CPT Posted February 9, 2012 Report Share Posted February 9, 2012 HI Folks: I have another question.... I'm still trying to figure out my manual kiln that I recently purchased off craigslist....it's in pretty good shape and I"m about to do a glaze fire on a few couple of test bisque pieces. Only thing is that it didn't come with a manual! I will use a cone 5 or 6 in the kiln sitter, prop the lid open and turn all switches on low for 2 hrs. Then turn all switches on medium for 2 hrs, close lid, but keep top peephole open. Then turn on all switches to high for another 2 hrs, then hopefully it will switch off sometime then. Any suggestions?? Link to comment Share on other sites More sharing options...
neilestrick Posted February 9, 2012 Report Share Posted February 9, 2012 With glaze firings, as long as everything has been bisque fired and nothing is unusually thick, you can really just go 1 hour on each setting. You're not going to blow anything up. For you first firing, it's not a bad idead to put a visual cone on the shelf to make sure it doesn't over-fire, since you don't know where to set your timer. Remember, the timer is just a countdown. It does not control how long it takes for the kiln to get to temperature. When you switch to high, set your timer at 10 hours. When the kiln shuts off with the cone, do the math to see how long it took on high. From then on, as long as you use the same firing schedule, you'll know exactly where to set your timer, about 1/2 hour longer than it took on this firing. Link to comment Share on other sites More sharing options...
CPT Posted February 9, 2012 Author Report Share Posted February 9, 2012 Thanks Neil, but this model does not come with a timer. I only have the Kiln sitter and the switches to rely on. Link to comment Share on other sites More sharing options...
perkolator Posted February 10, 2012 Report Share Posted February 10, 2012 If your new kiln does not have a timer then you definitely don't want to leave the kiln unattended when it's nearing cone temp. I've personally seen kiln sitters fail a couple times - piece blows up and touches sitter, bad cone doesn't drop, object touching sitter, etc. Only one of those times the timer wasn't set properly and it overfired a few HOURS because the cone didnt drop (bad cone) and we lost about a dozen shelves (oval kiln) that warped like bacon, an element, and cracked the floor, besides losing the work. Luckily, the timer stopped it at around cone 12-13 (^6 firing). Not saying it will happen but it's definitely possible. Even automated kilns screw up - like relay stuck open. I agree that for glaze firing with no freshly glazed work, you can speed up a little. I dunno if you need to leave the spy plug out. I've never fired that way but have heard of it. Not sure how you bisque fire, but you could use this kiln for that also if you want. For a firing with greenware inside you can do something like: -lid cracked, bottom on low for preheat. You may or may not be able to put a 2nd section on low depending how hot kiln gets or how wet work is -lid closed, same setting again depending on how hot bottom of your kiln gets on low for extra purge and start warming it up nice and hot. -all low -all medium -all high First two ramps are drying/ preheat and time will depend on what goes inside. Thin pottery only needs a couple hours total preheat but a sculpture will most likely need closer to overnight to purge and get toasty. Check kiln for moisture then fire as normal if nice and dry. Sorry to say it, but blowing things up is probably the fastest way to learn your kiln. Then you know how fast it fires witness cone inside is not a bad idea. Good luck! Link to comment Share on other sites More sharing options...
neilestrick Posted February 10, 2012 Report Share Posted February 10, 2012 Like perkolator said, don't trust the sitter, especially without a timer. They fail all the time. SEE HERE. If you ever have the cash, upgrade to one with a timer. They're not all that cheap new, but you may be able to find an old small used kiln for cheap with one that you can swap out. Link to comment Share on other sites More sharing options...
neilestrick Posted February 10, 2012 Report Share Posted February 10, 2012 I agree that for glaze firing with no freshly glazed work, you can speed up a little. I dunno if you need to leave the spy plug out. I've never fired that way but have heard of it. I dip pots in glaze, put them into the kiln, and start it up. That first hour on low will dry things out just fine without blowing them up as long as they are of 'normal' pot thickness. You need to leave the top peep open if your kiln is not vented, to allow gases to escape. Link to comment Share on other sites More sharing options...
SunsetBay Posted February 15, 2012 Report Share Posted February 15, 2012 I agree that for glaze firing with no freshly glazed work, you can speed up a little. I dunno if you need to leave the spy plug out. I've never fired that way but have heard of it. You need to leave the top peep open if your kiln is not vented, to allow gases to escape. I always leave the top peep open, but I just discovered when I went to turn the kiln to high (I'm doing a glaze firing) that I'd forgotten to prop the lid, too. Any idea what effect that will have? (Though I guess I'll find out tomorrow when I unload the kiln.) Your post seems to imply that the open top peep should be sufficient to vent an unvented kiln. Is that true? Thanks! Link to comment Share on other sites More sharing options...
neilestrick Posted February 15, 2012 Report Share Posted February 15, 2012 I agree that for glaze firing with no freshly glazed work, you can speed up a little. I dunno if you need to leave the spy plug out. I've never fired that way but have heard of it. You need to leave the top peep open if your kiln is not vented, to allow gases to escape. I always leave the top peep open, but I just discovered when I went to turn the kiln to high (I'm doing a glaze firing) that I'd forgotten to prop the lid, too. Any idea what effect that will have? (Though I guess I'll find out tomorrow when I unload the kiln.) Your post seems to imply that the open top peep should be sufficient to vent an unvented kiln. Is that true? Thanks! No effect whatsoever. The only time I've ever propped lids is to slow down kilns that only have on/off switches, not low-med-high. You'll be fine! Link to comment Share on other sites More sharing options...
SunsetBay Posted February 17, 2012 Report Share Posted February 17, 2012 No effect whatsoever. The only time I've ever propped lids is to slow down kilns that only have on/off switches, not low-med-high. You'll be fine! It WAS fine, you were right! Thanks! Link to comment Share on other sites More sharing options...
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