PeterH

I wasn't successful getting the gold to reduce with just pine resin, if you buy Greg Daly's book "lustre", he details making it from elemental sulfur and gold chloride. This works well.  Commercial lustres using pine resin thinned with toluene use a different gold salt, I'm guessing that's the reason they work.  I think the compound is a chlorohexanoic salt of gold. 
You'll also need a bit of bismuth in there to act as a flux bridging the gold and glaze.  
I had some luck making a silver lustre by making silver soap.  Silver decanoate.  But it was difficult to dissolve in almost everything so it was a pain to apply.  Was conductive though and I made a few touch lamps using it.  Also had success doing a similar thing with copper.

Posting a reply to push this (newly split?) thread to the top of "Topics" and "All Activity" lists...

Hello folks!

Curious if people are still checking this thread? I started throwing bone china about a year ago and am getting some decent results. I'm looking for more online resources, as well as colleagues to discuss with. I simply cannot find either of those. Bone China people seem very guarded, it is so nice to see someone helping others in here.

I learned the hard way about oil from your fingers being enough to resist glaze.

Is it just me, or is glaze fit unpredictable? I've had glazes that craze normally shiver, glazes that craze normally fit well, but also had glazes that fit normal ceramics also fit bone china. There seems to be no rhyme or reason, it strikes me as odd. 

Edit: Oh, I almost forgot, my bone china glows green! I've googled and searched everywhere, but cannot find any information at all. I've tried with florescent, incandescent, and sunlight, all green. What color does yours glow? 

https://insight-live.com/insight/share.php?z=7WnpT9vC3b

This has some great info on your glaze, as well as multiple revisions meant to solve known issues.

Just to point out that your approximation does not allow for the volume occupied by the clay particles. That's what Brongniart's formula addresses.

I think the usual form of Brongniart's formula will give you answer. 

This often uses a value of  2.6 for  the density of "typical glaze solids". Which seems close to the density of clay particles.
Particle Density
https://link.springer.com/referenceworkentry/10.1007/978-1-4020-3995-9_406
Densities of clay minerals range from 2 to 3, but many are near 2.65 g cm
PS An old but good ref for t-sig is
Super-Refined Terra Sigillata
https://digitalfire.com/article/super-refined+terra+sigillata
... but note that it doesn't mention the more modern deflocculants.
... the use of hydrometers has been replaced by weighing an empty and full calibrated syringe in many glaze applications
... it mentions several ways of concentrating thin t-sig, eg  As another option, use a crock pot set on medium heat with the lid off. In either case, the rate of drying will depend on the atmospheric humidity and the mount of heat applied. It will take some experimentation to learn the ideal conditions. You may find a cheap crock pot at your local thrift shop.
PPS Two threads on the use of  Brongniart's formula for glazes "in the bucket". Including references to the formula and a calculator.

Is there any US charity you can turn to for advice. (In the UK Citizens Advice might be worth trying.)

I've been there.  and learned to ignore the "official methods" and simply crushed the dry clay as small as possible using a hammer and kitchen screen utensils to get rid of the "big" rocks.  
Mix the clay with water to make a slurry that is somewhere between the buttermilk and the milk level (or a little less).  Let the mixture set for a while to let the heavy particles to sink, and then pour the liquid into a separate container which will contain most of the sig.  Stir up the original container again and let it set a while, and repeat pouring off the water to get remaining sig. Yes, this is not the official method, but it has worked just fine for the clay I take from my ponds and roads to them.  I have also used that same method for making sig from scrap commerical clay bodies. 
If you are able to get wet clay from the backyard just start with that; add water and mix well; if you have sand, it will sink along with the heavy particles.  I have a pond that collects fine clay every time there is a decent rain. After the rain there will be a thin layer of fine clay above the big paricles.  My first round on terra-sigillata I followed the "official" method; it worked ok.  After noting what was happening in the ponds and just getting a bucket of pond mud and water I begin to make my own method which has worked just as good as the textbook. 
The best "official" recipe I have found (beyond my own) is Vince Pitelka's version:
http://www.vincepitelka.com/wp-content/uploads/2022/10/Super-Refined-Terra-Sig.pdf   
/*/

I'm using various recipes of my own creation, all closely based on the classic 25:50:25. Notably I'm in North America, so I've been testing subbing soda spars and various frits (mostly 3110) + silica to replace the cornish stone. For Kaolins I've been using NZK, Grolleg, and Standard Kaolin. I've used both TCP and bone ash, the real stuff burns whiter and fluxs much more in my experience.

I worry that green is a red flag that I'm doing something wrong, but the ware is very well vitrified and very strong. If it were a common problem I'd imagine I'd be able to find information on it. 



 

Copper is interesting and there are limits but most often found in an industrial setting when testing for heavy metals.. Sounds like you need a real environmental air test and lab analysis to figure this out ……… then figure out the source. Clay may or may not be a concern here so a real test with real quantities of constituents likely is the best way to know with reasonable certainty. For now, no exposure or very limited exposure until you can correct seems important. Adding cleaning chemicals, moisture etc… can amplify effects. I suggest get  a real test and lab analysis ……. on paper by an industrial hygienist or equivalent.

I just can’t see my self no offense but half rigging it I want a nice basin that I can fetch water from when I throw something that helps keep my studio clean and organized I need something that holds water. However I did email the persons email that came on the owners manual and he didn’t even have his own domain for the email. He responded within eight hours and wants to know if it was the factories fault, it is not. My father bought the wheel without the basin. So I am currently in contact with this person trying to get him to provide the replacement I told him I’d pay for it I don’t want it free. So that’s where my studio is clay on the shelf wedged and no throwing going on
:/

Nope, trivalent chrome does not convert to hexavalent chrome in glazes.Re zinc chromate, according to Hansen "Chrome in zinc glazes tends to form the stable crystalline compound, zinc chromate (ZnCr2O4). which is brown." from this link. 
I plunked your glaze recipe into the glaze calc program I use but I'm not confident in the accuracy of it since specific types of potash feldspar, talc and china clay aren't mentioned in your recipe. Using generic analysis the formula is on the low side for silica though. I would do a lemon slice test on it and see if the colour changes., also keep a test piece in the dishwasher, if you use one, for a few months then compare that to an unwashed piece.What is really important is to have a stable base to prevent leaching. With colouring oxides, aka transition metals, less is better.
 

Yes I think you’re right, a plaster mold would be complicated and unlikely to work. Pictures are after 1 firing. The wood has completely burned out but I don’t think casting inside the bisque will work for my aims. I want to keep the translucency. 

This is exactly the challenge: enough coats to survive the kiln YET STILL have the details that makes it unique. The pictures attached are from my first attempts where I painted on paperclay slip with a brush.  (Banana for scale lol) Most of the branches were 50-60cm long so all of them are only partially intact.  I'm getting better coverage by dipping rather painting the slip but I don't want to lose the thorny-ness of the thorns.  Maybe a plaster mold would work? Hmmm...

The photographs suggest multiple techniques. Slip casting or a two part sprig mold to capture the finer details seems more appropriate for some parts. Paper clay is a good choice to get something long and skinny to survive the process. I imagine it’s possible to slip cast paper clay  
Coating with slip progressively diminishes surface detail, and you've got to build up a little just for structural integrity. It’s also going to shrink around the branch. Paper clay is miraculous, not sure it’s this miraculous.
Good luck on your challenging project! 

I know zilch about wheels, but loud pops can be caused by an electrolytic capacitor blowing.
Can you post a picture of the component side of the circuit board?

It sounds like they are a special case of  "oxide washes".  (Which may be a productive search term.)
https://www.vincepitelka.com/wp-content/uploads/2016/03/Surface-Design-Patinas-and-Glazes.pdf
Dry-Effect Oxide Patinas
An interesting category of patinas are those which simply approximate the accumulation of dirt and debris found in much ancient claywork. Varying proportions of zircon opacifier or tin oxide and coloring oxides with some 3134 frit (to flux the patina onto the surface) will give a range of “dirt” colors from very light to dark brown or black.
https://ceramicartsnetwork.org/pottery-making-illustrated/pottery-making-illustrated-article/In-the-Studio-Washes-and-Patinas#
In the Studio: Washes and Patinas
Gerstley or Gillespie borate, Ferro frits 3110 or 3124, borax, or any other flux-based material can be used in combination with colorants to create patinas.
... so I think the message is to use a flux appropriate for your firing temperature.
If you say what cone/temperature you fire to an expert will probably chip in with a recommendation (or confirmation that 3134 is OK).

It sounds like they are a special case of  "oxide washes".  (Which may be a productive search term.)
https://www.vincepitelka.com/wp-content/uploads/2016/03/Surface-Design-Patinas-and-Glazes.pdf
Dry-Effect Oxide Patinas
An interesting category of patinas are those which simply approximate the accumulation of dirt and debris found in much ancient claywork. Varying proportions of zircon opacifier or tin oxide and coloring oxides with some 3134 frit (to flux the patina onto the surface) will give a range of “dirt” colors from very light to dark brown or black.
https://ceramicartsnetwork.org/pottery-making-illustrated/pottery-making-illustrated-article/In-the-Studio-Washes-and-Patinas#
In the Studio: Washes and Patinas
Gerstley or Gillespie borate, Ferro frits 3110 or 3124, borax, or any other flux-based material can be used in combination with colorants to create patinas.
... so I think the message is to use a flux appropriate for your firing temperature.
If you say what cone/temperature you fire to an expert will probably chip in with a recommendation (or confirmation that 3134 is OK).

In case it helps: clicking either "image link" opens up a web page inviting me to create a Gmail account. So its neither an image nor a direct reference to one.
BTW The A123-B wiring diagram and parts identification document is at
https://eadn-wc04-7751283.nxedge.io/wp-content/uploads/A123WD.pdf
The diagram part is a bit blurred, in B&W and stylized (top, bottom & back views)

 
PS I assume you have looked at the section on switch replacement starting on p42 of the manual, which might be this one:
https://eadn-wc04-7751283.nxedge.io/wp-content/uploads/IM5-A-and-B-Paragon-Inst-Man-Jan2017.pdf

If it's the manual Bill mentions an "F-1" message doesn't seem to conform to the format of the other alarm messages (none of which have a hyphen). Can you confirm exactly what you see?
PS
BTW it looks to me like a message containing "F 1"  would be generated while setting the safety temperature.

     =================================
 

Sounds like you need to get the /air/ tested in your home.  Find out what it /is/ that you are smelling.  Mold, mildew, sewage, gas, etc?  Then you can have a home inspector help you locate the source of the problem.  As stated, it may have something to do with a clay foundation or nothing at all, but anything that is a health hazard like that needs to be addressed by a professional quickly who can first give you an air analysis, not guesses.  It sounds like you shouldn't even be in the home until you find out what is the issue.  Some molds for example and sewage can be life threatening issues.  As for the clothes?  Until you know what is making the smell you won't know how or if it /can/ be removed.   And that is the least of the problem.  Good luck with this and I hope you will sort it out quickly!

Try a google for paperclay nest, then click on the images option. It may at least give an idea of the state-of-the-art.
Hits include
https://www.google.com/url?sa=i&url=https%3A%2F%2Fdeniserouleau.com%2Fworkshops%2Fadventuresinpaperclay&psig=AOvVaw24dMc2zyf9RW6-ztQqTML1&ust=1711619956846000&source=images&cd=vfe&opi=89978449&ved=2ahUKEwj2n7Wtl5SFAxUqVKQEHdaCBYoQr4kDegQIARBi

 
https://judithrosenthal.com/section/125628-Sticks and Stones.html

 
https://judithrosenthal.com/section/125628-Sticks and Stones.html

Yes, but it may introduce more problems than it solves.
To my untutored eye it looks like firing with a sitter would probably solve your slumping issues.

... but would introduce glazing issues.
The classic bone china solution uses a supported high-fire bisque and an unsupported lower-fire glaze, which creates its own problems.
Bone China https://digitalfire.com/glossary/bone+china
The process is completely different than what a potter would do: Bisque fire, glaze, high fire. Bone china is bisque fired to high fire and then glazed at a very low temperature. Since the porcelain has zero porosity, getting a glaze to stick and dry on it is not easy, the process needed goes well beyond what a normal potter would be willing to do.
PS
Balancing slumping and decoration has a long history. Robert Tichane expressed his surprise when he finally realised that the ancient Chinese cup he regularly drank from had a guilded rim to disguise the lack of glaze on the rim (a result of firing the cup rim-down to minimise slumping). 
I'm having difficulty visualising your "handmade leather molds". I assume that they are semi-flexible press-moulds, but am unsure how you extract the bowl from the mould.

Noted.  And sometimes I use IPA - depends which one is handier.  I've never had an issue with either one since I literally only use a drop or so in my water spray bottle of the bleach.  The generic bleach I buy only lists one ingredient and nothing added for scent.  (I also incidentally use it for phytosanitary applications like tissue culture of plant materials.)
Yes!  This method of cutting up the piece is typical for casting porcelain and bone china in the UK and Europe.  Indeed it was a few photos shared here with me from another member (who may or may not wish to be named) that helped me figure out this problem.  I also worked with porcelain sometimes and I've been working on perfecting and testing English bone china slip I've made here in my studio.  So I went ahead and produced this multi-part mold for that purpose.  It works just as well for earthenware. 
As I knock some rust off I'll be pushing to try and make more complex molds that would allow me to cast Porthos as whole and as close to one piece as possible.  Body with three legs attached most likely, with the head and neck separate and that cocked back leg.  That would take less assembly and thus less time.  And problem solving with mold making is an excellent challenge to practice if you want to get better anyway.
One of my new sculptures I have started is the 'Spider foal' that is rolling.   I'm jokingly calling it my 'spider' sculpture for now because it looks hideous!  But it's in the early 'skeleton' stage where I flesh out the proportions of the bones and set the joints as points of reference from which I will build up tendons, muscle, skin, etc over top.  Anyway, you can see that I do not like to sculpt with molding limitations in mind.  So being able to mold them in pieces and assemble ANY kind of pose or complex arrangement really frees me up to do anything I want.  

Very minor point.
Domestic bleaches often contain a variety of substances in addition to sodium hypochlorite (generally known as bleach).  While baby products for sterilising nappies, bottles, etc tend to just contain sodium hypochlorite. UK brands include  Milton, which I use for purely sterilising purposes.