Crazing and Shivering
Welp, this has officially been the worst couple of weeks I can recall having in quite a long time, and it’s probably not a coincidence that the downward spiral began exactly when Mars went into retrograde, lol. I don’t follow astrology much at all, other than the monthly Chani Nicholas horoscope that shows up in my email inbox which I don’t even read regularly. But sometimes I get so overwhelmed by the way life is life-ing that I have to consult with my tarot reader friend who then gets me up to speed: “yep, everything sucks, for pretty much everybody, pretty much everywhere, so struggle through it, it ends mid-November” (not a direct quote).
a shot of my workspace in the Pot Studio. I need lots more storage down here and more table space would be great too, but I am very thankful for this set up we have created using stuff we already had in the garage/house.
It’s been both big things and little things. My best buddy got an unexpected, very unwanted medical diagnosis that I remain optimistic about but still feel devastated by. My partner has been experiencing unparallelled stress and anxiety that has manifested itself physically and emotionally in ways that I feel powerless to rectify. My brother’s mom passed away suddenly and the hospital may have some responsibility in not giving her the care that she needed because she had no health insurance. I accidentally washed my face with sunscreen. Twice in one week I used the wrong side of the salt shaker to ruin a meal, mistakenly using the “pour” side instead of the “shake” one; four tablespoons of salt into a freshly made pot of kale and white bean soup one day, two tablespoons onto my just-heated tupperware of leftovers on another. Then earlier this week, I realized that the last big batch of pottery I had completed and was finally ready to sell on etsy was ruined because of an issue called “crazing”, where the glaze essentially does not fit onto the claybody it has been applied to, so the glaze shrinks smaller than the ceramic underneath and creates (an admittedly pretty) cracked effect. Crazing is a technique that is often used on purpose, but only for decorative ceramics. For domestic pottery, crazing renders the piece unusable because it isn’t food safe- bacteria can get into the cracks of the glaze, tiny as they are, and create an environment of bad news for bodies. Some people insist that crazing was present in the majority of ceramics made throughout the ages and is not that big a deal but…our ancestors weren’t exactly THRIVING back in the day, with their short life expectancy and ignorance about food-born illnesses. I’d rather be safe than sorry, particularly when selling wares to others. So it’s back to the pottery wheel for me.
This is one of the more obviously crazed pieces, where the crazing shows up even when it’s dry. It was briefly a drinking cup but now its relegated to being a pot for claire to put plants in.
Given what the rest of my life has been looking like lately, I am actually not too devastated by the news that I have to essentially build my merchandise stock back up from scratch- this feels like small potatoes compared to everything else. I think it’s also because I am still so deep in the process of learning that everytime I pull a completed piece out of the kiln, I already have between one and eighteen things I know I want to do or change for the next time I make it, so at least now I have the opportunity to implement those changes and have my offerings look even better than before. Next time I wanna make this part bigger, next time I should attach this when they are still a little wet, next time I want to pull my handles separately so they are all uniform, next time, next time, next time. Normally I don’t mind the “next time” thinking because it reminds me that I am learning and experimenting and still being challenged in my creative pursuits, which I love. But it can be really overwhelming when you’re in the middle of a learning curve while simultaneously trying to capitalize on the stuff that you do know how to do. It just feels like a lot. But as I said in an earlier post, ceramics have given me something to focus on and immerse myself in, which has been an absolute blessing during this pandemic. It has kept me (mostly) sane, grounded and engrossed, and allowed me to obsess over something I actually have control over, something that brings me joy, unlike all the things happening in the world in which I feel a mere stunned observer.
This pot is made of the same clay and has no crazing- totally smooth and non- crackly both inside and out- it’s safe!
So even though the crazing was so disappointing to learn about, I feel like I have the information necessary to move forward from it. Here’s a simple breakdown of the crazing issue for anyone who is interested (there is lots more detail to the information I am providing so please only consider it a brief overview): Clay is generally divided into low, mid and high fire ranges, which coordinate with the temperatures at which the clay vitrifies (vitrify= becomes it’s strongest self and can effectively hold water without being porous anymore): low fire clay gets fired at a lower temp, mid fire is higher than that that and high fire is of course the highest. More specifically, the clay is referred to by it’s “cone” number, which is essentially the effect of time + heat on the clay. When you fire clay, depending on what kind of clay you are using, the clay will shrink a certain percentage which is why when you make stuff with raw clay you have to account for the size you want it to end up after firing, not the size of what you have actually made.
Now in addition to the variables with claybodies, you add even more when you add glaze to the equation. Glaze is a combination of clay ingredients + water + glass, and when heated to a certain temperature (glaze is categorized by cone numbers as well), it melts and then hardens to form the glossy, brightly colored finish you find on most modern ceramics. An important thing to note is that, like most substances on this earth, glaze also changes when heated and cooled, expanding and shrinking in tandem with the temperature it’s withstanding.
In my little “pot studio” I have been working with cone 5 clay and working with glazes between cone 06 (lowfire range) and 5 (midfire range). And here is where my Learning Success™ lies: sometimes if you put a lowfire range glaze on a mid or high fire clay body and only fire it to the low range of the glaze, the clay hasn’t fully vitrified and/or shrunk down to it’s smallest self, so essentially the glaze is firing smaller than the body of the clay. When the piece cools the glaze shrinks more rapidly than the clay underneath does, which causes the glaze to crack and create the “crazing” effect as seen above. All the pieces that I have fired to mid range have come out perfectly with no crazing at all, but most of the pieces that I fired to low range (to accommodate the low fire glaze I painted them with) have come out crazed, though I didn’t know it at the time. For my pieces, the crazing wasn’t evident until they were rinsed with water, and then all of a sudden I could see this crackle effect all over! I didn’t even know it was “bad” initially- I thought it was just something happening with my glaze application or the brands of glaze I was using. Thankfully I did some research after seeing it happen on so many pieces and was able to alter my process before I started selling them. Although I have so enjoyed learning at my own pace and in my own space, this is the price of learning without a ton of professional guidance along the way. Trial and error is my preference, but it does not come without its’ downsides!
This is the mishima design that I have developed over the past couple months and I love it so much. Unfortunately these aren’t safe but I will absolutely be making a new and improved batch soon.
Anyways, to remedy the crazing issue on my future work, I ordered a new lowfire clay body to try out which should work better with the low fire glazes I have in my studio, and I also ordered a midfire clear glaze to use with the midfire clays I already have (the clear glaze is important for the mugs I make with mishima decoration seen above). Ideally I prefer firing my kiln in the low range because it uses less energy, but the actual midfire glaze effects are some of my favorites. Their finish has this antiqued look to it and the colors look a little vintage and worn, which I love. But many of my speckled glazes are low fire and I LOVE the speckled glazes, so I want to get as much use out of them (and everything else I currently have in my studio) as I continue to hone in on my style and design preferences.
edit: A lot of people on IG wrote me asking whether or not I could save the crazed pieces by reglazing them, so I guess I didn’t clarify the details of this well enough. I put a low fire glaze onto a high fire claybody and fired it at a low fire temperature to accomodate the glaze. The lowfire glaze cannot withstand a higher temperature (otherwise I would have been firing at that temp all along). So reglazing the pieces with high fire glaze wouldn’t rectify the fact that there is low fire glaze underneath, which will have a bad reaction to being fired at a higher temp and will likely ruin the entire piece in a new way, not to mention the fact that putting a new glaze on top of an unstable (crazed) glaze would probably make the new glaze malfunction as well. So no, there is no fool proof way (that I am aware of) to save a crazed piece of pottery that would keep its’ original condition intact. Apparently you CAN reglaze non-crazed pottery if there is an issue with the glaze or color or something, but I personally haven’t done it to great success- my pieces either came out with more issues or didn’t fix the issue that made me reglaze it in the first place. Also, some ceramics are totally fine at first and then can develop crazing over the years, so if you’re uncomfortable eating off of non-food safe ware, just relegate the pieces to decoration or get rid of it.
if you look closely at the far right side of the bowl in this picture, you can see a little shadow inside the lines… that is where the underglaze has bubbled and lifted up off the claybody during the bisque fire. SHIVER.
Another issue I have been faced with trying to remedy is something called “shivering”, which is peripherally related to crazing. I’ve been experimenting with a decorating technique called sgraffito, where you cover greenware (unfired clay) with something called underglaze, which is a product that behaves a bit different than regular glaze. Once the underglaze has dried, you can remove the underglaze and some of the leatherhard clay underneath with a tool to create images and decoration on the piece. Once the clay is bone dry, you bisque fire it and the underglaze, muted and matte, is permanently attached to the clay body. Next I cover the piece in clear glaze which allows the underglaze color to pop a bit and makes the whole piece glossy and water tight. Similar to mishima, I love this technique so much because it allows me to essentially draw on the ceramics in a way that gives the piece texture and visual and tactile interest, but for some reason a lot of my bisqued pieces end up with the underglaze flaking off in small chunks, even though it’s supposed to be firmly adhered to the claybody. Apparently a potential cause of this is that the underglaze is firing and shrinking at a different rate than the claybody, but there can also be issues with the chemical makeup of the underglaze (which I will be the first to tell you is absolutely over my head- I use pre-made commercial glazes so I’m not mixing the ingredients up and adjusting the recipe myself). When I read up on shivering, the easiest ways suggested to remedy it were using fewer layers of underglaze on the claybody and diluting it with water to lessen its’ strength. I also read that it tends to happen on very round pieces as opposed to flatter pieces, which made sense as my mugs and bowls were all affected the most. So hopefully I can test out these fixes soon and see if it makes any difference.
A close up of sgraffito on a mug. These haven’t been bisque fired yet, so not sure if they will shiver. Instead of leaving the lines “raw”, I’m going to try slip trailing darker underglaze into them to see what kind of effect it creates.
It’s been so interesting committing to selling handmade things while also experimenting and learning and testing and inspecting and studying the process of making ceramics. It’s like both things, the manufacturing and the learning, are on the same highway traveling at the same speed, but they started in different places, and they are struggling to stay in line with each other. I have so many ideas in my head of what I want to make and offer that it’s hard for me to keep up with them all, but I am also learning so much that it sometimes feels like there isn’t room for all my ideas. As soon as I make something for the first time, I very quickly figure out how I want to make it even better the next time, and then I get so caught up in “next time” thinking that the piece I made, which was perfectly lovely and nice, suddenly feels obsolete.
People on IG love these toast plates so much, which I am so grateful for! Previously I have been handbuilding them from slab and molding them into a slightly upturned plate shape on the edges, but next I want to try the “poof” technique, where you use foam and a piece of wood to create a recess in a piece of clay. Hard to explain so I will take a video of it if it’s successful and share what the process looks like.
I’m not sure what the rush is, why I can’t just sit back and enjoy the process of learning (which you know I love!) instead of doing that while also trying to sell things at the same time, but I blame COVID-19. In truth, I think it’s partly due to the enthusiasm of my instagram followers, who have been so supportive and excited to consume whatever I end up sharing in my etsy shop, and of course partly due to the unwanted stasis that the pandemic has brought to us. My life changed abruptly from being super busy with work, flying between 2 and 6 times a month to and from Vancouver, to suddenly not even needing (or wanting, for safety’s sake) to leave the house for more than a grocery run. So I think focusing on selling the ceramic items I’ve made has afforded me some forward momentum in my life to keep me engaged and feeling productive and creative.
I call this mug “Bow Down, Stitches”, which obviously has a sewing theme. It didn’t turn out well when I made this design with some of the lighter colored underglazes but it works beautifully with this coral color, and this is one of the only sgraffito mugs I made that didn’t shiver!
Now a lot can be said about the concept of “productivity” and the “capitalist inside of all of us” which makes us feel like we must force ourselves to work and be fruitful and busy all the time in order to be “valuable”, and I totally appreciate the conversations that have been springing up around this topic. But I also know my habits well and can recognize that I am not pushing myself to do something I don’t feel like doing, but rather I’m pushing myself out of my comfort zone, a small, but important difference. And quite honestly, something that my brain really needs these days. Worst case scenario for me is that I spend a lot of energy on the physical and mental work of developing a line of products to share on etsy and then I realize I just don’t enjoy the process at all. Thankfully the stakes for that are not very high, and if it does happen, the fix is easy: I just won’t sell publicly anymore, and I will save my makes for bestowing upon my friends and family.
These are incense holders and small bowls!
Thanks to Claire for most of these pics, and thanks, as always, for your encouragement, readership, support, and enthusiasm. It’s very inspiring and I do hope to be able to offer some fun ceramics products in the near future!
