There's one other thing I'll mention about compression, and it relates to making large bowls (which I'll talk about in more detail in another blog). I've seen many potters use a torch to harden the clay near the base when they're throwing large bowls with walls that spread out widely. There's no need to do that. If you use ribs on both sides of the wall and don't add more water or slip, you'll line up the clay particles on both sides of the wall which will make the wall stronger. The thinner the wall becomes as you stretch it out, the higher the proportion of clay particles that are lined up together which allows you to bring the walls out even farther. Using this technique, you can almost lay the walls out flat without them falling down.
When I first started throwing pottery on the wheel more than 11 years ago, my teachers repeatedly encouraged me to "compress" the clay. They would usually refer to "compression" when they were working on the rim or the base. Compressing the base meant pressing down lightly on it with your fingers or a sponge or a rib. Compressing the rim meant pressing down lightly on it with your fingers or a chamoe. I was encouraged to do this so I wouldn't get nasty cracks in the base or the rim. But what is actually happening when we compress the clay and how does it help prevent cracking? At first, I figured it meant we were making the clay more dense in some way. Isn't that what compression means? Not in this case. In pottery terms, I think compression refers to at least two things. First, it refers to removing a layer of slip from the surface of the clay. Slip is clay mixed with water to form a slurry. The clay particles in the slurry are going every which way and if allowed to dry like this, cracks can develop. Second, it refers to lining clay particles up so they are running in the same direction and are stacked up together. When you compress the bottom of a pot or compress the rim, what you're really doing is lining up the clay particles very thinly at the surface. You don't need to line up every clay particle all the way through the body of the pot, just the ones on the surface on both sides in order to keep cracks from developing. It's usually enough to use your fingers or a chamoe to remove slip on the rim and line up the clay particles. At the base, it's important to compress the clay on both sides of the pot. Compress the bottom when you're throwing, but also compress the bottom on the other side when you're trimming the base. After trimming the foot, I usually take a wet sponge and very lightly wet the inside of the foot to create a little slip. Then I use a small red rib to smooth out the bottom. When you're done, you know the clay particles are lined up because the surface almost looks shiny, like it's been burnished. This is one of the main reasons why pieces thrown off the hump so often develop S-cracks: they are only compressed on one side of the base.
There's one other thing I'll mention about compression, and it relates to making large bowls (which I'll talk about in more detail in another blog). I've seen many potters use a torch to harden the clay near the base when they're throwing large bowls with walls that spread out widely. There's no need to do that. If you use ribs on both sides of the wall and don't add more water or slip, you'll line up the clay particles on both sides of the wall which will make the wall stronger. The thinner the wall becomes as you stretch it out, the higher the proportion of clay particles that are lined up together which allows you to bring the walls out even farther. Using this technique, you can almost lay the walls out flat without them falling down.
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I'm a member of the Windward Potters and we'll be having our first sale in two years on Saturday, November 27th, from 8:30am to 3pm at the Daybreak Church lanai, 1230 Kailua Road. Daybreak is right next to the YMCA just before you get to Kailua Town. It used to be Faith Baptist Church, if that name's more familiar. Hundreds of pots will be available, and a free pot can be chosen if you purchase $100 or more. Below are photos of a few of the pots I'll have available. I hope to see you at the sale!
The Arts and Crafts Center at Hickam has almost 30 glazes available for students. I made cups to test the glazes, some made with a light recycled clay and some with a dark recycled clay. I'm including a few examples of the same glaze on both light and dark clay. Below are the results in alphabetical order.
Update 12/12/19: Yesterday I had quite a few pots come out of the kiln and I'll be offering them for sale at my house on December 14 and 21 from 9am to 3pm. I've included photos of some of them below. You can find the new pots beginning about half way down this list of photos.
I'll have sales at our house in Kailua on two Saturdays, December 7 and 14, from 9am to 3pm. If you're in the area, I hope you'll stop by and take a look. You might find something special for that someone special, or just for yourself! Our new address in Kailua is 641 Manu Oo St. You can park in the driveway, and there's plenty of parking on the street or at the YMCA which is only a few houses away. Below are photos of some of the pots that will be for sale. Hope to see you here! The Hawaii Craftsmen 2019 Annual Statewide Exhibition is on now at the gallery at the Honolulu Museum of Art School until the end of September. I photographed all of the ceramic pieces. I didn't submit anything to the show this year.
I'm having two sales at my studio in Manoa this spring just before Mothers' Day. The first sale will be Saturday, May 4, from 9am to 2pm or so. The second will be the following Saturday, May 11, from 9am to 2pm. I have quite a few new pieces and below are photos of some of them. Our address is 2966 Oahu Ave. in Manoa. We have a few parking spots in the driveway and street parking is available just around the corner on Lowrey.
The owner is selling the house we've been living in (I almost said "our house") for the past 3 years so we're moving to Kailua at the middle of this month. This will be the last sale I'll be doing in Manoa. I appreciate all the support I've received from the people of Manoa and hope I can begin having sales at a different venue in Manoa by this November. For the sale on May 11, I've also decided to offer several antiques that I've collected over the years because we're moving into a smaller place. Most of these are baskets but I'm also offering other pieces like an oak settle from Gus Stickley made in 1915/1916, a beautiful Japanese hibachi, an inlaid tray with metal fittings, and a large platter that I bought from John Glick at his studio in Michigan shortly before he passed away. John Glick was one of America's most important potters, the last of the "abstract expressionists" who worked in clay that included artists like Toshiko Takaezu. Images of the pieces along with prices, brief descriptions and dimensions are included after the images of pots. Please let me know if you have questions about any of this: (808) 358-0717. Several years ago I took a workshop with Julia Galloway. During one of her presentations about decorating and glazing bisqued pots, one of the students mentioned she had dozens of bisqued pots in her garage that she'd never glazed because she couldn't decide how to glaze them. Julia laughed and said she knew many potters like that, so many she'd come up with a name for them: bisque potters.
I've met many potters who struggle to decide how to glaze their pots. At HPG we have over 50 glazes, so there are plenty of glazes to choose from, and that might be part of the problem. There are so many choices that people can't make up their mind. Following are some suggestions that I hope will make your choosing a little easier. I should also add that the following information is really about how to prepare to glaze your pots and not the actual techniques for glazing. Those are best handled through demonstrations or videos. First, start a notebook. I have a longer blog about that right here: www.jonrawlingspottery.com/blog/keeping-a-notebook I draw simple pictures of each pot and include basic information about what clay I used to make it and what I may have done to decorate it before glazing, especially if I carved it. I usually wait until I have at least 10 large pots before I start glazing them. I number each pot on the bottom of the foot and put that down in the notebook since it's easy to get similar pots mixed up. I lay them out on a table and begin thinking about how to decorate them. I take my time with this. I try to get the juices flowing by thinking about simple things like how to glaze the inside of vases. Okay, I'm usually going to use a white glaze like Glossy White or Miller White so I write that down. With large bowls I start by deciding whether or not to use a wax resist pattern on the inside or outside. All of these decisions can be tweaked as I glaze, but using a notebook helps me organize my thinking, decide what I want to do, and keep a record of those decisions. Second, think about the clay you're using. As I draw each pot in my notebook, I note above it what clay I used. After numbering each pot, I start with pot #1 and start thinking about how I might glaze it. Glazes look different on different clay bodies. If I use Butter Yellow on Rod's Bod, it looks like burl wood; if I use it on porcelain, it looks light yellow. After some experience, you'll begin making certain shapes with certain clay bodies with specific glazes already in mind. For more detailed examples about how to glaze different clay bodies, see my blog on black and brown stoneware: www.jonrawlingspottery.com/blog/black-and-brown-stoneware Third, think about what glazes are appropriate for your pot's form and function. I'm often surprised by the glazes some potters use on their pieces. For instance, I've seen potters carve a piece with meticulous detail only to cover it all up with a thick Shino glaze. Or they use a glaze that seems inappropriate for a functional piece. I'm no expert on what glazes are more food safe, but it certainly seems we need to give more attention to this at our potters guilds. I didn't even know it was an issue the first year or so I was making pots, so I sold small bowls to unsuspecting customers that had copper or cobalt or chrome in the liner and I even sold them bowls with crystalline glazes inside. When I started learning more about some glazes being food safe and others not so much, I asked more experienced potters and teachers about what glazes were appropriate to use. Everyone waved off my concerns with comments like "Oh, I heard it's fine" or "Don't worry about it. Just don't store spaghetti sauce in it for a week." Maybe we should send examples of all of our glazes to a lab so we can be sure how much stuff might be leaching into food from our glazes. Commercial makers are held to high standards because it could impact public safety; maybe we should hold ourselves to the same high standards as well. As an intermediate step, I try to use only glossy glazes as liners for small bowls, especially glossy white. I'm also doing experiments on clear glazes that won't craze as much since we have several glazes based on a single chun recipe that tend to craze dramatically. Fourth, think about how you'll apply the glazes and in what order. If I dip a pot in Butter Yellow it will be a glossy light yellow; if I spray it, Butter Yellow will be a matte light brown or tan depending on the clay body. Some dark clay bodies like Black Mountain will turn every glaze dark brown if they're applied too thinly. A second coat is necessary to get any of the original glaze's color to show up at all. Some glazes look awful on porcelain but on darker clay they look terrific with lots of variation in color depending on the thickness. I use several techniques to apply glazes to pots. With bowls I tend to pour glazes inside to give it a thick layer. After waiting a day for the glaze to dry. I turn the bowl upside down and spray the outside. If I've made a wax resist pattern outside, I'll pour the glaze. Wax resist doesn't work that well with spraying as the glaze tends to build up on the edges and stops shedding off. I'll then turn the bowl over and apply another glaze inside using techniques such as spraying, spritzing, or different designs with a ketchup bottle or rubber syringe. I also consider what order I'll use to glaze each pot. For instance, I glaze the inside of a bowl first. I want a thick layer so I usually pour a glaze inside, swish it around for a few seconds, and pour it out. If I spray a glaze inside, I've found it difficult to trail glazes over the sprayed layer. The sprayed glaze usually is fluffy and the trailed glaze will sit up on the glaze and often flake off. I also need a thick enough glaze layer to get some of the effects I'm going after, especially on darker clay. I'll usually wait a day for the pot to dry and then turn it upside down on a banding wheel and glaze the outside, usually by spraying. If I'm spraying or trailing another glaze on the inside, I'll turn the pot right side up and glaze it the same day. No need to wait another day. Since it takes so much time to set up the spray booth and then clean it after, I always wait until I have at least 10 pots before I start glazing. I glaze the insides of all of them, wait at least a day, then glaze the outside and finish up the inside. I organize pots according to the glazes I'm going to use. If I have four bowls that need to be sprayed outside with Butter Yellow, I'll spray them one after another until I'm finished. Then if I have two that need Sky Blue Chun I'll spray them next. After I'm done on the outside, I'll reorganize them according to what glazes I'll need on the inside, if I'm spraying them. So some of them will need to be sprayed with Oxblood, some with Pete's Cranberry, and so forth. I plan on writing a blog about how to spray pots so I'll say more about spraying in the future. Fifth, prepare pots for glazing. If I have the time, I completely wash my pots after they've been bisqued, especially porcelain. I do some sanding on all of my pots and they typically have quite a bit of clay dust on them. Removing the dust is imperative if you want the glaze to adhere well. I'm especially careful with pots that I've carved. I'll use a toothbrush and water to remove all of the dust from recesses that might cause the glaze to not adhere to the pot. If I wash a pot like this, I have to wait at least a day before the pot is dry enough to glaze. If the pot doesn't have much dust on it because I only lightly sanded it, I'll use a sponge to wipe off all of the surfaces. I'll wait an hour or so until the pot has had some time to dry before glazing it. When pots are bisqued, they are strong enough to handle more aggressively and yet are still porous since they're not fully vitrified. Glazes are a slurry of powdered minerals mixed in water and very little material in glazes is soluble. When applied to a porous bisqued pot, the water is absorbed into the body of the pot leaving a thin layer of powdered minerals on the surface. If the pot is too saturated with water, a glaze applied to the other side of the clay body will not absorb much water and will leave a layer of glaze that's too thin. The thinner the walls of the pot, the more important it becomes to wait until the inside of the pot is dry before glazing the outside. It's already difficult to get a thick enough layer of glaze if the walls of your pot are very thin since the walls cannot absorb much moisture before becoming fully saturated. Sixth, prepare your glaze. Start by taking a metal whisk and stirring the glaze from the bottom. You should use a motion that not only goes around but also begins lifting the material up toward the top. Whether you're dipping a pot into the glaze or scooping it into a pitcher, the glaze you're using will come from the top of the glaze. That's why it's important to make sure you mix the glaze until the stuff on the bottom has worked it's way to the top. HPG has several glazes that take some time and arm power to get thoroughly mixed. If you stop mixing too soon, the glaze will be watery and won't have all the material in it that you need. After the glaze is thoroughly mixed, I sieve the part I'm going to use. The only exception to this is if I'm glazing a large vase and need to dip it into the larger bucket. Otherwise, I always sieve the glaze to remove debris that's fallen into the bucket, material that hasn't mixed in well, and even pieces of plastic from the bottom of the bucket that have been shaved off by the whisk. This is worth the extra effort since it gives a more consistent result. If you've ever used unsieved glazes, you know how often debris can cause blemishes in the glaze. While I think sieving is usually the best thing to do when preparing glazes, it's absolutely essential when preparing glazes for spraying. I use a pretty fine stainless steel sieve that I picked up at Williams-Sonoma. You might think that sieving is a waste of time, but I've seen how much time people waste when their spray gun gets clogged up and they have to take it apart to remove the debris. A few simple steps will save you more time in the end and help you get a better result. Hawai'i Craftsmen recently held its annual juried exhibition at the gallery at the Honolulu Museum of Art School, Linekona. As usual, it included a number of stunning pieces in several categories including clay. Some of the best pieces were purchased by the Honolulu Museum of Art and the Hawai'i State Art Museum. Below are photos of all of the ceramic pieces in the exhibit. Sorry I couldn't include each piece in every medium, but it would have been a little too much. I start the photos with pieces by Jennifer Owen from Maui who was one of three artists who was chosen by Hawai'i Craftsmen to present a small exhibit of her work at the show.
The holiday season is upon us and I'll be having pottery sales at my studio the next three Saturdays, December 8th, 15th, and 22nd from 9am to 2pm. My address is 2966 Oahu Ave. in Manoa. Below is a preview of some of the pots that I'll be offering. Hope to see you soon!
In the September blog I wrote about my visit to Raku Ho'olaule'a on the North Shore of O'ahu. I took photos of people decorating and firing pots and generally having a good time. I should mention that although the event is called Raku Ho'olaule'a, many of the potters also pit fire pots. The visiting juror, Scott Young, chose the best pots on the last day and these were included in an exhibit at Jeff Chang's gallery at Windward Mall in Kaneohe.
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AuthorI hope this blog will be encouraging to potters, especially beginning potters, and a source of helpful information and comment. Archives
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