Bill Kielb

Thanks Min and Bill.
I'll work on your suggestions over the next week and report back.  

I am thinking this is bisque to 04 not 4. One thing strikes me in the recipe, boron is fairly high for cone 6. About 0.15 ought to get you cone 6, so this likely begins to melt much earlier. Might be worth an experiment or two reducing the Fritt a bit. Saves on an expensive ingredient and ought to reduce fluidity a bit which might be ideal. Definitely need to test to see if it affects the glaze  positively or negatively. 
 

Just realized, harder to do with LED Christmas lights these days!

I usually fire my kilns at night so I don't really see what's happening with actual temps in the kiln, but today I started it up in the morning and was in the studio in the evening and got to see exactly what was happening during the cooling cycle. I do a slightly-slow cooling cycle to even out the results in my 3 kilns because they all cool at drastically different rates due to their sizes. I do a drop from the peak down to 2000F, then cool at 175F/hr down to 1500F. This gives me identical results from all 3 of my kilns. This firing I'm talking about here is in my 10 cubic foot L&L EQ2827-3, which has 3 zones, and was packed very tight in the middle. I was surprised at just how much slower the middle cools compared to the top and bottom. This photo shows how it's going part way through the initial drop from peak temp to 2000F:

As you can see, the middle and the top are nowhere close to each other. In a normal firing segment, a 73 degree difference would stop the firing with an error code. So why isn't it doing that here? It's because the cooling rate is set at 9999, or full speed. Any time you use 9999, whether it's climbing or dropping, the controller lets the kiln do its thing and doesn't care if the sections aren't even. Firing up or down at 9999 is the fastest, but you sacrifice evenness. As the temp continues to drop, we see this:

Here you can see that the top section (TC1) has started firing again. The set point for this segment was 2000F, at which point it should start cooling at 175F/hr, yet the top section passed that by about 20 degrees before the relay kicked on and the controller stopped the drop. Why did it let it get so far below the set point? Because it's averaging the 3 zones. Once the average of the 3 zones hits the set point it will start to fire each section again as needed to match the set point.
I get a lot of questions from customers about error codes and cooling cycles. The biggest problem is that the kiln can't always keep up with the programmed cooling rate. There are a number of firing schedules out there on the internet that people are trying that use a rate of 600F/hr or more for the fast drop portion of the cooling cycle, and many kilns simply cannot cool that fast, especially the middle section. When you have a specific rate programmed, the controller will send out an error code if the kiln can't keep up with that rate. So if you want a really fast drop you should use 9999F/hr, not a specific rate. For most people doing slow cooling with cone 6 work it won't matter if the sections are not totally even during the drop. If you do need more precision, like if you're firing crystalline work and it's important that you don't overshoot any target temps, then you'll want to put in a slower drop rate that the kiln can actually keep up with, and the controller will keep the sections even and not overshoot set points.

That's a cone 05, not 5. That would explain why the cone 5 glazes didn't melt.

So what turned the kiln off? Did the safety countdown timer turn it off too soon or did the cone melt in the sitter? If the sitter, then check it was not cone 05 instead of 5 (likely), sitter calibration ( that’s a lot of mis calibration, confirm everything else first before drastically recalibrating). You made it to red heat, that’s 1000f + so no stove oven would ever get near there. If all the above is not helpful, then testing the elements is likely next.
The good news, it made it to red heat and something shut it off. First task, what shut it off?

So what turned the kiln off? Did the safety countdown timer turn it off too soon or did the cone melt in the sitter? If the sitter, then check it was not cone 05 instead of 5 (likely), sitter calibration ( that’s a lot of mis calibration, confirm everything else first before drastically recalibrating). You made it to red heat, that’s 1000f + so no stove oven would ever get near there. If all the above is not helpful, then testing the elements is likely next.
The good news, it made it to red heat and something shut it off. First task, what shut it off?

I can second the cone 5  experience it did not like to go to cone 6 for me without pinholes with our clay. Also needed to apply it fairly thick, else it was just sort of some ugly. Just a reminder: it is NOT listed for food surfaces when we tried it. Took lots of firing tests to get one family bragging rights trophy fairly pinhole free. Also as it aged it became more black chrome than bright chrome.

The good news those appear to be silicon carbide elements which tend to have decent life ……. But the somewhat bad news is they have very different resistance readings as they heat up. Hopefully I am wrong and it’s just the picture and they are standard coiled kiln elements. If silicon carbide: my best thought, It may be necessary to run this kiln up to temperature and measure the hot resistance by actually measuring the amperage the kiln is drawing at top temperature. And if it makes top temperature then you will already know it is still serviceable or what temperature it can make. Place cones in this firing for sure and a pyrometer would be very useful.
If you are or have someone technically familiar with kilns and electric, it may be easiest to safely temporarily wire this kiln and fully supervise the firing. At peak temperature the amperage would be measured and wattage can be compared with the nameplate as well as hot resistance of the elements will be able to be derived from the amperage measured.
Sorry - I am at a loss for an easier method here, unfortunately silicon carbide resistance can change significantly when heated as well as aging. Maybe someone here has an easier way, this is the only definitive way I am aware of. Hopefully I am wrong and they are really traditional elements which means measure the resistance cold.
The Nova 1 manual seems to match your kiln shape and indicates 1/2 of the element with the fiber is a part number, so my thought would be when worn the entire fiber and element group would be replaced and installed 1/2 section at a time.

Ah, NOVA kiln
Here's a manual for what might be similar kilns novaman1.pdf (aakilns.com.au) ...which have lid vents!
Hence, the lid vent may be orginal.
The same company has a manual for NOVA controller novaman2.pdf (aakilns.com.au)
From this archived thread My weird kiln won't reach temp - Studio Operations and Making Work - Ceramic Arts Daily Community :
*begin quote*
Duncan bought rights to the Nova kiln during the 1970s. All the Duncan kiln manuals can be downloaded from the Paragon website. (We list the Duncan manuals because we contracted with Duncan to sell their kiln parts after they discontinued kiln production in 1997.) Here is the link to the manual for the Duncan EA-092 The Crafter-Plus and the EA-122 The Artist-Plus ceramic fiber kilns. I believe these models were originally Nova kilns
http://www.paragonweb.com/ManualInfo.cfm?CID=171
Sincerely,
Arnold Howard
Paragon Industries, L.P.
*end quote*
I'm not finding a direct match.
The EA092 does look similar ...but it isn't 240v and is much smaller.
LX855_Duncan_EA-092_EA-122_Manual.pdf (nxedge.io)
Try contacting Paragon?
 

Thank you so much. This is exactly the information I was looking for in terms of firing this kiln. 
 
the 60 orifices were just what comes in the burners I used. I was planning on drilling these as need be once I actually had some run time on this kiln. I do have a Testo stack analyzer that I can see exactly what is happening with my combustion so I can tune this unit very precisely. Once my valve train is built I will be able to dial the burners any where between 4” WC up to 10 Psi. I am trying to make it as automated as possible with at least 3 different firing rates done through some different controllers I have. I will be installing a ProFire 2100 BMS with flame ionization detection as my safety shutoff and with this I get some different control options and communications so we can monitor remotely. 
 
The exhaust is currently 6x6” 3/8 thick square tubing. The kiln walls are approximately 6” thick soft finer fire brick and the exterior is lined with about 1/2” thick refractory blanket covered in a galvanized tin. 
 
So we will run oxidizing flame till around 1500f and then go to a reduction firing after that. That’s really good info. Do you know what PPM of CO you would expect to see at reduction. Probably would need to be under 250PPM to prevent sooting. 
 
What material are you guys using for dampers in a brick chimney and how are you installing them. Any pictures of that would be handy. For testing I was just going to slide a plate over the top of my exhaust.
I am not the potter (that’s my wife) so any pottery terms kind of blow right over my head. I am just taking care of the fire end of things so any help is greatly appreciated. My background is natural draft tube fired heaters up to 20mm btu/h and forced draft boilers up to around 50mm btu/h in oilfield and industrial applications. I have worked on hearth and fore hearth burners in fibreglass production but never anything to do with pottery kilns.   I do have a large assortment of tools at my disposal so I’m sure I can get this kiln dialled right in for her. 
 
once again thank you for all the help. It’s very much appreciated. 

Really good to have the combustion background, definitely half the battle. Now some stuff that may help with your background and hopefully allows you to work through the design and tuning. In the end It’s pretty simple basic combustion stuff
The split between primary air and secondary air is about 50% Knowing that will allow you to figure reasonable over cuts around the burners where secondary air will enter, if not  1– 2 inch clearance is fine. Too small is generally the mistake. An ideal ratio air / fuel will be approximately 10:1 (oxidation) Reduction will be a dirty flame, producing lots of carbon monoxide and ……… pressurizing the kiln so very little air is drawn into the kiln through the over cuts. Reduction is achieved by  closing the damper and and pressurizing the kiln from top to bottom. Very slight adjustments will establish this. Slightly  pressurizing the kiln  (very slight) will be enough to keep secondary air from coming in the over cuts which drives the kiln into reduction. (Very dirty flame - no soot needed, too rich and decreases reduction) Never go into early reduction below the PEL of the gas 1500 f or better. #60 is pretty small as most propane kilns are regulated down to inches, but at .#60 (for now) you likely will operate this in the 1-2 psi range, here is one of my favorite orifice tables https://www.gordonpiatt.com/wp-content/uploads/2021/07/Propane-Orifice-Chart-7.E.80.6-Rev-3-05.01.pdf easy to figure just what pressure you will need after you figure how much Btuh you need as well. Total guess, start at prox. 300,000 btuh, work your way down as practical.The kiln will be easier to fire and adjust in firing using low pressure. Inches of wc pressure Design your flue by table p41 here can help or 4” - 5” is likely reasonable and allow you to tune the height in the end. https://www.selkirkcorp.com/literature/Chimney_Venting_Sizing_Handbook.pdf Higher increases draw but also makes damper adjustments more sensitive. For an updraft kiln placing the thermocouple as near the kiln as practical in the flue likely give a decent reading of the average temps. Gas kilns are fired supervised by cone so watching when cones bend will be more important than peak temperature. Firing rates 500-600 f degrees per hour are generally considered fast for clay, but once in reduction your flame will have much less energy so 100 -200 f per hour will still be fast. Reduction has its nuances, but simplified, very dirty flame, slightly pressurized kiln not allowing any oxidation. Reduced pieces can and often are reoxidize by plain old air going past them if the kiln is not kept slightly pressurized while in reduction. Onlya handful of metals are affected by reduction. without an O2 meter, you fire by eye, reduction flame poking out spyholes Really nice example reduction flame below from an updraft. Firing with someone who is used to reduction firing is generally a patience saver.

Really good to have the combustion background, definitely half the battle. Now some stuff that may help with your background and hopefully allows you to work through the design and tuning. In the end It’s pretty simple basic combustion stuff
The split between primary air and secondary air is about 50% Knowing that will allow you to figure reasonable over cuts around the burners where secondary air will enter, if not  1– 2 inch clearance is fine. Too small is generally the mistake. An ideal ratio air / fuel will be approximately 10:1 (oxidation) Reduction will be a dirty flame, producing lots of carbon monoxide and ……… pressurizing the kiln so very little air is drawn into the kiln through the over cuts. Reduction is achieved by  closing the damper and and pressurizing the kiln from top to bottom. Very slight adjustments will establish this. Slightly  pressurizing the kiln  (very slight) will be enough to keep secondary air from coming in the over cuts which drives the kiln into reduction. (Very dirty flame - no soot needed, too rich and decreases reduction) Never go into early reduction below the PEL of the gas 1500 f or better. #60 is pretty small as most propane kilns are regulated down to inches, but at .#60 (for now) you likely will operate this in the 1-2 psi range, here is one of my favorite orifice tables https://www.gordonpiatt.com/wp-content/uploads/2021/07/Propane-Orifice-Chart-7.E.80.6-Rev-3-05.01.pdf easy to figure just what pressure you will need after you figure how much Btuh you need as well. Total guess, start at prox. 300,000 btuh, work your way down as practical.The kiln will be easier to fire and adjust in firing using low pressure. Inches of wc pressure Design your flue by table p41 here can help or 4” - 5” is likely reasonable and allow you to tune the height in the end. https://www.selkirkcorp.com/literature/Chimney_Venting_Sizing_Handbook.pdf Higher increases draw but also makes damper adjustments more sensitive. For an updraft kiln placing the thermocouple as near the kiln as practical in the flue likely give a decent reading of the average temps. Gas kilns are fired supervised by cone so watching when cones bend will be more important than peak temperature. Firing rates 500-600 f degrees per hour are generally considered fast for clay, but once in reduction your flame will have much less energy so 100 -200 f per hour will still be fast. Reduction has its nuances, but simplified, very dirty flame, slightly pressurized kiln not allowing any oxidation. Reduced pieces can and often are reoxidize by plain old air going past them if the kiln is not kept slightly pressurized while in reduction. Onlya handful of metals are affected by reduction. without an O2 meter, you fire by eye, reduction flame poking out spyholes Really nice example reduction flame below from an updraft. Firing with someone who is used to reduction firing is generally a patience saver.

Hmm, I don’t not know if I fully understand. Underglazes are not glaze and often consist primarily of clay and stain. Many do not really melt so unglazed they are very matte but more sintered than melted hence durability or longevity would be difficult to guarantee. For a gloss finish it’s common to apply clear gloss glaze over the underglaze. For matte appearance with reasonable durability it’s also common to use matte clear glaze over the top of the underglaze. Any clear matte will cloud to some extent because of the diffraction of light. Thin application definitely better than thick as far as glaze clarity. As far as a glaze that works for you and your clay and the desired finish you will likely need to test.
If you look on Glazy.org Marcia’s matte https://glazy.org/recipes/19734. Was created to be very dry ( but easily adjustable) and melt over fairly heavy underglazes. It has great reviews, but it may not work for your clay, desired aesthetic, etc…. Sadly clear glazes often tend to take testing to meet an artists needs. There are many matte glaze recipes though - which one works for you will require testing.

The answer is #3
#5. The kiln will stink more than usual as well
# 6 try it and learn .
School of hard knocks has the best lessons

One idea that comes to mind using underglaze, you can free form your initial design on greenware and bisque fire. The piece will contract a bit and your strokes will become more dense on their own. From there it is often enough, but if not then adding a second coat to cover often gets folks there. Stay between the lines to keep the original form true or judiciously accent and over paint the design to preserve brush strokes and depth. The second coat is a precision thing I know and not for everyone. The point though, when applied to greenware, just bisque firing it may get you the density you desire  ……. or at least close, or maybe something to experiment with. I think the pot in the picture could be recreated on greenware and likely not need touch up and a second bisque.

We added a 100 amp service in the garage.  I will put the kiln in the corner with easy access to an outside wall and close to a window.  In addition to a dedicated circuit for the kiln itself, there are normal outlets which I assume can power any venting system.  Am I thinking about that right?  
My current plan is to talk to Seattle Pottery Supply and pick their brains about the electrical requirements for a home kiln as well as do some online research.  I will have to decide if it makes sense to buy a new kiln or a used one.  That's the rub as far as figuring out the specifics of the amperage.  I think it would make sense to install a 6 gauge wire to the box,  I could then adjust at the breaker for the specific kiln.  
I would like to buy a used kiln which may also include a venting system ( as well as shelves and accessories).   It seems that a powered kiln vent is a good idea with an overhead vent as a good add on. 
So at this stage of construction I will ask the electricians to install  #6 wire instead of the #10.  Am I forgetting anything?

This is my first time on this forum and I am deeply appreciative of the thoughtful advice so far.  Thank you!
 

Kilns 7 cubic feet and smaller will need a 60 amp breaker at most, with an actual draw of 48 amps at most. 10 cubic foot kilns, if you want it rated to cone 10 (which you do if you're glaze firing to cone 5/6) will need an 80 amp breaker, with an actual draw of 63 amps. That's a really big kiln for most home studios, though. 100 amp service will be great, and leave you plenty of power for running lights, wheels, etc. Kiln vents run on a typical 120 volt household circuit. The only thing that may max out the system is heating, depending on how that's done. Depending on the layout, you may not need to run the heat while the kiln is on.

Outlets at counter level ...where your counters are (or will be) can be handy.
A second outlet where your wheel goes might be handy.
Integrated lighting - never, err, hardly ever need dusting - setting your baseline wash(es) of light in the space.
  I'm liking the round flat led units - cut the hole, wire it up, set the light temp, done. Lots of light at low (looong teerm) cost.

Just a few things to suggest to start with.
I would suggest laying out as best you can where the kiln will go. There likely is only one logical best place that you will place it. If you can do that, then roughing a circuit in for a future kiln and ensuring it Is 3/4” pipe (raceway) rough opening will allow you to pull the appropriate size wires when you get most any kiln.
Now, where the kiln will go - probably adjacent to an outside wall, most likely in a corner so there is decent access to ventilation outdoors. You should not combine systems, this one is for the kiln. 
You should decide  if you intend to remove the excess heat as well as all the fumes or a portion of the fumes as in counterflow systems you will likely need electric at or near the kiln for the ventilation accessories you have chosen as well. So maybe another rough electric opening in pipe to be pulled at a later date. Maybe another 3/4” rough opening so if you decide on full ventilation just about any wire size ought to fit.
depending on your ventilation choice above you will likely need to plan on makeup air from outdoors as well. So just some things to start to think of

I think hard to generalize and no way to guarantee anything is craze free forever. I do think there is reasonable correlation though. Differences in the expansion rate of clay and glaze being the prime issue, followed by the long term reliance of the glaze to tolerate the slight inevitable difference. The fired COE is often a result of fully firing so a clay body or glaze not fired or fully melted may have a different COE than one that is. Just imagine a clay body or glaze under fired by two or thee cones, we would normally expect it to behave very differently than fully fired stuff because it is under fired. If both are under fired the same amount will their under developed  COE somehow be even between them?  While I think in the ranges you are working in, likely a decent indication, just firing hotter does not necessarily mean the glaze will have greater flexibility and could actually become harder and more prone to tensile failure.
I think your logic is reasonable, but believe it’s always best to test the the clay and glaze combination fired to cone.

Crazing to me is a result of the differences in the rate of growth or shrinkage. Once fired clay and glaze  are the same size, so the clay has shrunk to what it will be and the rate of future expansion and contraction will be affected by its composition and its  physical (and thermal) properties such as density etc…. Firing the body to its rated cone will provide the best chance of a fully melted body with repeatable characteristics. So the COE will likely be different for a cone 6 body fired to cone 4 or even cone 5. Our glaze on the other hand if able, may tolerate the difference in speed of expansion / contraction  and not fail or craze as if pulled apart. As a glaze is fired higher will its COE change? Very likely yes. Will its physical characteristics change? Very likely yes. Glazes more resistant to wear as in surface hardness may fail more so in impact. 
I think the difference here for me, none of this is about the starting size and all about rates and whether the glaze can keep the clay body in a slight bit of compression without the glaze failing. So firing both to their rated cone likely gives the best repeatable representation of the match for both. Firing lower and assuming the next cone higher will improve the COE match between the clay and glaze is likely not really reliable in my view. So in the end, fire to rated cone, firing to lower cones is very likely not a good indicator for how these materials react when fired to rated cone.

I think hard to generalize and no way to guarantee anything is craze free forever. I do think there is reasonable correlation though. Differences in the expansion rate of clay and glaze being the prime issue, followed by the long term reliance of the glaze to tolerate the slight inevitable difference. The fired COE is often a result of fully firing so a clay body or glaze not fired or fully melted may have a different COE than one that is. Just imagine a clay body or glaze under fired by two or thee cones, we would normally expect it to behave very differently than fully fired stuff because it is under fired. If both are under fired the same amount will their under developed  COE somehow be even between them?  While I think in the ranges you are working in, likely a decent indication, just firing hotter does not necessarily mean the glaze will have greater flexibility and could actually become harder and more prone to tensile failure.
I think your logic is reasonable, but believe it’s always best to test the the clay and glaze combination fired to cone.

I think hard to generalize and no way to guarantee anything is craze free forever. I do think there is reasonable correlation though. Differences in the expansion rate of clay and glaze being the prime issue, followed by the long term reliance of the glaze to tolerate the slight inevitable difference. The fired COE is often a result of fully firing so a clay body or glaze not fired or fully melted may have a different COE than one that is. Just imagine a clay body or glaze under fired by two or thee cones, we would normally expect it to behave very differently than fully fired stuff because it is under fired. If both are under fired the same amount will their under developed  COE somehow be even between them?  While I think in the ranges you are working in, likely a decent indication, just firing hotter does not necessarily mean the glaze will have greater flexibility and could actually become harder and more prone to tensile failure.
I think your logic is reasonable, but believe it’s always best to test the the clay and glaze combination fired to cone.