Mudfish

Just unloaded kiln from doing a single segment 9999 program. Went a little hotter than cone 8, just wanted to see what my base glazes looked like at a higher cone. Thought I could manually do a slow cool after a soak at 2320f.., but controller would just shut off burners, so next time I will do same program but add a slow cool segment also. Some bubbling over my base glaze, due to cooling off too quickly, but I'm just going to smooth them with sandpaper and call it good. Kiln fired evenly also. Thanks all for the helpful responses.

yes, it is on/of controller. I am going to call Bartlett Control Systems and see if they can walk me through an override or something so that I can manually fire and just use the controller as a temp reader

yes, the gage does indicate inches. I have just now noticed that. So I actually fired in at 3", which was low. I thought I was at 3 kPa's , so this was my error. I do have experience firing gas kilns, but not very consistently successful. it seems I usually have problems evening out temps. I used to fire a electric converted to natural gas, and my results were not consistent. So that is my experience. The previous owner had venturi burners set to natural gas, which is what I am firing on. Gas lines are 1 and 1/4". Here is my firing schedule as it reads on my controller: Six segments. Seg. #1 - 150f - 180f no hold. Seg #2 - 150f -250f no hold. Seg #3 - 400f - 2030f no hold. Seg #4 120f - 2280 with a 30 minute hold. Seg #5 9999 (drop) to 2050 and a 30 minute hold. Seg #6 - 150f - 1500f no hold. So, I did fire it like a "set it and forget it", but I mistakenly set gas valves to read at 3" on the gage. I thought this was 3 kPa, and I looked up a conversion, and thought I was firing at 7" wc. So now I know this was a mistake and was too low water column. I did adjust the damper to get a reduction, but wares did not get much even though I did see flame from the spy holes. Maybe this was due to wc being too low. Also, should I set gas valves to read at 7" wc and maintain that throughout the entire firing, or do I set valves to build up to 7" wc ?

Hello all... I have recently acquired a DD12 Olympic kiln. It is properly installed to natural gas in my studio and it also operates with a Bartlett controller. I have fired it at about 3/4th full recently and I have some questions about reading the gouge and what numbers I should be looking for. I had the gas valve set to maintain at number three on the kPa guage. Now that I have looked up a conversion on kPa to water column inches, I see that this valve setting provided about 13 inches on the water column. For natural gas that is too high, right? I know that it should be at 7 inches water column. I have two questions..,maybe more but here goes. Is 3 kPa's maintained throughout the firing why my kiln fired hotter on top that on the bottom, or is that from some other issue? I have read on the Olympic website that the primary air plates should be opened up more to bring temp up on the lower level. My second question is should the kPa reading (converted to water column inches) be steady at 7 inches, or is that a maximum to build up to? The kiln did fire without any error readings from the controller, so I thought everything was going ok during the firing, until kiln cooled off and I could check the cones and discovered the uneven temps. I was firing to cone 8, and cone 8 was bent halfway on top, while cone 7 on the bottom level was barely bent. The spy holes are so small that it is very difficult to monitor a cone pack because of the thick kaowool on the door where the spy holes are, so I am kind of firing blind. Any advice would be greatly appreciated. Thanks