In this episode of the garden potting bench build I’ll make the form and cast the concrete countertop, then add the sink and upper and lower shelves. In the previous episode I built the frame, poured footings to secure it to the ground, and added a corrugated metal roof. This is Part 2 of the series.
Background for Pouring the Concrete Countertop
(transcript of the Build Video Part 1)
This video will focus on pouring the concrete countertop, setting it on the top rails, installing the sink and drain plumbing, and adding the top shelves, then finally adding the bottom shelves with the corrugated panel back wall.
Concrete Countertop Form
The cast concrete countertop will be poured in a shallow form made with a melamine coated board and one by walls.
The back of the countertop will be notched around the center back 4x4 support. I’ll be casting two holes during the pour: one for the sink, and the other for a waste shoot.
Make the Countertop Sink Knockout
I need to create a hole in the countertop for my DIY sink I’m making from a stainless steel mixing bowl. I didn’t have any pipe or anything else the right size for this so, I’ll have to make a disc from scratch.
I glued two squares of 3/4″ plywood together to give me a 1 – 1/2″ tall disc. Which is also the thickness of the counter I’m making. When the glue dried I scribed a circle with a compass. Then rough cut this disc with a jigsaw.
Sand the Blank Smooth
I slightly tilted the table of my disc sander to create a draft angle on the disc. Then I rotated it to sand it round and smooth.
I gave it two quick coats of spray polyurethane to seal it from the concrete. To keep it from absorbing any water and hopefully make it easier to knock out after the concrete hardens.