temp for opening kiln?
#1
Posted 02 January 2012 - 08:09 PM
#2
Posted 02 January 2012 - 10:00 PM
For a glaze load, I'll prop open the top at 120F and open fully when it gets down to 100F. If it's a cool/cold day (my kiln is in the garage), I might wait a bit longer and let it cool some more.
I fire an electric kiln. I fire with a vent . . . turned on at start of firing, turned off when unloading. Plugs stay in.
At the studio I also use, some have unloaded glaze kilns at higher temperatures . . . to a chorus of "pings" and crazing.
#4
Posted 03 January 2012 - 03:08 AM
I should add that I have a fairly high tolerance for pain.
#5
Posted 03 January 2012 - 04:04 AM
Usually the kind of clay determines thermal shock strength. Clay consists a lot of free quartz you must be patient for opening the kiln, but for earthenware you no need worry to much. Also the pot in slip casting technique is more stronger then other technique such as throwing or slabbing in thermal shock phenomena.
I usually open the kiln in step by step. First I open the spy hole. Than if fell warms in your hand, I open the door kiln just little bit. Every a half an hour I open just little bit too.
Kupu Ceramic Studio, Indonesia
www.butterflyceramic.blogspot.com
#6
Posted 03 January 2012 - 08:21 AM
Getting the oops messages again and I purposely resigned in before posting. I get oops messages when I sign out too. Anyone else having this problem?
#7
Posted 09 January 2012 - 05:54 AM
#8
Posted 09 January 2012 - 09:01 AM
#9
Posted 09 January 2012 - 09:44 AM
SShirley, on 09 January 2012 - 09:01 AM, said:
I've wondered why we can't open an electric kiln and take things out at up to 425 since we take pottery out of an oven at this temp sometimes, but I haven't risked it and usually wait until the temp is around 120.
Mossy Rock Creations
High Point, NC
#11
Posted 09 January 2012 - 11:02 AM
SShirley, on 09 January 2012 - 09:01 AM, said:
One of the reasons I schedule an outing after firing a kiln, so that i won't be around to get anxious about opening it. Sometimes I sleep in quite a while, because even though it is electric, it has no kiln setter-all manual baby!
#12
Posted 09 January 2012 - 01:13 PM
I'm a new potter, 72 years young and after taking classes I've now had my own cellar studio for one year. I LOVE making pots! Electric kiln in the garage, and I agonize every time about this kind of question. How about the other end of the firing cycle—is it okay to close the lid and bung holes at the beginning and set it for a fast glaze firing?
And how about the bisque firing. If I'm sure the greenware is fully dry is it okay to do a fast firing, with everything closed??
Ginny Clark (Fort Wayne IN)
#13
Posted 09 January 2012 - 01:47 PM
Ginny C, on 09 January 2012 - 01:13 PM, said:
I'm a new potter, 72 years young and after taking classes I've now had my own cellar studio for one year. I LOVE making pots! Electric kiln in the garage, and I agonize every time about this kind of question. How about the other end of the firing cycle—is it okay to close the lid and bung holes at the beginning and set it for a fast glaze firing?
And how about the bisque firing. If I'm sure the greenware is fully dry is it okay to do a fast firing, with everything closed??
Ginny Clark (Fort Wayne IN)
Fast firing a bisque-na na na with a waving finger at the same time! You have all sorts of issues to deal with when firing the bisque. First the clay only gets as dry as the atmosphere so, you water smoke for 2 hrs with the lid cracked or open to drive out the atmospheric moisture. The you fire slowly to around 500F to remove impurities (organic) from the clay-burning them out. then around 1100F the clay goes through quartz inversion, which can cause a lot of cracking in bisque if gone through too quickly-then you can turn up the kiln to high and fast fire! However, by that time most of us have taken at least 6 hrs to get there! Some even more. To do otherwise would mean opening the kiln to a pile of rubble that could have damaged the brick, elements lid and floor-could have, not often though.
#15
Posted 14 November 2012 - 03:53 PM
#16
Posted 14 November 2012 - 06:31 PM
So ambient temperatures for the most part.
One time the kiln was 100F.
I'm in no particular hurry.
#17
Posted 14 November 2012 - 07:24 PM
Jim
"But it does move," said Galileo under his breath.
#18
Posted 14 November 2012 - 07:35 PM
Since then I have read a lot about firing my kiln, and I have always been horrified at the sound of the crazing pings, and that is not something I usually am trying to do, so I leave it alone. I pull a plug at 350 or so, but usually let it get down to 150 or so before I prop the lid open a little. When I can touch the lid after that, and it doesn't feel hot, I open it all the way, and can unload then. I (knocking on wood, here) have never had anything break or explode in the kiln- YET, that is-, and I don't look forward to that.
I appreciate all the info here. It is a great help to me.
#19
Posted 15 November 2012 - 11:50 AM
some of you have mentioned "dunting" without realizing that it is a condition caused by poor glaze fit, not firing. dunting can happen weeks after a firing and will startle you with the loud PING!!! i had this problem until i changed the clay body, the glaze recipe and the kiln. dunting is not a good thing. somewhere there is a crack in the pot even if you can't see it. a well made stoneware bowl will ring like a bell if tapped. if it goes clunk, it has a crack.
#20
Posted 15 November 2012 - 12:33 PM

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