TortoiseAvenger Posted July 12, 2014 Report Share Posted July 12, 2014 I've been trying to fire some glaze test tiles, and as of this morning, I've failed twice. When I first got my (used) kiln I fired it empty to cone 8 to see if it would work, and it did. Everything went fine. I followed the directions that came with it. Then I put in round one of test tiles. They all exploded on me, because when the kiln sitter shut off from firing #1, I forgot that all of the power switches were still switched to on. It probably ran for 20 mins before I shut it down. I made more tiles, and put them in yesterday. However, even after 11 hours of firing, the kiln wasn't getting up to temperature. I was trying to fire to cone 6. I put in a cone 5, 6, and 7 to observe. Cone 5 may have slightly bent, but I'm not sure. The only difference I can think of is that for this firing I left the bottom peephole open. The directions say to only leave the top peephole open during firing. I also left the bottom open because I needed to see the cones, and I assumed that the open 1" hole would make little difference. During the final hour of firing last night, I closed the peephole in hopes that it would help, but no progress was made in that hour. Could it be that the peephole being open kept the kiln from getting up to temperature? I'm really frustrated, and I don't really want to make another set of 20 glaze test tiles for them to get screwed up again. Any ideas? Thanks, TA Link to comment Share on other sites More sharing options...
Wyndham Posted July 12, 2014 Report Share Posted July 12, 2014 Then I put in round one of test tiles. They all exploded on me, because when the kiln sitter shut off from firing #1, I forgot that all of the power switches were still switched to on. It probably ran for 20 mins before I shut it down. The kiln should have gone off when the kiln sitter shut off, even with the switches on the "ON" or "HIGH" position. A possible cause is a relay burned out or a connection to one element set burned out or something with kiln sitter has arched/burned out, hard to say . The other thing that might have happened is that the test tiles that exploded, some of the glaze material went into an element . When you started the next firing the glaze fused in the element causing it to melt and fail. Several things that might have caused the problem, but the kiln staying on after the kiln sitter tripped is not a good sign. Wyndham Link to comment Share on other sites More sharing options...
TortoiseAvenger Posted July 12, 2014 Author Report Share Posted July 12, 2014 I think you misunderstood me. The kiln did shut off just fine from the kiln sitter, but the five manual switches remain in the "on" position, and I forgot this the next time I fired the kiln. Link to comment Share on other sites More sharing options...
John Hertzfeld Posted July 12, 2014 Report Share Posted July 12, 2014 Hi TA, just wondering about a few details that might help everyone help you out with your tile issue 1) Are these glazed tiles the 12x12 tiles I think you were speed drying from another post? 2) Are they bisq or still green when you fire them? 3) If bisq, what ^ did you go to. If green, how did you determine they were dry enough? 4) Again, if green, did you use a pre-heat to allow residual moisture to evaporate prior to climbing above 200F? 5) Are you monitoring your firing to the point you know when they might have exploded? 6) And finally, are you making a glaze from raw material or a commercial product. Thanks, John H Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted July 12, 2014 Report Share Posted July 12, 2014 I wouldn't think the peep hole being left open would make it drop by 4 cones. Try turning it on and see if all the elements and heating up. Best place to start. Turn the lights off to see them glow better. Link to comment Share on other sites More sharing options...
Wyndham Posted July 12, 2014 Report Share Posted July 12, 2014 sorry about the misread, but the exploded tiles could cause an element failure. Wyndham Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted July 12, 2014 Report Share Posted July 12, 2014 I agree. Maybe before turning on the kiln check the elements over for glaze or burnt out bits. Link to comment Share on other sites More sharing options...
TortoiseAvenger Posted July 12, 2014 Author Report Share Posted July 12, 2014 I took a pic of my kiln with the elements on and am posting it to a new topic for help. It seems that some of the elements are not firing up. Link to comment Share on other sites More sharing options...
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