The sand pit

You'll be handling a lot of sand so be sure to acquire clean fine grit sand and keep it that way.
Lumps of all nature are kept out and also keep your sand covered when it's unattended, your cat or young child has no good business in there!
All of my bins have covers. My white sand for cement making is kept dry in it's own large barrel. I have a yellow sand for the sand pit which is kept in a plywood box near by. This sand is damp and ready to be shoveled in or out as required.

Essentially, we'll be doing what is known as "green sand molding" in our sand pit.
The profile is mounted on simple nails pivots or vertical poles and they carve down into a compacted bed of damp sand.
You'll be using a sand pit with an outer ring that can be removed. This gives us free access to the sand bed around the dish. The green ring you see in the photo above is a roll of plastic garden edging I got from the hardware store. It goes around several times and thus becomes well strong enough for the job. It is held in a circular position by a tie down strap. This whole arrangement is resting on a stack of levelled up pallets to my preferred height. I'm aiming for a well levelled sand pit, as I use a fluid level to trim our final heights to during carving down stage....

This large sand pit in the photo above is directly on the floor of our shed. It's outer ring is stacked with paving bricks and the top course is tied in place with a strap. Notice in the photo below the pivot assembly has a double clamp. It holds onto the profile cutter and also slides / clamps onto the vertical pivot pole. The pole is located by a hole on the floor, and attached by a simple pipe bracket onto a rafter above. The pole is able to rotate freely but without any wobble! An assembly like this will be needed if you intend to build large dishes.

This large dish is heavy so making it on the floor is sensible. The sand pit is easy to remove from around the dish. Once hardened for a week, this dish was lifted vertically onto it's edge and carefully turned upside down onto a layer of boxing cardboard. It took 3 strong people to do the flip. It's plinth was then built on top.

This green sand mold is ready to fill with cement. We are viewing the outside surface of a single dish.

Link to next tutorial. The Cement.