Pottery Making illustrated 1 2 Summer 2000 Features Throwing Square and Oval Plates with Kirk Mangus..9 by Anderson Turner A demonstration of throwing squares and ovals on the wheel. A Colored Clay Project...... 15 by Chris Campbell Using neriage technique to create colorful ornaments. Raku Pit-in-the-Box...... 21 by George Juliano with Elizabeth Hudgins Get consistent post-firing reduction from an airtight box you can build. Making a Moribana Tray...... 25 by Daryl Baird Create decorative planters using extruded forms with this step-by-step procedure. Twice-fired Glazes...... 28 by Lili Krakowski Mix up glazes that improve when fired a second time. Using a Throwing Stick...... 30 by Ivor Lewis Discover how to form broad-shouldered and narrow-necked forms. 2000 National K-12 Ceramic Exhibit ...... 32 Representative work from the third annual student ceramic art exhibition. Empty Bowls...... 37 by Craig Hinshaw Kids learn to use both heart and hand with a community project. Simplifying Glazes...... 41 by Sumi von Dassow Develop new glaze bases with an orderly testing method. Cut-off Wire Bow...... 44 by Don Adamaitis Forget the tangles, knots and sliced fingers with this do-it-yourself cut-off wire. Departments Clay Linksby Barbara Coultry ...... 6 Click That Page—A selection of magazines and newsletters online. The Budget Potterby Sylvia Shirley ...... 19 Glaze Sieve—Make an inexpensive glazing tool from department store parts. Off the Shelf by Sumi von Dassow...... 46 Glaze Calculation and Formulation—the basic texts for making glazes.

Cover: Square plate, 12 inches in width, stoneware with slip decoration, by Kirk Mangus. See story on page 9.

Pottery Making illustrated 3 Editor: Bill Jones Production Manager: John Wilson Circulation Supervisor: Cleopatra G. Eddie Graphic Design: Debi Hampton Graphic Production: David Houghton Advertising Manager: Steve Hecker Advertising Assistant: Debbie Plummer Customer Service: Mary Hopkins Publisher: Mark Mecklenborg Editorial, Advertising & Circulation Offices 735 Ceramic Place PO Box 6136 Westerville, OH 43086-6136 Phone:(614) 794-5890 Fax: (614) 794-5892 E-mail: [email protected] www.potterymaking.org Pottery Making Illustrated (ISSN 1096-830X) is pub­ lished 5 times a year by The American Ceramic Society, 735 Ceramic Place, Westerville, OH 43081. Periodical postage paid at Westerville, OH, and addi­ tional mailing offices. Opinions expressed are those of the contributors and do not necessarily represent those of the editors or The American Ceramic Society. Subscription rates: 5 issues (1 year) $18, 10 issues (2 years) $34, 15 issues (3 years) $49. Add $15 per year for subscriptions outside North America. In Canada, add 7% GST (R123994618). All payments must be in US$ and drawn on a US bank. Allow 6-8 weeks for delivery. Advertising: Ad rates and ad information are available on the web site or by contacting Steve Hecker at the address above or by phone at (614) 794-5809. Change of address: Send your change of address via e-mail or to the Circulation Department. Allow six weeks advance notice. Contributors: Writing and photographic guidelines are available on request and on the web site. Mail man­ uscripts and visual materials to the editorial offices. Photocopies: For a fee, searchable databases and document delivery are available through The American Ceramic Society’s Ceramic Information Center, PO Box 6136, Westerville, OH 43086- 6136; e-mail [email protected] ; or phone (614) 794- 5810. Permission to photocopy for personal or internal use beyond the limits of Sections 107 and 108 of the U.S. Copyright Law is granted by The American Ceramic Society, ISSN 1096- 830X, provided that the appropriate fee is paid directly to the Copyright Clearance Center, 222 Rosewood Dr., Danvers, MA 01923 USA (978) 750-8400; www.copyright.com . Prior to photo­ copying items for educational classroom use, please contact Copyright Clearance Center, Inc. This consent does not extend to copying items for general distribution, for advertising or promotional purposes or to republishing items in whole or in part in any work and in any format. Please direct republication or special copying permission requests to the Director of Publications, The American Ceramic Society, PO Box 6136, Westerville, OH 43086-6136. Back Issues: When available, back issues are $5 each plus $3 postage for the first copy and $1 for each additional copy thereafter. For orders outside North America, add $6 ($2 for additional copies). In Canada, add 7% GST. Postmaster: Send address changes to Pottery Making Illustrated, PO Box 6136, Westerville, OH 43086-6136. Form 3579 reauested.

Copyright © 2000 The American Ceramic Society All rights reserved www.ceramics.org 4 Summer 2000 Pottery Making illustrated 5 Click That Page In the future will we click all our magazine pages? Will we forget the pleasant shwip sound as we flip from back to front? Maybe, but I’d prefer things stayed as they are—a delightful mix of electronic and paper media. We no longer have to wait weeks to receive the trial issue of a magazine before we decide to subscribe to it, and we can now subscribe to a variety of newsletters, often free of charge. Here’s a list of quality magazine and newsletter sites where you can click the pages while by Barbara Coultry shwipping your coffee. Check out additional magazine and newsletter sites on the web at www.p0tterymaking.0r2.

The Crafts Report Mosaic Matters www.craftsreport.com www.users.dircon.co.uk/~asm No matter what kind of craftsperson you are—potter, silver­ You’ve already begun making tiles, or you soon will. In either smith, weaver—or whether you’re in business for yourself or case, Mosaic Matters’ electronic pages will hold your interest. would like to be, this magazine is for you. Its web site is filled Published twice yearly in its paper version, this newsletter has with online articles from the current issue all the way back to information on equipment, materials, techniques, suppliers, 1995. Go to the December 1997 issue, for instance, to discover books, workshops, exhibitions and current news. If you add to how to do “Credit Card Processing,” or click forward to this the comprehensive list of links to other mosaic sites, the October 1999 to read about “Finding and Selling through forum where readers can ask and answer questions and the illus­ Online Galleries.” If it’s a subject that applies to the business of trated features from past issues, you have a fine example of how craft, it’s either covered or it will be. paper and electronic media can truly complement one another.

Sunshine Artist Resource Library Magazine www.sunshineartist.com www.tfaoi.com/resourc.htm For those of you who do the traditional circuit of craft shows Subtitled “Americas Magazine for Representational Art,” this and fairs, here’s a magazine to fill some of your needs. Though online magazine’s spectrum is broad, covering all media, indexing not specific to clay, there’s plenty here for you.You’ll find arti­ all kinds of Internet art sites, leading you to articles about a vari­ cles about insurance, copyright, dealing with customers, display ety of art from the distant past to the present. You’ll find ceramics tips, even handling the weather, plus a whole lot more. Because here, but you’ll also find lots of inspiration in its broad selection. they keep the site up to date, you might want to bookmark Don’t it miss clicking about among the magazine’s columnists. so you’ll remember to return periodically to see what’s new. View additional sites containing articles from magazines and newsletters selected byBarbara Coultry on our web site at unvw.potterymaking.org/claylinks.html. Summer 2OOO rottery Makingillustrated ( 8 Summer 2000 WITH KIRK MANGUS by Anderson Turner Southeast of Cleveland, nestled on the rim of the Cuyahoga National Recreation Area, is the quaint town of Kent, Ohio, where the

tallest building is still a working grain eleva­ PHOTO: KEVIN OLDS tor. Within the town is Kent Sate University, which is home to many hidden treasures, including one of the leading craft depart­ ments in the country. Many artists and arti­ sans have walked the footpaths between buildings; among them is Kirk Mangus, head of the Ceramics Department. Always the craftsman and artist, Mangus takes the skill of throwing to interesting lev­ els by intermingling contemporary subject matter with a very old philosophy—he preaches simplicity and keeps his forms tra­ ditional, if sometimes unconventional. Square plate, 2 inches in height and 10 inches in width, iron stoneware with white slip, Chun Ash Glaze, Oval plates, 2 inches in height and 9 inches in length, iron stoneware with white slip, Gowdy Ash Glaze with Copper Ash over, fired to Cone 9.

“I began throwing square and oval kickwheel. I also learned how to throw moves apart allows me to juxtapose cir­ plates in 1985 when I did a workshopfive- and six-sided things. I had actual­ cles or spots or lines, making it possible in Chico, California,” Mangus ly seen people work this way before for me to create a certain tension on the explains: uThe idea was to make a using ribs, but it takes a little while for plate. They are also nice for painting 100-piece project, and I had to create all the light to go on sometimes. Once fish, I animals, people or even scenery. the work and put up the show within a realized I could spontaneously throw Since I paint all these sorts of things, week. I wanted to create something that something as an oval, square, five- orthey lend themselves to a horizontal or was graphic and strong, so I sat down six-sided object, I ran with it. The vertical landscape like a growing tendril and threw a hundred plates. project was very exciting in that regard. ” or a mountain range. One of my inter­ “I noticed a number of the plates had Mangus is intensely aware of the his­ ests in pots has been how to depict some hardened on one side from sitting ontorical context of his work. He has made sort of panorama. A panorama can either canvas and, as I was throwing them, the a study of Asian pottery, and uses thatbe something as simple as a division of plates often fell into an oval shape. knowledge I often as a source of inspira­a cell to painting mountains, rivers, trees liked this and started generating these tion.( Tve always been fond of old Shino and canyons. In both cases, you feel as forms, realizing how I could force theplates, like the square magpie plate from though you're looking into some sort of clay into the form I wanted. After the Mino area of Japan. Those pots often space. These layers of surface and densi­ awhile, I figured out how I could throw have pictures on them. I also like the ty are what interest me about pottery; squares and ovals and I started to be oval shape because it reminds me of a glaze and drawing on pots. ” able to control the throwing style on jellyfish a or cells dividing. The way it

Pottery Making illustrated 9 Oval plate PROCESS PHOTOS: ANDERSON TURNER

Step 1. To throw an oval plate, begin by Step 2. Gently shape the clay into a flat, Step 3. Slowly rotate the wheel in one placing a log of soft, well-wedged clay thick oval until it has a uniform thickness. direction and gradually bring up the walls across the center of the wheel head. of the plate.

Step 4. Reverse the rotation of the wheel Step 6. To trim the plate, position four and continue bringing up the walls. This balls around the center of the wheel- will reduce torque on the piece and keep head, then place the oval plate upside it from cracking or warping. Repeat sev­ Step 5. Finish the form with a rib tool in down on the balls. eral times. both directions.

Step 7. Hold down the plate while trim­ Step 8. Mangus uses a bent piece of ming the outside of the foot, and clean up metal to trim out the center of the foot, the plate exterior. then continues trimming to achieve the desired look.

10 Summer 2OOO SQUARE PLATE

Step 1 . To throw a square plate, begin by Step 2. Center the clay, then pull up the Step 3. Pull the walls out using the space placing a slightly larger than fist-sized sides to create a small thick bowl shape. between your first and second fingers. To piece of soft, well-wedged clay in the help compress the clay, alternate the center of the wheelhead. rotation of the wheel as you go.

Step 4. Reverse the direction of the Step 5. Continue reversing and shaping Step 6. Remember, work slowly and wheel often, and begin shaping the slowly and gently. Watch the overhang. If gently, and reverse the direction of the square by gently defining the corners of the form has too much overhang, it will wheel! Stay relaxed and don’t force the the plate. collapse, since the farthest point from the clay. center is the corner.

Step 7. Keep reversing the rotation of the Step 8. ...you’ve achieved the desired Step 9. At this point, it’s possible to clean wheel—a few turns in one direction and shape. up the shape with a tool, but your thumb a few in the other. Learn to compress the is also very effective. clay and get it to go where you want it to go until...

Pottery Makingillustrated 11 SQUARE PLATE (CONTINUED) Glaze Recipes Chun Ash Glaze Cone 9 reduction Ash...... 33% Potash Feldspar ...... 33 Ball Clay...... 30 Cedar Heights Redart Clay ...... 4 100% Gowdy Ash Glaze Cone 9 reduction Ash...... 20% Nepheline Syenite ...... 60 Flint ...... 20 100% Step 10. To trim a square plate, place three Step 11. Begin trimming the outside of balls in the shape of a triangle around the the foot, keeping your hand on the plate Copper Ash center of the wheel. Place the square plate so that it isn’t forced off the balls. Cone 9 reduction upside down on top of the balls. Ash...... 50% Nepheline Syenite ...... 50 100% Add: Copper Carbonate ...... 3% Shino Glaze Cone 9 reduction Ash...... 20% Kona F-4 Feldspar ...... 65 Kaolin...... 15 100%

Step 12. Clean up the exterior surface of Step 13. Gouge out the interior of the the plate. foot until you’ve achieved the desire look. Clay Recipes White Stoneware Kaolin ...... 60% Cedar Heights Fireclay ...... 20 Silica Sand...... 20 100% Add: Potash Feldspar ...... 10% High Iron Stoneware Clay Cedar Heights Redart ...... 30% Ball Clay...... 20 Kaolin...... 30 Fireclay ...... 20 100% Add: Potash Feldspar ...... 5% Silica Sand...... 5% The trimmed square plate. Kirk glazes his plates using splashed slip decoration. Iron Earth Slip Mangus dug this natural clay from the side of the road while driving across Nevada. It appears to be an ochre earth and starts to melt at high temperatures (Cone 1 and up). Anderson Turner is currently a graduate student at Kent State University working toward an MFA in ceramic art. He is a former Assistant Editor of Ceramics Monthly.

12 Summer 2000 Oval plates SQUARE PLATE PHOTOS: RHUE BRUGGEMAN

Square plate, 2 inches in height by 12 inches in width, White Stoneware with Iron Earth Slip and sgraffito decoration, Shino Glaze, fired to Oval plates, 2 inches in height by 7 inches in width, White Stoneware with Iron Earth Slip brushwork and Shino Glaze, fired to Cone 9 Cone 9 reduction. reduction.

EIGHT-SIDED PLATE FIVE-SIDED PLATE

Eight-sided plate, 2 inches in height by 12 inches in width, White Stoneware with Iron Earth Slip and brushed decoration, Shino Glaze, fired to Cone 9 reduction.

Five-sided plate, 2 inches in height by 12 inches in width, White Stoneware with Iron Earth Slip and sgraffito decoration, Shino Glaze, fired to Cone 9 reduction.

Pottery Makingillustrated 13 14 Summer 2000 A C olored Clay P roject

by Chris Campbell

For a studio to stay financially sound it needs a solid product that generates sales year round. Porcelain Coloring C lay holiday ornaments fill this slot for me, and I currently market eleven If you want to work with tinted porcelain, start with basic colors such different designs. While I add at as blue, yellow, pink and black. Your pottery supplier will be able to advise least two new ones to the collection you on which stains will give you the colors and percentage you want. I each year, I also produce custom- use the highest percentage of stain to color my clay. Why so much? made ornaments for the exclusive Coloring clay is a hard, messy job, and this dark, rich-colored clay will last use of my clients in galleries, busi­ for years since you can always be diluting it with white clay. nesses and charities. Recently, Pauline Lutkenhouse CAUTION: of the Hawai’i Tropical Botanical Always use a respirator and rubber gloves when mixing the stains Garden asked me to design an orna­ and clay. Use rubber gloves when working with colored clay. ment of the humu-humu-nuku- nuku-apua’a fish. The humu fish is The stain usually comes in a plastic bag, so I simply add warm water found in the waters off Hawai’i and to it and shake to mix well. I transfer this liquid to a large mixer and blend is a tourist favorite, as well as the in the porcelain until I have a thick smooth slip. When the color is even, I official state fish. Being an avid add the rest of the clay. For smaller quantities, you can use an old blender scuba diver, I considered whether I to make the slip, then knead this into the rest of the clay by hand until it could write off a trip to see the lit­ is an even color throughout. You want the colored clay body to be very tle guy in his habitat, but realized soft so that you can mix colors easily. that this wonderful idea would not Once you have your basic colors, the tedious part starts. Get your likely thrill the IRS. Since getting melon ball tool from the kitchen (you have only used it once for cute customer input is a crucial part of melon balls anyhow, so keep it in the studio). Use it to measure out your any custom project, I had Pauline basic colors. Now, mix them with each other and with white. Pat these send me photos of the fish so I samples into rounds and mark the proportions on the back (for exam­ could get an idea of what it looked ple, 1 Bluel2 White/1 Yellow). This will tell you how to re-create that like. I’ve learned over time that the color. Put a hole in the circle for hanging, glaze and fire. Now you will image the customer has in mind is have a dependable visual palette of the color options available to you seldom the same one I have. (see figure 3). I decided to try making the To get started with making your own neriage, I recommend you get ornament with colored clay using a some books that describe working with polymer clays. They have step- technique called neriage, a process by-step directions for building patterned blocks of clay. The principles where colored clays are stacked in a are the same, but with colored clay you can also use colored slips loaf to form a design, then sliced to between layers. reveal a pattern that goes the depth of the slice. A wonderful resource book for working with all I’ve included some information types of clay and coloring agents is Colour in Clay, about how I make colored clays (see by Jane Waller, available from The Crowood Press. box), and the step-by-step process I used to create the custom-made humu ornament.

Pottery Making illustrated 15 Figure 1 Figure 2 Figure 3 After receiving photos, the first step was The ornament needed to have a solid The real fish is a pale yellow/green color to produce a series of prototypes, first on presence, yet leave enough room for with bright-colored markings. I have a paper then using white porcelain clay. I shipping protection. I created an orna­ stock of color sample discs that I use to made sure that the fish looked authentic, ment consisting of two parts—a thin slab match with the fish markings. yet had a personality. I also tried to antic­ of untinted clay in the overall shape of ipate production problems and to be sure the humu with a neriage overlay for the it would fit in the gift box after a firing color decoration. When a sample had shrinkage of about 15%. been fired and looked right, I had cutters custom made to the outlines of the fish.

Figure 4 Figure 5 To get different shades of the same color for the fish body, I Using a template, I cut the tinted block into sections that mixed yellow-tinted and white clay in various proportions. The matched the stripes and markings on the fish. result was a block of colored clay approximately the size of the fish body.

Figure 6 Figure 7 Thin strips of tinted clay were placed between the yellow-tinted sections to make the stripes of the fish. Once they were in place, the block was gently put back together.

16 Summer 2OOO Figure 8 Figure 9 Next, the clay block was evenly rotated and dropped from an I made the ornament in two pieces. The larger bottom piece is inch or two above the work surface to remove any air, then white and the smaller top piece is the tinted body. A light mist wrapped in a damp cloth and plastic to let it rest for a day or of water and a gentle touch with the roller attaches the two two. After the moisture level evened out, I sliced the clay block pieces. into even slices about Vie inch thick using thin flat guides and a thin wire.

Figure 10 Figure 11 The fins and tail were marked with a needle tool to give the I painted in some black details with underglaze and let them body some curl and movement. thoroughly dry before applying a clear glaze. (Note: I had decid­ ed to single fire these ornaments, but they could have been bisqued prior to glazing.)

For over 13 years, Chris has worked as a full-time studio pot­ ter in Raleigh, North Carolina. Her interest in colored porcelain began in a workshop taught by Jane Peiser, a well-known North Carolina clay artist. Terry Campbell has been a photographer for more than 20 years and specializes in craft photography. If you have any questions, contact Chris by e-mail at

PHOTOS : TERRY CAMPBELL [email protected]. Figure 12 The finishing touches included a light spray of sparkling glitter, then a surface sealer. Once the ornament was signed, this charming little fish was ready to be shipped to the customer.

Pottery Makingillustrated 17 18 Summer 2000 GLAZE SIEVE

By Sylvia Shirley

Here's an inexpensive sieve that sits neatly on the top of a 5-gallon bucket.

MATERIALS

Largest plastic bowl from a set of 4 nested bowls with Step 1. Cut the bottom out of a large lids. These are about $2.50 bowl. a set at WalMart. Straining fabric. I use cur­ tain fabric (called “sheers”) for a fine mesh to strain glazes. They are available at garage sales for next to nothing. A paint strainer from a hardware store works well for medium mesh, and works really well for sifting wood ash. Duct tape Hot glue gun X-acto or utility knife Step 2. Stretch mesh TIGHTLY over the opening. Secure all around with duct tape.

TIPS

The middle-sized bowl from the bowl set fits an ice-cream bucket. Use a rubber spatula to work the glaze through the mesh. Bowl lids and cut-out bot­ toms can be cut to make handy flexible ribs.

Step 3. Run a bead of hot glue on the Sylvia Shirley is a free-lance drafter, technical illus­ trator and part-time potter. She can be reached at inside, creating a smooth transition from wshirley@sunnetworks. net the bowl to the mesh. The glue seam also helps in cleanup.

Pottery Making illustrated 19 20 Summer 2000 Achicve Color Consistency Create Unique Flashes of Color Increase Quality Control

Raku vases by George Juliano reveal the intense colors achieved from post-firing reduction in airtight con­ tainers. George states, “I am pleased with the finished pieces and the colors I consistently get from the ‘pit- in-the-box.’ Of course, some of the people who drive by wonder about my odd assortment of wooden boxes, lined up and set to use, but that’s a great source of interest and gossip in the neighborhood and a small price to pay for superior raku.” Raku Pit-in-the-Box

by George Juliano with Elizabeth Hudgins

One of the drawbacks in raku firing for me has always been achiev­ ing consistent colors when doing postfiring reduction. For a tightly sealed reduction chamber; I buried a trash can in sand up to the rim. After placing the pot in the can, I put on the lid and scooped sand up to the rim to keep oxygen out (see PMI, Fall 1998, p. 15). While the sand pit helped, the sand was always washing away from the area of the reduction container and the quality control for the pits just wasn't as solid as I desired. After a number of trial-and-error attempts, I developed a upit-in-the-box}) that seems to greatly increase the consistency of achieving color during post firing reduction.

Pottery Makingillustrated 21 Getting Started

To build a “pit-in-the-box,” begin with a metal trash can and lid, available at any hard­ ware store. The size of the trash can dictates the size of the box, and I use 5-, 20- and 30-gallon cans. Next, get ½-inch-thick, exterior-grade (CDX) ply­ Figure 1. Begin construction by attach­ Figure 2. Assemble the sides using wood and 2x4s and cut them ing the 2X4 posts to the plywood panels screws. When finished, you should have as follows. using 1 1/4-inch galvanized deck screws. a fairly solid box that’s missing a bottom Note: A 2x4 actually Use a screw about every 6 inches. The and top. measuresl 1 Ax31 A”. posts reinforce the corners of the box. 5-gallon can 18x18" plywood (4 pcs.) 2x4x18" (4 pcs.) 20-gallon can 24x24" plywood (4 pcs.) 2x4x24" (4 pcs.) 30-gallon can 30x30" plywood (4 pcs.) 2x4x30" (4 pcs.)

Figure 3. Drill holes in the can so that it Figure 4. Place the trash can in the will drain if water should get into it. (This finished box, centering it in the opening, is also why I don’t put a bottom on the then carefully shovel sand around the Recipe box.) can, making certain that the sand comes just to the top of the can with enough room to place the lid on firmly. The following glaze was used on the vases shown on page 21.

Gordon Hutchens Copper Matt Cone 06 Gerstley Borate ...... 66.6% Bone Ash ...... 16.7 Nepheline Syenite ...... 16/7 100.0% Add: Copper Carbonate ...... 5.8% Cobalt Carbonate...... 2.5% Apply a medium coat by dipping or pour­ Figure 5. The “pit” is now ready to use. Figure 6. To prepare the pit for post-firing ing. Bring ware up to as close to 1800°F as reduction, line the can with loose news­ possible before placing them into the “pit.” paper. Tip: I often leave about a third of the burnt paper in the can from the previ­ ous firing because it seems to increase the brilliancy of the color, and I place the unburned paper on top of this base of burnt newspaper.

22 Summer 2OOO Figure 7. As soon as the pot comes out Figure 8. Place the pot in the prepared Figure 9. Leave pots in the container of the kiln, hold it in the air letting it oxi­ can. Wait for the newspaper to catch fire anywhere from 30 to 40 minutes (with no dize for several seconds (eleven seems and roar, then carefully throw some fresh peeking...something that’s very difficult to work well). newspaper on top. The fresh newspaper for me). When the time is up, lift the lid, produces flashes of color on the shoul­ and reach into the container with raku ders and sides of the pot. Firmly place gloves and remove the finished piece. the lid on the can and weight it with sand Some potters will leave work in contain­ or a brick to create an airtight seal. ers for two hours or more, especially when firing large pieces.

A frequent contributor Pottery to Making Illustrated,George Juliano teach­ Elizabeth Hudgins is a retired English teacher and has had a number of es ceramics at Robinson Secondary School in Fairfax, Virginia, as well as teach- articles and poems published. She is also an iconographer whose work appears ing graduate classes for Virginia Commonwealth University. He completed in a colleges, churches and homes around the world. Visit her web site at recent showing of his work at the National Institute of Health Galleries inwww. tidalwave. net/~ehudgins Bethesda, Maryland. E-mail questions and [email protected] to

Pottery Making illustrated 23

PHOTOS: LINDA HOLDEN

Three moribana trays, 12 Fred Sweet has been teaching ceramics at inches square, constructed from extruded parts and Richland College in Richardson, Texas, since slabs, by Fred Sweet 1982. He has successfully kindled a passion for

working with clay in hundreds of his students.

While Fred is accomplished at the potter's

wheel, his true passion is the extruder. Here, he

demonstrates how to make a vessel used in

Ikebana, the Japanese art of flower arranging.

Step 1 Fred begins by selecting one of the wall con­ tours from the six on this multiple opening die. A die mask will block the other five.

Step 2 When they become leather hard, the extruded walls are cut to length using a combination square.

Pottery Making illustrated 25 Step 3 Step 4 On his table saw, Fred beveled the edge of the board 45°. He Slip is squeezed onto the edge of the ½-inch-thick slab that uses this as a guide for beveling of the ends of the tray walls will be the bottom of the tray, with a Surform tool. Before he starts beveling, Fred aligns the lower edge of the tray wall with the edge of the board.

Step 5 Step 6 Step 7 The first wall is positioned on the base, Starting with the bottom edge, the The fourth wall is fitted, making certain aligning the ends and the bottom edge. second wall is attached. At the wall-to- that the wall aligns at both ends. wall joint, the bottom is aligned first, then the top, and finally the entire piece is squeezed together to ensure adhesion.

Step 8 Step 9 Extra slip is applied along the floor-to-wall joints. Fred sometimes uses the end of a broken artist paint brush handle to remove the excess slip inside after it has firmed up. The shape of the brush handle makes it a good tool for refining the joint.

26 Summer 2OOO Step 10 Step 11 Fred also uses a sharpened chopstick to refine the Extra slip is removed from the outside bottom joint, where the interior seam of the tray. walls meet the bottom, and the tray's profile is refined.

Step 12 Step 13 A beveled stick is used to shape the bottom-most edge of A fettling knife is used to smooth and redefine the outer edges at the tray. the joints. This is done at all four corners.

Step 14 With all the attachment points cleaned and smoothed, the moribana tray is ready for slow drying.

This project appears in The Extruder Bookby Daryl Baird, available page full-color gallery exhibit of works created with the extruder. Nine illustrated from The American Ceramic Society. This extensive how-to book emphasizes step-by-step projects, of which this is one, offer valuable tips and ideas and illus­ creative ways the clay extruder is being used in pottery studios. The book cov­trate how to make one-of-a-kind works with an extruder. Over 450 photos and ers in detail all commercially-available extruders and associated equipment drawings depict the versatility and indispensability of the extruder and shows hun­ on the market, and ceramic artists using extruders. Also included is a 96-dreds of ways for artists to improve and expand their work.

Pottery Making illustrated 27 In May 1984, Ceramics Monthly published recipes for twice-fired Albany slip glazes. At Cone 5, these glazes were in the brown family, but refired at Cone 04, they were vibrantly rust/Irish setter red. by Lili Krakowski What truly amazed me about the refired glazes was their richness and depth of color, which surpassed that of the original ones. But because Albany slip is no longer available, I

PHOTO: SUE ULRICH set out to replicate the beauty of these glazes using Cedar Heights Redart clay. To compensate for the differences between Albany and Redart, I concocted this mix for Albany-based glazes that contained added iron: Albany Slip Substitute I Redart ...... 84.7% Dolomite ...... 11.7 Two examples of twice-fired glazes. The bowls on the left were glazed with Cassie’s Whiting...... 3.6 Buckwheat Honey and the bowls on the right were glazed with Hannah’s Apple 100.0% Butter. The bowls in the back were fired to Cone 6 and the bowls in the front were fired to Cone 6 then again to Cone 04. For recipes that call for Albany slip without extra iron, use the following: Albany Slip Substitute II Big Alex’s Madeira Redart ...... 66.7% Gerstley Borate ...... 16% Recipes Kentucky Ball Clay ...... 16.7 Albany Slip Substitute II...... 72 Dolomite...... 8.3 Silica...... 12 Little Alex’s Currant Jelly Wollastonite ...... 8.3 100% Dolomite...... 9 100.0% Nepheline Syenite ...... 18 Cone 6: Semi-transparent coffee over buff Frit 3185...... 18 clay, prettier on light clay or over white slip. This is mixed wet, then dried and Albany Slip Substitute I ...... 55 Cone 04: Smooth rich red with some stored. It is the base for the glazes 100% breakup and fine mottling where thick. shown here, but I expect that plain Redart would do as well, and that Add: Red Iron Oxide ...... 5% Noah’s Sherry Gerstley Borate ...... 25% other red-firing surface clays would Cone 6: Rich black, shiny, with some hints of pur­ Bone Ash...... 7 give equally beautiful (if not identi­ ple. Same over light clay. Wood Ash...... 7 cal) results. Cone 04: an almost metallic, satiny, rich brown, with hints of a rich dark red. No streaking. Albany Slip Substitute I ...... 44 These glazes, named for my great- Silica...... 17 nieces and nephews, are extremely Cassie’s Buckwheat Honey 100% pretty. Even those that are just plain Bone Ash ...... 6% Red Iron Oxide ...... 7% coffee brown at Cone 6 pick up tex­ Talc...... 9 ture in the clay very well and offer Nepheline Syenite ...... 9 Cone 6: “Furry” golden on inside of pot, more effective contrasts over white and Frit 3185...... 9 translucent over white slip, “furrier” where Frit 3134...... 9 thick over black slip. Light gold over light clay. black slip. Refired at Cone 04, they Pnno n A ■ Dnrl pmrt/i+k pnmn m/-\++li Albany Slip Substitute I ...... 58 turn vibrant, rich reds of the auburn, 100% Ari’s Plum Jam chestnut, Madeira, or plum variety. Test these glazes on different bodies, Add: Red Iron Oxide ...... 7% Gerstley Borate ...... 21% Bone Ash ...... 4 as the outcome is affected by the iron Cone 6: Dark, "furry" brown with lots of blue. On light Wood Ash ...... 4 in the body underneath. clay more golden. At Cone 04:: red, smooth, slight­ Albany Slip Substitute I ...... 57 Like their namesakes, these glazes ly mottled, golden where pooled. Silica...... 14 belong to one family yet differ from Hannah’s Apple Butter 100% each other—something that no Talc...... 13.5% Add: Red Iron Oxide ...... 7% doubt will be borne out when they Wood Ash ...... 13.5 are tested in other kilns and on other Cone 6: Caramel turning a hare’s fur-like gold Albany Slip Substitute II ...... 73.0 clay bodies. 100.0% where runny; more translucent over white slip, slightly too fluid, some nice blue streaks. Both flu­ Cone 6: A rich, satiny butterscotch semi-matt. Better idity and streakiness accentuated on light clay. maturity over slips. Lili Krakowski is a professional potter residing in Cone 04:, a rich satiny reddish apple-butter color. Cone 04: Cloudy red on outside of pot, golden Constableville, New York. She teaches pottery at Of these glazes, Hannah’s is the only semi-matt. olive with fine black or dark blue streaks on inside. the Gibbes Museum of Art in Charleston, South Carolina, during the winter months. 28 Summer 2OOO Pottery Makingillustrated 29 using a: throwing stick by Ivor Lewis

Rotund pots with robust con­ tours and broad shoulders blending into well-proportioned necks achieve a distinction reminiscent of ancient Greek styles. However, major problems may occur when throwing such forms due in part to the mechanics of the shape. The first problem occurs when the shape sweeps out from the base and there is insufficient strength in Figure 1 Figure 2 the lower wall to support the Begin with a well-wedged 6- to 10-lb. ball Draw the clay up to make a rounded weight of clay above it. This over­ of clay. Throw a tall cylinder about three shoulder. Remove excess water from the hang is a weak point, and if formed times higher than it is wide. The walls inside of the base, then collar the top to early, the sloping clay has a tenden­ should be relatively thick and uniform leave an opening just wide enough to from top to bottom, and you should be insert the end of the throwing stick. cy to fold or collapse. While but­ able to get your folded hand inside and tressing the base by making it thick­ reach the base. er or adding a concave contour adds strength, these solutions negate any intention to achieve a spherical or ovoid form with a bold convex contour. A second problem arises when the opening at the top of the form is too small to put your hand inside to stretch and shape the clay wall. The solution is to use a throwing stick (see PMI, Spring 2000), which allows you to expand the girth of the pot, avoid slumping and to fin­ ish the shoulder, collar and neck with an opening just wide enough to accept the throwing stick.

Figure 3 Hold the stick firmly in your left hand so that its head faces to the right (assuming your wheel turns counterclockwise). Practice moving the stick upward and outward and inward, imitating in the air the track you anticipate to make inside the pot as you cre­ ate your intended profile. Notice the shaft and its position in relation to the rim of the pot and think of the shaft passing though a narrow opening (see A).

A frequent contributor toPottery Making Illustrated,Ivor Lewis is a potter who has had a lifelong interest in clay. He lives in Redhill, South Australia 5521 and can be contacted via e-mail at [email protected]

30 Summer 2OOO Figure 4 Figure 5 Figure 6 When you feel familiar with the weight As the base of the wall moves outward, Moving from the base and merging with and movement of the stick, wet one end move the stick slowly upward until the the shoulder may need repeating several to lubricate it, then insert it into the neck profile merges with the curve of the times until the two curves blend. If the pot and lower the head to the bottom of the shoulder. Follow the new profile on the has not achieved sufficient girth, stretch rotating pot. Let the head rest against the outside with only your right-hand finger­ the belly wider on subsequent passes, rotating clay right at the base, and, with tips or knuckle. Because the area of con­ but not too far. Watch how the contour of the wheel turning between half and quar­ tact is small, drag is minimal and snag­ your pot develops and pay attention to ter speed, stretch the clay slowly outward ging, which might buckle the wall, is the shape. against your right hand, which provides avoided. Try to keep the lubrication uni­ support. form inside and out. Tip: Palm a wet sponge in your right hand to supply lubrication. This prevents your fingertips from snagging the clay.

Figure 7 Figure 8 Because the preliminary throwing After expanding the body to its final form process is designed to retain a and refining the profile, the collar of clay mechanically strong wall from top to at the top of the pot can be drawn up and bottom, it’s possible to retain height and shaped. Use a rib to assist in blending While learning to use a throw­ prevent the belly, toward the foot, from the contours as they move from convex ing stick, you may experience sagging. In addition, throwing a thick to concave. If there is sufficient clay, dec­ setbacks and failures, but wall at the top of the pot ensures that orative treatments can be added to give don’t be disheartened! Size there is clay to form firm shoulders. If character and shape. limitations are determined by the initial cylinder wall had been the clay, your strength and tapered, there would have been insuffi­ controlling the moisture con­ cient clay to form the shoulder. The pot Note: Slight, controlled, but efficient tent. You may feel inept and would have collapsed inward and lost lubrication reduces the degree to which awkward in the beginning, but height as the clay was stretched. your clay absorbs water, further enhanc­ as your skill develops through ing the strength of the clay. Minimum practice, you’ll find that you’ll contact with the clay reduces the twisting eventually create pots of stress so the pot is less likely to collapse. unquestionable merit.

Pottery Making illustrated 31 In 1995, K-12 teachers attending the NCECA widely respected artist known for his ceramic work, (National Council on Education for the Ceramic Arts) scholarship and teaching. Daley selected 57 finalists conference decided an exhibit of young student work from a total of 485 entries submitted by students from would increase public awareness of K-12 art programs. 48 schools across the country. In 1998, the idea became a reality with the first juried Leah Schlief of Ursuline Academy is the contact K-12 ceramic exhibit held in conjunction with the person for the 2001 National K-12 Ceramic Exhibit NCECA conference in Ft. Worth. This year the third to be held in Rockville, SC, in March. She can be annual National K-12 Ceramic Exhibit was held in reached at (214) 363-6551, fax (214) 363-5524, or by Denver and hosted by Downtown Aurora Visual Arts mail at Ursuline Academy, 4900 Walnut Hill Lane, (DAVA). The juror for the exhibit was Bill Daley, a Dallas, TX 75229.

Contemplation, Robert Drakulich, 12th grade, Amoebic Dance, Emily Collins, 11th grade, Francis Parker School, San Diego, California. Stivers School for the Arts, Dayton, Ohio.

Classical Towers, Heather Purple Passion, David Mottram, Jar, John S. Vorhies, 11th grade, McCullough, 12th grade, Stivers 11th grade, St. Mark’s School, Bishop Lynch High School, School for the Arts, Dayton, Ohio. Dallas, Texas. Dallas, Texas.

32 Summer 2OOO Untitled/Burnished Earthenware, Girl with Dog, Ap-Phia Perkins, Peeper, Luke Helwig, 1st grade, Jeremy Zick, 12th grade, Conifer Senior 5th grade, Edgewater Elementary, The College School, High School, Conifer, Colorado. Edgewater, Colorado. St. Louis, Missouri.

Resting Tiger, Cassie Philips, 8th grade, Compliment Your Java, Alfred McCloud, 10th grade, Gilpin County School, Blackhawk, Colorado. Stivers School for the Arts, Dayton, Ohio.

Girl, Rob Minervini, 12th grade, Mask, Brandi Girtman, 5th grade, Old Man, Nick Zimmer, 11th grade, Conestoga High School, Carbondale Clay Center, Verona Area High School, Berwyn, Pennsylvania. Carbondale, Colorado. Verona, Wisconsin.

Pottery Making illustrated 33 34 Summer 2000 Pottery Making illustrated 35 36 Summer 2000 by Craig Hinshaw

Each month atHiller Elementary School, teachers emphasize a different aspect of character to their students on a school-wide basis. During February, citizenship was to be emphasized, and the teachers felt that having the students participate in Empty the Bowls program would be a good real-world lesson in citizenship.

The Empty Bowls program is a unique method of raising money to help feed the hungry. Students donate handmade bowls for a soup luncheon. A $10 admission to A newspaper stencil was used to mask off the the luncheon gives an attendee a soup hand motif. After underglazes were applied, the lunch served in a handmade bowl, which newspaper stencil was pulled from the clay, he or she is then allowed to keep. The revealing an unglazed hand with a heart in the monies raised are donated to a local soup palm. The bowls were dried for a week then kitchen. bisqued. A clear glaze was brushed over the The teachers asked me if it would be bowls before the final firing. possible for all 350 students at the school to make bowls, but I felt that kindergarten and first graders would have a difficult time making functional bowls. Therefore, we decided to pair students—fifth graders with kindergartners, fourth graders with first graders and second graders with third graders. After explaining the Empty Bowls program to the students, I told them they would be using their hands to make the bowls and their hearts by giving their bowls away to help someone less fortu­ nate than themselves. (The Empty Bowls name refers to the idea that many people have an empty bowl at mealtime.) The bowls the students would make would have both a hand and a heart inside.

Hiller School has a diverse population of stu­ Craig Hinshaw is an elementary art specialist in the dents, representing at least 22 cultures. When Lamphere School District in Madison Heights, Michigan. making the bowls, we used white clay for some E-mail comments to Craig [email protected] . and terra cotta for others. The finished bowls For more information on the Empty Bowl Project, check out revealed both white hands and brown hands the web site at www.emptybowls.net holding a heart, honoring that diversity.

Pottery Makingillustrated 37 Step 1 Step 2 The students, working in pairs, traced Next, each pair of students made 30 one of their hands on a piece of newspa­ marble-size balls of clay. per and cut it out. Then folding the cut­ out hand in half, they learned how to draw and cut a heart from the palm area. The paper hand would be used later as a paper stencil.

Step 3 Step 4 The kids received a plastic bowl with a A tennis ball was rolled around inside, piece of plastic wrap large enough to line further smoothing the bowl interior. the inside to keep the clay from sticking to the plastic bowl. Students were shown how to press the balls into the bowl—flat­ tening, connecting and smoothing them together to form a bowl.

Step 5 Step 6 The paper hand was laid into the clay The bowl was lifted out of its mold, the bowl and the tennis ball rolled over it, plastic wrap was carefully peeled away forcing out wrinkles and embedding the and the students’ initials scratched into paper. Students brushed low-fire under­ the base. The lip of the bowl was glaze inside the bowl, covering the edges smoothed, then students brushed under­ of the paper hand. Red underglaze was glaze on the outside. brushed over the heart. 38 Summer 2OOO Pottery Makingillustrated 39

Mixing glazes for the classroom too fragile coat on the bisqueware Hopper Flux Variation Base last year, I realized that even though and not run too much when fired. Feldspar ...... 35% we had over two dozen glazes, I was For a clear glaze, my main goal Ball Clay...... 12 still dissatisfied with a few of them. was that it would not become milky Whiting ...... 17 Some glazes had a large number of when applied thickly or on a dark Flint...... 19 ingredients, including materials in clay (many old clear glaze recipes Flux...... 17 such tiny percentages they couldn’t based on large amounts of Gerstley 100% possibly be vital; some settled too borate displayed this characteristic). I decided to further simplify this rapidly and were difficult to stir into Also, I wanted a clear glaze with a formula with one that substitutes suspension; and some required large high enough calcium content that I wollastonite for the whiting and amounts of Gerstley borate, now could use it as a base with commer­ flint. Though wollastonite is more unavailable, so the need to replace it cial stains to achieve the red colors expensive than whiting or flint, the was urgent. These and other small students so often requested. Finally, cost of glaze materials is usually inconveniences added up to make as with the white, I wished to avoid negligible compared with the time me determined to embark on a application and suspension prob­ involved in mixing up a glaze. If round of new glaze tests. lems. This presented a certain con­ such a simple substitution would Setting Goals flict of interest, since avoiding produce a usable glaze, it would be Gerstley borate often means relying worthwhile. I started out working to improve on frits, which may settle badly white and clear glazes. My ideal for a when used in large amounts. Hopper Flux Variation Base II white glaze was one that could be Feldspar ...... 35% used with liquid wax resist to buildFinding a Solution Ball Clay...... 12 up layers of glaze resist decoration. Instead of turning to recipe Wollastonite ...... 36 (Some glazes soak up the wax and books and trying dozens of different Flux...... 17 render it ineffective.) Further, I formulas, I decided to try a series of 100% wanted to use it as a base for paint­ tests suggested by Robin Hopper in ing with commercial stains, as in his book The Ceramic Spectrum, majolica (many colors require a high specifically the “Flux Variation” calcium content in the glaze). chapter. The following basic recipes Finally, the glaze should consist of can be varied using different Sumi von Dassow teaches pottery at the Washington relatively few ingredients, stay in sus­ feldspars and fluxes, some of which Heights Center for the Traditional Arts in Lakewood, pension well, form a smooth and not are bound to result in usable glazes. Colorado. Visit her web site atwww.well.com/~sumi .

Table 1 . A series of 24 tests using the two flux variation base recipes with four feldspars (Custer, Plastic Vitrox Clay (PVC), spodumene, and Cornwall stone) and 6 fluxes (dolomite, lithium carbonate, pumice, talc, magnesium carbonate and Gerstley borate. These 24 tests were repeated using wol­ lastonite as a substitute for the whiting and flint. The wollastonite tests would are rows 5 through 8 not shown due to space limitations.) T A B L E 1

Pottery Makingillustrated 41 Table 2. Combining promising-looking glazes from Table 1, created new mixtures that con- Observations tained either two feldspars (pink) or two fluxes (blue). In the first series of tests (see Table 1), I observed suspension and application characteristics as follows: • Magnesium carbonate, PVC, pumice, Custer feldspar, Gersdey borate and, to some extent Cornwall Stone, seemed to aid suspension. • Wollastonite, dolomite, talc, lithium carbonate and spodumene seemed to increase settling. • All the mixtures were easy to apply by dipping. • Magnesium carbonate seemed to pro­ TABLE 2 TABLE mote a powdery glaze coat susceptible to being brushed off. More Testing In a second series of tests (Table 2), I decided to match suspension-pro­ moting ingredients with those that settled rapidly, and made 24 combina­ tions each consisting of two of the original 48 glazes. Each new mixture then had either two feldspars or two fluxes. For example, I paired Gerstley borate with pumice, and lithium car­ bonate with magnesium carbonate (these pairings were a personal prefer­ Table 3. In a third series of 16 tests, I substituted the Ferro frits 3134 and 3195 for Gerstley ence out of the 84 possible combina­ borate in some of the more promising mixtures (in purple). By using the Gerstley borate mix­ tions). Obviously, not every possible tures as a sort of scientific control group, I was able to determine that neither frit is a perfect substitute, yeilding a milkier glaze. This is probably due to their silica content, and would sug­ combination was made! gest further tests with reduced silica. I tried some new combinations of the above ingredients In a third series of tests (Table 3), I that seemed potentially interesting (shown in yellow). substituted the Ferro frits 3134 and 3195 for Gerstley borate in some of the more promising mixtures. By using the Gerstley borate mixtures as a sort of scientific control group, I could determine that the frit mixtures yielded a milkier glaze, and would suggest further tests with reduced sili­ ca. I also tried some more combina­ tions of the above ingredients that seemed potentially interesting. Conclusions Not surprisingly, quite a few of the 88 tests yielded promising results. I’ve used some as glazes and am beginning the process of replacing the base of some of my old complicated recipes with new formulas. It will be interest­ ing to examine and compare these recipes and observe the effect of chang­ ing one or two materials.

42 Summer 2OOO Recipes The following simplified Cone 6 oxidation glazes provide a starting point for replacing more complicated bases. 3A1/3A2 Clear Gloss Spodumene ...... 35.0% SGP-1 (ball clay) ...... 12.0 Whiting...... 17.0 Flint ...... 19.0 Ferro Frit 3195 or 3134 ...... 17.0 100.0% Of the tests without Gerstley Borate, this was the clearest. Frit 3195 yielded a slightly clearer glaze, but seemed to cause more settling than Frit 3134. Try adding 2-3% bentonite. Add oxides or 10% commercial stain for hard-to-get colors. 4A1/4A2 Semi-gloss Clear Cornwall Stone ...... 35.0% SGP-1 (ball clay) ...... 12.0 Whiting...... 17.0 Flint ...... 19.0 Ferro Frit 3134 or 3195 ...... 17.0 100.0% The Clear Gloss note regarding the frits applies to this variation as well. It doesn’t settle as badly, so unless a perfectly clear glaze is needed, this one might be preferable. Add oxides or 10% commercial stain for hard-to-get colors. 8H Semi-gloss Clear Cornwall Stone ...... 35.0% SGP-1 (ball clay)...... 12.0 Wollastonite...... 36.0 Magnesium Carbonate ...... 8.5 Lithium Carbonate...... 8.5 100.0% Add oxides or 10% commercial stain for hard- to-get colors. 1G1/1G2 Gloss White Custer spar ...... 35.0% SGP-1 (ball clay) ...... 12.0 Whiting...... 17.0 Flint ...... 19.0 Ferro Frit 3134 or 3195 ...... 8.5 Pumice ...... 8.5 100.0% For a good opaque white, add 10% superpax. Works with wax resist. Can be used as a majolica base with stains. Minimal settling. 5B Semi-matte White Custer Spar ...... 17.5% Spodumene...... 17.5 SGP-1 (ball clay) ...... 12.0 Wollastonite ...... 36.0 Dolomite...... 17.0 100.0% A nice smooth, slightly off-white semi-matte. Not a good glaze for wax resist decoration. 2H Very Matte White PVC ...... 35.0% SGP-1 (ball clay) ...... 12.0 Whiting...... 17.0 Flint ...... 19.0 Lithium Carbonate ...... 8.5 Magnesium Carbonate ...... 8.5 100.0% This white is quite matte. May be a good base for strongly fluxing oxides.

Pottery Making illustrated 43 Step 1. Determine the length of the leg Step 2. Align the arrow of the conduit of the cut-off bow you wish to make. The bender to your mark and bend to about length should be greater than 12 inches, 80°. If you pass the 90° mark, you will and around 18 to 20 inches works best. kink the conduit. Mark this distance with a marking pen or by Don Adamaitis a small piece of tape.

A cut-off wire bow is an excellent tool with many uses and is simple to make. I have several in my studio strung with different types of wire to produce different tex­ tures. If you’re making tiles, this tool is great for producing flay, even cuts

from a block of clay using Step 6. Punch a guide hole with the cen- Step 7. Drill a %2-inch hole, which is lath side rails. It also makes terpunch on each flattened end. slightly larger than the bolts you’ll use. a good cut-off wire for pug- Use a drill press or hand-held drill, and back the metal with a block of wood to mills, extruders and remov­ prevent the drill from grabbing and spin­ ing pots from the wheel ning the metal. head.

• Thin-walled electricians pipe • ½" diameter thin-walled conduit such as Radio Shack. All the hard­ bender (3 to 4 feet) ware stores I checked carried only • Metal C-clamp • ½-20 V2" stainless steel bolts (2) 10-foot lengths of thin-walled elec­ • Tape measure • ½" stainless steel washers (4) trical conduit tubing. If you can’t transport something this long, ask an • Tape or marking pen • ½-20 stainless steel nuts (2) attendant to cut the tubing to length. • Pipe/tubing cutter • ½-20 stainless steel acorn nuts (2) • Centerpunch • Stainless steel braided fishing Note: Hardware stores will proba­ bly not bend the conduit for you, but • %2"-diameter metal drill bit leader wire they do have pipe benders for sale. • Vie" to ½" shrink tubing (1½ in.) • Electric drill Some equipment rental stores will • Metal hammer or vise The materials needed are readily bend and cut their conduit tubing for you for a fee that may be equal to or To bend conduit past 90° to available. The drill and stainless steel more expensive than the conduit pipe almost a 180° bend requires nuts and bolts can be found at most bender would cost at other stores. multiple bends and you may have larger home improvement stores. The to try more than once to get stainless steel fishing leader wire is it right. available at most fishing stores. Shrink tubing is available at electronic stores,

44 Summer 2OOO Step 3. Keeping the pipe bender even Step 4. Measure the first leg to the bend, Step 5. Flatten the first inch of each end with the first bend, shift the bender about then measure the same distance from with a hammer or vise, 2 inches away from the first bend and the final bend. Mark and cut the conduit clamp the locking brace snugly with the with the tubing cutter. C-clamp. Give the pipe bender another bend, again not exceeding the 90° mark. Continue this procedure until you achieve the curve that is approximately 140°.

Step 8. Insert a bolt through the hole and Step 9. Brace the completed end of the Step 10. Back wind the pig tails down add a washer. Wind one end of the wire bow and compress the unfinished end the wire and slide the shrink tubing over around the bolt then wrap the loose end toward it. Insert a bolt and washer then the wound ends. Use a heat gun to down the wire length. Add the other fasten the wire using the same proce­ shrink the tubing to lock the loose ends washer and nut and tighten firmly. Slip dure as in the previous step. Place acorn of the wire for a safety covering. two 11/2-inch-long pieces of the shrink nuts on the bolts as a safety covering tubing onto the wire. and to prevent the first nut from loosen­ ing with use. If the bolts are too long for the acorn nut to seat snug against the first nut, file down the end of the bolt.

A wire cut-off bow can be used to slice slabs from a wedged block of clay, or as a cut-off wire.

Don Adamaitis has been an active potter since 1962. He has a degree in the physical sciences, and, since retiring in 1987, has devoted his attention to glaze chemistry and the physics of kiln firing and construction.

Pottery Making illustrated 45 Glaze C alculation and Formulation

Too often, potters approach glaze formulation as an arcane you desire a particular glaze color or characteristic, or you science understood only by a few wizards, and prowl through are open to anything new and exciting, one of these books books and magazines looking for the “right” recipe. However, is bound to help with the search. Whether an experienced to make pottery that is really your own, it is important to under­ professional potter or student, you’ll find something in any of stand glaze formulation and to spend some time these books to pique your interest, increase your understand­ experimenting and developing new glazes. The following ing, and improve your pottery. books take a variety of approaches to this goal. Whether

Greg D aly— Robin Hopper— Glazes and Glazing The C eramic Techniques Spectrum Gentle Breeze Publishing, Oviedo, FL, 1996 Krause Publications, lola, Wl, 1984 Greg Daly takes a wildly experimental This excellent book guides the reader approach to glaze formulation—two of his through developing glazes empirically, with­ suggestions are to try “random glazes” by out the heavy mathematics of classic glaze picking materials and amounts out of a hat, calculation methods. It is designed to help and “rotating a glaze” by taking any glaze the experienced potter or dedicated student recipe and switching the percentages around. He points out that move beyond mixing up someone else’s recipes, toward the sat­ by stepping outside the normal limits of glaze calculation you isfaction of developing original glazes. Hopper discusses glaze may discover truly unique and interesting glaze finishes. The materials, types of glazes, and factors influencing color devel­ reader who is prepared to do a lot of testing is likely to end upopment. The standard techniques of blending two or more with some worthwhile glazes. In addition, this book includes a materials in graduated ratios (line blends, triaxial blends, etc.) lot of information about color development, and an extensive are explained, with suggestions of materials to try together. The chapter, illustrated with step-by-step color photos, on glaze chapter on “flux variation” offers a unique and interesting series application techniques. Glaze recipes from Cone 03 to Cone 10 of tests using various feldspars and fluxes. Hopper helpfully are discussed.The reader should be aware that Daly relies a great includes suggestions for a variety of temperature ranges, from deal on frits, which can be inconvenient to use. Since this is an Cone 04 up to Cone 10. This book is a guide for serious Australian book, the exact frits he uses may not be available experimentation, but it would also be helpful in adjusting throughout the world, although American equivalents are listed recipes that don’t quite work. in an appendix. Daly also frequently suggests the use of barium carbonate, which potters in this country usually avoid.

Harry Fraser— MlMI OBSTLER------Glazes for the Out of the Earth, CRAFT POTTER Into the Fire The American Ceramic Society, The American Ceramic Society, Westerville, OH, 1998 Westerville, OH, 2000 The traditional approach to teaching This very focused book is a guided tour glaze chemistry involves breaking the of the basic glaze materials and their various materials down into their function in promoting the formation of a molecular formulas and mathematically glaze. It is essentially a course in empirical calculating how much of which materials glaze chemistry aimed at imparting an understanding of all the will result in a mixture that matches a theoretical ideal. commonly used glaze materials and their characteristics when This book covers this method of glaze calculation and explains used in combination with other materials. Obstler’s approach is the classification of the various types of glaze materials to start with feldspars—materials that by themselves are almost according to their contributions to the glaze melt. The a complete glaze—and explore the effects of adding various molecular formula method of glaze calculation involves a fair materials to these “glaze cores” by hands-on experimentation. amount of math, and can be daunting for many potters. By working your way through this book, you can gain a very However, it is helpful at least to be aware of the principles of clear understanding of the action of a great number of glaze the method, and this book offers a great deal of other useful materials and end up with a variety of promising glaze recipes. information on subjects, such as glaze preparation, application, The temperatures covered in this book are Cone 5/6 oxidation firing, pottery faults, and health and safety considerations. and Cone 9/10 oxidation or reduction.

46 Summer 2OOO Pottery Making illustrated 47 48 Summer 2000