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live casting

updated fri 12 oct 01

 

Snail Scott on wed 10 oct 01


At 02:35 PM 10/10/01 -0400, you wrote:
>
>Be prepared for some sticker shock. This stuff is not cheap. Even the
>plaster bandages will run you $50 - 100* for enough to do a complete torso.


A cheaper alternative is to dip damp burlap pieces
into plaster - builds up quicker and cheaper. The
pieces should not be too big to go around the
sharper contours of the body, though bigger pieces
are fine for large flat areas like backs. Also
be sure to rub each piece well when applying, to
force the plaster through to the contact surface.
Several layers will be needed for strength.

A decent compromise is to do the 'impression coat'
(1st layer) in medical-type gauze/plaster bandages,
and use the burlap for all the later coats.

You can additionally reinforce the mold by attaching
wooden lath or metal rods to the outside surface
while layering on the later coats of burlap/plaster.
This can really help with long molds where the
tendency to fold or flex is exacerbated by size,
and you can worry less about the strength of the
plaster/fiber layers having to do all the work.

Note that fiber-reinforced plaster doesn't work so
well for slip-casting because the fiber holds the
moisture, but it works fine for press-molding. Or,
as someone suggested, use the life-mold to make a
new plaster 'positive', and make a solid plaster
slip mold from that.

Consider also the position of the model for this
process. Holding still can be genuinely painful
after a long time! Make sure the model is comfortable,
and using no active effort to hold the pose. It can
be tempting to let the model lie down, but if the
piece is intended to depict a standing figure,
remember that everyone sags a bit, and a reclining
figure will not look quite right if the mold is
stood upright afterward. (The effect is especially
disconcerting with large-breasted female models.)
This can also cause trouble with two-sided molds,
showing the figure 'in the round'. If the model has
any body fat at all, you can't do the front while
they're lying on their back, and then their back
while they're lying on their front, and have the
two molds line up afterward.

Better to put the model in the pose that you intend
for the final piece, and prop the model as need
for comfort, with things to lean against etc.

And remember to grease that body hair, unless you
want a do-it-yourself hair-removal treatment when
you're done. A good coating of hair gel or hand
lotion is usually less disgusting than vaseline.

As Bruce observed, dental alginate has a finite
lifespan. There are other life-molding compounds,
all of which can capture astonishing detail, but
most of them aren't cheap. A good reinforced-plaster
mold will probably be the most economical.

-Snail

Marie Gibbons on thu 11 oct 01


another thing you can do to strengthen a plaster mold is to .. on the outter
layers, I wouldn't do this directly on a person... use pieces of fiberglass
fabric, cut in smaller pieces, dipped in the plaster as it was explained to
do the burlap.
This makes a very strong plaster jacket, it is how it it done when making the
mother mold for bronze pieces.
marie gibbons
www.oooladies.com