Thursday, 6 June 2013

35th ENTRY - From Eyelids to Limbs

You persisted with the plaster eyelids and with the tools you had, eventually coming to the cold truth that the tools you had were not enough.
You spent some time searching for 4mm round burrs and ordered some.
They took many, many days to arrive.

In the meantime you thought about the problems of new moulds, of separating head, hands, and feet, and devising a secure method for locking the armature in place into the mould, and casting separate parts that would join together precisely as you wanted.

You also thought not to risk losing the work you had done in the plaster heads, at the arrival of the burrs, and so decided to teach yourself a different method of making a mould.

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Eyelids - Plaster - Isolde - To make reaching the eye sockets at angles with the tool easier, a face was cast and carved, to then be placed back into the mould and joined to the rest of the head.
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Not having a round burr of the correct scale, carving out a precise fit for the eyeball became a clear impossibility. The eye is still too sunken.

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Silicone cast of Russeau's original hands, to use for making a new mould in silicone.

The rubber hands, however, were so soft that it became very difficult to accurately lay the clay on top without distortion, and hence creating a negative space that was not large enough.  This mould was abandoned at this stage, and the original resin mould was used to make Degas 90 Plastilene casts that would be fixed after demoulding.

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After the second attempt at injecting the silicone into your first approach to making a matrix mould.
The first injection failed because you neglected any thought to clamp the mould down before injecting.
The second attempt failed due to a large air pocket in the top (face) of the mould.
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Second endeavour in making a matrix mould, this time for Isolde.
A key was carved in her belly, so that she would lock into the face shell of the mould.
The negative space for the silicone was created in clay, over the sculpture, with wet paper towel between the clay and the sculpt.  These clay keys were far more successful than the previous attempt, and a great deal better than any of the keys made in previous brush-up moulds.

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Front and back shells.

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Sculpture locked into the face shell.

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Sculpture sitting in place in its back shell.
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The finished mould. Plaster and PlatSil Gel 10 silicone, which was injected with a large syringe.
A relatively successful mould.

Resetting the Armature

Head, hands, and feet are to be separated, and each with their own new mould.
This means fitting the armature precisely in the right position within the body, and designing the joining points.

Russeau Back matrix mould II
Third mould of this kind.
The original resin back half of the Russeau mould had deep undercuts, mostly in the ribcage. For a Degas or plaster cast you needed a rubber mould.
Russeau Back matrix mould II
injecting the silicone to finish the mould.  Screws to shut bleeders.
Russeau Back matrix mould II
Rubber part of the new back mould.
Resetting Armature
Degas 90 cast from the new back mould.

Resetting Armature

Resetting Armature

Resetting Armature
Experimenting with a mixture of plaster and clay.

Since the clay unavoidably shifted in the Russeau figure, changing certain dimensions in the body, and forcing things to be resculpted, you worried about this happening to Isolde.  Liz has already worked so many hours on the costumes for Russeau, and now is starting with Isolde. The thought of proportions changing and her work going to waste haunts you.
Since Isolde was already completely resculpted and refined previously, there is no reason to go back and change her further (though you easily could).

So how to avoid the cast from changing?

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Resetting Armature
PlastoForma & Degas
Plaster was one option to avoid things changing, but not strong enough at very fine thicknesses (clavicle area for example). You also did not want to risk trapping the armature in plaster.
Moreover, water will rust the armatures.

Above is a test using, on one half PlastoForma, by Prochima, which is described as a bioresin, a non-toxic alternative to fiberglass. 
You had no fine glass fiber to test reinforcing this with, so the way you have it, the PlastoForma seems to basically be plaster with acrylic; a little lighter, less powder in the surface, but also very brittle.

The other half is Degas 90, brushed in thinly and then poured around the armature locking it in, and building more thickness.  This may be the best option.

Resetting Armature
Headaches over the cut off point in the arms. Leaving the shoulders was mainly for testing dimensional changes with respect to the costumes. But the undercut that was created seemed too complicated to mould, so here you are removing the arms at the chest.  The difficulty is in the way the limbs detach; rather than at a tailored, flat-fitting point mid arm, between the joints, it is in the joints themselves that you are forced to work.  This is a further defect in the armature design which will need resolving in a future project.
Resetting Armature

A quick mould was made to test a way for lining up the skin from two separate casts, maintaining the armature in the correct position, using keys.

Armature suspension mould key test
Armature suspension mould key test
Armature suspension mould key test
A quick silicone cast. Photo taken before merging together the skin at the neck.
The fit seems adequate.

You wanted to make a rigid mould, testing two different options for the eye sockets.  You cast a plaster head in two parts, in the hope that you could remove the positive from the new mould, without the mould part filling the eye socket breaking off with the positive.
So with the burr that finally arrived, you cleared out the sockets.

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Eye socket mould test

Eye socket mould test

But what were you thinking, pouring a plaster mould and hoping to be able to remove the plaster positive afterwards.
Eye socket mould test

So you started over again, and made a quick silicone mould just to test the theory.

Eye socket mould test
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After days away from the project, you returned with new ideas.  Remove the face from a plaster cast, creating a mould into which to pour wax, while this faceless mould is fitted back into the original mould it was created in.  You were hoping this might help fight the shrinkage of the wax, if the wax was indeed only a thin, flat face, without the sides of the head, which otherwise warp inwards during the shrinking.
But the plaster is very hard, and half way through preparing the empty face, you came up with a different idea: to burr out the eye sockets, and re-sculpt the eyelids in clay or wax, over the plaster face.
Russeau Eyelids

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And in doing this you enjoyed two days of pleasant sculpture, first in Degas plastilene, and then preferring to work in Castilene wax.  Two days completely forgetting the terrible conclusion you had previously made, that you would not be able to make a rigid mould from a plaster head.

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Returning pragmatically to reality, you spent a couple of days, yet again, trying to minimise shrinkage in wax casts.  Brushing, pouring, heating the plaster mould jacket, and the silicone mould.  Melting the wax from inside the mould, by blasting heat underneath, onto the jacket, with a heat gun.  Every attempt to try and keep the face of the mould hotter than the wax itself, as the wax tends to warp towards heat.
Seemingly impossible to control the heat before getting to a boiling temperature, creating bubbles in the wax, you even tried heating the mould first, brushing in the wax, and submerging part of the mould in hot water to slow down the cooling process.
But in the end, no method seemed clearly superior to another, and you surrendered, returning to the Degas Plastilene, which you felt was inferior enough to the Castilene to warrant these hours of experimentation.

hot and cold

mixed media
mixed media, Castilene eyes, Degas head (fighting the shrinkage),
and Castilene thinly brushed, Degas inside.

A New Character