Scared of buying a kiln?
You’re not alone. I was terrified. Which is why I decided to cheer you on and share my personal experience!
When you start ceramics in a community studio, firing is the one part of the process you don’t participate in. Usually the kilns are in a separate area and make it harder to even see glimpses of the process. In my experience the kiln masters don’t want you anywhere near the kilns. Your bisque pieces and finished pieces just appear on a shelf like magic.
As a result, while you’re getting better at throwing or handbuilding, at recycling your clay or experimenting with glazes, applying transfers or burnishing, whatever part of the process you need to figure out, you never get to learn one fundamental skill in ceramics: firing your pots. An entire step completely escapes you.
It’s extremely frustrating. I remember putting a note asking the kiln master to fire my pot upright, when I had put it on the shelf sideways so they didn’t get knocked over. Did it happen? No. Not sure if they didn’t see my note or couldn’t be bothered. One time a beautiful tray or mine ended up on the shelf right next to someone’s piece which was the wrong type of clay and melted, engulfing my beautiful tray in an interesting very edgy 3D art piece akin to Dali’s melted clocks, just not on purpose. There are pieces who exploded in the kiln and damaged my pots as -to be honest- some of my pieces have exploded too, so I probably damaged other people’s pots. All that to explain why having your own kiln is awesome: all the mistakes are yours and yours alone and you have control over the entire process.
My beautiful tray engulfed in gooey ceramics…
Having your own kiln, if you have room (in your garage, or a shed with a cement floor) and the financial means is really a dream come true for any potter, and it’s a lot easier than you’d think. To be clear, I am talking about an electric kiln, not a wood fired, gas or raku kiln. And not just any electric kiln, but a programmable kiln.
I heard a potter once say she wanted to buy a manual kiln, because that was the traditional way. IMHO it’s completely stupid. It’s like doing your laundry by hand when you could afford a washing machine. Sure, it’s more traditional, but it doesn’t work any better and it’s a pain. Go for the electronics, it will save you a lot of grief.
I bought a used Skutt electric kiln from a potter’s friend who wanted a bigger one. We asked an electrician to install the outlet (get the installation checked by an electrician if you do it yourself!) then I installed a vent, which apparently is not compulsory but recommended. You have to put an exhaust on the outside, so we made a hole through the wall to let the exhaust pipe out. You also need to leave space around the kiln on all sides (how much is written in the manual). That’s it, you’re ready to go.
My kiln in action (you can see the exhaust vent attached to the wall)
Shelves, posts and in the background some discarded cones
I don’t know if all programmable kilns work the same, but on my kiln I need to enter basically 4 information to program it: the speed of firing (slow, medium, fast), the cone setting (temperature), if you want a preheat cycle (warming slowly to allow the moisture to escape) or a hold cycle when it reaches temperature. And that’s it, you click enter and you’re done, you just wait for the cycle to be finished , to cool down and then you can open the kiln and discover your new treasures. Ta-Da!
I know several potters who create their personal program for firing their kiln, programming how long the kiln should take to reach the first temperature, then the second, and so on until peak temperature. After that you can program a hold, a slow cooling or both. Some people I know have 15 segments on their programming. I am not sure why? Maybe it gives them the impression that they have more control on the result? Personally with my own kiln I haven’t needed to try the manual setting yet, I just use the preprogrammed schedule and it has worked really well for me. That being said, I mostly use clear glazes, so there are some effect that might be achieved by a specific programming of the kiln that escapes me and I suspect the fact that my slabs keep cracking might be due to a fast cooling, so I should probably add a segment to my cycle. But in most cases, you’re just heating up your pots to a certain temperature and that’s it. Ceramics has been around for a lot longer than electric kilns, and they did just fine with very little control on the firing cycle.
An example of a ramp program that was passed on by a potter friend who got it from another potter friend, and this way magic formulas that are supposed to keep your pots safe are passed down without anyone apparently knowing which ingredient in this formula is actually important, and which one is just a flourish. Pulling the plug in and out is an additional flourish I would say, unless you don’t have a vent.
Community studio covering their asses, just in case… That’s why you need your own kiln!
Things I learned
1) You need to put kiln wash on your shelves to minimize your pots sticking to the shelf, but also on the tips of your posts (the surface that is in contact with the shelves), or they might stick when you take off the shelves and fall on your pieces (speaking from experience).
It’s easy to make your own kiln wash: 50% kaolin, and 50% alumina hydrate (by weight, get a decent scale) , both of which you can buy at your ceramic supply store. Add 4-5 parts water to one part powder. Yes, it’s very runny and you just need to put a thin coat on your shelves and post from time to time (maybe every 4-5 firing).
2) Make kiln cookies as well. They’re just circles (or triangles, or stars, whatever you want, use a cookie cutter) of clay that you bisque and then put underneath your pots when you do the glaze firing like a coaster, so that if they are drips, they will hopefully fall on the cookie and not on the shelf.
Touch wood, I have not needed to buy a grinder yet to clean up my shelves, but that’s something I will need one day for sure, especially as I am starting to experiment with lava glazes. To delay the day, put kiln cookies everywhere you can, or if you have a new untested glaze, you can even use a bisque bowl to catch the drips.
3) Make sure your pots are very dry before firing them. Moisture is your enemy. Then do the bisque firing on a slow setting with a preheat included, so the temperature ramps up slowly and the moisture has time to evaporate.
4) You’ll need to buy or make your own glazes since you’re not in a community studio any more. I managed to make a clear glaze that works just fine for my needs so I can dip my pots and don’t need to brush them, but commercial glazes are fine if you want variety or are not quite ready for this particular challenge yet.
Pyrometric packs
Self-supporting pyrometric cones
Pyrometric cones
I use pyrometric cones in my kiln on different shelves, at least 2 sets, sometimes 3, so I can see what the temperature really was and whether I reached my target temperature on all levels. It’s also a good way to know when to replace the thermocouple.
I use self-standing cones, because then I can just use them out of the box and don’t have to prepare packs and worry about putting them at the right angle. I had left over of the old ones and did the packs for a while, but they’re famously not as reliable as the self standing ones and you have to plan ahead to make the packs. However (there is always a downside) the self-standing cones are twice as expensive.
To give an example, since I want to fire my pots at cone 6 for the glaze firing, I put cones 5, 6 and 7 on the shelf close to the edge (in general, in front of the peep holes and I put a post behind them). In theory in a manual kiln, you check the cones through the peep holes during the firing and when the desired cone starts bending, you turn off your kiln. Despite buying welder’s glasses and blowing through the peephole to see the cones during the firing (like I read online), I can barely see them, the heat is just too intense, so I don’t worry about them until I unload the kiln. At the end of the firing, cone 5 should be touching the shelf and cone 6 should be bent anywhere between its starting position and not yet touching the shelf. According to Orton, the main manufacturer of pyrometric cone in the US, as long as the cone is bent, it has reached the right temperature, or more precisely, it has gone through the right chemical reaction. As for cone 7 it shouldn’t have moved.
I like having this extra point of reference, and it has allowed me to know my kiln better: the bottom shelf is usually colder than the middle shelf. The more shelves, and the closer the pots, the longer it takes for the kiln to reach the ideal temperature. Then you can tweak the firing. For example, when I first used the kiln, programming it for cone 6, it was too hot and cone 6 was completely melted. I contacted Skutt, who suggested to program to cone 5 and just put a hold so it would reach cone 6 eventually but not overshoot. I have been increasing my hold until cone 6 was bent the way I wanted (half way between the original position and touching the ground, with some variation depending on the shelf it’s on). Then, if my kiln is really packed, I can add a little more hold time to compensate for the fact that the heat will not circulate as well.
That being said, I know potters who don’t put cones at all in their kiln and just trust the thermocouple, but I like the extra information.
Maintenance
I haven’t had to do much maintenance on my kiln. It is, after all, a pretty simple apparatus. However, I had to change the thermocouple, and I just looked up a You tube video from the manufacturer and followed it step by step. Voila, it wasn’t even that hard! At some point I will have to replace the elements, since it was a used kiln when I bought it and they’re not going to last forever, but I know a few people who did it on their kiln, and it’s the same: check the You tube video and follow along. It’s not hard, it just takes time. Skutt has also been extremely helpful when I reached out to them, even though I told them it was a used kiln when I bought it, so don’t hesitate to ask the maker of your kiln if you have a question.
Conclusion
Having my own kiln has been great, with a lot fewer disappointments and headaches than I was expecting. I was so scared I would burn the house down, that all my pots would explode in the kiln, that glaze would run everywhere and ruin my shelves. Not so far! I program it in the evening, and come in the morning to make sure the firing is done. It’s important to be around toward the end of the cycle, so you can turn off the electricity in case the kiln is somehow not turning itself off and keeps getting hotter and hotter because of what is called a stuck relay apparently. Yes, I don’t know much about electricity, and still I manage. Then the hardest part is to wait until the kiln is cool enough to peek, and finally unload. I recommend getting fire-proof gloves if you’re the impatient kind.
To summarize, it’s totally worth getting a kiln if you’re in love with ceramics and want to have full control over the whole process. You need a covered space with a cement floor to put it in (a garage is ideal) and the finances to buy it as well all the accessories, kiln posts, exhaust, cones if you’re going to use them. They are used kilns out there that are cheaper, but they’re hard to find and really inspect the inside of the kiln to make sure it’s in good shape (not too many cracks and crumbling bricks) . I was lucky in that the friend who sold me his kiln had been taking very good care of it and sold it to me for a reasonable price. Expect a higher electricity bill too.
Once you have a kiln, there is still a lot to learn. For example, learning to load your kiln is not as easy as you’d think and will depend a lot on the type of pieces you’re making and what length of posts you have. Leaving enough room around the thermocouple is an extra headache when planning your shelves. Read the manual, and then you’ll learn by doing it. One small pleasure of mine is to fit all my pieces in the kiln with no room to spare. It’s like winning a game of 3D Tetris!