PeterH

I've no practical knowledge, so treat this all a here-say
I'm interested in how you get on, but ...
- I don't think either bones -- or seashells -- will survive high firing sufficiently intact to act as a stilt.
- I doubt that bones will help form a "glaze" in the same way that seashells do.
Firstly I think shells are used as a separator between the pot and clay wadding placed inside the shell. Shells seem a much better shape for this than most bones.
Effective Side Firing
https://ceramicartsnetwork.org/pottery-making-illustrated/pottery-making-illustrated-article/Effective-Side-Firing#
While wadding is traditionally only used in atmospheric kilns to prevent pots from sticking to the shelves, it is necessary for side firing in electric kilns.  Sea shells turn to powder (calcium oxide) during the firing, and will not support the weight of a pot.  Using wads under the shells prevents the pot from falling onto the drip tray and sticking to it.
Secondly the chemistry is different, perhaps critically so.
Shells in Ceramics
https://www.weloveclay.com/read/53007/53007/
Why then were shells not adopted more widely? Australian wood fire potter Owen Rye has pointed out that though ancient potters were keen observers of their craft, none could have understood or intuited the science of shell use. The shells themselves are formed from calcium carbonate which, when heated, converts to calcium oxide or ‘quick lime’, a powerful flux. In isolation, calcium is one of the most refractory oxides, only melting at 2572˚C+. But combine that calcium with alumina and silica and you have what is known as a ‘eutectic’ – a combination of oxides that melt at a lower temperature than they would on their own (in this case, a much more manageable 1170˚C).
Why then were shells not adopted more widely? Australian wood fire potter Owen Rye has pointed out that though ancient potters were keen observers of their craft, none could have understood or intuited the science of shell use. The shells themselves are formed from calcium carbonate which, when heated, converts to calcium oxide or ‘quick lime’, a powerful flux. In isolation, calcium is one of the most refractory oxides, only melting at 2572˚C+. But combine that calcium with alumina and silica and you have what is known as a ‘eutectic’ – a combination of oxides that melt at a lower temperature than they would on their own (in this case, a much more manageable 1170˚C).
All this means that on the interface between shell and pot there is a melt that leaves a shell-like scar on the surface of the clay. As the shells are stuffed with clay to prevent them from collapsing, the same happens on the inside. The core of the shell remains pure calcium, which is dry, friable, expands when wet and can be easily removed after the firing. An aesthetic bonus of using seashells is that they contain small quantities of salt. During the firing, this salt can volatilise, leaving a subtle halo of salmon pink or orange on lighter coloured clay bodies.
 
Shells decompose into calcium oxide, bone eventually decomposes to a mixture of calcium oxide and phosphorous pentoxide, which may well prevent a suitable eutectic forming. Also bone ash tends to retain some of its structure, probably making both oxides less available for forming a "glaze".
https://en.wikipedia.org/wiki/Bone_ash
Bone ash is a white material produced by the calcination of bones. Typical bone ash consists of about 55.82% calcium oxide, 42.39% phosphorus pentoxide, and 1.79% water.[clarification needed] The exact composition of these compounds varies depending upon the type of bones being used, but generally the formula for bone ash is Ca5(OH)(PO4)3. Bone ash usually has a density around 3.10 g/mL and a melting point of 1670 °C (3038 °F). Most bones retain their cellular structure through calcination.
 
 

I've no practical knowledge, so treat this all a here-say
I'm interested in how you get on, but ...
- I don't think either bones -- or seashells -- will survive high firing sufficiently intact to act as a stilt.
- I doubt that bones will help form a "glaze" in the same way that seashells do.
Firstly I think shells are used as a separator between the pot and clay wadding placed inside the shell. Shells seem a much better shape for this than most bones.
Effective Side Firing
https://ceramicartsnetwork.org/pottery-making-illustrated/pottery-making-illustrated-article/Effective-Side-Firing#
While wadding is traditionally only used in atmospheric kilns to prevent pots from sticking to the shelves, it is necessary for side firing in electric kilns.  Sea shells turn to powder (calcium oxide) during the firing, and will not support the weight of a pot.  Using wads under the shells prevents the pot from falling onto the drip tray and sticking to it.
Secondly the chemistry is different, perhaps critically so.
Shells in Ceramics
https://www.weloveclay.com/read/53007/53007/
Why then were shells not adopted more widely? Australian wood fire potter Owen Rye has pointed out that though ancient potters were keen observers of their craft, none could have understood or intuited the science of shell use. The shells themselves are formed from calcium carbonate which, when heated, converts to calcium oxide or ‘quick lime’, a powerful flux. In isolation, calcium is one of the most refractory oxides, only melting at 2572˚C+. But combine that calcium with alumina and silica and you have what is known as a ‘eutectic’ – a combination of oxides that melt at a lower temperature than they would on their own (in this case, a much more manageable 1170˚C).
Why then were shells not adopted more widely? Australian wood fire potter Owen Rye has pointed out that though ancient potters were keen observers of their craft, none could have understood or intuited the science of shell use. The shells themselves are formed from calcium carbonate which, when heated, converts to calcium oxide or ‘quick lime’, a powerful flux. In isolation, calcium is one of the most refractory oxides, only melting at 2572˚C+. But combine that calcium with alumina and silica and you have what is known as a ‘eutectic’ – a combination of oxides that melt at a lower temperature than they would on their own (in this case, a much more manageable 1170˚C).
All this means that on the interface between shell and pot there is a melt that leaves a shell-like scar on the surface of the clay. As the shells are stuffed with clay to prevent them from collapsing, the same happens on the inside. The core of the shell remains pure calcium, which is dry, friable, expands when wet and can be easily removed after the firing. An aesthetic bonus of using seashells is that they contain small quantities of salt. During the firing, this salt can volatilise, leaving a subtle halo of salmon pink or orange on lighter coloured clay bodies.
 
Shells decompose into calcium oxide, bone eventually decomposes to a mixture of calcium oxide and phosphorous pentoxide, which may well prevent a suitable eutectic forming. Also bone ash tends to retain some of its structure, probably making both oxides less available for forming a "glaze".
https://en.wikipedia.org/wiki/Bone_ash
Bone ash is a white material produced by the calcination of bones. Typical bone ash consists of about 55.82% calcium oxide, 42.39% phosphorus pentoxide, and 1.79% water.[clarification needed] The exact composition of these compounds varies depending upon the type of bones being used, but generally the formula for bone ash is Ca5(OH)(PO4)3. Bone ash usually has a density around 3.10 g/mL and a melting point of 1670 °C (3038 °F). Most bones retain their cellular structure through calcination.
 
 

Interesting video. Thanks for posting, Peter.
I disagree with a few of his methods. For some reason he sprays a release substance into the silicone mold before pouring plaster. If I'm not mistaken there's no need to do that. My urethane rubber molds have lasted 10 years and they release easily without any release substance.
My other disagreement is with the wooden frame concept.  (For the rubber molds.) Rubber comes in a variety of hardnesses.  Polytek recommended using a urethane rubber with a hardness of 55 and it works very well. (7455) It keeps its shape and it flexes when it's time to remove the plaster mold. I've used the 10 yr old molds to make 60 molds to date.  I'm not patient enough to gently remove a wooden frame 60 times and have it retain its original shape and precision. (If this gent does than he's miles ahead of me in that regard.)
I do appreciate that he has had the fortitude to make videos to show the process to those getting started. 
 

I was reminded of a different approach to the same 3D printing idea. It used sacrificial 3D prints, and produced moulds with minimal  excess plaster.

3D Printing a Mold for a Slipcasting Mold
https://www.instructables.com/3D-Printing-a-Mold-for-a-Mold/

Obviously horses for courses, but maybe something for your notebook.

To get started I would enroll in a studio ceramic's  class,  this will give you the basic knowledge and you can decide if this is a area you want to pursue.   I decided to take a stone carving class,  after a solid day of chipping I decided I had enough of stone carving.    I  managed to finish my piece,  it made a nice door stop.     Denice

Over the years I have, on occasion, attempted to clean a bristle brush, that is covered in porcelain slip, by brushing it against a plaster mold. The resulting thin layer of slip dries quickly and shrinks from the plaster surface quickly as well. I would suggest this method for producing a thin porcelain slab. 
Give it a try. You'll find it an interesting method to play around with.  You have to brush on additional layers soon after the previous one has stiffened but with patience you can create thin porcelain sheets. 
How you prevent them from warping, as they dry/stiffen, is completely up to you but at least I've given you a starting point. (Are you looking to make flat sheets or is a slight warp acceptable?)
Good luck

Hot spots at the elements connections don't cause the relays to fail, they just cause that connection to fail. There's no safe way to get access to a Skutt relay while it's under load, due to the way the box is constructed. You just track the number of firings you have on a set of relays, and if they're burning out under 150 firings then you replace the wiring harness and it's good to go.

They work well. I have just a bit of over 40 years experience with lots of machinery, big small, inductive, resistive likely miles and miles of high, medium and low voltage wiring. I never teach or allow replacement of unit assemblies  without testing to confirm why it is failing.

Just trying to understand in this situation how to diagnose and I think the answer is there is none, the wiring wears out - just install new if your relays aren’t lasting.  
The IR stuff is supposed to help be somewhat predictive and fairly non invasive in lieu of measurements with a meter. Regular measurement techniques work on other stuff for these (kilns) - I don’t know there is a clear answer. Lots and lots of very old wiring, kilns and machinery, that are still working as designed. 
My guess, it is a real thing with some Skutt equipment and maybe just adds enough heat to the cabinet to cause issues. In other words the wire is known to wear out.
If they simply wear out, the IR solution likely would be the same as for motors. Measurement of temperature above ambient or the trend of measurements above ambient over time could provide reasonable confidence in prediction.
Interesting to note in the picture above, the loose connection is adding heat to the wiring, noticeable on both sides of the relay. The fix here is new connector or tighten the connection -all the heat goes away. This is a very common failure. Her picture shows melting within the relay but very good looking connections, not even discolored, pointing to a relay contact issue or overloaded contacts for reasons unknown.

I'm certain you will enjoy experimenting with paperclay.
Just measured my printer paper, it's 0.06mm thick (a stack of 500 sheets measures 3cm). I cannot see you getting anywhere near that.
OTOH playing with home-made paperclay years ago I achieved 2-3m very easily with a rolling pin. I just rolled it out on under a cloth on a slightly porous surface and draped it onto a balloon. Handling thin sheets, especially when drying, may be an issue.
Pouring slip seems to be trying to cast it. I cannot see you getting thin sheets this way -- or getting them off the casting surface either.
Weakly related article.
THE MAKING OF PAPERCLAY PORCELAIN BANNERS
https://www.grahamhay.com.au/harrison1998.html
I mention it because he achieves 1.0-1.5mm with rolling. Which I suspect you could do with most paperclays.
Using a light weight cellulose/cement batt as a backing, spread a jumbo garbage bag over the batt, held in place with paper clips. Spead a layer of paper clay mix fairly evenly over the plastic sheet with a spatula. Place another sheet of plastic garbage bag over the top and roll out the clay in all directions with as much pressure as you can muster until it oozes out off the batt on all sides. Alternatively, the batt can be placed on the slab roller and reduced in that way. Keep rolling until it is as thin as you can get it. 

    PS Not relevant to you, but an interesting idea I haven't seen before, using ceramic fibre to strengthen the clay during firing (after the paper has burnt out). He apparently needed to do this because he was using very highly/deeply textured sheets.
Firing is to Orton Cone 8 in 4 to 8 hours, depending on the decoration. If the marks are many and vigorous, a longer firing is required to stop the tile splitting up along the incisions. This is why the ceramic fibre is added, as it doesn't bum out like the paper but persists. The paper does a sterling job at room temperature of binding the surface together but the tell tale waft of smoke at 250,C spells its end, and that is when the normal paperclay tile will crack if the fibre isn't added, as the fibre remains intact until elevated temperatures resisting any tendency in the tile to crack apart along the stress lines created in the decoration. Eventually the ceramic fibres dissolve into the ceramic body glass, which is created by the high proportion of nepheline syenite in the recipe.
 

Interesting to be reminded of prior work, but from pp74-75 of the 2nd edition of Contemporary Studio Porcelain by Peter Lane (2003).
The methods used to make the components for constructing his sculptural installations were developed during a ten-year period of intensive experimentation and intensive research.
...
The procedure of actually casting thin slabs of porcelain is the the most difficult part of the whole process of manufacture because small mistakes can create big problems. The most common faults resulting from incorrect casting are: cracking, warping, and distortion with corners curling to destroy the flatness.
The details of the process cover about a page of A4.
Rolling paperclay seems likely to be a lot easier and more fault-tolerant.
PS If you are interested in the book, it's available from A$40 via
https://www.bookfinder.com/search/?full=on&ac=sl&st=sl&ref=bf_s2_a1_t1_1&qi=iA,O6ra27IBsie2OptRYjTAhne4_1702997710_1:9810:16802
... check against other sources such as Amazon

For me I would initially be interested in the following:
a context picture of your control board showing the connections to it , maybe from about two to three feet away so we can see the connections and the wires leading away a context picture of the element connections showing them and the wire that leads to the relays post the element resistance if you can measure them, if not can someone measure them for you so you can post here? So top elements measured resistance =______ ohms, middle section measured resistance = ____ ohms, bottom section measured resistance = ______ ohms. post a picture of the thermocouple itself and the wires leading to where it connects and tell us why you believe it is a type S If you hit the little  + quote  below this message and post the items named above it will be a  direct response to this message

Maybe this one?
 

Maybe this one?
 

The controller cycles the SSR's twice per second (500ms). When I put a meter on mine it gives a fluttery reading.
@Lilith Rockett This is a long shot, but 3 times in the last 20 years I had kilns similar in size to yours have a very strange stalling problem. It turned out to be an electrical interference issue (there are a lot of magnetic fields and whatnot created by the elements and bricks), and the solution was to make sure the controller was directly grounded, not just through the transformer. It's an easy fix and worth trying if yours isn't already grounded that way. Take a look at the backside of your controller, there needs to be a wire that goes directly from the Center Tap terminal to the grounding stud. Not to the transformer or anywhere else first. You may need to get a terminal doubler so you can add another wire.

If the only fault is the elements -- and they are run at the correct voltage -- surely they must be drawing the wrong currents. That's all an element does, turn electricity into heat.
So using current-sensing to measure the per-section currents when at full blast gives an end-to-end test of the elements. (Providing that the current sensing is wired correctly.)
If the elements -- when fully powered -- are meeting the design specification for power output, then it looks like their duty-cycles aren't correct for at least part of the firing.  

PS Question for the experts.  Do the solid-state relays switch at a sufficiently high frequency for the current sensing to accurately measure the time-averaged current?

Yes I believe they will be just fine. They are zero crossing so the fastest they can be commanded off or on will need to wait for zero crossing. I think the default for typical heating  controllers would be approximately 200 milliseconds  ( so 2 seconds, something on that order). The default typical fastest for kiln relays (if my memory serves) approximately 10 seconds.  Measuring the amperage of a resistance load by ct ought to be fine especially at maximum output.  I think your idea is fine and reveals the heated resistance as well,  I am a sequential troubleshooter so any data with integrity  is helpful to me. Not everyone troubleshoots in the same way though.
aTo your other point about duty cycles, yes …….. and the controller generally is set to compensate or even things out using the top or bottom element to help the middle. That the kiln actually stalls is very interesting to me. It has potentially symptoms of several faults, yet everything has tested good. My take, I need to know some real values, thermocouple type, wiring sequence ….. something is wrong but without real confirmation I cannot speculate.

Without pictures, real measurements, response to all that’s been asked above, I think this will be difficult to solve.

Well it is the UK spelling.

Well it is the UK spelling.

Good advice, but I think it should be site:community.ceramicartsdaily.org
For example google PeterH community.ceramicartsdaily.org gave me 76,400 hits, while google PeterH site:community.ceramicartsdaily.org gave me 186 hits
PS Note that these figures vary between users and invocations. A second call produced 957 & 76,400.

Good advice, but I think it should be site:community.ceramicartsdaily.org
For example google PeterH community.ceramicartsdaily.org gave me 76,400 hits, while google PeterH site:community.ceramicartsdaily.org gave me 186 hits
PS Note that these figures vary between users and invocations. A second call produced 957 & 76,400.

Welcome to the Forum botrytis!
I'm not recalling finding detailed documentation on Alpine wheels.
This potters.org thread might be helpful
clayart - thread 'alpine electric wheels' (potters.org)
Alpine may still be responsive?
Alpine Kilns | Contact Us
Pottery Wheel Foot Pedal Stuck To On - Equipment Use and Repair - Ceramic Arts Daily Community
Refers to threads above, AND there are scans of original docs! !!!
A.D. Alpine, Inc Pottery Wheel Repair - Equipment Use and Repair - Ceramic Arts Daily Community
Confirms model designation (DCW-2)
Amaco 1-101 Motor Hums but Wheel does not turn - Equipment Use and Repair - Ceramic Arts Daily Community
Added: Forum internal search feature only returns "open" (UNarchived) threads; to search all, try using an external search engine, and include somewhat like "community.ceramicartsdaily.org" in your search string...

I was doing a bit of reading and stumbled across a new Stull chart. He seems to be doing the same experiment but at cone9 instead of cone11. It is interesting that the OG Stull chart is cone11 but everybody uses it at any cone.
This time he is glazing tiles and making the glaze into cones to see the deformation temperature. The solid line AB is his same “best gloss line”. The dashed line CD passes through the lowest deformation temperature in relation to Silica and the dotted line EF the same for Alumina.
 

 
He then goes on to plot it on top of the original Stull chart but misses out his new gloss line so I have done my best to add it back in blue.
 

 
It’s interesting how different the best gloss lines are. I tried adding on Silica:Alumina ratios but I haven’t had any good ideas yet. The wiggly silica line and shape of the deformation eutectic look like they tell me something but I haven’t figured anything out.
 

 
If you want to read the paper - Deformation temperatures of some porcelain glazes – R.T Stull and W. L Howat. Transactions of the American Ceramic Society Volume 16. Page 454. Copyright 1914 by Edward Orton Jr Edward Orton Jr - https://archive.org/details/transactio16amer/page/454/mode/1up

Just a possibility: is the zener diode called a surge protector in Shimpo-speak (as they can be use to provide over-voltage protection)?
https://kruegerpottery.com/collections/vl-lite-parts/products/rzzaa005394-vl_lite

Sounds like maybe the elements aren't in the proper locations in the kiln. Like Peter said, there are 3 different elements in that kiln, and if they're in the wrong positions the kiln won't fire evenly. Check the element resistance of each section of the kiln. I don't know if your kiln is 240V or 208V so here's both:
1231PK 208V  Top 6.7  Mid 8.5  Bottom 6.7
1231PK 240V  Top 8.9  Mid 11.3  Bottom 8.9
If the resistance measurements in your kiln are not correct, then you've either got the wrong elements or the right elements but in the wrong place. Depending on the condition of the elements, you may be able to pull them out and put them in the correct locations. That would definitely be preferable to buying a new set, given the price of APMs. If you find they are in the wrong locations, you should be able to determine which go where based on the resistance readings of the individual elements.