High Bridge Pottery

Is there no way to get any money for your kiln? Even if you managed to get 50% that seems like enough for a small pug mill.
 
Such a shame that they are putting up barriers for you instead of trying to help. In the end we are all trying to get to the fired ceramics and whatever way that is done doesn't really matter.
I found wedging to be a bit of a showoff game with some people "oh look how much I can wedge at once to get rid of bubbles" I can understand that he likes the consistency one way but why force that onto everybody? The only other idea I have is adding some grog into the clay, that should give it more working strength.
 

Is there no way to get any money for your kiln? Even if you managed to get 50% that seems like enough for a small pug mill.
 
Such a shame that they are putting up barriers for you instead of trying to help. In the end we are all trying to get to the fired ceramics and whatever way that is done doesn't really matter.
I found wedging to be a bit of a showoff game with some people "oh look how much I can wedge at once to get rid of bubbles" I can understand that he likes the consistency one way but why force that onto everybody? The only other idea I have is adding some grog into the clay, that should give it more working strength.
 

I thought you had already moved but from reading a bit more it seems you are still waiting to move? Hopefully your new location will have a better studio.
 
I wonder if there's problems with the pug mill which is why they mix it up wet. Seems like others are finding it too wet if they are making arches and trying to dry it out. I wish there was a better answer than leaving it out to dry and wedging it. I did wonder if you could dry it enough and get them to send it back through the pug mill. Do they make the clay from scratch or does it arrive this wet from the suppliers or it it when they recycle the clay?

I thought you had already moved but from reading a bit more it seems you are still waiting to move? Hopefully your new location will have a better studio.
 
I wonder if there's problems with the pug mill which is why they mix it up wet. Seems like others are finding it too wet if they are making arches and trying to dry it out. I wish there was a better answer than leaving it out to dry and wedging it. I did wonder if you could dry it enough and get them to send it back through the pug mill. Do they make the clay from scratch or does it arrive this wet from the suppliers or it it when they recycle the clay?

Sounds like low power ultrasonic applied at the right time might be a mobilization and coalescing vehicle. Just need to make sure the kiln doesn’t turn into vintage vibrating football / soccer game.  I am thinking the mass of the ware is much greater than the molten glaze 

Don't joke befre you try it. Some folk spray starch to get the glaze to adhere properly :-000

The issue would be it needs to be wet and put under the glaze when the glaze is molten to produce steam. Sorry it was a bad joke, I am not very good at jokes 

The issue would be it needs to be wet and put under the glaze when the glaze is molten to produce steam. Sorry it was a bad joke, I am not very good at jokes 

The issue would be it needs to be wet and put under the glaze when the glaze is molten to produce steam. Sorry it was a bad joke, I am not very good at jokes 

So, with safety override in place, kiln errored at about 200oC. With it unplugged, kiln has now fired twice without error so Im think that's where the problem lay. It is superficial as the safety override now comes from the controller so I think the mystery is solved. Thank you to everyone for your engagement and help.

@Gonepotty - You can get it at any big box store:
Home Depot HardieBacker 1/4" = 1/4" for real
Home Depot HardieBacker 1/2" = 0.42"
You score and snap it with this tool unless you are crazy like me, have a big drill, and use the hardiebacker all the time, then you use THESE shears which you run off your big powerful drill that you already have.  The version with its own motor is over $200.
I've been using 1/2" for everything because that's what I have but I'll be switching to 1/4" for everything but the worktable-wedging table and/or reclaim.  I don't have a ware board longer than 2' because I simply can't carry a ware board longer than that full of ware.  Not sure I SHOULD be carrying one that long, time will tell.  And I'll use it for my shelf liner.  1/4" is plenty for that.
This stuff never warps, I've never seen it mold, it dries fast, it helps what's on it dry properly.  I have lots of individual piece sized "ware boards" and if I want something to dry slower, I just dip the Hardiebacker in a bucket of water, put a piece of newspaper on it, and set the piece on that and cover it.  It provides moisture at an even pace while its wrapped - not too fast, not too slow.  Adjust for local humidity by how you wrap your piece.  I've used it in humid NC and here in dry Tejas.  Love the stuff.  
Especially for a worktop.  NO CANVAS!  If I have some sloppy stuff I want to work up I can slam it onto the hardiebacker and the slop doesn't get all stuck onto the canvas. The hardiebacker will pull excess moisture out and I can work it up lickety-split.  If the board is a little dry a quick spritz with a spray bottle will give me a good worksurface.  Its just way more flexible than canvas or plaster, and longer lived.

I'm not a chemist but it seems the salts move through the mold and accumulate on the surface. Washing the plaster might help but sanding the surface, and actually removing the salty buildup, would be more beneficial. (People who slip cast a lot have told me this.)
Drywall sanding screen is a wonderful way to take plaster down easily and quickly. (Though it is kind of messy.)

Potato water after boiling potatoes? Dry Potato flakes?

I don't think they are talking about organics in the bisque, most are burnt off pretty easily just the sulphur stays around. I feel it's pretty relevant to getting rid of glaze bubbles  the question is do I really have to get rid of bubbles you can only see through a microscope when the glaze layer is thin? Probably not but I want to see if I can.
I gave up trying to make money from my own pottery long ago and instead have fun testing and experimenting. I am not even sure how relevant my fritware tests were to any of my work but I enjoyed doing it. 

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.

I was thinking her optimum silica and alumina observation are consistent with your findings actually.  For clear glazes, thinner just a common sense pottery practice really.  Any thoughts of enhanced removal mechanically by ultrasonic excitation.

The difficulty we noticed and actually humans have to navigate, are the very small pressures to monitor and interpret.  Linear movement of a damper changes area / draft exponentially. Minor gas pressure changes that vary the output again exponentially by nature and valves are not proportional while the kiln dynamic losses increase. Reduction was a bit difficult as well. In the end we settled  to build and program a monitor that could help folks fire manually. Seeing the effect of minor changes and managing a firing rate definitely helped folks learn the techniques.
Interesting project, remote monitoring and reminder timers ended up to be an important tool that got a lot of use, plus folks learned real firing rates, minimal adjustment and consistent reduction strategies. A monitor ended up a far better teaching tool than pure automation.

Interesting fact: once a plaster form has thoroughly dried, after the initial pouring, re wetting it, and allowing it to dry a second time, will completely open the pores contained within. This is probably inconvenient, regarding a wedging table surface, but it would enable you to take the utmost advantage of the plasters aborbing capabilities.
The degree to which the plaster slab no longer can absorb water is dependent upon the clay you use. If your clay contains soluble salts, sodium silicate or barium carbonate, for instance, it may slow down with age, but most likely your clay doesn't so you can expect many years of use.  
As for drying a plaster form: heat is good but air movement is better. Too much heat, above 120 for instance, can start the breakdown process, too much air movement, has no bad impact at all. Put a fan on your plaster slabs and they should dry much sooner than simply letting the still air dry them. 

This may be of interest to you. Not scientific nor entirely about bubbles but an interesting way to dial in best clarity. Just some studio tested methodology which focuses in on the perfect silica and alumina levels for best clarity. Anyway, other interesting aspects as Sue seeks some practical ways to obtain the clearest. https://suemcleodceramics.com/getting-clarity-with-clear-glazes/

I don't think they are talking about organics in the bisque, most are burnt off pretty easily just the sulphur stays around. I feel it's pretty relevant to getting rid of glaze bubbles  the question is do I really have to get rid of bubbles you can only see through a microscope when the glaze layer is thin? Probably not but I want to see if I can.
I gave up trying to make money from my own pottery long ago and instead have fun testing and experimenting. I am not even sure how relevant my fritware tests were to any of my work but I enjoyed doing it. 

It a tricky one to decide, will the initial cost to get an electric kiln up and running save you money in the long term with lost ware and time you could be doing something else. 
 
I have semi automated a gas kiln adding a controllable valve onto the pipe but that is not the easiest thing to do. It just meant instead of turning it up every 20 minutes the computer did that for you. There was no brains really, the first firing I did have to turn it up via the computer and record what was set and run a simple program to repeat that for me the next firings.

It might be worth trying excess hot vinegar first.
Mechanism and kinetics of wollastonite fibre dissolution in the aqueous solution of acetic acid
https://www.sciencedirect.com/science/article/abs/pii/S0032591010005267?via%3Dihub
The dissolution of fibrous wollastonite (CaSiO3) in the aqueous solution of acetic acid (3 mol dm− 3) was investigated in the temperature interval from 25 to 50 °C using mixed batch-type reactor.

I'm a bit uncertain, but I think that 3 mol dm− 3  is about 18% vinegar. The pickling vinegar I use for descaling my kettle is 6%, so it would be weaker than that used in the paper, but might still be strong enough to dissolve your crystals (if they are derived from Wollastonite).  Perhaps worth trying before you buy the HCl.
PS You might be wise to check my workings.
Molar mass of acetic acid ~60g  https://en.wikipedia.org/wiki/Acetic_acid
1dm = 10cm. 1 dm 3   = 1000ml = 1 litre
So 3 mol dm− 3  = 3*60g/l = 180g/1000g = 0.18 = 18%
 

I don't think they are talking about organics in the bisque, most are burnt off pretty easily just the sulphur stays around. I feel it's pretty relevant to getting rid of glaze bubbles  the question is do I really have to get rid of bubbles you can only see through a microscope when the glaze layer is thin? Probably not but I want to see if I can.
I gave up trying to make money from my own pottery long ago and instead have fun testing and experimenting. I am not even sure how relevant my fritware tests were to any of my work but I enjoyed doing it. 

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.

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.