elenab Posted February 19, 2023 Report Share Posted February 19, 2023 Hello everyone, I got an old Paragon kiln A81B with a kiln sitter, I fired it for cone 6 and it never reached the right temperature, it was on for 24 hr. Then I tried to fire for cone 4 and it reached the temperature in about 2-3 hours. Would it be enough to change only one element for cone 6 firing? Also, because my kiln is outside (I am in Whitby Ontario) would it make difference to fire in warmer temperature ( it was - 5C when kiln was working)? Thank you so much! ( I am very new to pottery and had never fired kiln before) Elena Quote Link to comment Share on other sites More sharing options...
Bill Kielb Posted February 19, 2023 Report Share Posted February 19, 2023 The elements wear together so generally if it needs elements, it needs them all. Firing at cooler temperatures definitely makes a difference but really at zero outdoor temperature that’s on the order of 3-4% change to a kiln firing over 2000f. Yes, very cold especially for humans who live in a very small temperature range but most often does not affect the kiln to a large degree. I don’t want to completely dismiss the outdoor temperature though. As elements wear by about 10% most kilns begin having trouble making top temperature. So on a very cold day and a worn kiln, that 1,2,3 % from the outdoor temperature could add up to be significant. More of a function of we wish kilns were designed with more like 120% of the energy needed than 110%. Quote Link to comment Share on other sites More sharing options...
neilestrick Posted February 19, 2023 Report Share Posted February 19, 2023 You'll need to check the element resistance and see if they're worn. It's a little odd that it would reach cone 4 that quickly but then not reach cone 6 at all, but I wouldn't expect the outside temp to matter, especially since -5C isn't really that cold. Are you sure everything was set properly for the cone 6 firing? Is there a timer on the sitter, and if so are you sure it didn't shut off the kiln? Quote Link to comment Share on other sites More sharing options...
elenab Posted February 20, 2023 Author Report Share Posted February 20, 2023 It is true that all elements are old, I can see it by looking at them, lol. I just didn't want to invest a lot and at once. It seemed odd to us too that kiln reached the temperature so soon, With cone 6 firing - the kiln was working all the time, I was checking it often. But now, I just realised that cone 4 was old (it came with the kiln). Cone 6 , was bought not long time ago. Could it make a difference? My husband will check the resistance tomorrow. Thank you for your help! Quote Link to comment Share on other sites More sharing options...
neilestrick Posted February 20, 2023 Report Share Posted February 20, 2023 11 minutes ago, elenab said: But now, I just realised that cone 4 was old (it came with the kiln). Cone 6 , was bought not long time ago. Could it make a difference? Age doesn't affect cones, but moisture does. If it ever got damp it could behave goofy. Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted February 20, 2023 Report Share Posted February 20, 2023 What colour was the cone? Are you sure it's cone 4 and not 04? I would think if it did get to cone 4 in 3 hours then a 20 hour hold should probably bend a cone 6. Was the kiln loaded with ware for both firings? Bill Kielb 1 Quote Link to comment Share on other sites More sharing options...
elenab Posted February 20, 2023 Author Report Share Posted February 20, 2023 Hello, we checked the resistance, from the top to bottom elements have : 9.2, 5, 8.4 and 8.5 And High Bridge Pottery was guessing right - the cone was 04! Sorry I didn't pay attention to zero. The kiln had the same ware both times - two platters and one bowl. Seems pathetic, I know Plus, one of the platters (better looking one) cracked and broke. Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted February 20, 2023 Report Share Posted February 20, 2023 (edited) The only reason I ask about loading was the other way your timings seemed possible was if you tried cone 6 with a full kiln and cone 4 with an empty kiln. Normally the low bisque cones are red in colour as they contain iron oxide, I have seen some that have a dot instead of a 0. I am looking at Bill's post in another thread but can't particularly figure anything out other than the element with 5 ohms looks wrong. It seems like they all run on their own 120v line on full power and in series at 1/4 power? (for each section) Should they be 16 ohms each? I am confused. On 9/17/2022 at 1:16 AM, Bill Kielb said: Just a first question, it is an old Paragon that requires 240v with a neutral and an earth ground. Do you have Two (2) 120v circuits and a fully rated Nuetral run to the machine? This should be your wiring diagram https://paragonweb.com/wp-content/uploads/A82B_A823B_A81B_A88B_AA8B_AA8B3B_WD_PL.pdf four way switch operation below requires both 120v circuits AND a nuetral. Edited February 20, 2023 by High Bridge Pottery Quote Link to comment Share on other sites More sharing options...
neilestrick Posted February 21, 2023 Report Share Posted February 21, 2023 3 hours ago, elenab said: Hello, we checked the resistance, from the top to bottom elements have : 9.2, 5, 8.4 and 8.5 According to the Paragon web site, they should be 8 ohms each. Something goofy is going on with the one reading 5, the one reading 9.2 is worn out, and the others are close to worn out. On the kiln serial plate, what is the max temp, and what is the amperage draw? Does it have a 4 prong plug? Bill Kielb and High Bridge Pottery 2 Quote Link to comment Share on other sites More sharing options...
elenab Posted February 21, 2023 Author Report Share Posted February 21, 2023 Thank you for the replies! Looks like the elements are dying. Sorry, my kiln didn't prove it's worth fighting for I like very much the idea of a gas kiln - no elements to get old or to replace. And it seems (from comments I found) faster in firing. ( I want to fire to cone 6) I found a group on facebook that is all about gas firing. At first I was scared of possibility of explosion, but my husband's reaction was different, so we will try. Thank you! Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted February 21, 2023 Report Share Posted February 21, 2023 Seems less of an investment buying new elements than buying a gas kiln. Bill Kielb 1 Quote Link to comment Share on other sites More sharing options...
neilestrick Posted February 21, 2023 Report Share Posted February 21, 2023 8 minutes ago, elenab said: I like very much the idea of a gas kiln - no elements to get old or to replace. And it seems (from comments I found) faster in firing. Gas isn't necessarily faster to fire, nor should speed be a determining factor. Most glazes respond better to slower firings. Gas has its own set of issues to deal with and generally requires more work and knowledge on your part to fire with, so do some research before jumping in. Changing elements is part of owning an electric kiln, just like getting new brakes on your car. It only needs to be done every 100-150 firings, so it's not really a big deal. Bill Kielb 1 Quote Link to comment Share on other sites More sharing options...
elenab Posted March 1, 2023 Author Report Share Posted March 1, 2023 Hello guys, I am back. The beautiful gas kiln idea should wait until spring, at least. Meanwhile, I decided to try to make one element from Kanthal A wire., but something is not working with my math. I watched a few videos on how to make kiln elements, researched info on Kanthal wire and got a book by F. Olsen where he has a chapter on elements. I also called Paragon office, but they can't help me with information about wire for the elements. MY Paragon kiln A81B has 4 elements, 7200W, 30 amp, 240v. Each element should have 8 ohms. The stretched length of each coil is about 15' (one coil goes around in the kiln 3 times ) , straight wire should be about at least 5-7 times longer than the coil's length. But it's not achievable with Kanthal wire. Kanthal A wire gauge 13 will be only 47 feet. (8 ohms/ 0.169 = 47) Here is the wire chart: https://duralite.com/resistance-wire-specifications For example, Kanthal gauge 10 wire to have enough length (of 8ohms) to make a coil, but it will be a very thick wire. If my math is not wrong, can the new coil go around the kiln only once instead of 3 times? But I believe something is wrong with my math, it can't be that ( for the same amount of ohms) the longer the wire the thicker it is. thank you! Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted March 1, 2023 Report Share Posted March 1, 2023 (edited) 38 minutes ago, elenab said: If my math is not wrong, can the new coil go around the kiln only once instead of 3 times? But I believe something is wrong with my math, it can't be that ( for the same amount of ohms) the longer the wire the thicker it is. Thicker wire has less resistance per ft so for the same resistance you will need a longer piece of thicker wire to get the same resistance as thinner wire. Not sure that you need 5-7x longer than the coil length as it depends what sized rod you are winding it around and what gauge wire you are using. I would just measure what gauge you have in the kiln now and go with something similar. If you need to stretch it to 15 feet then then it's probably going to be around 5 feet before you stretch it and need a mandrel (rod) at least that size and matches what internal diameter you need for the coil. Edited March 1, 2023 by High Bridge Pottery Quote Link to comment Share on other sites More sharing options...
elenab Posted March 1, 2023 Author Report Share Posted March 1, 2023 The existing wire is about 16 gauge, I just compared to wires I have at home. (I have Nichrome 12 ang 16 gauge) Here is the video where the guy make an element coil, he used wire of length 7 times longer than stretched coil. It seems Paragon didn't use Kanthal wire, High Bridge Pottery 1 Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted March 1, 2023 Report Share Posted March 1, 2023 (edited) 16 awg might work if D is 5mm, couldn't find any exact numbers on what the internal diameter is but they look about 5mm. Can you post what the internal diameter is? 8 / 0.3388 = 23.613m 23.613 / (0.005 x Pi) = 1503 windings 1503 x 0.001291 = 1.94 meter (6.36 feet) length unstretched which you can stretch to 15 feet and is within the 2-3 stretch ratio 4.57 meter (15 feet) x 5 = 22.85 meter so under the 23.613 length of straight wire. Edited March 1, 2023 by High Bridge Pottery Bill Kielb 1 Quote Link to comment Share on other sites More sharing options...
elenab Posted March 1, 2023 Author Report Share Posted March 1, 2023 8 / 0.3388 = 23.613m Unfortunately, it's feet not meters. If I am wrong I would be happy. But the inner diameter looks like 5 mm! High Bridge Pottery 1 Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted March 1, 2023 Report Share Posted March 1, 2023 You are right, sorry about that. I also noticed in the video he is adding the wire thickness to get the D value so I will rerun the calculations and not mix up feet and meters! Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted March 1, 2023 Report Share Posted March 1, 2023 (edited) Ok think I got it right this time and didn't confuse my metric and imperial. 12 gauge comes out a bit under the 5-7 length but I wouldn't worry as it is in the 2-3 stretch length. 12 awg - 0.1340 ohm per foot, 2.052mm diameter. d = 0.002052m D = 0.007052m 8 / 0.1340 = 18.197m (59.7f) 18.197 / (0.007052 x pi) = 821 turns 821 x 0.002052 = 1.685m (5.53f) wound length Looking at 13 awg you can probably just get away with stretching it a bit further than recommended. 13 awg - 0.1690 ohm per foot, 1.8288mm diameter d = 0.0018288m D = 0.0068288m 8 / 0.1690 = 14.429m (47.34f) 14.429 / (0.0068288 x pi) = 673 673 x 0.0018288 = 1.231m (4.04f) Edited March 1, 2023 by High Bridge Pottery Quote Link to comment Share on other sites More sharing options...
neilestrick Posted March 1, 2023 Report Share Posted March 1, 2023 Coil spacing varies greatly from kiln to kiln, and yet they all work. There's a lot of leeway in the math. If you're using the same thickness wire and the same size winding mandrel as the original element then you're good to go. Wind it up and stretch it till it fits. Easiest way to do it is to lay out a length of wire on the floor that gives you the correct resistance (measure from ends with a meter) and just wind that up. High Bridge Pottery 1 Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted March 1, 2023 Report Share Posted March 1, 2023 I always found it pretty tricky to get an accurate reading from long lengths of wire as it liked to coil back onto itself and give weird readings by shorting out sections. Measuring the length with a stick cut to 1 meter and adding 5-10cm extra for the tails seemed to work pretty well. Wearing safety glasses is a good choice when measuring and winding as it likes to spring back and swing for your eyes. Quote Link to comment Share on other sites More sharing options...
elenab Posted March 1, 2023 Author Report Share Posted March 1, 2023 Oh, thank you for the tip! Your math looks great. Thank you for everything, I will more confident now! will buy the wire and let you know when it's done. Quote Link to comment Share on other sites More sharing options...
elenab Posted April 4, 2023 Author Report Share Posted April 4, 2023 Hi High Bridge and everyone! I am back with good news! last week I did firing with the new elements we made and my kiln reached cone 6 temperature in 4.5 hr, yay... I didn't buy 12 g wire, it was too expensive, instead, I bought 14 g, cut enough wire to make 8 ohms for each element, winded it, then stretched it to the length we needed, and installed it. Accidentally, the rod I was winding the wire on had a perfect size and fit perfectly. Later I realized that if the rod was bigger I would not be able to insert the elements in the grooves. Changing the elements was so much simpler than I feared. I probably was reading F.Olsen's book too much, lol. But after all the self-doubt I made my kiln work, and thank you for your support! Elena High Bridge Pottery, neilestrick, Bill Kielb and 1 other 4 Quote Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted April 4, 2023 Report Share Posted April 4, 2023 That is great Good that you happened to have the right rod! I just guessed that they looked like a 5mm diameter. What size rod did you use in the end? Quote Link to comment Share on other sites More sharing options...
elenab Posted April 5, 2023 Author Report Share Posted April 5, 2023 The rod is 3/8" in diameter. It's a brass rod that turned out to be very soft for this job, it got bent and I wasn't able to use it with the drill after the first element. I winded the rest manually, but because I had made an attachment for winding, the coils turned out great. Yesterday I was glazing my wares. What a disaster... I believed Amaco and used the glaze straight from the jar inside of the bowl, but it turned out to be too thick, and my bowl was drying all night. Now I glazed the outside of the bowl with diluted glaze, it's still not great. I will have to sand it and apply the glaze with a brush. I checked videos on Youtube, potters show that the glaze is drying within seconds, mine doesn't even with severe dilution! and they never mention the type of clay they used and what type of glaze, is it because it doesn't matter? Sorry for this, I thought the hardest thing would be the elements, but turned out the elements were the easiest part... Quote Link to comment Share on other sites More sharing options...
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