DMCosta Posted August 6, 2019 Report Share Posted August 6, 2019 Hi All, Lately I’ve had a handful of my pyrometric cones not show any movement or melt at all after firing. This has happened at my job in their kiln a few times and it just occurred at home in my smaller kiln. Both are skutt select fire kilns. I checked to ensure I put in the right cone for the temperature and I did. I also just completed a review on my skutt kiln at home and looks like it fired properly. I was also home watching the firing yesterday so I know it at least ‘said’ it reached the proper cone. The pieces appear to be fully bisqued as well. Anyone know what could be going on? Can pyrometric cones expired ever? Thanks, ~Dianna Link to comment Share on other sites More sharing options...
Bill Kielb Posted August 6, 2019 Report Share Posted August 6, 2019 Generally rare but they could be incorrectly marked. I think I proved this to myself by including them in another firing or a cone ten firing just to see. Cones are basically glaze : silica, alumina and flux so it’s pretty rare to get them incorrectly marked, but I have a time or two over the years. In a glaze firing results are everything so if the cone didn’t bend and my pots were all fully fired as usual, looked melted, took about the same amount of time as usual, and ended close to my cone temperature I would assume the cone was defective. For bisque, harder to know other than the time it took and the final temp along with the look and feel of the bisque and perhaps it has the approximate same dull ring as other pots previously fired. Interesting tidbit: If you ground up a cone 4 cone and applied it to something it will fire as a fully melted glaze at cone ten. Link to comment Share on other sites More sharing options...
liambesaw Posted August 6, 2019 Report Share Posted August 6, 2019 16 minutes ago, Bill Kielb said: Interesting tidbit: If you ground up a cone 4 cone and applied it to something it will fire as a fully melted glaze at cone ten. World's most expensive glaze. I've had some cone 04 cones not fall, but they were like 40 years old and had gotten wet at some point. Link to comment Share on other sites More sharing options...
Mark C. Posted August 6, 2019 Report Share Posted August 6, 2019 If cones get wet it can throw off the melt points Link to comment Share on other sites More sharing options...
DMCosta Posted August 6, 2019 Author Report Share Posted August 6, 2019 Interesting, the box of cones was open in my old studio then I moved and they were in storage/unused for about three years. Not sure they were drenched with water but definitely could have been damp/moist for a long period. Thanks for the info Link to comment Share on other sites More sharing options...
neilestrick Posted August 6, 2019 Report Share Posted August 6, 2019 Are they large cones or self supporting? Link to comment Share on other sites More sharing options...
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