For a rock-solid drinks rider that’s huge on thermal mass, you can’t beat this icebox on wheels.
The phrase ‘heavy drinking’ takes on a whole new meaning with this durable concrete cooler box. With castors for mobility and an industrial finish, it’s a unique way to keep your guests refreshed.
Use 16mm melamine sheet for the formwork and a holesaw to bore a hole for a 150 x 15mm threaded outlet pipe.
To make the void inside the cooler, instead of building a negative form, take a shortcut by assembling a 670 x 345 x 300mm block of polystyrene insulation and pouring the concrete around and over it so the sides and base are about 50mm thick.
Once the concrete has cured, simply dig out the polystyrene insert.
To finish, a plywood base is embedded into the concrete and castors are secured, with a garden tap wound onto the threaded outlet pipe.
When the concrete is dry, which will take about two days, apply an epoxy based concrete sealant inside and out.
This will stop the ice from being contaminated by dissolved minerals from the concrete, in case people add it directly to their drinks.
The concrete’s high thermal mass means that once it’s been cooled by the ice you pour into it, it will stay cold for a long time, keeping the interior temperature stable.
This cooler is an open design, since a lid made out of concrete would be too heavy to handle.
A matching lid can easily be made from butt-joined decking boards or plywood, and lined with a leftover piece of the insulation.
To enhance the industrial aesthetic of the chiller, choose an outlet tap with a polished chrome finish and heavy-duty castors.
Cut three pieces of 16mm thick melamine to 800mm wide x 445mm high, and two to 445 x 429mm to build the formwork box using 30mm x 8g particleboard screws. Use a drill with a 20mm holesaw to bore a hole centred about 150mm from the top of the box
Use a caulking gun to apply silicone sealant into the corners of the formwork box. Cut polystyrene insulation into five 670 x 345 x 60mm pieces then use PVA adhesive to glue the stack together, and centre it in the formwork to create the void.
Using a utility knife, cut away a slight recess at the edge of the insert to house the end of a 150 x 15mm threaded pipe. Position the pipe in the outlet hole and seal off the end with heavy-duty tape to prevent it being clogged when you pour the concrete.
In a wheelbarrow, make up a wet mix of concrete and shovel it carefully into the formwork, spreading it evenly around the insert. Tap the side of the formwork to expel air bubbles and keep filling until the concrete covers the outlet pipe by about 50mm.
Use a timber float to roughly level the concrete then cut a piece of 18mm thick exterior ply to 700 x 345mm and centre it carefully inside the formwork. Press down evenly until the plywood is embedded in the concrete, roughly flush with the surface.
Let the concrete cure for 48 hours, then disassemble the formwork and dig out the polystyrene insert. Wind
a chrome plated garden tap onto the threaded pipe and secure the castors to the underside of the plywood base using the supplied screws.