Park Avenue Bench and Planter

TWO: FORM CUBE PLANTER

The completed planter forms can be reused for many castings. Simply take care of the molds between castings by cleaning and waxing them.

What You’ll Need

Step 1 – Cube End

  • The Cube End of the bench is formed in the same way as the long planter.
  • 3/4″ melamine walls are used as the casting surface, and they are reinforced with 3/4″ plywood to keep the form from distorting after it’s filled with concrete.
  • Blue insulating foam is used to create the void in the concrete.

Step 2 – Install the Knockout

  • After the form has been assembled and sealed with silicone, the knockout can be installed.
  • Secure the knockout to the form with spray adhesive.
  • A short length of PVC pipe can be used to hold the knockout down in the form.
  • Build a small frame and drill through the PVC to secure everything in place.
  • The PVC pipe keeps the knockout from floating up, but it also creates a drain hole in the bottom of the piece.
Previous: Forming Long PlanterPark Ave Concrete Bench and Planter - Forming Long Planter | CHENG Concrete Exchange

The narrow planter box mold is constructed from 3/4″ melamine with 3/4″ MDO as structure to prevent “bowing” of the walls.

Next: Forming Bench TopPark Ave Concrete Bench and Planter - Forming Bench Top| CHENG Concrete Exchange

The bench top is just 2″ thick and spans more than 30″ between the two planters. Heavy reinforcing with rebar and mesh is what keeps the bench intact.