hershey8 Posted August 3, 2015 Report Share Posted August 3, 2015 How much space it too much, when lid warps. Will flipping lid help. My lid sets pretty well when cold, but develops a lot of space when firing. I know some space is ok, but mine looks abnormal, over 1/4" in places. Is there a high temp blanket that would help with this? 1/8 - 1/4" would seem to add up around the perimeter of a 10-sided kiln, to make for substantial heat loss. I'm still trying to get my kiln up to ^6; last try was 15 hours and still didn't quite make it. New, homemade elements that ohmed out pretty close to spec. when made. They are the correct length and diameter, and they fit pretty well. Using #6 copper cable from plug, about 8 feet long. Have replaced infinite switch. Still scratching head on this one. All elements light up, but I'm just not reaching ^6 with a fully loaded kiln. EEEEEK. Link to comment Share on other sites More sharing options...
hershey8 Posted August 3, 2015 Author Report Share Posted August 3, 2015 I'm going back into the control panel. I just fired up tonight and found that two of the lower ohm elements are not burning as bright as the others. I would love to find something as simple as a corroded connector. Should have replaced all of the connectors with new ones when I replaced the elements. I just couldn't swing it at the time. I just found something about old relays that can fail at high temp. This may also be a factor. Cone 6, here we come. Link to comment Share on other sites More sharing options...
DirtRoads Posted August 3, 2015 Report Share Posted August 3, 2015 It took me about a year to realize that some kilns will not reach Cone 6, even though they can reach the temperature, they can not do it on a consistent basis. One thing I do is put kiln shelves over the top layer in the kiln. I still do this out of habit even though I have 2 L&L kilns that have no problem reaching Cone 6. And yes relay switches fail quite often in some kilns ... in my experience. That said, I think "my experience" with kilns has got to be one of the worst. I replaced a relay switch in a kiln about 2 weeks ago. Saturday I replaced all the thermocouple wires, thermocouples and tested all relay switches (just to be sure) in one of the L&L's and the kiln fired perfectly to 6. That's the first thing I've had in 3 years other than relays, TC's and one set of elements with the L&L. Saturday night I loaded my Paragon with bisque and for some reason there is no power at all. Hopefully it's just the transformer. I only use this Paragon for bisque 05 and in 2 years I've replaced about 6 or 7 relay switches. If you are not reaching 6 it may be that the kiln may have Cone 6 firing capability, but it really can't do it more than a few times. There is really no way to fix some of these kilns. You've got to get a kiln that will get to 6 ... for some reason this issue does not seem to be discussed much. That some of these Cone 10 capability kilns, can NOT really make it to Cone 5, much less Cone 10, on a consistent basis. Link to comment Share on other sites More sharing options...
Marcia Selsor Posted August 3, 2015 Report Share Posted August 3, 2015 I feel really lucky that my kilns can fire regularly after 10 years. Lately I haven't fired to ^6 just bisque firing in them. But they take the same time as always.They are super up Olympics from Axner with ITC coatings and 3.5" bricks. And rated for ^10.My little Crusader test kiln that has fired lots and lots of glaze tests to ^7 for 20 years has only required a new switch once.I have had a spare element waiting. The clay bodies have been mostly ^6 porcelain or raku. Some ^2 earthenware. I think some bodies that could have sulphur, like in Goldart, are detrimental to the elements. Marcia Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted August 3, 2015 Report Share Posted August 3, 2015 I have always seen these refractory ropes, could a thin one, maybe a double seal round the kiln work? Only an idea. https://armilcfs.com/refractory-products/high-temperature-ropes-and-braids.html Link to comment Share on other sites More sharing options...
Chilly Posted August 3, 2015 Report Share Posted August 3, 2015 At the centre we have a front opening kiln, and it has that rope around the front where the door closes. Also on the doors of my wood-burning stove at home. I have fibre on top of the bricks on my little top-loader, but it scares me, and I try not to touch it. I wonder if the rope is more skin friendly? Link to comment Share on other sites More sharing options...
hershey8 Posted August 3, 2015 Author Report Share Posted August 3, 2015 I have always seen these refractory ropes, could a thin one, maybe a double seal round the kiln work? Only an idea. https://armilcfs.com/refractory-products/high-temperature-ropes-and-braids.html YES! I have some of that lying around for my wood stove. Definitely worth a try. Link to comment Share on other sites More sharing options...
hershey8 Posted August 3, 2015 Author Report Share Posted August 3, 2015 At the centre we have a front opening kiln, and it has that rope around the front where the door closes. Also on the doors of my wood-burning stove at home. I have fibre on top of the bricks on my little top-loader, but it scares me, and I try not to touch it. I wonder if the rope is more skin friendly? I just found some left over from my wood stove repair. I'm on it! Link to comment Share on other sites More sharing options...
hershey8 Posted August 3, 2015 Author Report Share Posted August 3, 2015 I just reopened my control panel, reviewed the schematics, and am in the process of making a few changes. This is/ was a 208v Paragon that someone converted to a 240v. BUT someone made a couple of mistakes. They left in a relay that shouldn't be there. That relay appears to be getting it's trigger from an infinite switch.....NAW...this is crazy. Maybe this and some glass rope will do the trick. I'll keep you posted. Thanks for the support, Ya'll. Link to comment Share on other sites More sharing options...
Babs Posted August 3, 2015 Report Share Posted August 3, 2015 When my fibre lined kiln lid warped on first firing I rang the supplier who said "Put a rock on the offending corner" Well... living well away from the supplier and needing to fire I did just that, and continued to do this till the killn died a natural death! Would be fearful of placing fibre blanket on the kiln aside form health hazard. Did this to a small electric which had a little swivelling cover for a vent hole?? on the lid, this melted during firing! And yes dripped thro' the hole onto the underlying platter. Link to comment Share on other sites More sharing options...
neilestrick Posted August 5, 2015 Report Share Posted August 5, 2015 Put a weight on the edge of the lid, or put a latch on it to hold it down. I would not mess with the rope seal. Not sure how there would be different relays in converting from 208V to 240V. You just have to replace the elements to do that. There are all sorts of different wiring systems out there, even some that use infinite switches and relays together. Are you going off of the wiring diagram from the manufacturer? Link to comment Share on other sites More sharing options...
Arnold Howard Posted August 5, 2015 Report Share Posted August 5, 2015 How much space it too much, when lid warps. Will flipping lid help. My lid sets pretty well when cold, but develops a lot of space when firing. I know some space is ok, but mine looks abnormal, over 1/4" in places. Is there a high temp blanket that would help with this? The center of the lid bows slightly inward toward the firing chamber at high temperatures. This is because the outside lid surface is cooler than the inside surface. The expansion of the lid causes a slight gap between the lid and kiln body but not enough to affect the firing. If the hinge does not allow the lid to float freely, the front of the lid can rise 1/4" - 1/2", causing heat loss. Placing a weight on the front of the lid can add stress to the firebricks. Instead, adjust the hinge so the lid has play that will allow it to float when the firebricks expand. Sincerely, Arnold Howard Paragon Industries, L.P., Mesquite, Texas USA ahoward@paragonweb.com / www.paragonweb.com Link to comment Share on other sites More sharing options...
hershey8 Posted August 5, 2015 Author Report Share Posted August 5, 2015 Put a weight on the edge of the lid, or put a latch on it to hold it down. I would not mess with the rope seal. Not sure how there would be different relays in converting from 208V to 240V. You just have to replace the elements to do that. There are all sorts of different wiring systems out there, even some that use infinite switches and relays together. Are you going off of the wiring diagram from the manufacturer? Neil, the 240 v model has no relays, no fuses, just one infinite switch that controls 4 elements, and two timer switches that control 4 more elements each. Total 12 elements. 4 that "flash" on and off with infinite switch. Max setting turns them on without oscillation. 2 more sets of 4 elements are controlled by 2 separate timer switches. The 208.v model had higher resistance elements that needed to be switched on and off by a relay; the infinite switch couldn't handle the load. Who ever remodeled this kiln changed the elements (12, 10-ohm i believe, not looking at that schematic at the moment) and replaced them with appropriate elements for 240v (6, 3-ohm and 6, 5-ohm). But the relay was left in place. Actually, it appeared that the relay would have toggled the entire kiln on and off the way it was connected to the infinite switch. The 240v model is supposed to toggle 4 elements on and off in the early stages of firing. The the timer switches are set to, then, power up the two remaining sets of elements in a sequence, each at full power. Oh, yes, I'm using Paragon schematics. And the folks there are very helpful! Link to comment Share on other sites More sharing options...
hershey8 Posted August 5, 2015 Author Report Share Posted August 5, 2015 How much space it too much, when lid warps. Will flipping lid help. My lid sets pretty well when cold, but develops a lot of space when firing. I know some space is ok, but mine looks abnormal, over 1/4" in places. Is there a high temp blanket that would help with this? The center of the lid bows slightly inward toward the firing chamber at high temperatures. This is because the outside lid surface is cooler than the inside surface. The expansion of the lid causes a slight gap between the lid and kiln body but not enough to affect the firing. If the hinge does not allow the lid to float freely, the front of the lid can rise 1/4" - 1/2", causing heat loss. Placing a weight on the front of the lid can add stress to the firebricks. Instead, adjust the hinge so the lid has play that will allow it to float when the firebricks expand. Sincerely, Arnold Howard Paragon Industries, L.P., Mesquite, Texas USA ahoward@paragonweb.com / www.paragonweb.com I'm going to try a slight lid adjustment, Arnold. Trouble is, the way is sits now, which is pretty close to "right" makes me wonder which way to adjust it. I'll pull it up in the back a little and see what happens. Link to comment Share on other sites More sharing options...
Babs Posted August 5, 2015 Report Share Posted August 5, 2015 My lid was a fibre filled lid not fire bricks, it warped where the flame "bounced" off the that corner of the lid, gas top loader, the hinges were discussed but it was a very definite warp on that corner at high temps. Rock fixed it. Link to comment Share on other sites More sharing options...
hershey8 Posted August 6, 2015 Author Report Share Posted August 6, 2015 My lid was a fibre filled lid not fire bricks, it warped where the flame "bounced" off the that corner of the lid, gas top loader, the hinges were discussed but it was a very definite warp on that corner at high temps. Rock fixed it. I'm gonna git me a rock too! Link to comment Share on other sites More sharing options...
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