How to Make Casting Plaster

Looking to make a cast of your arm, your kids hand, your pregnant belly? Or do you want to be the next great sculptor? Well it all starts here! Learn how to make casting plaster with your own bare hands!

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Plaster-One of the following: casting, pottery, molding, or art.
• A level table
• 5 Gallon Bucket (this is a bucket of water)
• 2 Gallon plastic pail or tupperware bowl (this is your mixing pail/bowl)
• Apron or clothes you are ready to ruin
• Approx 5 gallons of water
• Dust mask

1. Estimate how much water it will take to fill your mold. You actually only need 2/3 of that amount, but over estimating is better than under estimating.

2. Put the amount of water you have measured into the mixing bucket. NEVER PUT THE PLASTER IN THE BUCKET FIRST-ALWAYS PUT THE WATER IN FIRST AND THEN ADD THE PLASTER.

3. 
    
   correct 'island' formation

   With your dry hand scoop up a handful of plaster and let it fall through your fingers into the water. This prevents large clumps of plaster from falling into the water. keep sifting the dry plaster into the water. Work quickly and spread the plaster all around the surface evenly. Do not mix the plaster or disturb it while doing this or this type of measurement will not work. Eventually you will have little 'islands' of plaster forming above the water surface . When these islands stay at that level and get damp and do not sink, this is the correct amount of plaster.

4. Depending on how long you have taken to get the plaster into the water (one minute should do for a small batch), let the mix slake (soak) for 1-3 minutes before mixing.
   You can use your hand or you can use an electric drill with a mixer attachment for mixing your plaster.

5. Batches over 2 Gallons are not practical for mixing with your hands. A mixer blade attached to a 3/8" or 1/2" electric drill will be needed.

6. When mixing with your hands always wear a long rubber glove made for the materials being used.
   Place your hand flat in bottom of bucket, spread fingers, shake your hand back and forth to agitate the plaster in the bottom. Use your hand to move some plaster from other areas to the bottom and continue shaking your hand back and forth.
   Plaster creams after a certain point-you must mix beyond this point for the plaster to set properly.
   keep mixing for 3 minutes.

Tips & Warnings

• Set a timer for mixing-you take a chance when you go beyond 3 minutes
• Wear the right gloves for the job when hand mixing-any kind of plaster is rough on your skin

Resources

• Plaster Master-Endless resource on plaster, sculpting, moulds, etc.

[olivierduhamel]

on 8/13/2009 One can also find more detailed instructions on www.bodyscape.net.nz This is an easy, fun and affordable DIY art project...

[grouch]

on 12/28/2007 This sounds like so much fun. I would have loved to have a cast of my prego belly and paint a landscape over the outside as a keepsake for the kids.