19: Clay Doctors

Introduction to NSEKA 360

0:00Welcome to NSEKA 360, a podcast that amplifies and uplifts the voices of the ceramic community. I'm Edith Garcia for the National Council on Education for the Ceramic Arts. Visit nseka.net to learn more about how membership cultivates a clay community and shapes content and opportunities for the field. Follow us on Instagram and Facebook for the latest information about NSEKA.

0:30Hey, this is Josh Green, and I'm the Executive Director of NSEKA.

2025 Conference Announcement

0:41I want to invite you to our 2025 conference formation happening March 26th to 29th in Salt Lake City, Utah. Visit nseka.net to learn more and register. Today's episode of NSEKA 360 features the Clay Doctors Panel, moderated by Paul Blaise and featuring panelists, Louise Derwal, Jessica Gardner, Bobby Scroggins, and Rebecca Hutchinson. This conversation was recorded in person during the 2024 NSEKA Conference Coalescence in Richmond, Virginia.

1:16Special thanks to the Brickyard Network for co-producing this episode and supporting podcasting in the ceramics community. If you enjoy this podcast, please support NSEKA's programming by donating at www.nseka.net forward slash donate.

Panelist Introductions

1:35Hey, well, I'm super excited that we get to be able to meet like this. I know that for me, it's always a mystery when we're doing podcasts about who is actually listening, and I'm just so grateful that over the years I get to come to NSEKA and we get to do these face-to-faces like this. It's so much fun. The Potter's cast that I have been putting on for 10 years now, it came out of the heart of just wanting to give something to a community that I had fallen in love with,

2:21but I was not an expert in. And so the idea that I'm sitting on a board to talk about the problems that can come up with clay, firings, glazes, all those things, I love that I am here because I am the least qualified person on the board. So when the questions are coming up, I'm going to be so grateful that I am not the person answering the questions. Although, I am very confident in my ignorance.

2:56But we do have a great group of people here, and I'm super excited that we have this board here to be able to share ideas, knowledge of what some of the problems that we have as potters out in the field, you know, doing our stuff, and we're trying to figure out, good night, why is this pinning on me? Why is my clay flaking? Or whatever the issue may be, it's great to have this opportunity to be able to talk to someone who's an expert.

3:31So that's what these people are all about here.

Panelist Backgrounds

3:36And so what I want to do is just take a moment and introduce each person, and so as we're going to come down from the end of the table and work our way across, and then we're going to jump into starting to do questions. And the bigger part of what we have to share today is not necessarily what we have to share from just us talking at you, but the real value is going to be those questions that you have, that you've been struggling with, and you would like to bring to the table, and then we can hear from the experts and find out the answers to those questions that have been bugging us in the studio.

4:14So if you've got questions, there is not going to be a dumb question, and if it is a dumb question, we won't let you know today.

4:27So let's just start down here. We're going to work our way down. We're going to say who we are. We're going to make sure we let you know what our Instagram feed is. Also, just so if you want to connect with them later, you can be able to plug that into your Instagram and say follow on that. But we'll just work our way down, and they're going to give you a little bit of their background, and then we'll get into the questions.

First Question

4:48Hi, everyone. Welcome. I'm super excited to be part of this panel. Very intimidated as well, because I think we are always learning. There's so much to learn in the field. So it's like I hope I can help you with your questions today. So my name is Luiz de Roal. I'm originally from Brazil. I've been in the United States for almost 11 years now. I moved here to go to grad school, to University of Nebraska in Lincoln, where I was a student of Pete, which is like, oh, hi, Pete.

5:21My work, I work in a lot of different ways. I do sculptural work, functional work, and I do a lot of layering of materials to create expressive surface. It's a way for me to talk abstractively about my emotions and feelings. So that's kind of what I am in a nutshell. My Instagram, I think, is luis-de-roal, but I can give you, if you're interested, I'll give you later, too. Thank you.

5:51Hi. I'd like to echo what Luis said about being excited but also a little nervous up here. My name is Jessica Gardner. I teach at Northern Virginia Community College, and so as part of my role, I teach both wheel and handbuilding, but my personal work ranges from installation to sculpture, primarily made from very small multiples. I do a fair amount of slip-dipped and then fired materials, and I'm also a big fan of over-firing clay and glaze.

6:30So if you have questions about that, my Instagram is jg.gardner, and I'm excited to see you all. Good morning. I'm Bobby Scroggins. I'm a professor of ceramics and sculpture at the University of Kentucky. I went to undergraduate school at the Kansas City Art Institute and did my graduate work at SIU Edwardsville. I've been there for about 34 years now. So my work has taken a lot of different changes over the years.

7:04Primarily, I started as a figurative sculptor, and my work has gone from mixed-media applications to functional pottery and also sculptural vessels with a lot of atmospheric firing, raccoon, soda, salt. Good morning. I'm Rebecca Hutchinson. I'm a professor at UMass Dartmouth, and I'm there working with undergrad students, post-baccalaureate students, and graduate students.

7:35And my own work is large-scale installation and format. I'm really looking at kind of the depth of what's happening in ecosystems and all the clues and interesting things within nature that get me going conceptually. I use clay kind of to the edges. I do a lot of non-fired. I do a lot of experimental mixing with my clay, so I'm happy to answer any questions on additives, paper clay, and all the sort of experimental things, latex paint, that kind of thing.

8:08So we're going to be going into a time here where you're going to be asking questions, and the best way to do that, if you've got a question, we have Ben Carter, Tales of the Red Clay Rambler. So if you have a question for me that you'd like to present, just raise your hand to get his attention, and we'll try to scan the room. And if Ben's not seeing you, hopefully one of us will see you, and we can be able to send the mic your way.

Wild Clay Discussion

8:33So at this point, feel free to start raising your hand, and we'll get the mic heading in your direction. I did have one question as Ben is going to you, but you said you do, Jessica, overfiring on glazes and on clays. And for me, that scares me to death. It's okay to overfire? So, yes, I think it's okay to test any material to its limits.

9:03But I think what I'm looking for is to find that edge, right? So if you've ever seen truly, like, cone O4 clay that's gone to 6, it looks kind of like a sad, burnt, bubbly cookie, right? Like, it's just not good. I'm not going, I'm not pushing it that far. But, like, if you have a glaze that's O4 and you're working sculpturally, like, do some test tiles. Like, what happens if I take that to cone 4, cone 6, cone 10?

9:36At some point, you're going to reach the bubbly cookie, and then you've gone too far. But sometimes, especially with sculptural work, you have a lot of freedom to see, like, wow, that really mats the clay, the clay I glaze out. The clay starts to wiggle a little bit and gives you some movement. And so I find that really fascinating. So test tiles, do not use your work as a test tile. Make test tiles, and then do it on your work. Test tile, okay, okay, great.

10:07Hey, so give us your name, and then also, if you don't mind, just so, because people might be totally stoked about your question, give us your IG account, so just, then that'd be great. So go ahead. Awesome. Thank you so much for being here.

Wild Clay Sourcing

10:19My name is Lindsay Rose. I'm from the University of Utah, and my ceramic Instagram is wheelthrownpottery. And my question is about wild clay. I'm wondering how you guys would recommend ethically sourcing local clays and successfully firing those kinds of clays and just the process compared to buying clay. So we've got three solid questions out there. Ethics about digging, and then sourcing was the other one, and then lastly about using commercial, right?

10:52Yeah, anything in that realm. Okay. Can I just throw out a quick, you definitely want the wild clay book, and I would also look up Margaret Boozer. She came and did a visiting artist lecture at my school and has some amazing information about that. I could provide some other secondhand information from her, but if anyone else wanted to jump in. Okay, I can start the conversation about wild clay.

11:22So I forgot to say that I'm teaching now at the University of North Carolina in Asheville, and North Carolina has a lot of clay in the state. And it's a big, I don't know, it's a big movement right now, right? Yesterday there was a panel about wild clay. Most of the people on the panel were from North Carolina. I think there's a lot of testing. The first, like what Jessica said, test, test, test, that's what you should do. So you can, you know, dig, find the clay, go, usually it's close to riverbeds, but I think it's like talking to your community, finding where you can find some clay.

11:58And then it's a long process. So it's very, you know, you have to dig it, you take it back to the studio, you wash it, you dry, you rehydrate, and then you put in the plaster, and then you start seeing workability, if it's malleable or not, if you need to add other materials to enhance your clay body. Sometimes the clay, just the wild clay itself, is not workable, depending on what you want. It's all like, what do you want from the clay? Sculpture has, it's such a big and vast, like you can do a lot of things.

12:29But if you want to make pottery, you might need to add some other type of clay to make it more workable. And then testing, like test, start firing at 06 and see how it behaves, and then go higher and higher and higher until testing the limits of the clay and see when the clay starts deforming and how you can, you know, come back or not.

12:50But I think it's all about, yeah, it's a lot of work, that's all I can tell you. It's a big field, it's a new field, and it's a lot of work in the studio. I was going to just jump in here and hit the more ethics part. I mean, to connect to site is ethical. I mean, that's what it is. It's connecting to site and understanding and researching place. And so that is a beautiful thing. And so you start to go through your resources to that, whether you're finding clay on private land,

Ethics of Wild Clay

13:20you're going to talk to the person, you're going to make a connection and a relationship, or moving it to state land or federal land. And I've done a lot of projects in public spaces, and that gave me the opportunity to reach out in letter format and ask permission. You know, my understanding is that there's local clay here. Can I, you know, have entrance to the land? And sometimes it takes weeks to get the letter chained through all of the proper admin connections. But, I mean, that is ethical. That is beautiful to understand place.

13:51And so reach out and connect to people, connect to organizations, ask permission, and follow through. You know, one place that's a great source is construction sites. I was going to say that, yeah. You see constructions going on. That, you can, as long as you get permission from the job site superintendent or the homeowner or the building that's doing it, that has already been permitted to be moved. And there is nothing unethical about taking that.

14:22Thanks. Bob, do you have any thoughts on that? I was just going to ask you what you were about to say about construction sites. I'm sorry. I just took the expertise away. Oh, my gosh. I was going to say, though, that with the construction sites especially, when they are digging through all of the layers, it's also really fascinating to be able to see the clay deposits in that way. And so if you have never harvested clay before, I think it's a good place to start because it's very evident where those stridations are,

14:56where if you're, you know, out in nature, it might be a harder find for a beginner. So I agree. Construction sites are excellent. I have my students look at the industries in the area, like what's being made in the area, and then connect to the geological society. You know, where have they pinpointed natural clays? So look for all the clues and follow sort of the breadcrumbs culturally and environmentally. Yeah. I'm sure that mic's moving around to someone else.

15:27I was going to make one more suggestion about that because it's only, this is really the only area of my expertise, is that you can get a hold of, in your area, any excavator or ground earth moving companies. Become friends with them and tell them you'll give them a pot, you know, after you're done. And you'll find some forever friends by those excavators. So, okay, we have a mic moved over to here. Yeah, name and give us your IG.

15:58Hi. My name is Madeline Mullinex. I'm currently interested in, I guess, incorporating ashes, so like wood ash or soda ash, into a clay body and how that would affect the clay bodies over time and with firing processes. Well, I mean, it's an additive, an aggregate, right? It's an aggregate. So it's between clay particles and it's going to give you stiffness and, you know, workability, just like grog, right?

16:29Grog is that aggregate that's going to give you that strength in working. So you're going to have the same sort of response with wood ash in terms of workability. It would be interesting to see what a panel member thinks about firing that. What do you think about it? What type of wood are you referring to? So I usually fire to around cone 5 to cone 6. Are you particular about the kind of wood, though? Oh, the kind of wood. I don't know yet.

17:02Because you're saying the wood, like different types of woods can make a difference. Well, I know different types of woods can react differently in glazes, for sure. So like hardwoods can do certain types of things. It's more of a porous, like firewood that you would use for a wood stove situation. Again, it becomes siliconic at high temperatures, and you'll find that what? Around cone 5 to cone 6.

17:33From 5 to cone 6. I don't think that it starts to form a glass until around cone 8. But I think it's really important, if you're trying to do that, to make sure that your glazes are washed really, really well. And that's a fairly long process. Have you got any experience with that, washing glazes, washing ashes? No, not yet. I can Google it, though.

18:04So you're saying that if we're going to be adding additives like ash, that it's not going to work on every type of glaze. Or I should say, not at every temperature. It might change the chemical, but you're not going to get the glassiness that ash brings to it, unless it hits at least an 8. I think it's about around 8, I think it would be like. So if you want the glass of ash, then you're going to 8. Right. So I think the important thing to think about, too, is that if you are firing to a lower temperature,

18:38then we need to encourage all of our materials to flux sooner, right? So I have not incorporated wood ash into a clay body. But like any material, if you need it to melt sooner, then you would need to explore different fluxes and to see if you can lower its temperature that way.

19:07While that mic's moving around, I'm going to just ask you, what type of fluxes are, when you're starting to experiment for that, what should we be looking for if you want to fire lower to get the flux to impact what she's asking about? Right. So when I'm using, like, in any glaze, right, when we have silica, silica doesn't want to melt at any lower temperatures. So when we use the soda ash or bone ash, we're trying to get it to melt, right?

19:40So if we're using a wood ash and that is not going to flux at the correct temperature, we might need to add some of that additional soda ash or additional materials like fritz that we know will encourage that chemical reaction at a lower temperature. Nice. Can I ask, why were you wanting to add wood ash to your clay? Just curiosity.

20:09Just, she said, just curiosity. And curiosity is a good thing. Do it, is the mic landed somewhere? Okay. Yeah, go ahead. Hi, my name is Riley Deller.

Mason Stains Discussion

20:20My Instagram is Riley Deller Art. I wanted to ask you a little bit about mason stains and adding those into clay, especially when it comes to high firing, like cone 10. I've experimented a little bit with cone 6, but I kind of want to bring that up to more of an atmospheric firing and was wondering, does that impact the clay's strength or anything that I have to kind of watch out for?

20:47So we just had visiting artist Kate Fisher to my college. And one of the things that I love about Kate's work is that she brings really bright, beautiful colors into cone 10 and to atmospheric firings. So what she was telling our students, and I hate that I'm repeating myself, is that you really do have to do those tests. Because yellows and oranges especially are really resistant to the higher temperatures, and so it's finding the right stain.

21:22I would reach out to Kate Fisher because she's got a really beautiful, bright palette in those atmospheric higher temperatures. I can add a little bit to that conversation. So when you're adding mason stains to clay in fire high temperature, think about the color of the clay that you're adding the stains to. So porcent responds better because it's a white clay body, and then you put the color in. And there's a lot of mason stains nowadays that is called encapsulated stains.

21:53They resist higher temperatures. So you do have to test, but there's a lot of beautiful colors you can get at high temperature. The one thing, like atmospheric firings usually include reduction firing. So you're reducing the amount of oxygen in the kiln, and those might affect the colors. So sometimes you might have, I don't know, like you chose a beautiful green, like in the mason stain palette, but you fire high temperature and it becomes reddish. So things might change because of the atmosphere of the firing.

22:25Another tip for you, usually the addition, like when you add stains, you have a beautiful saturated color, is 10%, 10% to 15%, depending on the pigment. So it is a lot of stains, and mason stains are, you know, quite pricey. So just test a lot before you go for it. So you're fine to count 10? Okay, so I think it's important to also, you, Louise was talking about reduction.

22:56I think that when you get up into your higher atmosphere, your higher temperatures, probably not reducing as heavy. Because reduction tends to darken your colors, even if it's a lighter clay. Is there a difference between manufacturers that would be important to take into consideration? Like, for instance, American pigments are supposed to be a stronger red source for pigments because they put a better ratio in there for getting that red.

23:31So I'm wondering, is brand name important to take into consideration?

23:38I think, I think testing is important to take into consideration.

23:46I'm going to keep saying that because, and I, and the reason I'm saying that is because I work with students, and I, you make this beautiful piece, and then you just, like, slob, like, glaze all over it, and then it comes out of the kiln, and you're really sad. So don't do that, right? But I actually have had really good experience, U.S. pigments, lots of different organizations, but it really is the percentage that I have found varies, right?

24:19So an encapsulated red in one company is not necessarily the same percentage, and so that's where that window of 10% to 15%, you're going to have to test to figure out where in that window. So another thing to test, too, is that if you're going to apply a glaze over this clay body, the colored clay body, depending on what is the flux or the raw materials in your glaze, it might change the color as well. So there's so many different variables.

24:51So you would have to, yeah, test a lot of different things. I think it's important to also think about the occurrence of zinc in your clay body or in your glaze, because that can alter the colors quite a bit if you're talking about those types of pigments. So just pay attention to that recipe if you're mixing your glaze and your clay. That's actually a really good point. I know that when we're, like, really excited about an idea, you know, that we can often forget to be very clear in our notes about what we've done.

25:28So that when we are testing, that we're also documenting, because it's the worst thing in the world, is to either, A, find the perfect thing and not be sure how you did it, or, B, make the same mistake again, because you didn't write it down. So just be really, you know, be really cautious about labeling your test tiles and writing very careful notes to yourself. Yeah. Yeah, I've got a couple of pieces that I think are amazing, and if only I remembered how I did it.

26:01I know. And I always have students bring me a vessel, and they're like, what did I do? And I'm, like, trying to be a forensic scientist, like, is there oxide wash? Is there oxide wash and slip? Are there two glazes? You know, so I think if we write it down, it can be, it can feel a little, like, stifling at times, but it's going to be really beneficial in the long run. What you did is you didn't write it down. Yeah. I know the mic has landed over there, but please be sure to raise your hand so we can start. He's going to be running that microphone around, so as soon as this question is answered, Ben will bring it over to you.

26:38So make sure you raise your hands for your next question. Okay, so as this one's going, raise your hand and get Ben's eye.

Firing Techniques

26:45So go ahead. Yeah. Hi. I'm Marie Wright, and my Instagram is mariewightpottery. I actually just wanted to make a comment because I do work with mason stains, encapsulated stains, firing to cone 11 with the zinc glaze, and I just wanted to say, if you're going to experiment with that, the rate of rise in the kiln has a really big effect on your results. If you can't get it to heat up fast enough, those encapsulated stains will start to degrade, and everything will go milky, and so I know some other potters who do it who can only do it on a fresh set of elements.

27:20They get great, vibrant colors on a fresh set of elements, but as the elements begin to degrade, those encapsulated stains start to burn out, and the glaces won't work anymore. I just love that, that all we have to do is change our elements after every fire. It's the best. How much did it cost to fire your kiln this week?

27:43I think all of the kiln companies would love that, too. Yes. Okay, I saw the mic land over here. Yes. Okay, so main questions. I work in non-functional sculpture, paper, paper, paper. That's, I love paper. But I do have questions about unfired paper clay, and the potential. Oh, yeah. I'm looking at you. Thank you. Hi. And my biggest concerns are regarding how fragile it could be, especially for transport.

28:21I mean, I know, test, test, test, I know. But I'm a little worried about, like, hey, I'm creating this piece. I do cold finishes. So I'm a little worried about transporting the piece, trying to get it safe to its exhibition space. Yeah, it's a really good. I have any tips. It's a really good comment. I mean, strength is, and durability is the temperature you're firing. It's not anything to do with cellulose or paper within the clay. Using paper, cellulose, in clay helps workability for some people, for some things.

28:58Okay? It is an aggregate, just like a choice, another aggregate, kitty litter, grog, or anything else that you're using as an aggregate. It's giving you an ability to work with the clay in a certain way. But if there's such a high percentage of cellulose, which, by the way, will all burn at 500 degrees, from 300 to 500 degrees, cellulose is burning. So there is no cellulose after 500 degrees within the clay body. So if you have put 30% paper fiber into the clay body, you have lost 30% of mass within your fire clay body.

29:35So, of course, you've increased your fragility. So you counter-respond to that by making sure you fire high, because durability is firing temp. So you make sure you fire always in paper clay, cone 6 and above, and it would be, you know, preferable above cone 6. And it's preferable if you're worried about strength, transporting paper clay objects after they're fired. Make sure you don't use 30% cellulose. Work in the 10, 12% cellulose volume in the clay body, and then you'll be fine.

30:12So remember, durability is firing. Okay? Durability in building is why the paper is there mixed into the clay. It gives you workability. Okay, so I found that a little bit of a different experience. I do agree that 30% is very, very high, because it makes your body very, very fragile. But 8% to 10% of the fiber can actually give you a little bit more green strength, I found.

30:48So that's a very important thing, too, is that not going too high, because obviously a lot of that material is going to burn away.

30:57And some of the other things that a lot of people think don't realize is that you can use various types of paper.

31:06I started out making paper clay with toilet paper, and it worked pretty well. But I also found that there's various qualities of paper, fiber that's really good. So I started to – I ran through so many paper shredders over the years, and I got tired of it, and I decided to take all my bills and soak them in water and turn them into pulp. And what I found was – That's the best use of the – Yeah, yeah.

31:34But I found that that paper had a really high quality. It was very, very, very strong when the fibers dissolved. So are you buying your paper clay, or are you mixing it? She buys it. So it might be good to make your own. I mean, your comment about currency is because it's a high percent of flax. Flax is a very, very strong fiber. Cotton, much less. Abaca, in between. Toilet paper, the cheapest and the least strength.

32:07Toilet paper, the least strength that you've found. So the kind of fiber does make a difference.

32:16So I have a question. Like, if – we're talking about firing the clay, the paper clay, and then losing, like, the strength and being more fragile after firing. But you can have a sculpture body that is just paper clay without firing. So in theory, if you have more pulp and more fiber, it's stronger because there's more network connecting things, correct? Correct. Because you mentioned – I think the question was, like, not firing the work. Ah, I didn't catch that even. I think so. Okay, so that's a good point. So adobe, non-fired paper clay, that's adobe, right?

32:48Whether it's beaten in a Hollander beater fiber or it's straw, it's all cellulose mixed into clay. Up to 40% gives you the optimal strength in building. So with non-firing, yeah, increase your amount of fiber if you want a really strong – that's what I do in my work. I work in the 30% to 40% cellulose volume in percent to my clay so that I can have a really, really durable form that's shippable and so on.

33:20So your point is right, Louise. Has that microphone landed somewhere? Okay, yeah, go ahead. Hi, I'm Sarah. My Instagram account is Sarah Catherine Clay. I'm a high school art teacher. And I have a question specifically about a dark cone 5'6 clay body called Kentucky Brown Bear. I'm loving the clay. I love the texture and everything. I don't glaze the outside of my pots. I only glaze the inside. And I'm finding that on the bottom of my pots, no matter how much I compress it, I have what

33:57looks like not as cracks but like random tears in the clay. And it's not necessarily always in the center. So they are like – yeah, it looks like tearing, pulling something apart. And my friend who uses the clay as well, glazes the outside and inside of her pots. So we're curious as to maybe it's the rate of firing that we're doing.

34:22Fascinating. It sounds like shrinkage. So you're getting the tearing when you're glazing the inside and the outside as well is what you're saying? Yep. Both if not and if you are. But it's the bottom, right? Usually the bottom. So that's – but it's not like an S-crap crack where it's following the throwing patterns, the spinning pattern. But it's – oh, that's weird. So it's hard to answer questions that are so specific because it's like, did you throw your pot?

34:54Did you hand-build your pot? Did you wedge the clay? How much did you wedge? So there's all these things to take into consideration. So I would make sure like wedge your clay really, really well so you're aligning the particles and getting everything really well mixed. And if you're throwing like compressing really well, those are – yeah, I don't know. I'm also curious about your clay storage. So clay that's gotten even not frozen but too cold does get very strange ripping if you don't properly re-wedge it.

35:26It's essentially like remixing the clay if it gets too cold.

35:31But I have to admit when you started, I was like, oh, it's because you're not glazing the inside. Because that would be my first reaction, right? Is that the glaze is pulling the interior of the clay in the way that the exterior is not being affected. But if you're glazing both sides, I would look at clay storage and tons and tons of compression. Did you try contacting the company to ask about it?

36:02That's my next step. Okay. That should be the first step. Always go for them. My friend did, but they didn't have a very clear response. I'd love to see a picture, though, because I'm really fascinated what that tear looks like. I mean, I think most of us are really familiar with the S-crack. But when your clay does something else, it's always really fascinating to be like, what happened to you? Why are you angry? I have a picture. And the other thing that I found interesting, because you're mentioning storage, we received the clay not during a cold time of the year.

36:42Darn, that was one of my best guesses.

36:45So did you fire that to cone 6? Is that what you said?

36:50She said yes, she did. Yeah. So have you tested to make sure that your kiln is firing to cone 6?

36:58Brand new kiln. Well, so actually brand new kiln is good. But have you tested with cones? Because there is the possibility that you're, okay, she has. So as they say, there is the possibility that you're slightly overfiring or that you're keeping it at 6 and the time over temperature is causing.

37:19But you're, nope, you're making all the head gestures at me that are like, no, Jessica, you're not helping me. So I'm going to, I'm going to let us, I'm going to let us move on. And then I'll make, if you've got questions up here in this section, I noticed we haven't got any questions from over here yet. So Ben will be grabbing one of y'all over here.

Test Tile Formatting

37:35But we got a question back there. Go ahead. Hi. My Instagram is Estra Arte. I was just curious if you guys have any experience using clay from caves and like what that looks like. We'll say clay from caves? From caves, yes. It's called cave clay. Cave clay. Yeah.

37:59I do not. No? I was going to say, I feel like this falls under the wild clay domain, which is not my expertise, but something where I think I'm going to. It's lost its ability to see. That's right. Like those.

38:18I mean, it sounds probable as a really good plastic clay because it seems like it would be the potential of drip or movement by water seems probable. And so that makes a really fine particle, clay particle, you know, transport by water, right? That's the fine particles. I would imagine less debris is being caught up in it. So it sounds like it would be worth trying and quite plastic. You might have to add the aggregate or a coarse, you know, a fire clay, a coarse particle to balance it if it's too plastic.

38:54Awesome. I also really enjoy a lot of the reading I've been doing and pieces I've been looking at where raw clay is being used as a terrace edge. So if you're finding a raw clay that has a really lovely color, but you're just not able to get that workability, then you can use that as a coating for maybe a more cooperative clay, a clay that will cooperate with you, and then use the wild clay as a surface treatment.

39:26And one tip, like just about this, if you're going to try and make a very thin slip to use this wild clay, some of those slips in higher temperature become a glaze. So really test the limit on those because you can get beautiful glazes at Conten. Testing. Oh, yeah. And sorry. And terra-stidging them, I think, is where I really have seen a lot of really beautiful sheens as well. Surfaces, yeah. My name is Ben Buse. My Instagram is Ben Buse Ceramics.

39:57So I'm curious about how you guys format test tiles, especially for labeling them and being able to get good information off of them. Because the amount of times I've made all these test tiles and then it's time for me to label them and it's like I could put just like one, two, three on them, then I'd have to like rifle through my book to find out what one, two, or three means. But I try to put all the information on there and then it's just, I don't have a lot of space. I'm just curious if you guys have any suggestions on how you format those in a way that's been successful for you. Well, you can do date, for example.

40:27You can put the date, like year, month, day. Like that gives you already like five numbers to, you know, isolate the test tiles and then an extra number if you're doing several test tiles on that day. That's one option. Another one is like if you just do one, two, three, after it's out of the kiln, you have to, you know, making test tiles is one thing, but observing the test tiles when they're out of the kiln is a big step that sometimes we don't take enough time doing it. But, you know, that's the information that we need to understand and take it in and then get a sharpie and write more on the back.

41:01So then you can really write like, I don't know, if I did this glaze with this flux, you can be more detailed. So you don't, you kind of, it's easier to refer to the book or your notes. Are you using raw oxides?

41:15So the response was that there's a red iron being used to mark the test tile. Is that correct? We have a high iron clay body. Oh, a high iron clay body. Gotcha. I've been trying to think about ways to label them, you know. Just curious if you like a form, it's like you can make a flat tile and you write on the back and it's a flat tile. Do you know those kind of stamps that, I don't know how they, like you would call, but they're stamps that have several numbers, like the one, like, I don't know, 10 rolls of numbers.

41:46So you can start like 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 3, and 4. So you can just, each test tile have a different number, so they're all serial that you can have. That's one way I would approach to. So it sounds like you're also thinking about the form that your test tiles are taking. Is that correct? Okay. So at my school, we do extruded triangle test tiles. So one side has a texture. One side has a line of a black oxide wash to help us to understand the translucency.

42:21And then one side is blank. We do the top two-thirds of the tile, which gives us the bottom third. And we do just do a number, but then when it comes out, we write oxidation or reduction, and we write additional information with Sharpie. And so they are pretty easily stored. And we also put a hole in them so that we have them hung on the wall for students to look at. But I also have a second set.

42:51I call them bucket charms, which is kind of ridiculous. But I call them bucket charms because I put a second set of the test tiles on the handle of the glaze bucket itself to try and help students to understand. But I think the three-sided test tile gives you a lot of great information. Hello. I'm Georgina. I'm Georgina T. Point Art. And I do irregular sculptures with circles. And I'm having a hard time finding good materials that I can use them as molds.

43:25Okay. So we usually use cast molds or, you know, something similar, but I want them irregular. So what do you suggest I can use as molds? So you're using plaster molds? Yeah, well, the plaster are regular.

43:41You know what I'm saying? They're regular. They are uniform. Uniform. And I want something that is different shapes, that I can make the shapes. Are you saying that you've got some that you've bought commercially from somebody, and now you're trying to find out how to make your own? That's correct. Okay. But not plaster, because, you know, like I say, I need movement on these shapes. So what other materials that I can use, like a sponge, but the sponge is not good because it's not firm.

44:16You understand me? Yes, so could you then use the plaster mold as a mother mold and then use clay to fill in the areas? Are you trying to – I'm not clear what – Okay. If you make, like, a line that is like this, let's say a curve, how do you do that without cast? You mean a support system underneath? Underneath – okay, now I understand.

44:48So you're looking for support systems underneath a form that's lifting off the flatness of the table. Right. Correct. So you said sponge. That can include my brain. Sponge is great. I mean, you can use anything to support under a form. One of my favorite things is to do, like, a sock filled with sand. You know, trying to think about the behavior of clay, behavior of clay has to shrink when it's drying, right? So I'm trying to support it as needed so that it can shrink with grace because if it's not shrinking with grace, we know it's going to crack.

45:24So if you can give it some sort of support underneath it that can move with the form as the clay is shrinking, you're not going to have the crack. So try to think creatively. It can be, you know, bound-up clothing. It could be, you know, the sponge is a great idea, but something that can move and breathe. I understand now. Newsprint is a really good material for that, too. Newsprint? Newspaper? Newspapers, yeah. And I used tar paper at the beginning, but obviously that's something that you have to remove before the clay gets too dry because it will adhere and cause cracking.

46:03But I find that tar paper lets me get some really nice undulation in the form. Well, it sounds like you're trying to make something you can reproduce more than once. Is that correct? No. Just once? Oh, okay. They're all different, she said. Okay, sounds good. Okay, as the mic moves around, I just wanted to say, Rebecca, that I really appreciate you, but that shrink gracefully, that's just a great way to describe it. Well, if you think about it, it has to do what it needs to do, right?

46:34If only I could shrink gracefully. It's so painful. So, yeah, go ahead.

Kiln Settings and Holds

46:40This is Jeannie Gray. I was wondering about the kiln settings of slow, medium, fast, and what that does in a hold and describing the different holds and what that does. Slow, medium, fast first. So, are you firing thinware, thickware? What are you trying to fire? Okay. General question.

47:10Generally speaking. Okay. Basically, I think a real good rule of thumb, and I would say this mainly for maybe sculptural things, is to try to extend the period of time at the lower temperatures to make sure that you get a lot of the steam out of it. So, I know there's a misconception, I'm going to challenge this one, the air bubble. Bring it, Bobby. The one that causes the explosions. I totally disagree with that.

47:42I think the biggest culprit in terms of losing pieces in BISC is not air, but it's steam. Steam is very, very powerful. You know, when water reaches about 212 degrees Fahrenheit, it turns to steam. It becomes very volatile. And having, you know, too much water in the clay during that time when it starts to turn to steam, it's got to go somewhere. That's where a lot of loss takes place. So, extending that period of time on a preheat, I think, is really, really important.

48:14And I think I've found sometimes that steam can leave a piece and migrate into a dry piece as well in the early stages of a firing. So, you have to really be careful about allowing moisture to leave that atmosphere. The kiln altogether, not just the clay. Yeah, really important. That's interesting. Yeah. So, removing a peep. Or venting. Or venting. Or at some point, because if you're keeping all of your peeps in and your lid is closed,

48:46then that moisture doesn't have anywhere to go for really wet, thicker work. High firework would intentionally put air bubbles in them, and they succeed all the time. But really, that's a really important thing. But now you're talking about holding. I think holding is more important with glazes than it is with clays. So, especially if you're talking about crystalline glazes, but I normally don't see a good reason to hold the temperature.

49:17Well, I would disagree. Like, I think there's a lot of great reasons, like programming your kiln and making, like, different holds. So, for example, you're talking about fast, medium, slow, like the pre-settings of the kiln. I always tell my students, no, no for fast. Never do the fast. Because fast is too aggressive, in my opinion. But we go, like, you can program and you can do the kiln, do whatever you want. That's a great advantage of having a computer now. So, you can go really slow. So, you decide how much, like, degrees an hour the kiln goes.

49:48So, you can go 10 degrees an hour until you reach 90 and then hold it for five hours. So, like, the moisture is starting to leave the piece. And then you can go 10 degrees until 180 or 190 before it's boiling, right? And then you hold it there until it's completely dry. And then you want to make sure you burn all the combustibles out of the clay. So, that's another hold in, like, I don't know the temperature, maybe 400. I don't know the numbers very well. I'm a Celsius person, not a Fahrenheit. There's quartz inversion.

50:19So, between 900 and 1200, if you're making sculpture and it's thick, you need to go slow. You need to give time for clay to, like, move on the way up and on the way back. So, it's, like, there's, it's a, I think it's a super great tool we have in the kilns, like, that you can have this computer. So, it's just a matter of studying what is the work you're firing and how, like, the best way, I don't know, for yours, if it's a sculpture especially, like, I don't know. It's, yeah. There's just, I cannot, like, give a general because it's very specific to the work it's being fired.

50:51But there's a lot to take into consideration, and I think coding, it's a great tool we have. I think slowing down. I don't usually hold during quartz inversion, but I do slow down to 100 degrees an hour between 900 and 1200 to really allow all the different clay bodies that the students are using to go through that quartz inversion properly. And so, I have a modification of the kiln program that Christina West used in my, like, grad program that's, like, kind of tweaked over the years.

51:26But I do think taking the opportunity to program it yourself and really get the things that you need is important. It really makes a difference to some of those bowls or plates, whether they come out wonky or not, is whether it's been given the time to adjust on the way up or on the way down because that clay is so, it's going through such a violent experience with the heat. And as it contorts, it needs to contort together, right? Is that accurate?

51:57Right. Well, but the other thing is, and I would be happy to share the program with anyone who wants it, but the other thing is that we have bowls, and then I also have, like, busts, right, in the same kiln, right, really thick sculpture and then really delicate teacups. And so, finding that we do have to go a little slower during certain periods that maybe the teacup doesn't need it, but that figure certainly does. So, trying to find something that most clay is happy with.

52:32I don't think that our particular BISC program is like magic, but it is, I'm happy to share it if anyone's interested.

52:42Carmelo Picconi from Beggar's Tomb Pottery. Just hoping you all can help me, can explain to me, there's paper clay that's commercial that they claim can go from 06 to cone 10. What happens with the glazes on this clay body? I would expect crazing with some of the glazes, and I'm told that it takes it. No, no, you don't need to worry about glazing fired paper clay. Because paper is present as you build and up to 500 degrees, and then it's gone.

53:18And so, you are glazing your clay body, just clay body, okay? But they're claiming that this paper, commercial paper clay, can go 06 to cone 10. That's true. I mean, I'm sure that's true. But why? But there's less, you know, but fragility is different from 06 to cone 10. Cone 10, you have the largest strength. It's dense, right? Density is temperature. So, the higher the temperature, the stronger the form is going to be when it's fired.

53:49So, 06 is still porous. You put your tongue on it. It can still receive water. It still has porosity, which means it's weaker. But there's still not a problem with glaze. Actually, glaze is glue in this case. Glaze on top of a low-fired paper clay form increases strength. All right? So, think about that. That's glaze as glue. That's glaze solidifying increasing density, okay? So, if you want to work in low-fire paper clay and you want to work in those low temperatures,

54:23glazing is a great idea.

54:26You also have more absorption of a glaze with paper clay at a bit's temperature because the body is more porous.

54:36I do have something to consider. When a clay body is rated 06 to 10, for me, it's, like, alarming because, of course, it can fire to 06 because that's the best temperature. But it's telling the max is con 10. So, oh, temperature's underneath, right? If you're making sculpture, I don't think it matters much unless it's a sculpture that is going to be put in the weather where there's snow and ice and thaw and all those problems that come with it. But if you're making functional work and you're getting a clay body that vitrifies at cone 10 but you're firing at cone 06, that is a problem because the clay is porous.

55:13And then, even if you put glaze, it's still not going to be strong and, like, incredibly functional. I would. That's my opinion, right? So, can I just really quick, like, so I always tell my students that when the clay is greenware that it's, like, and bone dry, it's, like, an infant, right? It's, like, as fragile as it gets. And then we bisque fire and I tell them it's a teenager. It's got big old open pores. It's not mature yet, right?

55:44So, then it can absorb the glaze. But if you take that clay all the way to its maturity, its pores are closed and it can't absorb the glaze. So, glaze is like roofing, right? You want microscopic nails to go down through your clay body. What's the thing on the top of the roof? Shingles. There we go. You want those nails to go down and hold on your shingles, right?

56:17My concern about body, clay bodies that have such a wide range of, quote, maturity is that the reality is they mature when the clay has gotten as tight of pores as they can be and is nice and strong. So, it does depend on what you're using it for. But if you just remember, like, that bone dry clay is an infant. Bisque is, like, that teenager, that awkward, not mature yet. But once you get your clay to maturity, that's where you have that strength.

56:48And so, yeah, I agree. Like, when the mature range is that big, it's concerning to me. I'm kind of getting to that point where I'm over-fired then, right? Yeah. I don't think you're over-fired. I think you're just perfectly done. You're good.

57:04Hi. My name is Mikey from Chicago. We were kind of touching on some durability stuff earlier. I had a question regarding that. I do slip cast porcelain. I use some commercial slips. I have this one slip that I mix myself. And I have a question about the durability, not even after firing, but kind of at the greenware stage. So I made this one batch, and I'm casting – it's, like, a translucent kind of body, so I'm casting super, super thin. And this one batch, I made it even at a greenware stage, even though it's thin.

57:37It was really strong. Like, I could kind of, like, bump it. It was fine. But this recent batch that I made, I've just lost every piece. Like, they haven't even made it to the kiln because, like, the littlest thing will just – so I don't know. It's a pretty simple recipe. It's, like, mainly EPK, custard for the time being, a little bit of tile six. And I was wondering if there's, like, an ingredient or an additive that I can add to the slip mix that can give it a little bit of durability, just kind of, like, in the handling process. Yeah.

58:08What deflaculant are you using? Yeah. I use Darvan. Like, deflaculant. Darvan at 11. We have time to give you a one-minute answer to that three-minute question. Because that's a big deal, but we've got to wrap it up. But go ahead, please. It sounded like it was a deflaculant issue, but I'm going to just throw out Jeremy Jernigan from Tulane. He mixes nylon fiber in with a slip and casts really, really thin and has tremendous success. Brilliant. Thank you. Well, listen, it's time for us to wrap up. I see hands are still being raised.

58:38I know that there's so many questions that we can be able to get to. These people are not leaving anywhere. They're going to stay here all day and answer questions inside the door. Or, hey, real quickly, there's going to be four, and I think we're announcing this at all the things. There's going to be a podcast party tonight at the Hive at start at 9 o'clock, and we'd love to be able to see you there. We're so grateful that you took the time to come and ask the questions. Seriously, we will be around for a few minutes. I know that we're going to have another one starting up soon, but we've got to kind of go out the door. So we're going to be heading that way, but feel free to come and grab us.

59:10But thank you so much. Lots of love to you all. Thank you. Thank you for listening.

59:44Thank you. Thank you. Thank you.