Bill Kielb

If this helps - The only situation where a single element of the pair runs on 120v appears to be the medium setting. Here is the location of the full diagram from the Paragon website. This kiln has a diagram for the quick connect switches as well. Quality still not the greatest. https://eadn-wc04-7751283.nxedge.io/wp-content/uploads/A82WD.pdf

Just a suggestion, maybe post pictures of what you have. Bottom plates is personally hard for me to interpret. Shelves, kiln section, bottom slab of the kiln, kiln stand…….. I am not sure I understand.

Let me add a caution here. When mixing power vents and a natural draft chimney it needs to be done with good forethought, engineering and or supervision later to ensure it is working as intended. If a combustion appliance is involved, combining powered and natural draft is usually discouraged by most combustion appliance manufactures. Combining ventilation and combustion also presents some real design and operational safety challenges. From a design standpoint under many codes and requirements, these are rarely combined. Again if this is a kiln with a built in exhaust port, Ie Rhodes passive exhaust design, this might be easy to achieve at least as intended by the manufacture.post the make and model of the kiln.

This kiln requires a traditional 4 wire 240v circuit so first question do you have: L1,L2, Nuetral, Ground wires? If you don’t, it will not work. (Drawing below) An addition here would be elements wear together and get replaced together. Worn elements that burn open are usuallly extremely brittle so I would be curious what the remaining elements measure resistance wise.

Does your kiln presently have an exhaust port? If so this is already setup for a passive exhaust system. Post a picturre or tell us the model number.

Generally available on kiln website with make and model. Amy’s kiln was a super fire so I do not believe anyone found a wiring diagram for it. A closer look ought to reveal where the thermocouple lead came from or connects to. If not obvious post a picture or two of your situation and back of the controller / pyrometer you suspect it used to connect to..

I don’t think the low fire firing will change it dimensionally a bunch. Can you repeat it but make a generous gallery so it will fit a wider range of opening?

My initial thoughts, Add enough battery storage to your solar so you can complete a firing on a sunless day - maybe two sunless days and your kiln choice broadens. Kilns consume more power as they fire so running out of solar at the wrong time is a no go firing wise. Kilns with greater insulation will have less shell losses so the 4” brick is likely best, followed by brick and insulation, followed by brick only. Years back we had an engineering student prove that two layers of kaowool was better than one so improving the insulation can pay off in a huge way. The challenge is improving the lid and floor which for the lid probably means adding high temp interior rigid. Added to the outside makes the lid crack and deform more than normal and adding to the interior decreases the volume. Cone ten rated rated kilns will provide roughly 150 - 200 combined bisque and cone 6 firings. In contrast a lesser rated kiln will provide significantly less cone 6 firings before the elements degrade by 10% which is usually enough degradation to require an element change to make top temperature again. So most kilns are designed roughly at 110% capacity by power restriction and shell losses. We had an individual here that conquered this with insulation very effectively. Still, enough battery storage and you can just run a regular small kiln. In the end paper specs and an overall best plan will probably serve you best and most kilns will operate on 50hz or 60hz, they are mainly resistance machines.

It sounds like the clay was fired to cone 5 and then cone 5 glaze was applied and fired to cone 03 which makes it simply an under fired glaze, so very matte, but only two glaze firings. Maybe I am reading this incorrectly. If you have a low fire glaze that is matte and very close, or perhaps an acceptable contrast then for the sake of speed, I think I would make the lid with a relatively broad gallery out of clay you are used to, so easy to fit, fire the clay to cone, then apply the low fire matte glaze and fire to its cone. I might be misunderstanding though.

The electro sitter expects to turn all the elements on 100% and off 100%. So having other controls interrupting things is just confusion. Normal procedure is to turn all the kiln controls to high or full on and let the electro sitter manage the firing. The firemate should go to maximum or 10 and depending on your model any other kiln control you have turned up to high. To answer the question of how it works, a timer motor slowly turns up a standard infinite switch. So the infinite switch cycles on and off proportional to its setting (likely starting around 22% and somewhat linearly to 100% power within prox 330 degrees of rotation) ……. and the timer motor ramps this setting upward over some amount of time. Generally the most confusing thing for most folks but an early attempt at semi automation.

PID programming (proportional, integral, differential) can be extremely challenging. Now days most are auto tune so that can help. Segment programming is a bit of a haseł as well for each firing but doable for many. SSR’s not exactly the miracle devices either but generally reliable. There are nuances though, for instance generally a definite purpose contactor needs to be installed ahead of the SSR’s to ensure potential leakage does not cause electric shock while loading the kiln. To that, there needs to be some safety circuit that drives that contactor such as a lid switch ……. If you are electrically savvy, then maybe a nice project with a temperature controller. For simplicity I usually suggest getting a bare - bones Bartlett controller and building upon it. It allows one touch cone fire programming so the simplicity is great and all that underlying setup and tuning is virtually done for you already. I would suggest download any temperature controller install and configuration guide and see if it appeals to you or it reads like another language.

These switches traditionally last a long time, but making sure they are not overloaded is important to their longevity. Hopefully you are not at maximum amperage. If so, one solution - this can drive a more robust relay which then power your elements.

Just some things you might want to double check- Not familiar with Radix brand. You might want to double check the olympic which very well might have been wired with MG (mica glass 450c). For connection to elements some of the silicon HT wire will char and burn to ash well above 200c. Also might double check the voltage rating (basically insulation thickness) and get 600v rather than 300v. For longevity sake.

Possibly true but often a function of a glazes fired viscosity and surface tension (oddly enough) and ability to heal. Search for drop and hold firing schedule, glaze pinholes, etc…. I would agree - glaze pinholes in wares intended for food, or even if potentially could be used for food, Certainly not a ware I would consider keeping -ever. I usually destroy the piece always worried someone at some point in the future might unknowingly use it for food service. I actually don’t know of any experienced potters who would consider filling the pinholes in their wares for food service with a chemical fix. Epoxy viscosity Epoxy comes in many forms, the typical household stuff is about the viscosity of maple syrup. Not super low, like water but not super high either. Epoxy also comes in a putty form - semi solid and stays where you put it so super high viscosity I guess. Epoxy even comes in a uv curable form so the viscosity of that - not necessarily relevant. Epoxy also comes in food grade compositions. An example: https://www.permabond.com/industries_served/food-safe-epoxy-adhesive/ Not many potters I know would risk this repair on any food surface. Instead they would bisque longer or solve the glaze issue or only use tested durable defect free glazes as a liner for their food service stuff.

my thoughts Renewing the wiring harness is a great idea. Making your own great too, but high quality crimp and crimp work is key. If you make your own, please buy a decent locking crimper and good quality welded seam crimps, else the premade harnesses likely a best choice. When I rewire, I use #12 and #10 MG (mica glass) rated wire good to 450c all in an overkill fashion so I can identify with make it better. Low voltage harness The current low voltage harness likely is ok and should currently experience less than 1/2 amp of load …….. but 18 gauge stranded is plenty sufficient. You should be able to read the side of the existing wire harness to determine what gauge and what temperature it is rated at. Again the crimp work is the important part with respect to longevity and kiln manufactures rarely seem to use high temp insulation on these. Again I strongly suggest Measuring the resistance at these element circuits ….. at the relay, would definitely be helpful, possibly for knowledge useful by others but now will also give you a real idea of how much over designed you would want to pursue by knowing your current amperage and looking in an open air amoacity of wire table. Lots of tables here is one https://up.codes/s/ampacities-of-single-insulated-conductors-in-free-air Since you are exploring rewiring general insulation and it’s typical ratings in order of temperature tolerance: Mg (Mica Glass) - 450c Teflon products - 200c - 250c (fep, etfe, pef, And others with f in them) Silicone Products 150c-200c (srg, srk, smrl - silicone motor lead developed for small motors vibration and temperature) All the above though generally is a decent reason to just buy a premade harness that fits perfectly though. Most wiring begins to fail at their connections which overheat, anneal the copper and continue to overheat more as the conductivity decreases. The physics says this will decrease the electric load on the relays, but a harness that overheats also adds heat to an already confined space. The latter being bad for the relays as well so replacing a harness not a bad thing, replacing with a better harness, even better, but does take some diligent work, good crimps and good crimpers to achieve this. Airflow and cooling helps everything regardless of gauge and insulation, so making sure there are no obstructions or the kiln is not enclosed in an overheated area with no way to get relatively cool air is a no cost best practice for all the electrical components inside. The control box depends heavily on stack effect which means relatively cool room air can freely flow from bottom to top and out of the louvers.

Just a couple thoughts 1200 f is about cone 020 ( likely not very sintered), folks who intentionally carve soft bisque end up around cone 012. 1860f is cone 05 / 06 so you likely would notice a big difference between the products including: look, touch, size, firmness, absorption, tongue test …… from 1220 f - 1860 f lots of things burnout including sulphur, calcium carbonate, etc… but they don’t burnout necessarily because of peak temperature. It’s rather time at elevated temperatures so bisque firings are generally slower than glaze. You could bisque something to 1200 and compare You could re-bisque the pieces in question to let’s say cone 06 to be sure You could slow your glaze firing schedule through 1200 - 1860 as sort of a modified once fire schedule. Slow bisque schedules generally go about 180 f from 1000f to 1700 f btw. I do not believe your actual glaze temperature has been referenced yet. What cone do you glaze fire to? Some of the above more or less assumes you glaze to cone 5/6. Cone 020 is really a China paint type schedule generally designed to just begin softening glaze, I think the bisque would be incredibly soft at this temperature and not very sintered, but easy to test to be sure.

@Hyn Patty Just curious, can you measure the resistance (unpowered kiln) across the two wires that go directly to the elements and post? Just curious how much load is on these relays and what their current specified rating implies. Also curious what the element insulators look like, basically if they are clean. A picture would be great.

Wires Might be a solution, but the connections and wire we can see look pristine and the copper in the relay overheated, but no signs whatsoever on the wire or connections. Bad wires / connections ought to raise the resistance of the circuit and lower the load on the relay unless they are shorted somewhat. Still - could be downstream of this picture and new wires never a bad idea but I would definitely measure the resistance from the relay terminals just to understand at what load this relay was running at. Only parallel I have experienced - carbon tracking or something slightly conductive acting as a slight short to ground around element connections etc… If the wires are replaced, also strongly suggest cleaning any coating off the porcelain element bushings and such. A resistance measurement at the relay terminals likely can confirm this.

In many many years, I have never found proof that one can polarize or directionally align reasonably wedged clay. I have not found that to be credible in my experience.

While not the expert I’ll offer this thought and suggestion: Both relays appear to have failed due to overheating resulting in the plastic melting enough so the quick connection tipped to one side. The corresponding moveable contact in the relay on the right appears to show signs of overheating as well. So why so much heat? Electrical load or inability to cool itself with the updraft in the kiln. It failed quickly so, electrically overloaded or just a defective relay that can not tolerate the load …. Or ….. new relays use a thinner moveable contact? First step tell us the model so we can look at the wiring diagram which should allow us to see how closely the relay is to or above the rated load and rated operating temperature. From they’re easy enough to measure the element resistance right at the relay contacts to verify the elements are as expected with respect to loading. Maybe the last piece in the puzzle would be this relay in spec is rated by horsepower. Converting to amps gets the contacts down to prox. 12 amps. Elements (resistance loads) cause significant heating in the controls and wiring, so it will be interesting just to see just how many amps the elements are and if the newest forms of this relay handle less than previous for a resistive load. Table below Just adding relay specs below - all appear spot on except for the meaning of 2hp @ …… rating.

Hmmm, pretty small actually I would feel better if it was stamped. .5mm is .0280” which is a number 70 orifice which gets you [5.9 kw] @ 34 Kpa so seems to be a high pressure burner. When burners burn backwards the combustion velocity is greater than the physical velocity so the flame travels back towards the orifice which is counter intuitive to having too much pressure. I assume it backfires in free air, so maybe an easy test I would suggest is to put a hand operating valve upstream of the burner and see if you can stabilize the flame slowly closing the valve ( in free air) - maybe to near zero flow. The primary air needs to be fairly open, don’t close it. Again counter intuitive but nothing makes sense here really. If that works then I think we can safely assume it is low pressure or medium pressure burner and work from there rather than buying a bunch of stuff guessing. Propane and natural gas have relatively slow combustion velocities which make this issue fairly rare for Venturi burners, stove burners, you name it. I think worth the test and observing the result.

Can you check orifice size for us. Wonder if one is in there, then what size. 3-5 Kpa would be typical sizing so at 100 Kpa unknown how that would react. We really want to know the orifice size but I am also curious if you drop this pressure down to single digits, does it operate. I think it would be good to see this orifice in a picture as well - any chance a little critter crawled in and made a home? Often spider webs. The orifice size will tell us its intended operating pressure. Pictures might tell us if someone drilled it out.

While I don’t use groggy clay, when I did, wet sand the bisque to smooth as much as practical ( rim and foot) and ALL pieces after glaze firing - foot diamond grit ( wet) sanded super smooth.

Very, very unlikely. Lowfire glazes melt about 2000 degrees. Fired on enameled porcelain is usually a mix of Frits and fires in the range of 1400 degrees. That’s probably the tip temperature of a propane torch, plus if cast iron - you need to heat the whole vessel. My thought is very very unlikely, removing to a restore shop possible but I am guessing replacement probably more economical.

Atmospheric burners contain orifices sized for a particular range of pressure and the fuel used to produce a certain amount of heat. No new news there, but for all that to work the velocity of the gas has be be greater than the combustion velocity of a fuel air mixture expected to enter let’s say at a 5:1 air fuel ratio or about 50%% of the required air. The remaining 50% of the required air must enter around the side of the burner through a sufficient overcut all the way around. So: Wrong pressure wrong orifice Too much back pressure from the kiln Any chance you are feeding liquid to this? Not enough overcut around burner Adding a metering valve upstream of the burner and downstream of the main gas valve allows variability, how are you controlling the gas to the burners? What size orifice, what is the burner rating (kilowatts, btuh - thermal output) , what pressure is this operating at (typically in the 2-3 kilo paschal range) not the maximum pressure ratings on the valves, what size regulator is installed on the tank, pictures of the installed burner, picture of it burning back ….. and never close the primary air 100%, it should likely sit at least 1/2 open or better and not really need adjustment. Propane boils about -41c so at 21c there will be about 850 Kpa of pressure in the tank. Definitely way higher than your burner rating. So in the end sounds like these might be high pressure burners and need a first stage regulator to operate correctly. This is fairly easy to solve but often folks, even licensed fitters confuse the pressures and installation requirements for kiln operation. Tell us a bit more