You are here: THE RAKU PROCEDURE The actual firing  
Getting started
Applying the glaze
Setting up the kiln
About the burner
Loading the kiln
The actual firing
Unloading the kiln
Temperature shock


If you fire the kiln for the first time than give it some time that warm up slowly. We have pre-heated the kiln shelf up to 950 °C for you but due to storage it can pick up some moisture from the air again.
Also for the ware it is better to start slowly with the firing process especially when you fire immediately after you have put the glaze on. All moisture should evaporate out of the ware and kiln shelf before the temperature gets too high otherwise you will have an increased risk of damage. Also your glaze layer may crackle and curl up when temperatures get too high too soon. And it may not flow out properly.

So you have put the kiln at an appropriate location. Gas tank is not too far away form the kiln, excess of pressure hose does not touches the kiln and is secured in a save way for example around the tank where is does not make you stumble when you have to operate the gas pressure regulator. You have something to align the burner horizontally in front of the burner port and the kiln is properly loaded. The kiln cover with flue gas port is still removed from the kiln. The pyrometer thermocouple can be placed at its position at the right side (when looking towards the burner port) of the kiln.

Everyone who is involved in firing the kiln should wear protective glasses and gloves.


Ignite the burner following the procedure as above and but it at its position in front of the burner port. We leave the gas pressure as low as it is for at least half an hour. Doing so we give both the kiln and the ware time to warm up slowly. After half an hour you put the kiln cover on the kiln while leaving the gas pressure unchanged. This enables the temperature to rise further. Give it another half an hour to adapt to this higher temperature.


The preheating as we describe it here is necessary when you fire the kiln for the first firing session. You can customise it when you fire the kiln multiple times a day. Make sure though that you ware is dry enough before allowing the temperature to exceed approx. 150 °C.
Even with this low gas pressure but with kiln cover at its place the temperature will increase quickly to values "dangerous" for ware that is not totally dry.


Pre-heating Even with a minimum of gas pressure, the temperature in the kiln can levels which are dangerous for your ware in case they are not totally dried. Take your time for this.


After this preheating and when the ware totally dry we can increase the gas pressure to a value that correspond with half capacity as specified on the kiln technical detail pages on this site. The temperature will rise quickly now and will be soon above 600 °C. Maintain this pressure for approx. 30 minutes.

Pressure indication manometer



If you work with a pyrometer it is easy to see that after 30 minutes the temperature increase gets slower. Time to increase the gas pressure to its peak value, which can vary for every typo of kiln. Please check at the technical details for the appropriate value. Maintain this pressure until you have reached the desired temperature and the glaze is matured.

Pressure indication manometer

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