High Bridge Pottery

I remember that thread! It was a pretty cool one. 
It’s interesting that Tony Hanson was pursuing a similar series of testing about the same time, seeking a really clear cone 6 fluid melt glaze. He kept going, doing a major update to his findings in 2019, and continues to add notes to the file. He took a slightly different tack than you, in that he was less focused on the silica beyond particle size as it contributed to melt, and wanted to embrace a multi flux approach for durability since his approach is based in making functional pottery. He did achieve a number of good results, and continued with the work to reduce COE values so it would fit a particular nuisance porcelain Plainsman makes. 
This is the link to phase 2 of his testing, which involved really eliminating bubbles and maintaining colour response. The links to phase 1 and 3 are at the top of the page.
I noticed in your original thread there were some mentions of using fining agents to get rid of seed in glass, and that you were using a red clay for some of your Currie blends. Iron is a fining agent in glaze, and if your aim is to create a clear glaze over a red clay, using an amber instead of a clear can be a solution. Reducing the high LOI ingredients and fine tuning your firing seems like the majority of the process, but if there’s remaining bubbles they might need that extra kick to evict them. 

High Bridge Pottery, they said because the gas kiln does not come with a controller, I have to watch the temperature rise very closely. Because I am firing pieces I have spent more than 10 days on, they wanted me to go safe. The 3 responses above are telling me I can bisque in a gas kiln, and I am willing to learn how to do it. Before deciding which kiln to get, I am going to get bids from contractors. Thank you very much.

Yes looks like I can source it there, thanks for the tip Callie. Not so sure about pool supplies in the UK Bill  I am sure there's commercial suppliers but not many people have their own.

@High Bridge Pottery, I don’t know about the UK, but HCl is used here to etch concrete for painting. I can get it at Canadian Tire, so maybe check DIY friendly stores?

I have been searching for a bubble free glaze on and off for many years. There's an old thread here -
 

A lot of the time I can't even understand what I am trying to say in my old posts (and I wrote them xD) but if you want some context it might be worth a read. I would like to thank everyone for being so patient with me over the years, slowly stumbling about in the dark trying to understand ceramics. I very much appreciate it  
For the "Too Long Didn't Read" the old thread tried -
Removing as many ingredients with loss on ignition as possible. Glazing an already vitrified clay body. Using holds and drop holds. Changing fluxes, silica and alumina amounts. In the end nothing really seemed to produce satisfactory results except reducing silica in the recipe. There seemed to be a link between silica joining the melt and bubbles being produced.
 
Recently I have found a few more papers on this subject and wanted to share my findings. The first was in Transactions of the American Ceramic Society Volume II, Blisters in Glaze - Stanley G. Burt. https://archive.org/details/transactionsofam02colu/page/138/mode/2up
Back then they seem to have a lot more issues with sulphates coming from the fuel but Burt seems to find the same thing with silica kicking out gasses dissolved into the glaze.

 
 
It seems to be confirming that the more silica you have in a glaze the less dissolved acids/gas it can hold which ends up coming out of solution. 
After a bit more searching I managed to find the Seger paper in question in The Collected Writing of Hermann Seger Volume II, The Defects of Glazes and Their Causes - IV The Operation of Sulphates in the Glaze. https://archive.org/details/gri_33125001394697/page/582/mode/2up

 
 
Again he comes to the conclusion that silica is the main offender for producing bubbles. In a previously bubble free glaze remelted onto an already fired body it will take up silica from the body and produce bubbles in the glaze.
Back in Burt's paper in the discussion at the end he talks about a few ideas to remedy the problem. One is to have a glaze higher in silica which is the opposite to what I have found. His reasoning seems to be that the glaze would have less action on the body so reducing any silica coming from the body into the melt.
His second idea is to fire the bisque in reduction to volatilise the acid removing it from the body before the glaze firing. 

 
 
Seger also seems to find reduction is one remedy to the problem but does it in the glaze firing. The Collected Writing of Hermann Seger Volume II, The Influence of Sulphuric Acid on Glazes and Bodies. https://archive.org/details/gri_33125001394697/page/644/mode/2up

 

Some interesting things to think about, especially trying to do a reduction bisque firing and seeing if that produces any different results in the glaze. I am not sure I agree with Burt that a glaze higher in silica will produce less bubbles but maybe that combined with a reduction firing could produce results. Now I just need come up with some tests and see what happens.

It does, not sure that is the shape of a diode though so want to double check. She has a remote controller and these power relays are a decent inductive load and take very little current to activate (I used to use them) so protecting the relay in her remote controller a really good thing. Just want to verify how they are doing it, hopefully it’s a diode to which it’s permanently crimped in the circuit so polarity likely not an issue as long as the wires go back. Just double checking, not something often found in kilns.
Edit
And yes, my interpretation is top and bottom on one relay, middle on another so really likely one whole relay out.

Did they say what was tricky about it? I have bisqued fired in a gas kiln before, the only tricky part was not going too fast at the start as the kiln had no pilot flame so it would like to climb fast on the lowest setting on the main burners.
 
Before electric kilns were common place everybody used to bisque with whatever fuel they used.

Does that work similar to having a diode across the coil contacts to stop it dumping electricity the wrong way when the magnetic field collapses or is it a different idea? 
 
As far as I can tell there's 6 elements in the kiln with one relay doing top and bottom and the other doing the two middle and two center.

Yep, you can trim them from the back with wire cutters. If it makes you feel better a thermocouple is made of one type of wire welded to another type at the tip. What makes it work is the connection of the dissimilar metals at the tip, so length is absolutely meaningless other than to fit the machine. For this reason I will often keep 12” around and just trim as needed.

They look about the same to me even though some are not very even. Lets hope they are all the same resistance and the floor just have a bigger hairpin. Do you have a multimeter to test the resistance of each element? You would need to turn the dial to select a low resistance setting. Depending on the type it could be 200 Ω or lower like 20 Ω but the lower the better as they will only be measuring around 1-2 ohms.
I have drawn a basic picture to give you an idea  You will have a black and red probe and put one on each leg/tail of the elemet to get the value. Make sure you turn off the kiln isolator switch first.

 
Still not sure what that black box is doing, I thought maybe it is the relay but then the controller has the relay inside so I guess it is another kind of safety switch? I don't think the bare copper is a problem but as Neil says you can just connect the element tails together with a connector if they are long enough.
 
Edit: maybe an actual picture could help 

@neilestrick @High Bridge Pottery At the risk of being the cause of a few exasperated sighs and head shakes: most of this is going completely over my head. I am completely out of my depth...but also stubborn and ready to learn.
I was worried you were going to say that. Yes, it is just bare copper (which even I thought was a bit odd) and, once I'd taken the cage off the back and cleaned it all up a bit, everything about it looks pretty old and tatty. 
I've tried to take some photos in sequence so the wiring might make a bit more sense:
        
 
and then some close ups of the two...er...connect-y thingies:
    

This is brilliant. THANK YOU! 
Could cracks in the fire bricks cause the firing to slow down significantly? They don't seem to be going all the way through but there is a pretty big one running across the top and I've just found one down the back when I took the cover off to take photos 
Photos of the back:        
 
...and cracks:       
 
I have some high temp cement to fix these. Would it be worth trying before getting new elements or will it not make that much difference? 

I think it seems to be a glass former, intermediate oxide and flux all depending on chemistry. I would maybe argue that in pottery we are using it more like a flux than a glass former due to its reactions with silica but it seems to be pretty versatile in its use. One comment that got me from the NCECA talk "Glazes without borders" from Peter Berg was that low fire glazes higher in boron were more durable and resistant to attack than high fire glazes with little or none so it seems to be fluxing while also acting like alumina by increasing durability and resistance. 
There's an interesting comment on the B2O3 page on digital fire that it can even be refractory. "B2O3 can actually be a refractory, frits with very high contents are used in the refractory industry. These frits do not contain SiO2 (depriving boron of a reaction with it to form a borosilicate glass)."

I am surprised pottery crafts said they wouldn't do it, probably just being lazy as they don't have the specification on file.
The few places I know who would probably wind them for you are
https://www.kilncare.co.uk/elements
https://www.kilns.co.uk/kilns/kiln-elements
https://www.cromartiehobbycraft.co.uk/Catalogue/Ceramic-Kilns-Electric-Kilns-Pottery-Kilns/Kiln-Spares-Kiln-Elements/Kiln-Elements-Element-Wire-Connectors

As far as I can tell it is an extended Si:Al ratio showing the relationship of acid (silica) to base (RO and Al2O3). There is a lot of discussion on if you should have B2O3 as an acid or a base and some interesting experiments showing that you can trade Al2O3 for B2O3 as they are both sesquioxides (an oxide in which oxygen is present in the ratio of three atoms to two of another element)
Some argue that if B2O3 was an acid you should be able to reduce silica when adding boron but most times you need to increase silica when adding boron so how can it be seen as the same as SiO2. 
 
If anybody wants to get copies of the Transactions of the American Ceramic Society volumes you can find them here - https://archive.org/search?query=subject:"American Ceramic Society" All in the public domain so I assume I am fine sharing here as it's not for commercial use. 
 

I am surprised pottery crafts said they wouldn't do it, probably just being lazy as they don't have the specification on file.
The few places I know who would probably wind them for you are
https://www.kilncare.co.uk/elements
https://www.kilns.co.uk/kilns/kiln-elements
https://www.cromartiehobbycraft.co.uk/Catalogue/Ceramic-Kilns-Electric-Kilns-Pottery-Kilns/Kiln-Spares-Kiln-Elements/Kiln-Elements-Element-Wire-Connectors

I am surprised pottery crafts said they wouldn't do it, probably just being lazy as they don't have the specification on file.
The few places I know who would probably wind them for you are
https://www.kilncare.co.uk/elements
https://www.kilns.co.uk/kilns/kiln-elements
https://www.cromartiehobbycraft.co.uk/Catalogue/Ceramic-Kilns-Electric-Kilns-Pottery-Kilns/Kiln-Spares-Kiln-Elements/Kiln-Elements-Element-Wire-Connectors

A few thoughts on your crystals
- As you cannot dissolve them in hot water this might indicate that they aren't boron-based.
- If you have dilute hydrochloric acid it will dissolve most calcium salts, including the silicate
... see A in http://www.pharmacopeia.cn/v29240/usp29nf24s0_m12120.html
If you find a way of reproducibly creating the crystals it might be interesting to try:
- Using a different deflocculant (Darvan?), which will probably change the pH of the slip which might change things.
- Seeing if a small addition of sugar to the fresh slip influences the growth of the crystals [*]
[*] Adding sugar would probably be very bad for the moulds, but just might form an interesting experiment. I mention it because sugar has a significant effect on the settling time of cement, apparently by its surface action on things like Wollastonite.
 


 

A bit more searching and I have found how they are calculating the oxygen ratio. Orton seems to say it is only useful in comparing similar glazes and they all seem unsure if you need to include B203.
 
I have no idea  what to do with it yet.

Thanks for finding those equations Joel. I'm wondering if its just adding another variable and / or a different equation that is muddling the difference between  the SiO2:Al2O3 ratio insofar as looking at those levels (in addition to having the flux ratio of 0.3 R2O:0.7 RO) to determine with math whether a glaze will be an alumina matte, gloss or somewhere in between without looking at slow cooling glazes and or different flux ratios that employ more than the one mechanism to get a matte.  
 

A wiring diagram sure would be nice! Can the manufacturer get one to you?

@High Bridge Pottery Thank you so much for this. So helpful...and makes it all slightly less overwhelming.
My kiln does have four elements up each side and two at the bottom, with the bottom two having a bigger hairpin (...is that right?!) than the side ones. 
I did get in touch with pottery crafts and they told me I would have to find an element winder to make them for me specially. Am I right in thinking I can send the coils to someone for them to make something similar? Would I just need to know the correct voltage, if so? Thanks again!
 

Nice research Joel.

The only reason I brought it up was because I feel if the door interlock was faulty then the controller would also be having issues and as that is not happening I feel you can rule that out even with it being old.

Just to mention the discussion of unwanted crystal growth in http://ceramicstoday.glazy.org/articles/flambe_magic.html
... it also makes me wonder if there could be a "pumping" action if the liquid is repeatedly warmed and cooled.