I have a friend that found a dead hornet and would like to cast it
in silver. I have never cast an insect. Any tips, advice or
experiences?
Thank
you, Patrick
Hello Patrick,
extremities of a dead insect usually are not in a natural position
and a dead insect use to be dehydrated after short time. It will
break apart when you try to put it in position for investing. Won’t
work.
To capture natural appearance it has to be caught alive and locked in
a freezer. After some time it needs to be defrosted and will remain
flexible enough to be put into a natural position, fixed with a
(very) thin layer of superglue here and there and sprued at the most
massive spot. Use a high temp investment like our Invest C/P or
Invest RP with deionized water instead of liquid binder or a
suitable gypsum bonded investment and heat up to 950 C or 1000 C.
Keep it at high temperature for a considerably long time (the result
will tell what that is) to make sure that there will be no organic
ash residues and cast with a centrifugal caster. Don’t break the mold
but clean the object carefully with 25 micron glass beads (coarse)
and baking soda (fine) at low pressure. Once a jeweler approached us
with a spider of suitable size just out of curiosity and it came out
well. No image - sorry. Good luck.
Sandor Cser
I take apart a segment or two of the exoskeleton and fill them with
modelingwax, taking care to fill every space, Once it’s got wax
everywhere inside Itake a very small and very hot tip and touch all
the fleshy parts inside, to prevent investment from coming inn to the
bug one this is done, I assemble it all and re wax all the thin parts
outside (legs wings antennae etc) an again I touch all with an extra
small and very hot tip to make the wax super liquid (it will soak in
the joints and almost disappear exchanging hot air from inside for
hot wax from the outside) I’ve found that sprues work very well in
the back of insects in the segment where legs are (right under the
wings in a wasp)
From Hans Meevis
Be sure you have good ventilation when doing something organic… did
a cast of a very tiny, very dead, very dry lizard once. ONCE ! The
resultingnoxious fumes are still the stuff of legend among my
students. (It turned out great, though.)
Interesting experience Susan
My experience of casting organics has been limited to plant material,
leaves and seed pods. I have a rhinoceros beetle I would like to cast
sometime but I estimate it would take at least 100 grams of silver
and I would have completely fill the body cavity with wax to ensure
there is no investment penetration during the debubblising. Perhaps I
will do it in bronze sometime. The question I do have about casting a
dead lizard is how clean was the burnout given that there is probably
a greater mineral content from bones than there is in plant based
organics. I have never found a need to clear ash out of the mould
cavity in plant based patterns as long as I set the soak in my
burnout at 650C for at least 2 hours. Perhaps next time I find a dead
gecko I will try. It could make an interesting piece. I could try
direct burnout but i might make a RTV mould instead.
As for the fumes from burnout, my casting setup, crucible furnace,
vacuum casting machine and kiln is kept in an outside shed. During
burnout I open the windows and doors and switch on the fan mostly
keep away until it’s time to fire up the crucible furnace.
All the best
Jennifer
This is also interesting. I am butting on someone else’s’s entry,
but I have cast a little lizard about 2 3/4 inches long. It turned
out perfectly down to the very very fine little claws on his feet.
This was in a class I was teaching at Ghost Ranch in New Mexico.
At the moment I can’t give you any instructions, since this is just
appearing. It was Lost Wax Casting.
I might add that when we displayed all the casting the class of 10
had made, It was amazing how the “Woodchucks” expressed themselves
about our killing a baby lizard.
Rose Marie Christison