How to: Plaster Traps

Plaster and clay sink traps are used to prevent solid wastes from clogging pipes and backing up sewer lines.
Avoid visits from the plumber by preventing clogs caused by solid waste.Avoid visits from the plumber by preventing clogs caused by solid waste.
Dental offices use these traps to keep plaster from entering waste water systems, but the traps can also be used in art facilities for sculpting or ceramic work. A homemade trap will filter solids from your waste water, but you should check your local regulations before installing a sink trap to ensure it meets building codes.

Step 1

Drill three rows of 0.5-inch holes all the way around the smaller bucket, just under the ridges around the top.

Step 2

Place the kiln posts inside the 5-gallon bucket and position the small bucket on top of the kiln posts. If you cannot find kiln posts, you can create stands out of wood or plastic. Just make sure the small bucket fits completely inside the large bucket but does not rest on the bottom.

Step 3

Cut a screen circle that matches the diameter of the small bucket. Cut a 1.5-inch hole in the center of each bucket lid and the screen. Push the drain pipe through the big bucket lid, the screen and then through the small bucket lid.

Step 4

Attach the P trap to the pipe that leads to the sewer line, using one of the trap's elbows and plumber's tape to seal the connection.

Step 5

Cut a hole in the side of the large bucket at the same height as the rows of holes in the small bucket and place the elbow pipe from the P trap into the hole. Affix a nut to the elbow on the inside of the bucket and seal both sides with flexible joint compound. If needed, remove the elbow from the P trap to complete this step and then reassemble.

Step 6

Place the drain pipe into the buckets with the screen below the small bucket's rows of holes. Attach both lids to the buckets, and attach the drain pipe to the sink.

Things You Will Need

  • 2.5-gallon plastic bucket, with lid
  • Drill
  • 2 kiln posts
  • 5-gallon plastic bucket, with lid
  • Screen
  • Scissors or craft knife
  • 6-8 inches of metal drain pipe, 1.5-inch diameter
  • Plastic P trap with elbows attached to both ends
  • Plumber's tape
  • Nut, 1.5-inch diameter
  • Flexible joint compound


  • It is a good idea to test the water flow of the trap before use by filling the sink completely full of water, draining it and checking for leaks.
  • Empty the buckets periodically, based on the amount of solid waste dumped down the drain, and recycle the materials inside. The buckets will be full of water after their first use, so be careful when emptying.
  • If needed, place the buckets on a shelf or cinderblock if the pipe is too short to reach your sink.


  • Use caution when cutting the buckets and screen to avoid injuring yourself.

About the Author

Alane Michaelson began writing professionally in 2002. Her work has appeared in Michigan publications such as the "Detroit Free Press" and the "Flint Journal." Michaelson graduated from Oakland University in 2006, earning a Bachelor of Arts in journalism.