The world's smallest concrete mixer is a sheet of plastic.
John Shoemaker invented the CreteSheet, a square piece of yellow plastic with four handles at each corner, about 30 years ago while making repairs to a deck at his vacation home in Oklahoma.
"I had to mix 20 bags of concrete, and the only thing in the house was a piece of Visqueen," says Shoemaker. "For 30 years, I never used a wheelbarrow again."
Shoemaker decided to market his simple invention about six years ago. Featured at this year's World of Concrete show, the CreteSheet has appeared in Popular Mechanics and earned other accolodates for its simplicity.
Ideal for small jobs or where access is limited, the $20 tool can mix an 80-pound bag in 90 seconds. You mix by holding the sheet with a partner and pulling the handles in alternating motions. You can also use it by yourself by tying two handles to a stationary object.
"It won't launch a rocket, but it will mix a bag of concrete," says Shoemaker.