How to build a pizza oven from a propane tank

I wanted a wood-fired pizza oven without spending a fortune, so I turned an old gas bottle (a propane tank, if you're in North America) into one, using only a drill and an angle grinder. It was my first metalworking project, and I learned a lot along the way. Working on gas bottles is extremely dangerous, so please don't try this at home.

Getting the valve off

The first hurdle was the valve, which wouldn't budge. I made a tool from scaffold tube to grip it, added a long pole for leverage and got a couple of friends to hold the bottle while I heaved. Once it was open, I filled the bottle with water to flush out any gas left inside before cutting.

Frame, brackets and legs

Everything is held together with nuts and bolts. I ground a groove down the middle of flat brackets so they'd hug the curve of the tank, and heated and hammered other brackets open to fit. The legs are handrail on handrail brackets. Those don't lock on their own, so I swapped the pins for nuts and bolts that clamp them at the angle I wanted. A second set of short rails lower down stops the legs splaying under the weight.

A steel firebox with an air damper

The firebox is a solid steel ammunition box that can take the heat. Its lid, drilled and fitted underneath, acts as a sliding damper to control airflow. I lined it with mesh so the fuel sits off the box and air circulates, and mounted it on curved brackets so it's removable for emptying ash (and could be swapped for gas later). Cutting oil turned out to be the game changer: before I discovered it I went through a pile of drill bits and possibly a couple of drill batteries.

Insulating the oven for pizza temperatures

A pizza oven runs at roughly twice the temperature of a kitchen oven, so every material had to cope. The panels cut from the tank at the start became a floating inner shell, bolted in with spacer nuts, with ceramic fibre insulation packed between it and the outer skin and high-temperature sealant on the gaps. Fitting the inner layer was the fiddliest part of the build. The floor is a 5:1 perlite and cement mix, which sets rock hard and insulates beneath the pizza stone. A new enamelled wood-burner flue became the chimney, after the salvaged water-heater flue turned out to be too soft.

Finishing and first firing

Paint stripper did nothing to the old paint, so a flap disc took it off (covering the workshop in red dust), and the oven got a coat of high-heat matte black. Finishing touches are a turned oak door handle (the channel's first lathe project), a fireproof door seal, a pizza stone and its name sprayed on the side. Then it was time to fire it up.