assume that you don't have vast prior knowledge
of materials and fabrication processes and that you are not going to
be producing these items in vast quanteties at this point.
your best bet would be to create your own mold since professional
molds for plastic products of this size will probably cost more than
$100k - and are normally not suited for this kind of embedded object
casting.
If you'll be doing these casts at home / studio (either should be VERY
well ventilated!!!) you'll probably be casting clear polyurethane:
(://www.google.com/search?hl=en&q=cast+clear+polyurethane&btnG=Google+Search)
as for molds for this material, there are a few options. for an almost
professional surface finish i would suggest making the mold from a
compound used in dentistry work. its quite expensive but you'll be
saving a lot of time on finishing work and it is flexible, meaning you
won't have any problem creating the mold and taking out the cast
object after curing. i have no idea what's it called where you live
but find a local dentistry supplier and they will probably be able to
help you out (i usually ask mine for "that green stuff").
there are also a few types of silicone used for molds and you might
want to experiment with those - as long as you use the flexible sort
you should be fine.
to create the mold itself start with one of these materials and try
casting a small item, like a small closed perfume bottle, a lemon or a
ping-pong ball. Try to see how you?re going to fit it in the mold and
attach two 1.5 cm round sticks to it (these will be used to create an
entrance for the poured material and an escape for air later, when
actually using the mold). Normally you?ll need the mold to have a wall
thickness of about 2 cm on each side of the object. After the mold
material has cured, cut it open and remove your model (bottle / lemon
/ ball and later a standard size us toilet seat) and then pour the
polyurethane to the cavity. Look carefully at the instructions since
some types will require different methods to get all the air bubbles
out ? from tapping on the mold to using vacuum while pouring the
material.
it might be a good idea to ask for advice and sources for these
material at a local art school, starting with the industrial design
department and also asking around the sculpture department if they
have one. another great place would be an industrial model-maker
(though usually not an architectural one). you might even find some
one there that will be willing to help you out and sve you some time
on the experimenting phase.
although you should feel free to use red-backs or reptiles in your
casts (just use collected dead ones ? death by polyurethane is not a
nice way to go) organic material normally does not survive well in the
curing environment.
one last note: do yourself a favor and read all instructions for all
materials CAREFULLY. some of these are very toxic and can cause
serious harm if not handled correctly.
good luck,
amok69 |
