Wednesday, January 12, 2011

Making a Simple Plaster of Paris Model.

When coming up with imaginary creations of the mind for a painting, it helps to create a version of it in solid form, especially if your planing to paint it somewhat realistically.

Dragon Eye Model made as reference for my next painting.

Depicting fantasy creatures realistically has a lot to do with light. A vivid imagination and a full understanding of the nature of light helps a lot in recreating the modulations of light and shadow that give form and substance to an imaginary subject and setting. A model of the subject is invaluable in helping with this aspect of the painting.

Next I'll show you how I made a small model (big enough for my needs) easily and quickly with just a few materials....

Materials

  1. Plaster of Paris (I just bought some at my nearest hardware store for RM5 a bag)
  2. Plastic ice-cream box. Choose one the size you wish your model to be. (this container should be pliable, this helps when removing the hardened plaster)
  3. Water
  4. Any instrument to carve out you model.. I used a small pen knife, a pencil and even a wire at times.


Preparing the Plaster


1. Be sure to allocate at least 15 mins of uninterrupted time to mix the plaster. You should not leave, even a moment, during the process. It would be a good idea to read all the following steps first, before beginning.

2. Fill the container with water, a little less than the volume you intend your sculpture to be. When you add the plaster this volume will increase. You can mix the plaster in the same container (mould) you wish to set (harden) the plaster in or prepare it in another container, pouring the plaster in to the mould when it's ready.

3. Start sifting the plaster in to the water and keep going till there is a small 'mound' of plaster powder protruding on the surface of the water. If this mound disappears after a few seconds, add more plaster till it doesn't.

Sift the plaster in to the water, break up lumps and smoothen the powder as you do so. Depending on the quality of the plaster and the source, you may find a few bits of foreign fragments in the plaster, just feel them out and discard. (sorry about the bad pic, will try to take a better one next time)

4. When enough plaster has been added, start mixing the water + plaster slowly (it's best to use your hand as you can feel for any lumps and unevenness in the plaster while mixing). Mix round in an even circular motion (only in one direction to minimize air entering the mix, making bubbles).

Do this at a steady pace, using your fingers to smoothen or break any lumps you may find in the mixture as your mixing. Do not lift your hand from the mixture other than to check it's consistency (this it to minimize bubbles).

Keep mixing continuously, the mixture will at first not seem to change in it's consistency for  some time, keep going, it will eventually start to thicken.

5. When the plaster starts to coat your hand thickly (check by lifted your hand out of the mixture a bit), you will know it's ready to be left to set or to pour in a mould. It will set very quickly as soon as you stop mixing.

6. When cleaning your hand and anything else of plaster, it's advisable to use newspaper or a disposable towel rather than washing down a sink (the plaster will harden in fragments and may block up the pipes).

Plaster is quite drying and can be quite rough on them hands, so a lil moisturizer will work a treat right about now...

Leave to set for a few minutes then remove from mould.

7. You will feel the plaster warming up as it sets in the mould. As soon as it's gone hard ( should only take a minute or two) you can remove the plaster block from the mould.

The ice cream container I used as the mould was a bit pliable and I was able to ply the sides away from the solid plaster block before turning it upside down and carefully removing the block from the mould. Handle the block carefully, for it's quite fragile.

As plaster on it's own is very fragile you can mix some PVA Glue with the water before adding the plaster of Paris for mixing... though carving may become a slightly more 'stickier' process...

Fresh block of Plaster ready to carve

Carving the Plaster

1. You can now start carving the block while it's still damp.
You can store your plaster block between carving sessions (if your carving something detailed or quite large that will take a couple of sessions to complete). Just wrap the plaster block in a damp towel and store in an airtight container till your next carving session. This can be done indefinitely though some discolouration may occur from properties in the water...

Transferring the image on to the plaster block. I just traced the image with a pencil, indenting the image in to the block.

Indented image on block


Starting to carve. The plaster is very soft and can be carved with even a blunt pencil or a damp soft cloth for smoothening. Find what works best for you. 

Dragon Eye Sculpture Completed!

2. Once completed you can leave out to dry. It will still be quite fragile so handle with care.


If you like, you can give a nice finish and little protection to the completed sculpture with a simple turp + wax solution....

As always, pop over with a comment if you have any questions!.. :)

Thats all for now folks!



10 comments:

  1. Thanks for the tips and espcecially for the detailed mixing instructions!

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  2. how do i get image of the dragon eye?

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    Replies
    1. I'm not sure what ya mean... You could check out my WIP of my original interpretation of a dragon eye that this sculpture was used as reference for here.. http://jackiegomezfineartist.blogspot.com/2011/11/dragon-eye-underpainting.html
      Hope that helps...

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  3. hi! great work! can i use modge podge or elmer's glue instead of pva glue? thanks!

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    Replies
    1. Hi there, sorry for the late reply!.. I'm sure elmer's glue would do for a simple sculpture like this one.. :)

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  4. Hi, I'm making a model out of pop. But the requirement of my model is such that I can't use any tumbler/or any boundaries to set the mixture. I want it to be laid flat on a cardboard and create small hills and valleys sort of structure. So is it possible to mix it in a container then pour on my cardboard with making it messy and without letting it flow down my board?

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    Replies
    1. Hi Chetan, I'm afraid, it would probably flow off the board and be quite a mess as you say. Pop is still quite liquid when you first stop mixing it and then very quickly hardens. You could try making an upside down mold of your hills and valleys first, pour the pop in, then once dry, turn it over onto you board, remove the molding and continue refining and carving it to exactly what you wish from there. ( I would suggest using something more sturdy than cardboard as your base though). However if I am imagining the structure you wish to create correctly, it would really probably be easier to use some sort of clay instead... Good luck and have fun! :)

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  5. Replies
    1. Hi kurogitsune110, Once the block (5 x 3 x 1.3 Inches) was completely dry with a wax finish, it was about 170 g...

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