Tenyoh Posted February 14, 2023 Report Share Posted February 14, 2023 Hi all, I am in the process of purchasing a large kiln. My figurative sculptures are getting bigger, and I am hoping to get a large enough kiln to fire my work as one piece. An inside dimension of W28.25" x D27" seems to serve my purpose, but I am too short to reach the bottom of the kiln or to load my delicate and heavy sculpture safely into it. A front-loader with car bottom is just too big. The next option I have is a raku kiln with a lift like this: https://kilnfrog.com/products/olympic-kiln-28-raku-gas-fired Olympic makes the size both in electric and gas, and I would like to get a gas one, if possible, because it allows me to experiment with reduction firing. The electric one costs $1000 more, and I was told I might have to pull a new wire from the pole to my house to supply the kiln. It must cost a fortune to do it. According to the above web page, we can bisque in the gas kiln, but a customer representative from Olympic said it would be tricky. Have you bisque-fired in a gas kiln? If yes, how do you regulate the temperature? Thank you for your expertise in advance, Tenyoh Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted February 14, 2023 Report Share Posted February 14, 2023 Did they say what was tricky about it? I have bisqued fired in a gas kiln before, the only tricky part was not going too fast at the start as the kiln had no pilot flame so it would like to climb fast on the lowest setting on the main burners. Before electric kilns were common place everybody used to bisque with whatever fuel they used. Tenyoh, Bill Kielb and Rae Reich 3 Quote Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 14, 2023 Report Share Posted February 14, 2023 6 hours ago, Tenyoh said: Have you bisque-fired in a gas kiln? If yes, how do you regulate the temperature? Most gas kilns can be fired by hand regulating the gas valve periodically as you climb. Also regulating the damper as well. Automatic gas kilns that can do this effectively are generally very expensive and automatic reduction gas kilns generally even more so. In the end, not difficult and a good skill to have. Gas kilns generally need to be supervised for the whole firing. Set it and forget it electric style firings not so much. Tenyoh 1 Quote Link to comment Share on other sites More sharing options...
neilestrick Posted February 14, 2023 Report Share Posted February 14, 2023 You can definitely bisque fire in a typical hi-fire gas kilns, but Raku kilns are tricky for bisque firing. They have a lot of power, and are designed to go fast. You may have to do something like keeping the kiln partially open at the start and slowly closing it. Get as many safety options as they offer. Rae Reich and Tenyoh 2 Quote Link to comment Share on other sites More sharing options...
Tenyoh Posted February 14, 2023 Author Report Share Posted February 14, 2023 10 hours ago, High Bridge Pottery said: Did they say what was tricky about it? High Bridge Pottery, they said because the gas kiln does not come with a controller, I have to watch the temperature rise very closely. Because I am firing pieces I have spent more than 10 days on, they wanted me to go safe. The 3 responses above are telling me I can bisque in a gas kiln, and I am willing to learn how to do it. Before deciding which kiln to get, I am going to get bids from contractors. Thank you very much. High Bridge Pottery and Rae Reich 2 Quote Link to comment Share on other sites More sharing options...
Tenyoh Posted February 14, 2023 Author Report Share Posted February 14, 2023 Bill and Neil, it seems I have to ask myself how much time I want to spend while firing. Based on the information, I am going to talk to a potter who knows a bit more about gas kilns than I. Thank you very much. neilestrick and Rae Reich 2 Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted February 14, 2023 Report Share Posted February 14, 2023 (edited) It a tricky one to decide, will the initial cost to get an electric kiln up and running save you money in the long term with lost ware and time you could be doing something else. I have semi automated a gas kiln adding a controllable valve onto the pipe but that is not the easiest thing to do. It just meant instead of turning it up every 20 minutes the computer did that for you. There was no brains really, the first firing I did have to turn it up via the computer and record what was set and run a simple program to repeat that for me the next firings. Edited February 14, 2023 by High Bridge Pottery Tenyoh 1 Quote Link to comment Share on other sites More sharing options...
Tenyoh Posted February 14, 2023 Author Report Share Posted February 14, 2023 You're right, High Bridge Pottery. I will be lost trying to do something that geeks like you can do easily. I just learned to check how many amp of electric service my house has. I may be able to pull 40 more amps without upgrading the service as long as I do not fire my current small kiln simultaneously with the large one. Yes, that means my decision is leaning toward another electric kiln. Thank you again for your advice. Quote Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 14, 2023 Report Share Posted February 14, 2023 24 minutes ago, High Bridge Pottery said: I have semi automated a gas kiln adding a controllable valve onto the pipe but that is not the easiest thing to do. It just meant instead of turning it up every 20 minutes the computer did that for you. There was no brains really, the first firing I did have to turn it up via the computer and record what was set and run a simple program to repeat that for me the next firings. Did you establish automatic damper management as more fuel was introduced ? Quote Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 14, 2023 Report Share Posted February 14, 2023 3 minutes ago, Tenyoh said: . I may be able to pull 40 more amps without upgrading the service as long as I do not fire my current small kiln simultaneously with the large one. You may find load splitters practical. With EV chargers becoming possible most load splitters will delay one load while another load is in use. Not saying it fits your need, but might be something to explore. A popular load to delay would be an electric dryer - if you have one. Tenyoh 1 Quote Link to comment Share on other sites More sharing options...
Tenyoh Posted February 14, 2023 Author Report Share Posted February 14, 2023 7 minutes ago, Bill Kielb said: You may find load splitters practical. With EV chargers becoming possible most load splitters will delay one load while another load is in use. Not saying it fits your need, but might be something to explore. A popular load to delay would be an electric dryer - if you have one. Yes, I will definitely consider a load splitter. It will probably prevent the current from going short while running the large kiln. Thanks a lot. Bill Kielb 1 Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted February 15, 2023 Report Share Posted February 15, 2023 12 hours ago, Bill Kielb said: Did you establish automatic damper management as more fuel was introduced ? I remember adding an actuator onto the damper but I don't think it was ever controlled by the computer. That was the plan but I don't think the project ever got that far as the damper was fully open until 1000c and then closed a little and left in the same place for the rest of the firing so it wasn't much effort to do that manually when it got to 1000c. In the end the guy got a second hand blaauw kiln which was much more advanced than my bodge job. Quote Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 15, 2023 Report Share Posted February 15, 2023 (edited) 2 hours ago, High Bridge Pottery said: I remember adding an actuator onto the damper but I don't think it was ever controlled by the computer. That was the plan The difficulty we noticed and actually humans have to navigate, are the very small pressures to monitor and interpret. Linear movement of a damper changes area / draft exponentially. Minor gas pressure changes that vary the output again exponentially by nature and valves are not proportional while the kiln dynamic losses increase. Reduction was a bit difficult as well. In the end we settled to build and program a monitor that could help folks fire manually. Seeing the effect of minor changes and managing a firing rate definitely helped folks learn the techniques. Interesting project, remote monitoring and reminder timers ended up to be an important tool that got a lot of use, plus folks learned real firing rates, minimal adjustment and consistent reduction strategies. A monitor ended up a far better teaching tool than pure automation. Edited February 15, 2023 by Bill Kielb High Bridge Pottery 1 Quote Link to comment Share on other sites More sharing options...
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