Carrick Posted February 28, 2019 Report Share Posted February 28, 2019 Hi all experienced potters . I have a small Evenheat Rampmaster 11 electric kiln . Very easy to use as it has built in programs. one option is slow bisque 13 hours or fast bisque 10 hours . I bisque to cone 04 using the slow bisque program. Can I use the fast bisque 10 hours for completely dry earthenware ? Looking forward to hearing from you . Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 28, 2019 Report Share Posted February 28, 2019 This is a trial and error thing. If your clay needs the slow program to get all the organics out then it will need it. Burning out unwanted organics often requires time and temperature so testing to see if fast is adequate for a particular clay body will be the only way to know for sure. Folks often use slow all the time simply because they do not want to risk random issues arising in the glaze firing later. Link to comment Share on other sites More sharing options...
liambesaw Posted February 28, 2019 Report Share Posted February 28, 2019 If your earthenware is brown or red you're gonna want to keep that slow bisque Link to comment Share on other sites More sharing options...
Carrick Posted February 28, 2019 Author Report Share Posted February 28, 2019 Thanks Bill , words of wisdom, I’ll stick to the slow bisque so no unwanted surprises when I glaze fire . I’ve only been potting for a year so value input . Loving it . Cheers Susie Link to comment Share on other sites More sharing options...
Carrick Posted February 28, 2019 Author Report Share Posted February 28, 2019 Thanks Liam , eathenware is white but decided to stick with slow bisque. Better safe than sorry . Cheers Susie Link to comment Share on other sites More sharing options...
PotterPutter Posted February 28, 2019 Report Share Posted February 28, 2019 I have a Skutt and bisque to Cone 04. I use the slow program, which takes around 11 hours. You might be ok with the fast option on your kiln, but better safe than sorry! Link to comment Share on other sites More sharing options...
neilestrick Posted February 28, 2019 Report Share Posted February 28, 2019 I use Fast Bisque for almost everything in my studio, and don't have any problems. Link to comment Share on other sites More sharing options...
Benzine Posted February 28, 2019 Report Share Posted February 28, 2019 13 minutes ago, neilestrick said: I use Fast Bisque for almost everything in my studio, and don't have any problems. Yeah, but you are "The Kiln Whisperer".... Link to comment Share on other sites More sharing options...
neilestrick Posted February 28, 2019 Report Share Posted February 28, 2019 2 minutes ago, Benzine said: Yeah, but you are "The Kiln Whisperer".... Ha! The Slow Bisque profile goes 80F/hr for the last 250 degrees. The Fast Bisque goes 108F/hr for the last 250 degrees. They both go 180F/hr for the segment before that. Not a big difference, only a 2 our difference total for the firing. Most of the difference is in the first 1100 degrees, where the concern is cracking or blowing up a big or thick piece. Link to comment Share on other sites More sharing options...
liambesaw Posted February 28, 2019 Report Share Posted February 28, 2019 Ahh I see, yeah I don't know that a slow end to a bisque makes a difference. I try to hit 108f/hr from 1200-1700 because my red clays have a lot of organics to gas off. Link to comment Share on other sites More sharing options...
neilestrick Posted February 28, 2019 Report Share Posted February 28, 2019 The slow end definitely helps to get things burned off, I just don't think there's much difference between 80F/hr and 108F/hr. Firing to 04 instead of 06 makes a big difference, too. Link to comment Share on other sites More sharing options...
Babs Posted March 1, 2019 Report Share Posted March 1, 2019 Neil I guess you've done the Math. Energy saving worth a consideration Energy in Aus is Expensive, as is clay , in fact all aspects of ceramics. I bought a single 12kg bag of clay to try.Close on $30 exc freight Link to comment Share on other sites More sharing options...
Carrick Posted March 1, 2019 Author Report Share Posted March 1, 2019 Thanks all , great replies , I’m going to bite the bullet and try the fast bisque option . I’ll make sure everything is very dry and do a test fire with a few pieces . As Babs said , energy in Australia is very expensive . What’s the worst that can happen ??? Open the kiln to a mess ? It’s all a learning curve . Won’t do it for a few weeks as we’ve got an exhibition coming up and I fire for a friend so I’ll stick to what works in the meantime but will post results after I run the test fire . Happy Friday to all . Susie Link to comment Share on other sites More sharing options...
Babs Posted March 1, 2019 Report Share Posted March 1, 2019 2 hours ago, Carrick said: Thanks all , great replies , I’m going to bite the bullet and try the fast bisque option . I’ll make sure everything is very dry and do a test fire with a few pieces . As Babs said , energy in Australia is very expensive . What’s the worst that can happen ??? Open the kiln to a mess ? It’s all a learning curve . Won’t do it for a few weeks as we’ve got an exhibition coming up and I fire for a friend so I’ll stick to what works in the meantime but will post results after I run the test fire . Happy Friday to all . Susie You could call the maker and ask what the clay will stand but also depends on what you've got in there. But upper end of bisque.. I go 150C/hr after 600 Deg C so the fast bisque would be fine if the time saving is only in the last 2 ramps.. Link to comment Share on other sites More sharing options...
Benzine Posted March 1, 2019 Report Share Posted March 1, 2019 17 hours ago, neilestrick said: Ha! The Slow Bisque profile goes 80F/hr for the last 250 degrees. The Fast Bisque goes 108F/hr for the last 250 degrees. They both go 180F/hr for the segment before that. Not a big difference, only a 2 our difference total for the firing. Most of the difference is in the first 1100 degrees, where the concern is cracking or blowing up a big or thick piece. In my classroom, I use a program, that is probably overkill. It goes pretty slow, and has a couple holds, at critical temps. It has served me pretty well, though it isn't fool proof, and I've had student projects explode regardless. It could be because there is no such thing as a "Fool Proof" student ceramic project... Link to comment Share on other sites More sharing options...
Babs Posted March 1, 2019 Report Share Posted March 1, 2019 Just leave it at " Foolproof or Human" Benzine:-)))) Link to comment Share on other sites More sharing options...
neilestrick Posted March 1, 2019 Report Share Posted March 1, 2019 8 hours ago, Benzine said: In my classroom, I use a program, that is probably overkill. It goes pretty slow, and has a couple holds, at critical temps. It has served me pretty well, though it isn't fool proof, and I've had student projects explode regardless. It could be because there is no such thing as a "Fool Proof" student ceramic project... Kids work can always use a preheat, even if they feel dry. All it takes is one thick spot to cause an explosion. The preheat cycle on most controllers runs at about 60F/hr to 200F, then starts the hold time you program. So even if you just program a 1 hour preheat, the pots are getting a couple of hours at higher temps, which will make a big difference in making sure they're totally dry and ready to fire. It also helps to load them upside down, since the bottoms are usually the parts that blow. Link to comment Share on other sites More sharing options...
Pres Posted March 1, 2019 Report Share Posted March 1, 2019 Ahh the days of programmable kilns. . . I envy many of you, especially teachers that have that option on their kilns. My experience at home was a full manual, not even a setter. Because of this, I became very aware of rising heat, the associated steam, and apparent dryness of the kiln atmosphere at my peeps and cracked lid opening. Raises in firing temperature from the time that the kiln started showing first red, to full yellow orange and the need to switch up were carefully judged. Also adding an extra thick lid for firings allowed for better cool down, especially in glaze crystallization. These items carried over to my awareness in the classroom of the same characteristics of a slow firing with a kiln setter. I would most often set the setter up, place the timer backup to a very high number and start the kiln with no plugs and an open lid. After a few hours the lid would come down, the atmosphere would be felt coming out of the peeps, and analyzed for further firing. At no time would steam coming out of the peeps indicate a rise in temp was needed. All that has been said before by the teachers here, is the best of advice, and student work, no matter what the age, should be fired as if it had explosive areas even though they look to be fine. best, pres Link to comment Share on other sites More sharing options...
Benzine Posted March 4, 2019 Report Share Posted March 4, 2019 On 3/1/2019 at 4:47 PM, neilestrick said: Kids work can always use a preheat, even if they feel dry. All it takes is one thick spot to cause an explosion. The preheat cycle on most controllers runs at about 60F/hr to 200F, then starts the hold time you program. So even if you just program a 1 hour preheat, the pots are getting a couple of hours at higher temps, which will make a big difference in making sure they're totally dry and ready to fire. It also helps to load them upside down, since the bottoms are usually the parts that blow. Yeah, I tend to fire the slab boxes upside down, with the lid sitting on the bottom. The only downside, is that they sit taller this way, due to how I have them make the lids (They create a fully enclosed cube, and cut the lid off from that, instead of just not attaching the last slab, and having that as the lid.) One of the most amazing things about firing student work, is when you think, "There is no way that thing, that was hastily thrown together the day before it was due, is going to survive!", and of course, it does. The Kiln Gods, have a sense of humor... Link to comment Share on other sites More sharing options...
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