The Papercrete Tow-mixer

This humble contraption is all you need to make and dispense Papercrete, fibrous adobe and many other kinds of mixes. Notice I said "dispense". Not all Tow-Mixers are created equal. Most will make Papercrete just fine, but not all are specifically designed to dispense the Papercrete mix into forms in a precise, controllable way.

Where did the Tow-mixer come from? I visited Mike McCain, whom I consider a great Papercrete pioneer, at his home in New Mexico several years ago, and he was kind enough to show me his equipment, including a well-used Tow-Mixer, his invention. The 'blade' rotating inside was simply a section of steel fence post bolted to the 'face' of the differential, and the valve he made to let the mix out the bottom was just a sliding metal plate. During his demo, he banged the gate with a large hammer to get it to open, as it apparently got stuck regularly (he kept the hammer handy). This metal gate also leaked when the mixer was full of water or mix. Nevertheless, this mixer performed well, and had done so for many years. I came up with an alternative that I think works better. It's a valve-nozzle made from an inner tube from a car tire, attached to the  tank and closed by a gate of plywood.

The Tow-mixer is made like this. It's basically a stock tank - the one we used is 165 gallons - with a blade rotating inside, like a giant food processor. When the mixer is towed behind a vehicle, the wheels turn the gears of the differential (back axle from an old car) and the part that used to connect to the driveshaft rotates facing upwards inside the tank. Here we bolt a lawnmower blade or, as in Mike's case, a piece of fence post, and this blade chops up the paper and mixes it with water and cement to make Papercrete. More about making this mixer in a movie.

After the Papercrete is mixed and ready to use, the mixer is driven over forms or molds waiting on the ground, and the mix can be released through the nozzle at the rear into the molds. So this Tow-Mixer is both mixer and dispenser, and with it you can make all the Papercrete and fibrous adobe you want for many years. The rubber nozzle  spout allows you to direct the flow of mix precisely into forms. Long wooden trowels make spreading and leveling the mix easy and fun.

The DVD covers all aspects of Tow-mixer construction and use, including mixing up a batch of papercrete and casting it into gang-molds to make blocks and panels. More about making the Tow-mixer and making Papercrete in the movie.