How to Build an Oil Fired Ceramic Kiln

Design the kiln before building it. Draw the plans or use computer-aided design. Measure required dimensions on site using a tape measure. Scale each measurement down by a multiple of 10. Transfer them onto your plans.

Clear your kiln area with a sweeping brush. Level the ground using a spirit level and spade. Wear protective clothing, thick gloves and eye goggles. Build a framework using rigid fabricated steel, a heavy duty metal saw or angle grinder, securing brackets, metal screws and a screwdriver. Rest the steel framework in position on the flattened ground.

Combine concrete powder with water in a bucket using a trowel. Work steadily until a malleable, thick paste forms. Pour the concrete onto the ground to make a solid foundation around the steel framework and to increase the kiln's stability. Allow to dry for at least 12 hours.

Build the bottom of the kiln around the steel framework using high duty hard brick. Ensure the base is large enough to accommodate the three walls and door at the front, yet still contains enough vacant space for the firing cavity and shelves.

Mix two spade-loads of refractory (fire-resistant) concrete powder with two spade-loads of sand and half a spade-load of lime and mix together dry. Add 6 liters of water in 2-liter stages. Continue until you have a thick paste. Add extra water if the mixture is gritty. Add more sand and gravel if it becomes watery.

Build three inner walls using insulating firebricks and a layer of cement. Press the bricks firmly together. Leave a small opening 1 foot from the base of the back of the kiln for the oil entry. Leave the front of the kiln open to create a door. Add an outer layer of high duty hard bricks and concrete to form the outer casing of the kiln. Leave under plastic sheets for 24 hours. Remove the sheets. Leave for 24 hours in dry conditions for full drying.

Build a basic framework to accommodate as many shelves as you can fit inside the cavity. Consider how big your pottery will be. Create lightweight shelves using nitride-bonded silicon carbide which has the lowest porosity (1 percent), the highest strength under fire (25,500 PSI) and the lowest weight (8 lbs. for a 24-by-12-inch shelf) compared to any material used for this purpose.

Fit three layers of 1-inch suspended ceramic fiber across the top of the kiln to create a roof using kiln glue. Locate a small oil tank at a safe distance from the kiln. Mount it higher than the top of the kiln to create a gravity feed. Connect the oil tank to the kiln using pipes and an oil tap. Create a small oil reservoir using a 2-inch square iron plate behind the kiln. Drip oil slowly through the back wall and onto the fire at the back of the kiln.

Block the front door up with loose bricks during firing. Number the bricks with a marker pen when you have found an efficient configuration.