Mixing Plaster

1.  Make SURE your mold is completely ready BEFORE you start mixing. 

  • No undercuts
  • Cottle boards properly supported
  • Everything coated with mold soap
  • Check with your Fearless Leader to make sure!!

2.  Measure the LENGTH, WIDTH, and HEIGHT in inches to determine the volume of plaster needed.

  • follow this formula: length x width x height = volume in cubic inches

3.  Make sure water is about 70 degrees. 

4.  Sift the dry plaster into the water.  Do not drop large clumps of plaster into the water. 

5.  Let the plaster soak in the water for 3 MINUTES. 

6.  Mix the plaster for 3-5 MINUTES – plaster should feel like heavy cream 

7.  Pour the plaster into the mold and vibrate the table and mold to remove air bubbles. 

8.  IMMEDIATELY clean the HECK out of the mixing bucket.  Use the water hose and a green scrub pad. Pour EVERYTHING into the dumpster.  Do not take any plaster into the studio OR the clay mixing room. For God’s sake, never into the clay mixing room.  All extra plaster, all water from cleaning plaster buckets, goes INTO THE DUMPSTER. Plaster that gets into the sinks will harden in the pipes and the only way to get it out is to jackhammer the pipes out of the concrete .. DEFINITELY not cool. 

9.  Wait about 20-40 minutes before removing the cottle boards. 

10.  IMMEDIATELY clean everything that even remotely applies to you in the room:

After you know the volume of your mold, use this chart to calculate how much plaster you will need:

Volume of mixed plaster needed:Measure this much water in quarts:Measure this much dry plaster in ounces:

Among other things, you should clean this stuff:

  • cottle boards
  • table
  • floor
  • brushes
  • buckets
  • scale
  • measuring devices
  • plaster bag
  • shurform