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Model making help

Does anyone have any good tips that would help me make light weight
models—here’s what I’m doing:

I make built up models out of that stuff like Play Dough and bake
it. Of course the model if cast solid as is would be way too heavy.
So I make an RTV mold of it, inject it with carveable injection wax,
then attempt to hollow out the back. Only troubke us injection wax
clogs my wax burs and to hollow out the back to castable thickness is
too tricky for me.

I’ve seen a pendant that had a wolf’s head with a long nose cast in
silver, very detailed and hollowed out the back to be very light
weight. I can’t imagine someone spending hours and hours hollowing
something like that out, the end result would be very fragile to work
on. Is there some trick to doing this right? Thanks again…Dave

Usually, for something like a wolfs head I carve it in the green
wax, you can hollow it out real easy and your burs won’t get
clogged. I then cast it and clean it up in the metal and I have my
master model. I have however worked on injection wax and its not
designed for carving, even the stuff they say is (somebody may know
wax that is good). If you are doing a lot of hollowing out in
injection wax use a heated spatula (precision waxer) on a low
setting and use it in a scraping action.

Ed Dawson
Maine Master Models

First off Dave I would suggest switching to wax as a sculpting
media. Then there is always a hollow armature to buildup the Play Doe
on if you insist on using play doe. Frank Goss

I would recommend that you try making your models out of epoxy
modeling putty. That way, you can build the hollow into the model as
you work, or carve it out with burrs after it has hardened. This will
save you a great deal of time over having to hollow each wax, and
epoxy putties give you the added benefit of being capable of forming
much greater detail than Play Dough. Also, with epoxy putty models
you have the option of vulcanizing molds instead of using RTVs. There
are many brands available, I like Magic-Sculpt.

Jack Reisland

what I have found that works great is a 6dwt naile bent at 90
degrees to go in the your drill [ L ] sharpen the end on the flate.
It will not pluge becouse it has only 1 flute it really hogs out the
wax. Don in Idaho USA

G’day Dave. I am not quite sure of the size of the object that you
are trying to hollow out so I will assume it is in the size of 2 to
4 inches. If it is this size then make the model in Play Dough as
you would normally do, dry it and make the rubber mould but instead
of making a small hole for the wax to be injected into, make a
larger hole, melt some wax and pour it into the larger hole, allow
this to cool until the wax on the outside (Mould Face) has
solidified to the desired thickness and then pour out the
un-solidified wax in the centre, it takes a bit of practice to get
the wall thickness that you want. PS Injection wax is not ideal for
this purpose try and find a Microcrystalline wax that is quite fluid
when molten.

Any further questions please do not hesitate to contact me best

Michael W Kohlleppel
Art Tech Castings Australia.
@MWKohlleppel or