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#11
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Them wobbles - wheel throwing
Thanks for your diplomatic view, Bob :-) Marianne |
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#12
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Them wobbles - wheel throwing
I do know about what temperature I am firing at. It is NOT out by 20 degrees, that has been established. I have done only 40 firings (including bisque) with this kiln, so it still is taking some getting used to. Even in that last kiln, I had a couple of pieces turn out really great. The clue is to figure out where I can fire so ALL (or almost all) the pieces turn out lovely. I don't use just one glaze, so my milage varies accordingly. The piece that bubbled the most was a combination I was trying for the first time. I'm sorry, Donna, but the people I know here who have electric kilns of varying sizes never use cones and they produce beautiful sculptures and crockery and you name it. If they can manage without cones, I am not going to stand on my head and run around Europe to try to find some - I will try their suggestions about temperature increases first. Even if my thermostat is slightly off, it will always be off by the same amount or percent, so that I will refire at 5 degrees more, then 10 degrees more. Keep smiling. Marianne |
#13
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Them wobbles - wheel throwing
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#14
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Them wobbles - wheel throwing
On Wed, 17 Oct 2007 22:59:58 +0200, "Bubbles_"
wrote: Thanks for your diplomatic view, Bob :-) Marianne Hmm, "diplomatic" is not something I'm often accused of! Seriously, I think the point that folks are missing is that a good kiln controller *does* take heat work into account. By "good", I mean one that follows a specified time-temperature curve, so that if you set it to (say) "hold at 1000C for an hour" at one point in the firing cycle, the controller cycles the power to the elements just the amount needed to hold at 1000C. That part is no different from the "inifinity control" on an ordinary electric oven. But in addition to this, if you tell it to ramp at a certain rate, it can adjust the power moment-by-moment to hold that ramp rate (within some tolerance, of course). This is critical, because it compensates for light or heavy kiln loads: If there is a light load, the elements (if unregulated) would heat it up more quickly than with a heavy load. One can debate that the controller only knows the temperature of its thermocouple, which is not the same as the pottery itself. But on the other hand, the exact same argument applies to the cone. There is nothing magical about the fact that the cone is made out of a ceramic substance and therefore holds some secret knowledge about other (wildly different) ceramic substances in your clay and glazes. The cone is just a "cheap and dirty" way to get an estimate of heat work. Before the advent of computer controls, it was the best show in town. Now, I think it is more like a security blanket if you already have a computer controller. Barring things like power outages that might confuse a controller, I you could have only one or the other the controller wins hands down, every time. After all, the cones only tell you about end-points, they don't allow you to program cooling soaks for crystal growth, etc. But I have a big box of number 6 cones, and they make dandy sacrifices to the kiln goddess! Best regards, Bob Masta DAQARTA v3.50 Data AcQuisition And Real-Time Analysis www.daqarta.com Scope, Spectrum, Spectrogram, Signal Generator Science with your sound card! |
#15
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Them wobbles - wheel throwing
Sorry about the mistake - I could have sworn you had said that your were
firing to 1270 but thought you were only reaching 1250.... I can only blame the memory on having a virus at the time. It seems we have only led you down wrong garden paths and have been no help at all. If you ever get it figured out, please let us know for our own education. Donna "Bubbles_" wrote in message ... I do know about what temperature I am firing at. It is NOT out by 20 degrees, that has been established. I have done only 40 firings (including bisque) with this kiln, so it still is taking some getting used to. Even in that last kiln, I had a couple of pieces turn out really great. The clue is to figure out where I can fire so ALL (or almost all) the pieces turn out lovely. I don't use just one glaze, so my milage varies accordingly. The piece that bubbled the most was a combination I was trying for the first time. I'm sorry, Donna, but the people I know here who have electric kilns of varying sizes never use cones and they produce beautiful sculptures and crockery and you name it. If they can manage without cones, I am not going to stand on my head and run around Europe to try to find some - I will try their suggestions about temperature increases first. Even if my thermostat is slightly off, it will always be off by the same amount or percent, so that I will refire at 5 degrees more, then 10 degrees more. Keep smiling. Marianne |
#16
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Them wobbles - wheel throwing
"Bob Masta" wrote in message ... On Wed, 17 Oct 2007 22:59:58 +0200, "Bubbles_" wrote: Thanks for your diplomatic view, Bob :-) Marianne Hmm, "diplomatic" is not something I'm often accused of! Hehe! Well - chalk up one, then ;-) Seriously, I think the point that folks are missing is that a good kiln controller *does* take heat work into account. -snip about computers and cones- clay and glazes. The cone is just a "cheap and dirty" way to get an estimate of heat work. Before the advent of computer controls, it was the best show in town. Now, I think it is more like a security blanket if you already have a computer controller. Barring things like power outages that might confuse a controller, I you could have only one or the other the controller wins hands down, every time. After all, the cones only tell you about end-points, they don't allow you to program cooling soaks for crystal growth, etc. I have a computer controller. Pretty basic, but it lets me set TIME to TEMPERATURE, TOP TEMP and SOAK TIME. When it is finished soaking, it shuts down and just shows the temperature until I shut it off. My hubby is so wonderfully supportive and I am getting a bigger kiln and a wayyyy better controller for Christmas.That controller has about 30 different times and levels to program - including cooling time, which is why I will wait until I get that before experimenting again with my more difficult glazes - see my reply to Donna on thread "Bubbly update". But I have a big box of number 6 cones, and they make dandy sacrifices to the kiln goddess! LOL! I made a huge sacrifice a few months ago - a sculpture of Patrick Stewart's face/head that had turned out pretty fine, but I didn't let dry by far long enough. Busted into a billion pieces on bisque firing. The gods should be sated for another year, I think, with that one! Have a gread weekend! Marianne |
#17
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Them wobbles - wheel throwing
"DKat" wrote in message ... Sorry about the mistake - I could have sworn you had said that your were firing to 1270 but thought you were only reaching 1250.... I can only blame the memory on having a virus at the time. It seems we have only led you down wrong garden paths and have been no help at all. If you ever get it figured out, please let us know for our own education. Donna Hey Donna :-) I said I suspected, but the firing proved me pretty wrong there. And it is a good thing that you tell me what you think I said, because sometimes I just don't say things clearly enough! In my other reply to you, I have outlined what I will do now, and I promise I will get back to you with results when I try out the new equipment. In the mean time, I am playing it safe(er). Have a great weekend! Marianne |
#18
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Them wobbles - wheel throwing
"Bubbles_" wrote in message ... "DKat" wrote in message ... Sorry about the mistake - I could have sworn you had said that your were firing to 1270 but thought you were only reaching 1250.... I can only blame the memory on having a virus at the time. It seems we have only led you down wrong garden paths and have been no help at all. If you ever get it figured out, please let us know for our own education. Donna Hey Donna :-) I said I suspected, but the firing proved me pretty wrong there. And it is a good thing that you tell me what you think I said, because sometimes I just don't say things clearly enough! In my other reply to you, I have outlined what I will do now, and I promise I will get back to you with results when I try out the new equipment. In the mean time, I am playing it safe(er). Have a great weekend! Marianne You too! I'm being wild and crazy - driving to the Bronx to pick up materials. I do know how to have a good time Donna P.S. If you decide to try our way of venting here is a doit yourselfer from Sondahl Cheap Electric Kiln exhaust I recently added a cheap kiln vent to my electric kiln. I bought some flexible aluminum clothes dryer vent and attached it to the bottom peephole of my kiln with three sheetmetal screws with added washers to keep from ripping through the thin metal. At the other end of the flexible section I used standard rigid aluminum dryer vent tubing to get it out of a window. Outside I added a small fan mounted in an A-frame of plywood (so as to protect it from rain/snow). From inside I can push the vent tube closer to the fan to create more suction, or farther from it for less. When I fire a bisque, I want more suction, to vent the sulphur fumes. You can tell how effective the venting is by how hot the pipe is getting. It never seems to get too hot to touch. No longer the taste of sulphur when I fire... Do bear in mind that in venting out fumes, you are also removing some air from the room, which must be replaced somehow. If you are in a confined area with fuel fired appliances (gas hot water, furnace, or woodstove), the draft created by drawing out kiln gases can also draw into the room some of the exhaust gases from these other appliances, including carbon monoxide. So you may need to run a vent hose into the kiln space to equalize pressure. http://www.sondahl.com/kiln.html |
#19
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Them wobbles - wheel throwing
"Bubbles_" wrote in message ... "Bob Masta" wrote in message But I have a big box of number 6 cones, and they make dandy sacrifices to the kiln goddess! LOL! I made a huge sacrifice a few months ago - a sculpture of Patrick Stewart's face/head that had turned out pretty fine, but I didn't let dry by far long enough. Busted into a billion pieces on bisque firing. The gods should be sated for another year, I think, with that one! Have a gread weekend! Marianne What a cruel thing to happen to such a sexy actor! My kiln god the blew up was a dragon - wouldn't you know that my next glaze firing was for sh!$. Maybe I will just go Bob's route and treat my cones as my kiln god... Congratulations on your new kiln!!! Can't wait to hear the next chapter. Donna |
#20
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Them wobbles - wheel throwing
"DKat" wrote in message news "Bubbles_" wrote in message ... "Bob Masta" wrote in message But I have a big box of number 6 cones, and they make dandy sacrifices to the kiln goddess! LOL! I made a huge sacrifice a few months ago - a sculpture of Patrick Stewart's face/head that had turned out pretty fine, but I didn't let dry by far long enough. Busted into a billion pieces on bisque firing. The gods should be sated for another year, I think, with that one! Have a gread weekend! Marianne What a cruel thing to happen to such a sexy actor! My kiln god the blew up was a dragon - wouldn't you know that my next glaze firing was for sh!$. Maybe I will just go Bob's route and treat my cones as my kiln god... Congratulations on your new kiln!!! Can't wait to hear the next chapter. Let's just say that the hours spent studying his face weren't wasted, even if he did blow into a thousand bits in the kiln! LOL! Just ordered the new kiln on Sunday and need to find a good electrician to put in a more powerful 400V 16 amp wiring to where I need it. Am in Mallorca with friends at the mo - an honestly not quite sober - so please excuse any typos! LOL! The wonderful thing about Patrick Steward is that you don't have to model his hair! *giggle* Okay - off for now - take care, Donna and others that might read this! Marianne |
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