Metamorphosis

Metamorphosis

Techniques of plaster casting (fine casting plaster)

29/09/15

plaster is a very good sculpting material and has a specific set of rules to go by when using it, as when misused, it can become dangerous. 

Rules to follow when using the material:

When mixing the plaster, only one third of a bucket of cold water is needed. The bucket should preferably be flexible, as it makes the cleaning process a lot easier. 

Pouring the plaster into the bucket should be done with care. Because of the lightness of the material, dust is likely to rise up when poured from a large height, and so when pouring it, it should be done as close to the water as possible and with a scoop. 

Keep pouring the plaster into the water until a small island/mound forms and does not sink into the water.

Mixing the plaster:

It is important to note that if any irritation is caused by using the material, you should wash any parts of your skin it may have touched and refrain from touching the material afterwards. 

Mixing the plaster takes some time. You will be required to put your hand into the mix. It is necessary for all small lumps of plaster to be squeezed out, and for the mix to be constantly stirred, slowly so that no bubbles form. eventually it will begin to thicken.

Once the plaster has reached a thickness similar to that of double cream, it is then ready to be poured.

The time span to use this material is between 2 - 5 minutes before it becomes unusable. It will continue to thicken throughout this small window of time, so you must be quick when using it.

Because of the change in thickness during the time this material is usable, it could be poured into something such as tights, and it will keep its form whilst creating a texturized pattern. 

Plaster Casting In Sand

This is one of the many different casting techniques. It requires the use of sand, which, while it doesn't enable you to include a lot of detail in your cast, does offer an unusual texture. When casting into anything, pushing into something causes the shape to stand out from the rest of the cast, whereas building up causes an imprint. 

When casting into sand, you first need to remove any of the big lumps, and you need a rather large pile. 

Once all of the lumps are removed, the sand then needs to be dampened so that you can actually mold it into shape and so that it will remain where you place it. To do this, you add enough water, kneading it in, so that the sand is damp enough that it sticks together and doesn't crumble.

The pile needs to be fairy loose so that you can actually push patterns into it or build on top of it. Once it is at this stage, you can then do the pattern you wish.

After creating the pattern, you then pour plaster onto it, making sure that you have an edge around the design that is taller so as not to spill any of the plaster. You can tap the plaster before it sets or band on the surface next to the work so that you can get an even surface and so that the plaster goes into all spaces. Then you leave it to set.

Once it has relatively dried, you then can dig under the sand, careful not to break the plaster cast, and lift it out of the sand. The cast must be resonably dry before you can begin to dust the sand off of it. Due to the abrasive nature of the sand, it could wear away the plaster if it is not dry

Plaster is very good for capturing small details, and so is a good material to use for sculpting.

Casting Into Clay

This technique follows the same guidelines as making a sand cast. The clay needs to be flattened so that a pattern can be made into or onto it, but it also needs to be thick enough for you to be able to work on it without breaking through the other side.

Once it is as this as you want it, keeping in mind that it cannot be too thin, you can then draw in or build on the desired pattern you want and cover it with plaster.

Once the plaster is resonably dry, you can then begin to peel the clay from around the mold.

Making A Cylindrical Cast

Using the same technique as the clay cast, you need to get a large piece of clay and roll it out, making sure it is thick enough, once it is at a decent thickness, you can then cut off all rough edges so that you are left with a neat square or rectangular piece of clay to work onto or into.

Once this is done, you then bend the clay, keeping the design on the inside, and wrap it into a cylindrical shape, making sure to press the seams together to prevent the clay from splitting when the clay is poured inside. if necessary, you could create a coil and fit it to the outside of the seam for extra support and strength. A coil is needed at the base of the structure to keep it from moving when the plaster is poured inside.

Once you have poured the plaster into the mold, you then leave it to set, once again, before it does set, you tap the surface it is on so that it goes into all spaces. 

If by any chane it splits, you quickly hold the structure in place, holding the seams together to prevent any more spilling. 

Eventually, when it is reasonably dry, you can then peel the clay off from around it. 

What Went Well?

While I did have some problems with getting the clay into the right shape at the beginning, as it kept cracking, when I eventually got it, it was easy to create a pattern. I was testing with the idea of communicating in a manner that could seem decorative to people who didn't know what the markings actually were, since I had an idea of using texture to convey emotions as research and development into my Metamorphosis project, and so I tested using some Braille, whilst also incorporating my idea of metamorphosis into it.

When creating the Braille pattern, I realized that it would need to be stamped into the clay backwards so that it read the right way when on the cast.

Next Time

One of the main issues I had with this technique was that my seem was not secure enough, and so it split, however, it also allowed me to think more about the project. Metamorphosis means change and transformation, and so it gave me the idea to try the technique again, but instead of trying to get the cast perfect, I would allow the cast to split and let the plaster leak out, showing the free movement and change of it, and how it could change with each different cast.