Plaster info for project #1

Plaster Info Sheet for Project #1 Thursday Sept 8th

What you Need Thursday Sept 8th· Plaster of Paris
· Water
-4 empty soda cans
- Putty knife
·2  1 gallon bucket
-2 chip brushes


How to mix it:

1. To mix the plaster, fill a 1 gallon plastic bucket or other container no more than one-third full of cold water. (Hot water accelerates set-up time and can compromise the quality of your block). The ratio is generally 1 part water to 2 parts plaster, but this is not an exact science. It is better to mix too little plaster at first, because you can make more batches to fill your form.

2. Sift the plaster of Paris through your fingers/ or with a metal strainer into the water. Distribute the dry plaster evenly throughout the waters surface. Keep adding the plaster until it stands above the water in dry peaks. This will take awhile, because the plaster will keep sinking. In order for the plaster to mix properly with the water, however, it's important to add the right amount. When the surface of the peaks begin to look cracked like a desert floor, you can move to the next phase.

3. When you reach this stage, you can mix the two together with your gloved hand. Do not stir, but rather gently squeeze out any lumps that may occur. Stirring will cause air bubbles to form in the mixture which you do not want. Stirring also accelerates set-up time, which again can compromise the quality of your block. As soon as the plaster is mixed to a smooth, creamy consistency and covers your hand, pour it into your form. Tap the bottom of the container on a flat surface to release any trapped air. Depending on how much you mixed, you may have enough, or you may need to repeat the process. You may check to see if the form is level and make adjustments with shims accordingly.

4. The plaster will harden in just about 15-30 minutes. When the block is ready, peel the box away, and discard the pieces. You can plan your model by drawing several views of the sculpture and then transferring a rough sketch onto the block. If you prefer, you can make a direct carving by improvising as you work. Use the table knife and spoon to create the sculpture. You'll notice that the plaster may be warm. This is because mixing the plaster with water causes a chemical reaction which gives off heat. The plaster will be soft, so working with the block is easy at this stage.

Helpful Tips and Information:

■ Keep plaster away from food or kitchen and out of the reach of small children and pets. Read all directions and safety precautions on the packaging of any plaster materials that you obtain or purchase. Take precautions to keep dry or mixed plaster off of skin and out of eyes. Plaster undergoes a chemical reaction that produces high heat and can cause severe burns. Never mix plaster using your bare hands.
■ If doing any body casting, always use a release like Vaseline on your skin. Only use thin layers and/or plaster bandages. Always leave an "out", meaning an open side or an area thin enough to cut with scissors.
■ Wear a particle mask when mixing plaster.
■To save money, buy plaster of Paris at hardware stores or a lumber yard, rather than at craft store.
■ If you want to make a larger sculpture, substitute your form for a Rubbermaid container or a cardboard box taped well at the seems. Mix your plaster in smaller batches adding them to the bigger mold gradually. When the plaster sets up, just peel away the carton, or pop the hardened plaster out.
■ Mixing plaster properly takes a little practice. If the mixture is too liquid, it will take a long time to set up, and the finished block will be weak. On the other hand, if you add too much plaster of Paris to the water, it will be too thick, harden very fast, and it will be difficult to use.
■ Never mix plaster in a metal container, because you'll be unable to remove it or clean the container when the plaster hardens. Also, be very careful about cleaning up after working with the material. Plaster can clog sink drains! Clean your hands by wiping the plaster on a rag or paper towels, and then rinse in a bucket of water. When the plaster settles on the bottom of the bucket, discard the water and let the plaster silt harden. Later, just dump the dried plaster chunks in the trash.