Bill Kielb

Well ventilated and thermally managed with wiring isolated from kiln infrared, hundreds of degrees above ambient. So most kiln manufactures create a channel adjacent to the kiln that creates an air gap (prox inch or two) where cooling air can rise from bottom to top freely for cooling. The remaining components and majority of the wiring are located on the other side of this partition and are also ventilated bottom to top. Done well, a few hundred degrees over ambient. It’s never been worth my while, so I just always used MG wire which is Mica Glass usually rated continuous at 450C which is upwards of 800 f. I order from wire supply though, McMaster is probably pricey. Definitely overkill by many of todays standards and lesser rated wires will work. Make NO mistake, they are lesser rated so not necessarily better for temperature resistance but adequate. Popular now is silicone. Wiring gauge is chosen by amount of current the wire will carry. So for me, really good ventilation design and my wire is overkill, but my remaining parts can be standard stuff. And all will last a long time. Your control box should be coolest furthest from the kiln wall and lowest where air comes in to ventilate. Ventilation (stack effect) and isolation are key. If your components can “see” the side of the kiln, they are not isolated from the infrared that will be emitted from it..

@davidh4976 I don’t have the Reddit location this was at @colormek8art but assuming you will be working lowfire and / or glass the cone 6 limit likely will be ok. It is a manual kiln though so fusing, slumping, squeezing, annealing can be a bit of a challenge compared with a kiln with an automatic controller. If you were to be using this for midfire clays (cone 6) then you will likely only get several firings from this before you will need an element change. I believe that plate says model 181 so to that end your electrician will likely find the 181 manual handy. You can download here: https://skutt.com/skutt-resources/manuals/kilnsitter/ These kilns often said to be three wire actually required two hot legs and a full sized neutral as well as an earth ground for safety. They were in effect two present day residential 120 v. circuits and an optional ground wire which I would suggest is no longer optional. So having your electrician figure this out in advance is important. See pic below, “if” this is your model. Note the four wire power cord.

Just to suggest, this looks to be a three phase kiln capable of about cone 6. To start maybe post a clearer picture of the equipment tag and possibly the cord end that is on it. If you know, what cone will you be working in: cone 04 (Lowfire) cone 6 ( midrange) and / or cone 10 (Highfire) then add that as well. Your home is single phase, so confirming that this is three phase as well as what cone you plan to work in are probably best first steps before ordering elements.

I likely would not. China paint and lusters are still more durable for my use and as accents. This depends on the conductive paint beneath so likely not as temperature resistant. Having said that, this process is pretty neat for vases and such and solves the mirror finish dilemma, especially when coating an entire surface.

Good trick to know for sure with the mirror for moisture! Bisque firing is also about Sulphur compounds which begin around 600 c and can be corrosive to elements and humans. Also some late off gassers above about 800c. Your mirror may clear before this. So when in doubt, closing the vent later would be a conservative way to try and ensure all the bad stuff is eliminated. As you might have noticed, the earliest Nabertherm suggests is 950c to be conservative I believe.

Nice just some conductive paint and you are on your way! Looks like somewhat non functional stuff (I should probably say non food contact or something like that) though, but nice for its use.

I agree with Neil, however reduction and your visuals likely will change a bit. That nice blue flame is not something you will see so much with propane. Propane literally has double the btu output per cubic foot used, but proper orifices will compensate for this. You should be firing on temperature and rate so manually controlling will compensate for slight faster or slower. For reduction, your visuals will change a bit but not something you will not grow accustom to.

Still a nice look. It’s really difficult to get true mirror like gold. The PVD coating above was actually a pleasant surprise to me.

Dishwashers can be fairly aggressive on non durable glazes. This a soda fired piece so not something designed and tested durable. Looks like the dishwasher dissolved some of the surface of the glaze. It’s soda fired so hard to predict and no guarantee it will end up durable.

Looks better than expected. I wonder if you can buff it, not necessarily to a mirror but glossy smooth?

No, I think my math. Assuming 8”round prox. 20.32 cm so area should by 3.14x((20.33/2)^2 ) = Prox 324 sq cm. So 22W (from above)/ 324= ..068W per sq cm. A bit more than your floor heater ought to melt ice off your mirror as opposed to heating a floor to comfort temps.. I think you are in range and my quick calcs are wrong above. All done flipping back and forth on this iPad, but seems right. Someone should triple check all the calcs if the OP does want to do this in some fashion, I think we can sneak up on a real potential load.

The density of snow varies significantly. I kind of really liked the heated mirrors above for approximate established data. I think we really need more of a description as much as practical as the mounting and what it is mounted to could significantly affect the required energy as well. Gotta start somewhere so maybe size, mounting, materials ….. Maybe a display case in the end is practical.

I think we can tell you more but you will need to tell us how big will this be ……. Tell us as much as practical. To be effective, I believe we are just going to need the potential load in watts which is affected by size and enclosure or lack there of. Sorry, the above is the best thoughts that come to mind to address the potential load. Maybe others will have more insight here. I would suggest describing what you envision as completely as practical though.

Still not sure ….. PVD coating that sticks to ceramic? (See below) it’s definitely not common and lusters have served this function with reasonable durability for potters. Most folks try and keep the lusters away from high wear and direct contact with food as well just to be extra cautious. I see this finish on many other materials such as steel and plastic more so than ceramic. I am not aware of a glaze that can produce the finish nor a traditional spray applied coating either. Spray applied coatings generally lack durability and are often not high temperature tolerant. If you figure it out, maybe you have something folks have been asking for for years. PVD appears a bit expensive unless it scales well to produce thousands of items.

Knowing that, I would suggest a carbon fiber heating element or flexible element often used in heated clothing. 80 meters of Nichrome is a very long distance so not sure what area you plan to heat or how you intend to distribute the heat from a single wire. My first instinct is to enclose or protect from snow, maybe move energy with air, but that may not fit your use. Maybe a full description here will sparks some ideas from others. Just to add a bit to this we are talking about raising some area from -15c to above 0c with only still air (undisturbed layer of air near the fabric) as an insulator. The slightest breeze makes that layer go away. This can become a very large loss of heating in a hurry. Maybe insurmountable wattage actually, when we look at available batteries and storage. I think the more accurately you can describe here it likely will improve your chances of suggestions by others. @Ahmad.khd Just looking at this further, car mirror heaters might give us an idea of the energy required. If my quick math is right - temperature dependent - it looks like on the order of 1-2 watts per square centimeter. Likely not trivial depending on how large an area you are trying to defrost. Cold climate Heat pump technology could produce this at 1/2 to 1/4 the electrical energy vs resistance heat. Assuming the above is correct my thoughts go to dark minimal awning, maybe using the existing sun as practical and a ducted heat pump only when essential. Maybe even automotive heat pump.

My thought is first work out the total heat needed which goes to what are you trying to heat up and what are the losses. Once you know the losses in watts we can figure out how to replace those watts with available nichrome wire (Diameter and resistance using your 80 meter length) and available batteries. It’s actually a very significant problem in my mind where no simple answer comes to mind. Perhaps a bit more description of what you are trying to heat would be helpful here.

Hmm, the machine should generally ought to do it better or at least more consistently than creating a custom program. So when you create your schedules do you follow the last 100c requirements in the Orton chart?

Just curious, since it is a Skutt with the touchscreen controller, why not use the cone fire programs rather than working with holds and various rates? Also - to get a particular Orton cone to fall it’s customary to set the last segment rate to that shown in the chart. Begin that rate 100c before the cone temp. If you follow Orton, just curious if anyone has explained how that chart is intended to work?

Not that it’s not possible for this to work, I would say with this level of cracking, highly unlikely. I am with min wondering about pouring dry.glaze in and out. I am not familiar with this technique from Mayco etc… or the expected look.

Usually cycle off after a test resets it. The interesting point though is to definitely cycle this test switch to make sure it’s not stuck and releases freely. Pretty funny though it’s either “off” or simply turn it to “No”.

Just a late add - Nabertherm does a nice job IMO of explaining a bit about the fresh air and exhaust port. In addition, they suggest when to open and at what temperature to close. Manual https://nabertherm.com/sites/default/files/noindex/2023-07/M01.1089_English_2023-06.pdf Section 5.5.6 - section about how the vent works with reference to piping, slope and height. Section 5.7 - first firing with fresh open 100% of the time to 950 c to season the elements and burnout in a new kiln. Just a good thing to know for future use. 6.5.1.1 - some nice preset program firing charts with reference of suggestions of when to close the fresh air inlet. Their range 950c-1250 c depending on type of firing, Anyway, it may seem confusing but this does give reference to a suggested temperature to close the fresh air vent, and these appear to be me to be relatively conservative numbers. This may help a bit. Perhaps confusing now, but likely will have greater meaning as you fire more and more and gain greater knowledge. sample schedule below with specific closure temperatures. Finally - why are we doing this? Here is a nice article from this web site that could give you an idea of what we are burning out and about when this happens. https://ceramicartsnetwork.org/ceramics-monthly/ceramics-monthly-article/Bisque-Firing-101#

Yes, lots of interesting advice. The basis for venting with respect to fumes is what I tried to convey. If I had one wish looking back, it would be that I wish I learned the underlying why parts first instead of looking for a magic number, temperature etc…. Very confusing I know. It’s a fun journey, no matter the path.

Many of these kilns use the buoyant properties of hot air to remove fumes instead of a mechanical fan, often called stack effect. At the conclusion of a bisque firing it is generally assumed all significant off gassing has occurred. Bisque firings work because of peak temperature and sufficient time in the firing for all this to occur. Even glaze firings have glazes which contain clay, and oxides which need to off gas almost as if being initially bisque fired. So suction is determined by the diameter of the pipe, final height of the vent termination above the kiln and the temperature difference of the air. Height being a very significant factor. So in general, at bisque temperatures most off gassing is done, so that sets a credible termination temperature and depending on the height of the installation the inlet and discharge ratio is set to maintain a very small amount of air through the kiln up the outlet pipe …… just enough to prevent fumes from infiltrating into the kiln room. opening the discharge a bit more than the inlet will ensure the kiln stays negative with respect to the kiln room. How much required is often a very very small amount and very dependent on final height. Open too much or too long wastes energy and in the extreme case could affect how even the kiln fires. So trial and error often establishes this. A reasonable way folks often figure this out is the smell of wax resist burnout. If one can smell the wax early on in the firing, the kiln atmosphere is leaking into the kiln room. So opening the vent (s) just enough or slightly more to ensure this smell is exhausted …. and establishing this ratio (of discharge opening to inlet) results in a reasonable expectation that all fumes are being removed. Closing these after bisque temperature reasonably ensures a minimal amount of energy is wasted. The challenge is often to get inlet and discharge ratio established during bisque and then close the inlet only after bisque temperature so any very minor leakage will be out of the kiln room. The stack effect will always try and pull air out of the kiln. Sorry for the complexity, but logic often says bisque temperatures are the magic number. Most manufactures stress the kiln must be vented but the variability makes it hard for them to provide uniform settings for all.

Your design is single stage high pressure so it already exceeds 1/2 psi. Most kiln orifices - operating and pilot are design in the 0-14” of water column range, so a second stage regulator is often placed at the kiln. If you use a low pressure safety on a high pressure system you risk valve failure. So Ward is right, most pilots are designed down around 3.5” and are regulated for consistency. In short, as designed you need the high pressure model if you keep the design as is.

Yes, this should be simple to diagnose for a kiln repair person. The 1/2 amp fuse only provides protection for the control board, its controlled loads and the transformer itself. So check ALL low voltage wiring to make sure no cuts and scrapes are touching anything. If you Unplug the orange, blue, white that will test the control board and its outputs. Unplugging (red, black).checks the low voltage output side of the controller (basically the relay load) Your transformer appears to possibly have burn marks on its secondary wiring side ( might be the smell) could be the picture though or could be from production. This could be from production, or defective as a result of overloading it. Secondary voltage — The nominal voltages measured - orange - Blue = 12VAC, orange - white = 24 vac, white - blue = 12 vac. This is a 24 vac center tapped transformer. The red and black are the output of the controller and ought to be 12vdc (nominal) when cycling the relay on. Green appears to be unused. All of these items can be checked for amperage draw by your tech to see which if any are drawing more than 1/2 amp. This should be your transformer specs https://www.mouser.com/datasheet/2/410/FD5_24-781304.pdf the U shaped jumper appears to be internal from the factory on this transformer. This should be your kiln wiring diagram https://eadn-wc04-7751283.nxedge.io/wp-content/uploads/S0743-1.pdf I would double check all low voltage wiring for a short to see if that overloaded the secondary of the transformer. You may need a new transformer if it cooked itself a bit. My experience paragon designs in accordance with code, UL and CSA so their wire size ought to be fine. Not sure who or where the undersized thing came from, but that saying seems a bit suspect to me.