About 15 years ago a coffee shop gave me a large salad to go in a plastic container shaped as two half shells. The bottom half was yellowish foam. The upper half was clear plastic.
At home I realized how interesting they were but did not know how they could be used intelligently and I felt miserable just eating the salad and tossing the nice looking containers.
Recently, two at the time I made roughly 100 shells, about 12” in diameter, which I used to make a unique and curvilinear planter in the back yard. After all those concrete shells, the half shell made of clear plastic finally cracked irreparably and after multiple tries to fix it with packaging tape it had to be set aside.
The second mold made of thin yellowish foam is still at about 95%.
Refer to the ‘concrete for the home’ category for tips on concrete, tools and molds.
Concrete at the price of $2.69 x 60lb bag would make the price of a concrete shell about $.34 if not less. The calculator is telling me the curvilinear planter cost about $34.00.