Rhomba Concrete Bench

THREE: DEMOLDING

Carefully dismantle the form by removing all the drywall screws before extracting the concrete casting and take precautions to assure the form can be used for future castings. Try not to chip or scratch the form surfaces and never pry directly against the finished concrete surfaces.

What You’ll Need

Step 1 – Grind the Concrete Flush

  • Before removing the top caps, you can grind the concrete down in that area. This will make the caps easier to remove and ensure the bottom of the piece is flat.
  • Remove the top caps and unscrew the form walls.

Step 2 – Remove the Form Walls and Knockout

  • Do not pry against the concrete!
  • Some force may be necessary to break the silicone seal and loosen the wall. Hitting it gently with a 2×4 or a mallet should work.
  • Pry up on the baseboard, using the knockout for leverage.
  • The knockouts should remove easily by hand.

Step 3 – Sand and Finish

  • Support the piece with scrap foam.
  • Sand down any sharp edges with diamond hand pads.
  • The piece is now ready for Finishing and the Bench Top can be built.
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We prefer to hand place the fiber reinforced concrete mixture onto horizontal surfaces and allow a few minutes for the recently placed…

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For our Rhomba Bench we decided to use cedar 2 x 4’s that were available at our local lumber yard and relatively affordable.