glazenerd Posted November 20, 2016 Report Share Posted November 20, 2016 Doing some research on cone 2-3. Cannot get the Poll to post.. hmm Would you use cone 2/3 if it was available, and safe for functional ware? Link to comment Share on other sites More sharing options...
Magnolia Mud Research Posted November 20, 2016 Report Share Posted November 20, 2016 I have done so using commercial low fire (cone 05) clay fired at cone 3 in oxidation gas kiln. used it for several years. LT Link to comment Share on other sites More sharing options...
neilestrick Posted November 20, 2016 Report Share Posted November 20, 2016 I guess I'm going to have to get working on my cone 2 formula I had started on a few months back. Why cone 2-3, rather than cone 1. Is cone 2 the limit for feldspars? Link to comment Share on other sites More sharing options...
Mark C. Posted November 20, 2016 Report Share Posted November 20, 2016 No not interested in cone 2-I would not use it . Link to comment Share on other sites More sharing options...
Joseph Fireborn Posted November 21, 2016 Report Share Posted November 21, 2016 I would use it. I don't see any reason to fire to cone 6 if I could get same results at cone 2, or close results. Link to comment Share on other sites More sharing options...
Pugaboo Posted November 21, 2016 Report Share Posted November 21, 2016 I might look at it but it would have to be pretty spectacular to get me to switch from Cone 6 Little Loafers. T Link to comment Share on other sites More sharing options...
bciskepottery Posted November 21, 2016 Report Share Posted November 21, 2016 My understanding is the shift from cone 10 to cone 6 was driven by the cost of fuel during the energy crisis days, along with environmental awareness to reduce carbon footprint/reduce dependency on fossil fuels. Absent a new energy crisis and with fuel (natural gas, propane, especially at low prices), folks will stay where they are today. Commercial industry has spent too many $$$ coming up with faux cone 10 reduction looks for electric cone 6 firings that they will hold off any change until they realize their ROI and then some. Costs will also be higher at lower cones due to increased use of frits in glazes to achieve melting of materials. It is not just the availability of clay, but also getting glaze costs to be competitive with cone 10 and cone 6 glazes. Link to comment Share on other sites More sharing options...
Joseph Fireborn Posted November 21, 2016 Report Share Posted November 21, 2016 My understanding is the shift from cone 10 to cone 6 was driven by the cost of fuel during the energy crisis days, along with environmental awareness to reduce carbon footprint/reduce dependency on fossil fuels. Absent a new energy crisis and with fuel (natural gas, propane, especially at low prices), folks will stay where they are today. Commercial industry has spent too many $$$ coming up with faux cone 10 reduction looks for electric cone 6 firings that they will hold off any change until they realize their ROI and then some. Costs will also be higher at lower cones due to increased use of frits in glazes to achieve melting of materials. It is not just the availability of clay, but also getting glaze costs to be competitive with cone 10 and cone 6 glazes. I didn't think about the frit issue. That is a good point. Link to comment Share on other sites More sharing options...
glazenerd Posted November 21, 2016 Author Report Share Posted November 21, 2016 Why cone 2-3, rather than cone 1. Is cone 2 the limit for feldspars? Neil: Cone 2/3 would be the limit for feldspars, absent frits. I could do porcelain below this point, but not stoneware. Stoneware needs 2050 up to 2125F to really develop mullite. Many of the the cone 6 glazes used currently, would work at cone 2/3 without the addition of frits. Some may need very minor additions of fluxes, and perhaps minor amounts of frit (doubtful). Cone 3 (2115 +/-) with a hold, would produce enough heat. Sodium carbonate melts at 1,564 F and potassium carbonate at 1,636 F ...Spodumene could always be used, as well as boron. Lots of options at these temps that do not require frits. Mesh size would also be a critical factor. Nerd Link to comment Share on other sites More sharing options...
Mark C. Posted November 21, 2016 Report Share Posted November 21, 2016 For me after 40 some years in this temp range with a huge following of my glazes It just would not pencil out. My 35 cubic car kiln fires for the cost of a few pots or one shelve of 35 say. I adapted well to left hand drive countries but this new range makes no sense to this old dog. Now if I was starting out thats another story. I have not like working with fritted glazes ever and even though (magma)suspension agent will suspend them I'm not going that way. I never bought into potters reducing carbon footprints anyway-believe it or not potters use fuels from the dino age no matter what. If I wanted to be only green I'd be growing algae . I think all potters have environmental impacts no matter what your temp range. Its part of the deal. Link to comment Share on other sites More sharing options...
glazenerd Posted November 21, 2016 Author Report Share Posted November 21, 2016 It's about element life, kiln costs, and electric bills. Type K instead of type S; with extended life as well. If Kanthanal elements last 100-120 firings, at cone 3 they should go into the 160 + range. (I am sure Neil will weigh in on this one). Have you not noticed a marked increase into low fire threads in the last four months? Kiln costs would be lower because of K23 2.5, instead of K26 3". I can see all kinds of reasons. I have grown crystals @ 2180F (peak), suspect I could get that lower. Nerd Link to comment Share on other sites More sharing options...
Mark C. Posted November 21, 2016 Report Share Posted November 21, 2016 I'm a gas guy-electric rates are high where I live always have been. If I had to make a living with electric kilns I would have folded up 40 some years ago. I can will say I have an used k23 2.5 wall kiln I can sell you cheap. Link to comment Share on other sites More sharing options...
neilestrick Posted November 21, 2016 Report Share Posted November 21, 2016 I get 150-160 firings out of my elements as a combination of bisque and cone 6- about 35% bisque, 65% glaze. I get about 25% greater element life than I did at cone 8. I've know people who get several hundred firings using their kiln for only bisque. So at cone 2 I think we could realistically see 225 firings (combined) or even more. I've got 1100+ firings on one of my kilns so far, and I don't see why it wouldn't go 2500 firings (probably a lot more) before it's dead. Over that lifespan that's 5.5 fewer element changes. At $312 per element change that's $1700 saved in element changes over the life of the kiln. In my big kiln, at $730 per element change, that's over $4000 over the life of the kiln. Put those together and I can buy a couple of new kilns! Add in thermocouple life and the savings are even greater. You'll also get great thermocouple accuracy at cone 2. I also think that relay life would be a little better too, because there's less heat from the kiln to burn them out. Over all kiln life would also be increased. If I save just $2 per firing by firing cone 2 rather than cone 6, that's $5000 over the life of the kiln (that's 2 more new kilns!), or enough to pay for a set of elements each year. And I honestly think the firing cost saving could be more than that for 28" wide kilns. There's a big increase in power draw to get from cone 2 to cone 6. In my big kiln, which is $35-40 per firing, I could probably save $10 per firing. At 75 firings per year that's $750 dollars per year in lower firing costs. That's a set of elements. As for the cost of clay, if the cost of the clay goes up 25 cents per pound (that's a lot) in order to get it down to cone 2, then I would have to add 35 cents to the price of every mug, a dollar to some larger things like pitchers, to cover the increase. The majority of what I sell is under 3.5 pounds. Done. Easy. Clay is cheap in the big picture. I already use a lot of frits in my glazes, so I don't think the glaze costs would increase enough to matter. Maybe a couple of cents per pot. If I just add $1 to every pot I sell I would come out ahead. On top of all that, we'll be using less energy, which is a big deal nowadays. I can see why someone like Mark, who has built their career on cone 10 reduction, wouldn't want to switch. He doesn't have a good reason to. That would be a drastic change. But for anyone working at cone 5/6 it would make a lot of sense. Link to comment Share on other sites More sharing options...
glazenerd Posted November 21, 2016 Author Report Share Posted November 21, 2016 Clay would retail in the .65-.70¢ a lb.: looking at the four blends I am studying now Link to comment Share on other sites More sharing options...
MatthewV Posted November 21, 2016 Report Share Posted November 21, 2016 Making a switch is always a difficult choice. I am still young but feel I have invested considerable time and effort into ∆6. So I would be skeptical and slow to adapt. After showing the body is vitrified (easy enough) there is also a question of durability. Does it hold up in a dishwasher? Does it ring with a pleasing tone? Only then do we start to see the positive sides... maybe a possibility of iron reds? More vibrant under glazes and stains? Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted November 21, 2016 Report Share Posted November 21, 2016 Even though there are many logical arguments I still love cone10. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted November 21, 2016 Report Share Posted November 21, 2016 I have Chappell book on 2/3 glazes. I was interested in that range for terra cotta architectural work. Lisa Naples does functional work in that race. Terra Cotta earthenware is mature at that temp. and very durable.A ceramic engineer told her earthenware is as durable as ^10 stoneware when fired to full maturity https://www.pinterest.com/jamechling/lisa-naples-pottery/ Marcia Link to comment Share on other sites More sharing options...
neilestrick Posted November 21, 2016 Report Share Posted November 21, 2016 Clay would retail in the .65-.70¢ a lb.: looking at the four blends I am studying now Is that just materials cost, or are you factoring in labor and packaging and all that, too? Link to comment Share on other sites More sharing options...
preeta Posted November 21, 2016 Report Share Posted November 21, 2016 is this conversation happening in the ceramic industry? from an environmental point of view. how big is the pottery community to have a significant impact? what about artistic expression? what if you prefer the looks of ^10 or wood fire or pit fire for that matter? Link to comment Share on other sites More sharing options...
glazenerd Posted November 21, 2016 Author Report Share Posted November 21, 2016 Is that just materials cost, or are you factoring in labor and packaging and all that, too? Forgot about packaging - .70-.75¢ a lb. Really not that much to formulate. Keep the mesh sizes in relative regard to heat, increase fluxes.... Preeta: just a conversation, with potters weighing in with thoughts and opinions. Marcia: have located a couple of clays that have the properties of terra cotta- less the red. Many clays floating around out there, not used in the pottery industry. Nerd Link to comment Share on other sites More sharing options...
SydneyGee Posted November 21, 2016 Report Share Posted November 21, 2016 Biggest problem I see is finding good glazes. You can't assume hobby clay people will just start making their own ^2-3 glazes when there are so many manufactured glazes that work so well at ^5+. If this is geared more towards those willing to formulate their own glazes, then yeah I can't see a problem as long as the clay is strong and vitrified. Link to comment Share on other sites More sharing options...
neilestrick Posted November 21, 2016 Report Share Posted November 21, 2016 If clay suppliers start selling cone 2 clay, they'll have to sell glazes, too. They don't make much on clay. Glazes are quite profitable. Link to comment Share on other sites More sharing options...
Min Posted November 21, 2016 Report Share Posted November 21, 2016 Yes, I would use ^ 2/3 clay in a heartbeat if it met my requirements. I like what Plainsman Clay does insofar as selling dry glaze that specifically fits a couple of their more troublesome low expansion claybodies plus they give the recipes out. Even a recalibrated limits chart would go a long way in simplifiying glaze testing for ^2/3. Link to comment Share on other sites More sharing options...
glazenerd Posted November 21, 2016 Author Report Share Posted November 21, 2016 as long as the clay is strong and vitrified. Sydney: what got me involved with clay formulation to begin with was crystalline glaze. It is applied nearly 3 times heavier than normal glazes: and subsequently warped every brand of porcelain I tried (over a 12). So if I can formulate porcelain to with stand the mechanical stress of crystalline: the rest is a calk walk. For the record: Neil is head of the glaze dept., I am a clay nerd. Nerd Min: I suspect the only major change to formula limits would be in the total fluxes. Silica and alumina would not move that much. Link to comment Share on other sites More sharing options...
neilestrick Posted November 21, 2016 Report Share Posted November 21, 2016 I'll need some clay bodies to run tests on. Get to work. Link to comment Share on other sites More sharing options...
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