Hulk

Some things I've made because somebody would ask me, "Do you make _____?" and I think, "How hard could that be?" to which I later reply, "What was I thinking?" 
I also largely make functional pieces. I like to think about whether what I make is suited for ceramics. For example, I wouldn't make a ceramic wine goblet because I think a huge amount of appreciating wine comes from looking at it. I also wouldn't make something for a cooktop because metal pots are so much better IMO. 
Probably a lot of people come to ideas as serendipitous offshoots of something else they are working on. I work with slabs often now because of a back injury and couldn't sit at my wheel. I had made an altered bottomless wheel thrown vase, and wanted to replicate the shape with slab, and that is now the main form of vases that I make. 
I love drawing in my sketchbook. Everything new goes there first before I try it out. It helps me visualize colors, patterns, angles and dimensions.

This weeks question of the week comes to us from @LeeU and is "what were you thinking?" insofar as how do you come up with ideas?
I tend to come up with an idea for something then think about it over a few days, make up a few prototypes, sometimes a drawing then look for design flaws or areas that could be improved. (I mostly make functional pots) I often do look at others work, not to copy but to kick start my thought process.
Thanks for your question Lee! If anybody else has some question ideas they are always more than welcome in this thread.
Lee wrote: 
"This is in the vein of "what were you thinking", which I ask myself often. My inquiry for a possible QotW subject is this: how do Forum clay artists, potters, sculptors woking in clay, hobbyists, professional gallery exhibiters, instructors, production ceramacists,  etc. come to their ideas? I'm curious about whether ceramicists do, or do not, or can not, articulate in advance formative ideas. Are there identifiable/describable processes that indivduals use, which they consciously recognize and employ as a route to generating ideas for their work? I think a "sampler" of such approaches and techinques would be really interesting!"

When you push in the power button, you're actually pushing together contact plates, which allows the power to flow from the bottom terminals on the ceramic block to the top terminals. There are two plates, one for each side of the Sitter block (left and right). Over time these plates can become corroded and need to be cleaned up. I've seen a couple of kilns over the years where power was only flowing on one side of the Sitter due to corrosion.  When the Sitter kicks off, the plates disengage and the power flow stops. The back side of the power button has a small ridge in it. When you push in the button, a little spring loaded lever goes into the ridge and holds the button in. When the cone bends and the weight drops, the little bump on the weight hits the lever and it releases the button. The timer knob has a little bump on the back side that does the same thing. When it gets to zero, the bump hits the spring loaded lever and releases the power button, which disengages the contact plates. It's very much a Rube Goldberg machine IMO, but it works.

The timer is powered by the load side so the sitter must be set to power it  but when time is expired it mechanically trips the sitter. Maybe think of the mechanics of setting a mouse trap, if the set lever is not just so, you can’t set the trap.
see page 8 of the manual http://www.fireright.com/docs/kilnsitter/lt3andk.pdf

These are the ones that I have been using: https://www.harborfreight.com/50-pc-diamond-rotary-point-set-69665.html.  They are pretty good quality at a good price.

I’ve had a couple 20” square ones, and 20” round ones, can’t remember the thickness, both warped fairly quickly. Fired to a hot cone 6 with heavy use. Size and thickness of the shelves will be factors.  Perhaps there is a quality difference between manufacturers or they are better suited for lowfire, at least the ones I had which were from Seattle Pottery Supply.
edit: good article by Bill Schran comparing the pros and cons of different types of kiln shelves. https://vincepitelka.com/wp-content/uploads/2019/04/Kiln-Shelf-Options-by-Schran.pdf

Thanks @Mark C. The pump is not as big in relation to the pugmill as the photos make it look. The rubber sheet idea is what I've always done in the past, and what I'll go back to between the 2 halves, but I've found it leaks a lot over the vacuum chamber, and around the screen covers. I tried an auto "gasket-maker" in a tube (a type of silicone), and the odour was low, but the seal was SO tight that I thought the plexiglass was going to break when I had to pry it off. It was also more effort to scrape off. 
*My current favourite gasket solution: plumber's putty! Stays soft and pliable, low odour, easily removable, and makes a good seal.  
@oldladyThank you for the suggestion! I can see why it looks too big in the photo. I get my Mason Stains from Bailey, so I'll keep that in mind if I need to replace this cover.  
I finally figured out what was going on with the vacuum pump. Actually, the idea credit belongs with my Dad. I used a tiny pipe-cleaner to clean the 2 little exhaust holes (area circled in photo below), and TA-DA!!! Only dropped suction once in about an hour instead of 2/3 times a minute. Poor thing was clogged up with oil and dirt, and couldn't breathe. That step of maintenance wasn't mentioned in the manual, but it's evidently important.
On another vacuum note, for those reading this later, the vacuum pump from an old dairy milker might work (also my Father's idea. Very clever man). I got to 70 kPa with one my uncle had, without trying very hard. Could have got stronger suction with more tinkering, perhaps?  

@oldlady’s advice worked well for me when I reconstituted ^06 glazes and  underglazes that had dried up in their jars. The coffee grinder idea is good if you need them faster than patiently waiting several days or longer (except for glazes with suspended crystals like Dalmatian or Tutti Frutti). Passing the re-wetted glaze through a strainer will even out lumps for consistency. 

In my exhaustive search for epoxies and varnishes and sealers that won’t yellow (I make large scale sculptures that have to be fired in sections and put together after glazing, doing cold finishing to cover the seam and match colors and glaze glossiness) I found every day thing yellows except aliphatic polyurethane. Now, your situation that doesn’t matter because they won’t be exposed to UV light. But they are great waterproofers, they withstand chemical attacks so well they are used on murals to protect from graffiti, so they would not degrade from any acid rain getting into the soil or any other chemicals. They are waterborne and not made of petrochemicals, don’t put of VOCs (or at least so low they aren’t detected). It is what I use to protect my outdoor sculptures, especially ones made out of adobe. The only real caveat is you should reapply every 5 years, which with what you said with the plants growing over them might not be possible. But I’d also guess, knowing what I know about these chemicals, that being face down in the dirt would lengthen its effective time and that I believe the waterproofness lasts a lot longer than the rest of its properties. You could also do what someone else suggested with flipping them over and coloring them with honestly anything, and then you would be able to reapply this if you felt you needed to. You could also do a little study and leave some that you don’t reapply and so how they do. 
There are not very many products made of this stuff, it is usually used as a topcoat for epoxy or concrete flooring or ramps, so it can be hard to find it in other than very expensive gallons (two part product, it has an activator). I have found that Lowe’s in the US carries a quart size version, which is very affordable. I’ll be experimenting with whether I can just mix portions of the two parts together so I don’t have to use all of a container up at once with the gallons.
I would also look definitely into how vitrified your clay is and the ASTM’s porouness test. It is generally considered that it is ok to have up to 5% absorption in clay that is outdoors in freezing weather, but you should remember this is really based on bricks and they will still have a huge amount of spalling even if they are within the guidelines. In order to avoid that I prefer to vitrify my clay to 0.5% or less and seal it, as it would be horrifying for me to have one of my 6 foot sculptures that took so much work have chunks fall off it ruining them forever. You aren’t really in that situation. But, vitrifying and sealing would be my suggestion if you don’t want little chunks of your collars coming off over the years…it wouldn’t be terrible, but I’m sure you want them to stay as nice as possible…

Hi Bam,
Tony Hansen's digitalfire.com site has entries on each oxide, including colorants.
Ceramic Oxides (digitalfire.com) and an article on colorants Colorant (digitalfire.com)
I like Susan Petersen's book The Craft and Art of Clay, particularly the glaze section, which includes an entry on each important ingredient (including colorants) and clear discussion of unity.
I use cobalt carbonate, copper carbonate, rutile, tin oxide, chrome oxide, iron oxide, uhm, oh yeah, zircopax.

Hi Bam,
Tony Hansen's digitalfire.com site has entries on each oxide, including colorants.
Ceramic Oxides (digitalfire.com) and an article on colorants Colorant (digitalfire.com)
I like Susan Petersen's book The Craft and Art of Clay, particularly the glaze section, which includes an entry on each important ingredient (including colorants) and clear discussion of unity.
I use cobalt carbonate, copper carbonate, rutile, tin oxide, chrome oxide, iron oxide, uhm, oh yeah, zircopax.

MC6 is an excellent book but skips quite a bit of information. I think you would find some of the things you are missing by reading John Britt’s Midrange guide, and Robin Hopper’s book is fantastic, even if it is a bit out of date and still has some stuff in it that we absolutely wouldn’t do today. It will especially help your color development. I enjoy Linda Bloomfield’s books, especially her Special Effects Glazes, although her books besides that one can be more heavily on recipes but do have background information you need first. I’m forgetting the author, but the New Ceramics series book Developing Glazes really helped me learn more about testing glazes, doing biaxials, triaxials, quadraxials and introduced me a little to Ian Currie’s methods. The only thing I found frustrating about the book was its constant inclusion of lead in lowfire glazes despite being written around 2013 when all other glaze books of the period had firmly left lead behind. If you really want to dig deep, read Ian Currie’s book…but I think that may be something you might want to keep until you have more of handle on things. Spend time on Glazy- when you have an account a feed will just show up that you can narrow down to recipes or to blog posts (I recommend doing both, the blog posts are fascinating and I have learned a ton about glaze chemistry from them. Also by spending time looking at recipes you are interested in, or just the feed, you will see a rich comment conversation for many of them that often have multiple people problem solving or answering someone’s question that you didn’t know. 
It seems overwhelming but I managed to teach myself glaze chemistry well enough to be ready to start teaching introductory workshops on it within just a few months- and that wasn’t me deciding I was ready, a mutual glaze nerd was the one who told me I was far and away ready to start teaching basic glaze classes, and maybe even some specialty ones like using silicon carbide in oxidation or changing cone 10 glazes to cone 6. I was completely shocked when she told me that as I felt I had so so much more to learn (and I do) but once you dive into it the information comes fast and steady and you can pretty quickly pick up a lot of information. * Do make sure you research your colorants, know their toxicities and routes of exposure, read MSDS sheets on them, and then after that…don’t freak out. Most you really aren’t going to get enough exposure to or be handing in such a way as it has a route into your body*. Check out the episode of the podcast For Flux Sake with the toxicologist, it is really good.
 I did it by checking out every single glaze book from the library and reading all of them, even the ones I wanted to throw on a fire for having very incorrect information. I spent (and spend) a huge amount of time on Digitalfire, it is like Wikipedia, you look up one thing or just go read the lasted blog and get sucked down a rabbit hole of page after page and learn a ton of information. And Tony Hansen is a real sweetheart, if you are confused by something on his website just fill out the contact form and he will email you very promptly and thoroughly answer any questions you have. I found that out because I was frustrated that the information on pyrophyllite and mullite said that you could substitute a certain amount for the silica or some of the feldspar, but there were not even vague guidelines, and I had a hell of a time finding guidelines elsewhere (eventually found that you can substitute basically as much of either of those for the silica, not the feldspar, as much as you want, including completely replacing it, but it is more common to do about 50:50.). Tony immediately went to work using Insight to test various potential recipes with how much pyrophyllite or mullite you put in, and what effect it has, so he’s actually putting in a lot of work to come up with good guidelines. 
Ceramic Materials Workshop is hands down probably one of the easiest and fastest ways to learn a lot of what you want to know,  not that it is a complete education. I felt I had learned enough on my own that I didn’t need their big intro course Understanding Glazes, so I chose their on demand Cone 6 Workshop which when you compare the lectures between the courses they are extremely close, with Cone 6 being a little shorter. You can sign up for the Intro course for lectures only or several times a year (like this July!) they do it with a full experience, labs, pre-lecture readings, meetings every two weeks with the Katzs for questions and chatting. I’ve never heard anyone say they regretted they took it, or really much of a bad word about it. I signed up for their clay class lectures only because I needed the information right exactly then, but they allowed me to upgrade for this July so I’ll be able to do the full class with labs and so forth, and while I managed to develop a pretty great porcelain recipe from just the lectures, I’m planning on developing a white stoneware and maybe also a porcellanous stoneware, although I’ll probably just mix my whit stoneware and porcelain together to make it a lot easier! If you don’t want to do that, I do believe if you sign up for a pretty low amount per month of the CMW’s Patreon there is a zoom open chat with Matt Katz towards the beginning of each month where you can ask tons of questions. It’s an affordable way to get face time and actually get your questions answered, unlike the lottery that is For Flux Sake. I’m planning on doing it after I have finished my clay class since I will have face time there. But I will probably only sign up for a few months at a time, when I have burning glaze questions. You don’t have to do it the full year. 
I have only actually so far done about 30% of my CMW cone 6 workshop, but that is because I skipped around instead of going in order to get the lectures I really needed answers from at the time, which was fantastic, and now I’m starting from the beginning and trying to mostly go through it in order, with plans to rewatch some of the ones I watched first. It is not the only way to learn by far, I definitely learn stuff from the CMW courses but a lot of it I already know through lots and lots of reading. It really is the cornerstone of learning glaze chemistry. There are some great resources on YouTube, John Britt does a fantastic free glaze course that he continues to add videos to and he is great at explaining things, and loves demos. And he will go over a lot of the real basic stuff, he does not skip that, so that might be just what you are looking for, as just like his books he really covers things but he gets to expand on his books a ton with his series. I highly recommend checking him out. 
For glaze software, honestly if you can get a refund on HyperGlaze try to, just using Glazy and opening up some extra features by becoming a patron (preferably through paypal- I just paid my whole year at once for $20 and I know it is going to an incredible nonprofit and that Derek Au is not making any money of it, quite the opposite actually). Glazy usually has enough of what I need, but the best glaze software is definitely Insight from Digitalfire and it is extremely reasonable, plus they have a free desktop version. You would have a lot less head butting with either of those options, you just need to know with Glazy that you want to be a supporter so you have access to Target & Solve, and a couple other great features. You can also put in the cost of your materials and calculate how much a batch of glaze is going to cost you. 
Sorry for the long post, I just had major surgery and can’t fall asleep, and it seemed silly to break up each topic into its own reply to you. I hope some of this helps. It seems really frustrating now but you will be totally shocked at what you will know in a few months. You’ll be a rockstar, especially with such an enquiring mind. 

Hi Bam,
Tony Hansen's digitalfire.com site has entries on each oxide, including colorants.
Ceramic Oxides (digitalfire.com) and an article on colorants Colorant (digitalfire.com)
I like Susan Petersen's book The Craft and Art of Clay, particularly the glaze section, which includes an entry on each important ingredient (including colorants) and clear discussion of unity.
I use cobalt carbonate, copper carbonate, rutile, tin oxide, chrome oxide, iron oxide, uhm, oh yeah, zircopax.

Speaking of copying  I long ago in another clay universe was a partner in a press mold ceramic pin and magnet  business we (the two of us which at that time was a girlfriend whom we spent 10 or so years together)
This business was concived as business that could fit in a very small space as the kiln was the only large item. We made the originals from clay and I made press molds and she glazed them. We used a small airbrush and very small compressor for glazing. We marketed zoos and aquariums from BC Canada to Hawaii  to the New England aquarium  and all in-between Places like the San Deigo zoo , Montery Aquarium buildt in 1984. Most of the marketing was personal as we went there and talked to them (Hawaii and BC) east coast was all on the phone and via mail.
I was alaways into fish from diving with them. My brother did the color layup master (a cibachrome) for us (he was a Art Professor at UCSB in Santa Barbara  and did cibachrome all the time back then) and had access to color equipment . Once I had a master I had a company print the color layouts
I have a few left even though this was all over 40 years ago-just a layout no price lists anymore. The  business was good for about 5-7 years and we moved on to other projects. I still have tons of pinbacks and magnets
 Now to the copyright  part of this story
At this time I was doing shows in the west coast callled harvest festivals in the late 70s early 80s and many clay folks where making ceramic pins I learned from them about copyrights.
We choose trhe cheaper copyright  path that many where taking and that is stamp the backs with the copyright logo  on pin backs and hope folks respected that. It worked and we never had any infringement that we know of. Her is that master cibachrome and final  color sales brochure. I still have a few magnets on the fridge of the more durable forms. We had 20 formscan you name them all? My guess is there are a few most do not know
The business was called Coruba Pins named from this rare rum label that I once enjoyed drinking -not much of a dinker past 40 years now.
Man I have done a lot with clay -most of this I had forgotten until this write up.
 

I (finally) went and rented a gear puller from auto zone, took me all of about 2 minutes to get it off! I couldn't get the key out first, but it didn't seem to give me any issues. Maybe the PB Blaster I sprayed the other day helped loosen it up, but it definitely seemed like it hadn't been taken off since it was assembled. Thanks for your help gents. I'll be taking the wheelhead to my small motor repair guys in the morning. Hoping they can replace them! Thanks again y'all

@ATauer, I would suggest you send @Marcia Selsora pm and ask her where she buys hers from. Marcia has a really good article on Saggar Firing with Soluble Salts in the 2020 Sept/Oct Pottery Making Illustrated magazine. Article is behind a paywall but you can access 3 articles a month for free if you want to read it. Link here to it. 

Thanks Hulk and Bill. Yes the other side has a square metal plate which holds the bolts in place. The spring is also attached to this part. And the belt also fell off...I put  all of them back on now! hopefully this won't cause any issue in using the wheel

Thanks everyone for your kind advice and suggestion. I tool the blue cover off and noticed that the square metal plate, the spring and belt were all loose. I put them back in place and hopefully the wheel will be working again!

I agree and I hardly know what I am doing. I tried to use the USE column to force what I wanted but it didn't work for me. I have been using glazy for the calculations then entering the recipe into hyperglaze to get an estimated COE for the glaze, which I haven't found a way to do in glazy. Also, hyperglaze does not do r20:ro, so even when I am using hyperglaze calculator to figure things out for me, I still have to enter it into glazy to get these, because I tried to manually calculate but was too... ahem  dumb... to figure out how. Also tried to calculate coe manually and was getting huge numbers. so hyperglaze has helped with that!
I am going to try what @neilestricksuggested, and see if this will make a difference for me. I kept wondering why the program would stop calculating when there were still two ingredients left in the list of the recipe after using sort, but now I see this was just because I had met the limits. At least i think!
 
Thanks again so much for all being willing to share their knowledge. so very appreciated

Are you working in the Glaze Calculator section?
When you put in an ingredient that fulfills the requirements for certain oxides, but overloads other oxides, it shows as a negative number because it's showing how much you still need to fulfill. Needing a negative amount means you have too much of it.
As for the calculate button, that's just how the program works. It's doing the work for you. If you want a certain material to only supply a portion of what it could use, then you can put a precent in the 'Use' column as a decimal.
Materials need to be put into the calculator in order from most complex to least complex, and starting with your source of Boron, or it will be forced to overload oxides. If you put silica in first, it will fulfill all the silica, and then if you put in feldspar next it will over-fill the silica as it fulfills the other oxides that feldspar has. Here is the order in which you need to put things in:
1. Source of Boron, either a Frit or Gerstely Borate or equivalent
2. Feldspar or other Frits
3. Any material that contains 2 oxides, such as Wollastonite or Dolomite
4. Materials that only contain 1 oxide, such as Whiting, Magnesium Carb, Zinc Oxide, etc.
5. Clay
6. Silica
If you do things in this order, you'll have very little overloading of any single oxide, at least not enough to matter.

Just to get things started ...
It's a form of offset printing called pad printing.
Basic idea is to form an image on a plate, pick it up on a flexible pad, and transfer it onto the target.
https://upload.wikimedia.org/wikipedia/commons/transcoded/7/70/Cetakan_Pad_pada_barangan_seramik.webm/Cetakan_Pad_pada_barangan_seramik.webm.720p.webm

More details at Pad printing https://en.wikipedia.org/wiki/Pad_printing
The machine you showed does colour printing using several pads, one for each colour.
PS If you were thinking of a manual DIY process, some of the issues would presumably be:
1) Making the image plate (probably a photo-engraved plastic printing plate?). 
2) Cleanly inking the plate for each transfer.
3) Making the silicone pad to fit your target ceramic object. Video of casting a pad at  https://youtu.be/VN0hESxwxXk No details about the ingredients. No idea if the vacuum chamber is optional.
4) Cleaning the pad after each use (I assume that the image registration achieved by the automation means this isn't needed for factory equipment).
5) Clean pickup of the image on the pad.
6) Clean transfer of the image onto the target object, and clean removal of the pad.
7) Choice of a suitable "ink" for your purpose. Maybe not that different from the ones used in silkscreen printing onto ceramic.
8) As you are transferring a 2D image onto a 3D object via a shape-shifting pad you may need to pre-distort the image so that it looks right on the object.

People can make things more scary than they need to be. Common sense when it comes to ceramics will go a long way. It's good you are interested in learning about glaze chem but please don't feel overwhelmed by it. If you use a well melted gloss glaze for liners that doesn't contain any transition metals / colouring oxides there won't be anything harmful to leach out. For sure there is a lot of information to take in.
The lemon  slice test (or household white vinegar) test mimics the ASTM test that uses 4% acetic acid to test for cadmium and lead where the leachate is tested. It won't rule a glaze as being 100% non leaching but it will rule out glazes that are visibly degrading as not being suitable for use on pots coming in contact with food surfaces. Same as the dishwasher alkaline test, it is meant to rule glazes out as being durable, not definitively rule them in. In the images above from Katz's paper on durable glazes it looks like copper was used in the base glazes. Copper is probably the most difficult colouring oxides to keep from leaching out of a glaze so keep that in mind. One other point from that same paper was a test with a flux ratio of 0.1 R2O : 0.9 RO being "surprisingly robust". There are many factors to be taken into consideration!
"Yet in this series 0.1 R2O:0.9 RO was surprisingly robust. The glazes themselves have an average baseline gloss of 68.8, higher even than 0.3 R2O:0.7 RO. The degradation levels showed adequate performance, with an average of 2.8%. This value may be misleading since a boron level of 0.5 had only 1.62% degradation, while the 0.4 boron level was a still low at 3.98%. But the curve and slope of this series matches 0.3 R2O:0.7 RO almost perfectly. This result will be explored in future research, along with the effects of altering the silica /alumina ratio and the role of colorants such as copper."

There are only a dozen or so main oxides that are used for ceramic glazes (not including transition metals aka colouring oxides, and opacifiers). Many of the materials we use are made up of multiple oxides. For example all glazes (and claybodies) are going to contain alumina. Alumina in glazes is most commonly found in either a kaolin or a ball clay. So if a glaze needs alumina the go to is to add kaolin or ball clay. If you take a quick look at either of these materials you will see they contain alumina but also silica + some fluxes and a tiny bit of iron. Therefore by adding kaolin or ball clay you are also adding the other oxides.
What you want to aim for is supplying the oxides with materials that suit the purpose the best. For example frits containing boron and Gerstley Borate (or Gerstley Borate substitutes) are what supply boron. (key for most cone 6 glazes) Many people prefer to supply boron with a frit as opposed to Gerstley Borate as frits don't have some of the negative issues Gerstley Borate has like gelling a glaze. It takes time to learn what materials contribute what but a brief chart here will get you started. There is a wealth of info on the Digitalfire website. 
Yeah, there is something wonky with your Hyperglaze flux data. I don't use it so can't help correct what's going on there. 
I don't want to do your "homework" for you but just for reference sake I put the original Selsor Chun that you linked from Glazy into Insight. I then did a 1:1 swap of the FFF Feldspar for Mahavir (second recipe). Honestly this is probably close enough to just test as is. The sodium and potassium amounts are different as FFF spar has a fair bit less potassium and more sodium than Mahavir. Could be a slight shift in colour between the FFF spar and Mahavir. 
To balance the sodium and potassium I added some sodium in the form of Ferro Frit 3110 (high sodium frit) then rebalanced everything and re-totalled to 100. Its common studio practice to have the base glaze equal 100. Makes it easier to compare glaze recipes and add colourants etc. 

Hi Retxy,
Was curious enough to find this video clip collection HyperGlaze - glaze software for artists but not enough to watch them, or install the software.
My guess would be the presentation reflects the limit set, and the limit set is likely configurable.
Perhaps someone who uses the software will yet reply, bump!
I'm using GlazeMaster; it has a compare to limit formulas view, which I do look at, if not very often. I'm using the unity/weight/mole view more.
Am also using Glazy (Glazy.org an online glaze resource) R2O:RO ratio calculator; adjusting the ratio seemed key to resolving my low expansion liner glaze issues. 

Just to add to the above, there are efforts to unify (Globally) various chemical compositions which in theory can lead to more uniformed application, classification and restriction globally. If you have not done so already, Mayco continues to explain some of this reasonably clearly as well as cite some US agencies in place to establish and protect people in general. You may find it a good read https://www.maycocolors.com/resources/health-safety/
An additional fairly recent study on durability and chemistry correlation you may find interesting as well here: https://www.ceramicmaterialsworkshop.com/uploads/5/9/1/2/59124729/katz_matthew_glossed.over.durable.glazes-2018.pdf
It does highlight the “acid test” may not really be the best indicator of degradation in all cases. Glaze durability is complicated, actual exposure to various substances especially by consumption is probably even more complex.