Electric to Gas Conversion: The Birth of My Kiln

My kiln is a gas kiln that was converted from an old electric kiln. I did lots of research so i could figure out what was going to be the best way to convert it. I found some forums online that were very helpful to me and I was able to avoid many trials and errors thanks to these helpful people. Now it’s time to give back. I hope that this section might help others out there as kind of a step by step demonstration.







First, I completely “gutted” the kiln, taking out all electrical components.








This is what the side of the kiln looks like now, on the side of the kiln where all the outer electrical components used to be.


Next, I marked and cut the hole for the MR750 gas burner and regulator combo that I bought at the local pottery supply store (this hooks to a 9 gallon propane tank).



The hole is about a 4” square on the outside, but I cut it at an angle so that when the flame shoots in it creates a spiral effect which will give me a much more even firing. In the pictures below you can see how I drew a couple different angles before I made my cut.


In the next two pictures you can see how I was able to cut the hole in the fragile fire brick without damaging the parts of the kiln that I wanted to keep.

In these two pictures you can see that I cut the hole so that the flame swirls counter clockwise. This is WRONG because I live in the northern hemisphere. If I lived in the southern hemisphere this would have been correct. I have since changed this and now, because of the coriolis effect, I am able to get a much better swirl and a much more even firing. I have the earths rotation working with me, not against me.

Also, when cutting your hole with the kiln section upside down don’t get confused as to which way the flame is going to shoot in when you reassemble the kiln. When you cut the hole with the kiln upside down, know that the angle you cut will be angled in the opposite direction when you flip the kiln back over. Just remember to cut your hole so it is angled the opposite as what these two pictures show, if your in the northern hemisphere. If you live in the northern hemisphere you want the flame to swirl upwards in a clockwise spiral. Hope that's not too confusing. Email with any questions. And for all you skeptics out there who think the coriolis effect doesn’t matter, I assure you it makes a difference. I have tried angling the flame both ways both ways and I have the pyrometric cones to prove it.

Next, I marked out the chimney and drilled holes to help me start to cut the chimney out.

Then I used a hacksaw blade to carefully cut a rectangular shape out for the chimney.

A rectangular shape is used because the heat is swirling through the kiln in a circle and a rectangular exit hole will require the heat to change direction before leaving the kiln, keeping the heat in longer, and making for a much more even firing.


I made the exit hole bigger than I needed it to be for firing so that I could use an old kiln shelf as a damper.




Another very important part about this kiln conversion is that I used square shelves. This helps me avoid getting cold spots in the center of the shelves.

It is important to leave at least 9” between the floor of the kiln and the first shelf so that the flame is not directly hitting the pottery. It is also important to leave at least 4” space between the top of the kiln and any of the pottery. This is because it is colder towards the top.

By the time I had left space at the top and bottom of the kiln and used square shelves, I realized that I had a lot less space for pottery in my new gas kiln than I would have had in a working electric kiln that was the same size. I don’t mind because now I am playing with fire.

Now I want to find another old broken down kiln that is the same diameter as my kiln so I can add another section and make my kiln taller.

Firing My Kiln

The pyrometer (found at your local ceramics supply store) is a crucial part of firing my kiln. The pyrometer gives me a digital read out of the temperature of the inside of the kiln. In the above picture my wife Leah reads a book while she keeps a sharp eye on the pyrometer. She will turn the gas up or down depending what she needs to do to keep to our predetermined firing schedule.


The hand written note on the left was the ^06 firing schedule given to me by someone from the local ceramic supply store. This firing schedule is normally used for electric kilns that have a built in computer to do the job of turning the heat up or down to meet the schedule. Firing schedules for electric kilns with computers are common and can be found for many different desired temperatures.



From the note that the guy at the ceramics store gave me, I made the firing schedule below. I first decided what time I was going to start the firing filling in the column under “time” and “ideal temp”. When firing the kiln, I check the pyrometer at the appropriate time and fill in the columns entitled “temp” and “max temp”. “Temp” is the exact tempature that the kiln was at the time that I checked it. “Max temp” is the hottest temperature that the pyrometer has recorded since the kiln was started (this varies because through the hour you may have to toggle the gas up and down). The firing schedule below is an example of a successful bisque firing. You can see that the schedule has some tolerance. I keep a schedule like this, sometimes known as a “kiln log” every time I fire my kiln. This way I can go back and evaluate my results and compare them to the kiln log.


The pyrometer is not 100% accurate so it is important to also use pyrometric cones so you can check what the temperature was at in different parts of the kiln. In the pictures below you can see melted pyrometric cones. They are melted consistently in different spots on the upper and lower shelfs. This tells me that I got a nice even firing. I stack my pottery in the kiln evenly and with good spacing for airflow. This ensures an even firing. Also in the picture to the right you can see the probe for the the pyrometer poking in the kiln where I had drilled the hole in the side wall for it. This tells us what part of the kiln the pyrometer is getting its reading from.