Connections...Though this is only the third issue of Pottery Making

Illustrated, we’ve already developed a few connections.From the Distant Past

In this issue, we welcome back Lenore Vanderkooi, one of the featured artists in the very first Pottery Making Illustrated (Ceramics Monthly Supplement January 1994). Lenore is a potter in Nashville, who has recently taken up ikebana, the ancient Japanese art of flower arranging.And the Not-so-distant Past

Our connection with recent authors continues with Sumi von Dassow, Barbara Coultry, Lili Krakowski, Jeff Zamek and Ivor Lewis. Sumi describes her proven step- by-step method for trimming pots that she teaches to her adult-education class; Barbara relates her solution to the Law of Diminishing Bats; and Lili illustrates how to make your own tools and wedging surfaces out of inex­pensive or found materials. Jeff Zamek, a ceramics con­sultant, receives about 5 to 10 calls a week from people afraid to go into their studios because of the health risks. He explains how working in the studio is like working in the kitchen—you just have to be aware of the hazards and follow the safety rules. And Ivor Lewis, who explained the mechanics of a teapot in our last is­sue, shows us a different approach to throwing one of the most basic forms—the bowl.With the Present

New to this issue are authors Daryl Baird from Love­land, Colorado, and Jeff Landis from Sun City, Florida. Daryl shows his step-by-step method for creating boxes from extruded parts, and is also working on a book on extruder art, due out next year. Jeff is a member of the Sun City Potters Club, which recently created a well- executed mural for the community pool.To the Future

Our coverage of student work provides a connection to the future. Seeing such talent in the millennial gen­eration means we’ll have plenty to look forward to for many years to come.The Connector

What really connects all these teachers, enthusiasts, students and retirees is the joy of working with clay.This joy is expressed in a poem from 10-year-old Octavia Bennet.

CLAYI love working with clay,I feel like I could work with it all day.The feeling of clay between my hands,Whoever felt clay understands.I love getting dirty, I love getting wet,I feel like I could be in the Telegram and Gazette!I love throwing, sculpting and pinchpotting.I think how other people are watching TV,With their brains rotting.I love wiping my hands on an old shirt,And if a pot breaks,It’s just water and dirt.

Pottery Making illustrated 1

2 Summer 1998

Cover: Flower vase, 18 inches in height, stoneware and rattan, by Lenore Vanderkooi—see story, page 9. Photo by John Cummings.

Pottery Making illustrated 3

Kiln Wash....................................................................... 6Basics on how a little whitewash can save you time and money

Flower Containersby Lenore Vanderkooi......................................................................9Combining clay and natural materials provides a stage for flowers

Hand Tools Made from Scrapsby Lili Krakowski.......................................................................... 14Make custom tools from scraps around the house

Extruded Boxesby Daryl Baird....................................................... ...................... 1617 steps to making boxes with an extruder

Trimming Step by Stepby Sumi von Dassow.................................................................... 2110 steps to successfully trimming your pots

1998 Ohio Governor’s Youth Art Exhibition............... 24Ohio high school students show their best

Making Batsby Barbara Coultry ...................................................................... 26Challenging the Law of Diminishing Bats

Wedging Boards and Tables: How to BuildYour Ownby Lili Krakowski..........................................................................28What you need to knead

Bowl Making: The Preforming and Inversion Techniqueby Ivor Lewis................................................................................ 30Rethinking a basic technique

The Potters of Sun City Centerby J e f f Landis ............................................................................. 37Retirees create a mural to enhance community pool

Studio Safety: Assessing Risksby J e f f Zamek.............................................................................. 42Knowing and avoiding hazards helps make potting safe

Editor: Bill JonesAdvertising Manager: Steve Hecker Production Manager: Thom Misiak Graphic Design: Debi Hampton Graphic Production: Carl Turner Production Specialist: Robin Chukes Circulation: Mary Hopkins Publisher: Mark MecklenborgEditorial, Advertising and Circulation Offices735 Ceramic Place P.O. Box 6136Westerville, OH 43086-6136 Phone: (614) 794-5890 Fax: (614) 891-8960 E-mail: potterymaking@acers.org Web Site: www.potterymaking.orgPottery Making Illustrated (ISSN 1096-830X) is published quarterly by The American Ceramic Society, 735 Ceramic Place, Westerville, OH 43081. Standard mail (A) postage paid at Westerville, OH, and additional 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: One year $12, two years $23, three years $32. Add $8 per year for sub­scriptions outside North America. In Canada, add GST (R123994618). All payments in US$. 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 magazine ad­dress label along with your new address to the Circulation Department. Allow six weeks ad­vance notice.Contributors: Writing and photographic guide­lines are available on request. Mail manuscripts and visual materials to the editorial offices with a self-addressed postcard for notification of receipt. Indexing: Feature articles are indexed in the Art Index and daai (design and applied arts index), avail­able through public and university libraries. Photocopies: 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, pro­vided that the base fee of US$5 per copy, plus US$0.50 per page, is paid direcdy to the Copy­right Clearance Center, 222 Rosewood Dr., Danvers, MA 01923 USA (508) 750-8400.This consent does not extend to other kinds of copy­ing, such as copying for general distribution, for advertising or promotional purposes, or for cre­ating new collective works. Requests for special photocopying permission and reprint requests should be directed to the Director of Publica­tions, The American Ceramic Society, P.O. Box 6136,Westerville, OH 43086-6136.Back Issues: When available, back issues are $5 each, plus $2 postage. Add $5 for orders outside North America. In Canada, add GST (registra­tion number R123994618).Postmaster: Send address changes to Pottery Making Illustrated, P.O. Box 6136,Westerville, OH 43086-6136. Form 3579 requested.

Copyright © 1998 All rights reserved

4 Summer 1998

Pottery Making illustrated 5

KILN WASH

For beginners, the safest route to protecting expensive kiln shelves is to use kiln wash. Kiln wash protects kiln shelves by serving as a separator be­tween fired glazed ware and the kiln shelves. It consists of powdered re­fractory materials mixed with water to a paint-like consistency. If a clay body fluxes too much or a glaze un­expectedly runs off a pot onto a kiln-washed shelf, the ware typically sticks only to the wash and not to the shelf

Most potters use kiln wash to pro­tect their shelves from glaze accidents or for keeping certain clay bodies from bonding with the shelves. Even potters who wipe glaze from the bot­tom of unwaxed pots need to use kiln wash, because glaze soalcs into the pores of bisqued ware, then melts during the firing.To Mix or Premix

Because of the variety of firing methods, kilns and materials, there is no one kiln wash that is ideal to all. Ceramic-materials suppliers sell the dry ingredients if you make your own recipe, but they also sell premixed kiln wash in both powered or liquid form. Here are a few kiln wash recipes that have shown up on Clayart (the Internet discussion group founded by Joe Molinaro and Richard Burkett) and in literature over the years. Experiment and select the one that suits your particular fir­ing needs.Before You Fire

Kiln wash may be applied with any wide paintbrush, a paint roller or by spraying. Coats should be thin, and only enough wash should be ap­plied to cover the surface. Care should be taken to not get any wash on the bottom or edges of the shelf. Dipping a new shelf in water first al­lows kiln wash to adhere better. Though this method takes longer to dry, the coating bonds better because it sinks deeper into the surface.

Easy OffAfter firing a glaze kiln, most

stuck pots or glaze drips are fairly easily removed from a kiln-washed shelf For the more difficult drips, many potters use a hammer and 1- inch masonry chisel, held at a low angle to the shelf, tapping lightly but firmly to remove the glaze.

WARNING: Wear protective goggles and long sleeves to avoid in­jury from flying glaze slivers when using a hammer and chisel.

Note:While some potters use a power grinder to clean blemishes and old kiln wash from shelves, this operation is quite hazardous because of the dust that’s generated. Caution must be taken to work in a well-ven­tilated area, always wear a NIOSH- approved dust mask, or if possible, dampen the surface of the shelf to cut down on the dust.

Some potters remove and reapply kiln wash after every firing, while others periodically apply wash only to affected areas where the wash is chipped or thin. Use the method that suits you best.

Where the kiln wash has chipped off, use a hard brick to level the old wash, then fill any irregularities with thick wash and rub level again.Problems, Problems• Since kiln shelves may be made

from a variety of materials (e.g., silicon carbide, mullite), a kiln wash that works well on one type shelf may not work on another.

• Washes containing silica are not suitable on shelves for firing porcelain or in salt/soda kilns due to the fluxing action in the materials or atmosphere.

• If kiln wash settles out rapidly (and some do between brush charges), adding 1% to 2% bento­nite to the dry mix will help suspension.

• Some kiln washes crack and chip off the shelf before firing. To

prevent this, add 0.05% powdered CMC gum to the dry mix.

• When shelves warp, it’s sometimes possible to fire them upside down to flatten them; however, first remove all kiln wash buildup to prevent flakes from contaminating glazed pieces.

No Wash?Some potters forego the kiln wash

because they use only known safe glazes (nonrunning or nonflaking) or don’t use glazes at all. When a ques­tionable glaze is used, the piece is placed on a piece of broken shelf or a blank tile. Not using kiln wash allows potters to flip their shelves over often without fear of any old kiln wash dropping on the ware below.

Other potters dust their shelves with alumina hydrate, kaolin, sand or grog before each firing and recycle it when the firing is over. Care must be taken not to allow any of these pow­ders to drift onto ware below.

Note: Do not dust shelves with powders if you have a kiln-venting system. The movement of air through the kiln may pick up the dust and de­posit it on glazed surfaces.

RECIPESTraditional Kiln Wash

Kaolin....................................50 partsSilica (200 mesh).................. 50 parts

100 partsMix to the thickness of paint and apply 2 or 3 coats. Flakes at Cone 10.

Tom Turner’s Kiln Wash Alumina Hydrate (100 mesh) 75 partsKaolin.................................... 25 parts

100 partsWorks well at Cone 10.

Robert Tetu’s Kiln WashAlumina Hydrate...................50 partsKaolin (EPK).........................25 partsSilica (200 mesh).................. 25 parts

100 partsVery smooth and long lasting. Difficult to remove glaze drips.

6 Summer 1998

Pottery Making illustrated 7

8 Summer 1998

by Lenore Vanderkooi

or years, I’ve enjoyed making containers with flowers in mind. The beginning of every crafts fair finds me in the booth arranging fresh flowers in various vases. I’m only now beginning to study the real art of ikebana, the very formal­ized Japanese method of arranging flowers. At the moment, I’m fascinated, but also overwhelmed, by the complexity of this art. The arrangement featured here and on the cover was made by Betty Lankford, one of my teachers.

My pots are fired in a gas kiln to Cone 10. Often I combine bam­boo and other natural materials with the finished pots.These additions are functional as well as visual. They are handles, feet or split bamboo spikes thrust through the walls of the pot to support flower stems.

Flower vase, 18 inches in height, stoneware and rattan. Arrangement by Betty Lankford.

Pottery Making illustrated 9

PHO

TOS:

JO

HN

S. C

UM

MIN

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J

How to Make an I K EBANA BOWL

Lenore Vanderkoois ikebana bowl (see page 12) is thrown upside down with a cone-shaped bottom and therefore won’t sit unaided on a table.

Figure 1Center and spread clay.

To support the form, she attaches three bamboo legs to the bowl. The bamboo adds a visual as well as a functional element to the bowl.

Figure 2Open clay all the way to the bat and draw it out into a ring.

Figure 3Press down on the outside of the ring to form a lip (remem ber, this is upside down), and begin to pull up the walls.

Figure 4Pull the walls straight up for a couple of inches, then begin angling them in as if throwing a bottle.

Figure 5Close up the opening completely.

Figure 6Smooth out. Since air is closed inside, the form supports itself well at this point.

10 Summer 1998

Figure 7

Cut from the bat and allow to become leather hard.Figure 8Trim the inside edge of the rim and smooth the inside of the bowl.

Tip: As a trimming aid, I use a 4-inch-thick piece of foam attached to a bat. With an electric knife, I carved a shallow cone shape into the center of the foam.

Figure 9

With a large dowel, make an indenta­tion in the rim and side in three places where the legs will be attached.

Figure 10

Cut slits in the wall parallel to where the leg will be. This is to tie the leg to the pot after firing. Bevel it well so rough edges won’t cut the tying material.

Figure 11After firing, measure and cut the bamboo sticks. Then attach them to the pot with chair caning that has been soaked in water.

To prepare the bamboo, wrap masking tape around the cane at the place you intend to cut. After cutting with a saw, finish the edges with sandpaper or a grinder. To minimize cracking, drill out the solid joint

in the bamboo. I heat the wood in a microwave or with a propane torch to bring out the oil in the wood and to kill any little eggs that may decide to hatch later. While still warm, rub the oil back into the wood.

Pottery Making illustrated l l

Preparing BAMBOO

OVALFLOWER

ARRANGINGVASE

“Ikebana Bowl,” 4 inches in height and 12 inches in diameter, stoneware and bamboo (see previous pages). Using a spiked frog (kenzan) and some small stones, this makes an attractive container for flowers.

Vanderkooi’s “Oval Flower Arranging Vase” incorporates split bamboo spikes thrust through the walls of the pot to support flower stems.

12 Summer 1998

A variation on the “Ikebana Bowl” is this “Tripod Bowl,” which is 6 inches in height and 16 inches in diameter.

Lenore Vanderkooi has been a professional potter for over 20 years in Nashville, Tennessee. She was

featured in the first Pottery Making Illustrated in fanuary 1994 (a Ceramics Monthly supplement now out of print).You can reach her by e-mail at lvanderkooi@mindspring. com

Tripod basket vase, 24 inches in height, stoneware with willow.

Pottery Making illustrated 13

Hand Tools Made from Scrapsere are some trimming and modeling hand tools you can make from found materials. Steel strapping is easy

to locate in the junk piles at lumberyards and garden centers—just ask a clerk for help. Strapping-steel tools can be sharpened with a metal file, but be sure to wear protective gloves when handling and cutting this material.In addition, used hacksaw, bandsaw and saber-saw blades also make perfect clayworking tools, and can usually be gotten free from woodworkers.

A. Strapping steel bent into shape with pliers, and bound by duct, adhesive, or cloth tape.

B. Strapping steel bent to shape and taped to a piece of flat scrap wood.

E. A tool that heralds spring! Take a Y-shaped piece of branch about ½-inch in diam­eter and 6 inches long. Peel back the bark from the top and, compressing the “arms,” wind discarded guitar, spring or leader wire around them. When the “arms” are released, the wire tightens, and you have a super tool for trimming pot tops. It’s a springtime tool because that’s the time when wood is really flexible and trees get pruned.

C. Strapping steel bent into a loop and attached to a 1/2x2- inch piece of hardwood about 8 inches long. Brass screws are used. The bottom edge of the wood is cut at a 45° angle—just right for undercut­ting pots on the wheel.

D. A piece of hacksaw blade or discarded saber saw blade is inserted into a slot cut in a piece of broomstick with a saw. The blade is epoxied into place and bound with dental floss, which clamps the blade to both glue and wood.

F. Another strapping-steel tool. Here the strap is halved lengthwise, so as to be only V\ inch wide. It’s bent and fitted into a narrow copper pipe, which then is hammered or pinched shut. The dotted line indicates how deeply the strap is fit­ted into the pipe. The bottom of the pipe here has been hammered shut, but it need only be filed down to eliminate sharp burrs.

G. An old foam paintbrush is stripped of its foam and the plastic insert, and a strip of strapping steel, cut as in F, is epoxied and bound into place with dental floss. Very good for smaller, finer work.

Lili Krakowski is a professional potter residing in Constableville, New York. She teaches pottery at the Gibbes Museum of Art in Charleston, South Carolina, during the winter months.

14 Summer 1998

by Lili KrakowskiH

by Daryl Baird

couple of years ago I chanced upon Yellow Springs Pottery, a top- notch cooperative in Yellow Springs, Ohio, and discovered small, extruded boxes by Evelyn LaMers. These boxes, simple in design and well-made, caught my eye and inspired me to begin creating boxes of my own. After lots of experimentation and refining a series of techniques that worked for me, I settled on a 17-step process for making boxes with an extruder.

Extruded boxes, stoneware, fired to Cone 9, by Daryl Baird.

Step 1. Wedge clay thoroughly.To smoothly move through an extruder, the clay has to be work­able and free of air. If it’s too firm, it will split as it passes through. If the clay is too moist, the extrusion will not hold its original shape. Air trapped in the clay will pop out as it goes through the extruder leaving scars, or worse, holes.

Daryl Baird is a professional potter and instructor residing in Loveland, Colorado. He is currently writing The Extruder Book, scheduled for publication by The American Ceramic Society in 1999. A search is on for high-quality slides of completed extruder art for possible publication in this book. For more information, contact Daryl at PO Box 1086, Loveland, CO 80539, or via his website at www.concentric.net/~clayguy

Step 2. Assemble extruder and load with clay. I use a 2/4-inch hollow square die assembly for most of my boxes, but excellent designs can be achieved with a hexagon-, circular- or triangular-shaped die. Before loading the clay, make sure the extruder barrel is clean and that the die assembly is securely attached to the barrel to avoid having clay squeeze out the sides. I spray the inside of the barrel lightly with no-stick pan coating from the kitchen. It helps the clay move smoothly through the barrel, and it makes cleanup much easier. (You can also use a lubricat­ing spray like WD-40.) Fill the barrel with clay. Take care to press it into the corners and pack it evenly.

16 Summer 1998

A

Step 3. Make the extrusion.As you press the clay through the extruder, a partner is valuable to guide the extruded clay and keep it as straight as possible. By yourself, you can press the handle with your chest and guide the clay with your hands, but this is awkward, to say the least.

Step 4. Handling freshly extruded clay. When the extrusion is about a foot long (notice the placement of the yardstick below the extruder barrel), a cutting wire is pulled from corner to corner near the base of the barrel to free it. As you cut through the clay, your partner holds it and takes it to a paper-lined tray or wooden board. True the shape of the extrusion by drawing a yardstick or paint-stirring stick through it on all four interior sides as it lays on the tray.

Step 5. Make a slab for the tops and bottoms.We now use a slab roller, but the “rolling pin-and- yardsticks” method also works. Make the slab about as thick as the walls of the extrusion.

Pottery Making illustrated 17

Step 6. Cut tops and bottoms. Make the tops and bottoms slightly larger than the box dimensions to ensure a good fit all around. Since my extrusions are 2V2X2V2 inches, I cut out squares that are 2¾x2¾ inches.

Step 7. Cut extrusion into segments. The trick here is to make straight cuts on all four edges, perpendicular to the walls, without crushing or splitting the shape. First, square up the sides using paddles or paint-stirring sticks. Next, use a small carpenter’s square as a cutting guide and a sharp-edged rib to make the cuts. After making the cuts, pull a stick through the inside to square everything back up. Working when the clay is near leather-hard gives the best results.

Step 8. Attach top and bottom. Before the clay gets much harder, attach the top and bottom with slip or Magic Water (see page 19). Scoring isn’t really necessary. Press the pieces firmly into place with a rap or two from a small paddle board cut to fit comfortably in the hand. Brush away any excess water or slip.

18 Summer 1998

Step 9. Trim excess clay. Use a metal rib or fettling knife to trim away excess from the top and bottom.

Step 11. Cut the top. Before you cut the lid, cover the assembled box for about 24 hours and allow it to set up. Cutting the lid is where artisan becomes artist. What’ll it be? A wavy rim all the way around. Or, maybe notches on each side. For me, it’s mountain- scapes that are cut to make a fitted lid for the box. It’s important to have some contour to the cut so the lid stays in place on the box and doesn’t slide off.

Step 10. Square up sides. The paddle boards are used again to square everything up.

Step 12. Finish inside. The seams inside the lid and bottom have to be smoothed to ensure a good seal and avoid cracking. I use the stubbed end of an old paintbrush for this, but a chopstick works well, too. The cut edges also have to be lightly scraped to remove burrs and give the lid and rim a good fit.

Magic Water1 gallon water3 tablespoons sodium silicate 5 grams soda ash

Use in place of water or slip when attaching pieces to prevent cracking and separation of parts.

Pottery Making illustrated 19

Step 13. Attach a stem or post. While the box isstill leather hard, one or two stems can be attached with slip or Magic Water. A small hole in the stem made with a stick allows ornaments to be attached later.Tip: I’ve found that a drill bit from the toolbox makes clean holes.

Step 14. Smooth the sides. I use a Surform and a rib to do a final square-up and smooth out the sides of the box.Step 15. Dry the box. Allow the box to dry evenly, since even drying is a critical step, especially with boxes over 6 inches tall. I dry my boxes on a wooden shelf with good air circulation all around. On the second day, I lay the lids next to the bottoms to allow drying from the inside out.

Step 16. Apply slips, engobes, glazes or stains.The key here is to apply the surface treatment in such a way as to avoid the risk of it running down, inside or outside, during firing and sealing the box shut.After bisque firing, apply wax resist on the edges (where the lid meets the bottom) to minimize the risk of this occurring.

Step 17. Add ornaments. If you’ve added a stem or a couple of posts to the lid, you can tie on all sorts of things to make the box unique. After glaze firing, I add my own ceramic leaves, driftwood, twigs, bamboo and even barbed wire to fashion handles for the lids.

20 Summer 1998

by Sumi von Dassow

The Preparationhen a pot is thrown on the

wheel, it’s usually necessary to leave a greater thickness of clay at the base of the wall than is desirable in a fin­ished piece. This extra clay reinforces the wet wall, preventing buckhng at the base. The extra clay is removed when the pot is leather-hard, which is when clay is at its strongest prior to firing. This is the trimming pro­cess, and it resembles carving wood on a lathe more than it does any other clay-forming process.

The basic tools I use for trim­ming are loop and ribbon tools, consisting of a wooden handle with sharpened steel blades. These tools come in a variety of shapes and there may be one or two blades at­tached to a handle.

It takes some practice to hold these tools in such a way that the clay is removed smoothly without gouging extra chunks out of the pot being trimmed. Because of the po­tential for ruining the pots they struggled to throw, students tend to be timid about trimming. However, a demonstration, a few tips and a bit of practice usually suffice to make them comfortable with the tools.

Figure 1A Figure 1B

Determine the thickness of the base. Lay a straight stick or tool across the top of the pot; with a ruler, measure the distance from the bottom of the inside of the pot to the ruler (1A); then measure the height of the pot from the outside (1B). The difference is the thickness of the base. Half an inch or more is enough to allow for a 1/4-inch base and a 1/4-inch foot ring. (Note: you can use any two long straight tools instead of rulers.) Use a needle tool to indicate this measurement on the outside of the pot.

Figure 2A Figure 2BFeel the thickness of the sides of the pot with your fingers, then measure the inside width of the pot with two fingers (2A) and mark the underside with the needle tool (2B).

Sumi von Dassow has been a potter for 18 years and currently teaches at Jefferson County Adult and Continuing Education in Golden, Colorado. Visit her web site at www.well.com/~sumi

Pottery Making illustrated 21

PHO

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JAC

K W

OEH

RWi

TrimmingStep

byStep

Centering

Figure 3Center the pot upside down by tapping with the thumbs while the wheel turns. Note: Learning to center by tapping with the thumbs takes a lot of practice, but there is another way when you’re getting started. Center the pot by placing it approximately in the center, then, while the wheel turns, hold the needle so that it marks one side of the pot. Push the marked side of the pot toward the center of the wheel, rub out the mark, and repeat until centered.

Figure 4Hold the pot down and secure it to the wheel with three wads of clay.

ChatteringChattering—the development of vertical ridges on

the area being trimmed—forms in much the same way a corrugated dirt road does. The tool bounces on a bit of grog, then bounces again when it lands, and keeps on bouncing its way around the pot until the pot is grooved all the way around. To smooth the pot again, it’s necessary to switch to a new (not dull) square-ended ribbon tool. Starting from a point below (or above) the grooved area, remove clay steadily while moving the tool slowly toward and across the grooved area.

The Process

Figure 5Use the rounded end of a ribbon tool to make a depression in the center of the pot’s underside as deep as you eventually want to trim.

Figure 6

Following the mark made earlier (see figure 2B), use the square end of the ribbon tool to mark the outside of the foot ring.

Figure 7Trim excess clay from around the outside of the foot ring and down the sides of the pot. Note that the tool is held in the right hand and held steady with the left thumb. The left hand also holds onto the pot to steady it and to catch it if it comes loose.

22 Summer 1998

Figure 8 Figure 10ARemove excess clay from the center of the foot to the depth of the initial depression. Do this only after the outside is completely shaped so that the outer circumference of the foot ring can be decreased as necessary. Note that the right pinky finger anchors the hand for better control of the tool.

Figure 10B

If the trimmed surface is rough, dampen the trimmed portion with a sponge (10A) and smooth with a rubber kidney rib (10B).

Figure 9

Use the needle tool to cut the foot ring level. Hold the needle toward the tip so it doesn’t bend when it touches the clay, and cut slowly through the foot ring.

Speed CuresIf the wheel rotates too

slowly, any unsteadiness in the hand holding the tools is likely to be transferred to the pot, resulting in an uneven trimming job, which is difficult to repair. This is particularly true of the last step, cutting the foot level with the needle. Though it seems counterintuitive, if you’re having trouble trimming evenly, speed up the wheel.

A trimmed mug ready for a handle.

Pottery Making illustrated 23

The Ohio Governors Youth Art Exhibition, now in its 28th year, is dedicated to the educational and artis­tic advancement of Ohio’s talented young people. This year s competition resulted in the selection of 300 pieces from over 12,000 regional entries. Here are a few of the ceramic art entries from this years competition.

“Buddhakaya,” 10 inches in height, Chad Stayrook, Hilliard Davidson High School, Grade 12.

“Hallow,” 8 inches in height, Anne Martin, Hilliard Davidson High School, Grade 11.

“Raku,” 18 inches in height, Geno Dunlap, Westland High School, Grade 12.

“Burgundy Raku Jar,” 36 inches in height, Joel Bullen, Westland High School, Grade 12.

“Gottcha,” 12 inches in height, Kami Meighan, Pickerington High School, Grade 12.

Summer 1998

“Roots of the Mind,” 14 inches in height, Matt Jenkins, Mt. Vernon High School, Grade 12.

24

“Broken Ice,” 9 inches in height, Lindsay Bruggemeier, Hilliard Davidson High School, Grade 11.

“The Sixth Element,” 24 inches in height, Jason Beard, Clyde High School, Grade 10.

Untitled, 8 inches in height, Emily Burhans, Athens High School, Grade 12.

Pottery Making illustrated

Thanks to Thad Ricker; Ohio Governor’s Youth Art Exhibition executive director, for submitting exhibition materials. Photos by Dan Gordeman and Jon Iddings

“Future Landscaping,” 9 inches in width, Nicole McGinn,

Hilliard Davidson High School,

Grade 12.

“Backlit Belltower in the Sea

of Scrape,” 24 inches in height, Amy Shepherd,

Mansfield Senior High School,

Grade 10.

The 1998 Ohio Governor’s

Youth Art Exhibition

“Hand Made Tea Set,”

teapot 6 inches in height, Kathleen

Friberg, Stow Munroe Falls High School, Grade 12.

by Barbara Coultry

I was sure that I could increase production. First I would wedge all the clay I needed' weigh and divide it, throw one stupendous work of art after another; and finally, take each piece with its bat off the wheel. Unfor­tunately, the bats ran out after the ninth tea bowl. This is the Law of Diminishing Bats.

ProcedureStep 1. Measure off 12-inch intervals on all four edges of the hardboard, then draw connecting lines to create 32 squares (see figure 1). Saw these squares into individual pieces using whatever type of saw is avail­able and works best for you.Step 2. Locate the center of each square by connect­ing diagonal corners to form an “X” (see figure l).The two lines cross at the exact center of the square.Step 3. Locate the placement of pin holes. Go to your wheel and measure from the center of one pin to the center of the other as shown in figure 2. Its likely to be either 9 or 10 inches.

nowing there must also be a corresponding Law of Increasing Bats, I went about figuring out how to make my own. Here’s how I did it.

SuppliesYou’ll need a 4x8-foot sheet of tempered hardboard

(Masonite), a small can of polyurethane varnish and a couple of those disposable foam brushes. Make sure the brush width is smaller than the can opening. (I didn’t.) You’ll also need a saw for straight cuts (such as a table saw or hand-held circular saw) and a saw for curved cuts (such as a scroll saw, band saw or hand­held saber saw). And you’ll need a drill. Please note that trying to do this project without motorized equipment will cause you to foam at the mouth. Warning: Follow all manufacturers’ operating instruc­tions when using power tools.

Barbara Coultry resides in East Greenbush, New York, where she owns and operates Coultry Pottery.

Figure 1

Divide a 4x8 sheet of tempered hardboard into 32 one-foot squares. When you allow for the saw cuts, finished bats will be just under 12-inches in diameter. Locate the center of each bat at the intersection of lines drawn diagonally from corner to corner after the sheet has been cut into squares.

Measure the distance between the centers of the pins on your wheel head.

26 Summer 1998

Figure 2

K,

Step 4. Using a thin strip of wood or metal that’s at least 13 inches long, make a hole in one end just large enough to allow a sharp nail to slip through (see figure 3). From this hole, measure off half the distance between your bat pins (either 4½ or 5 inches). Make another hole at this point large enough to accommo­date a pencil point. Then mark a spot 6 inches from the original nail hole. (Note: You might want to check the hardboard squares—they may be a hair under twelve inches because of the saw cuts. If so, mark a spot slightly less than 6 inches on your strip.) Make a second pencil-point hole.Step 5. Slip the nail through its designated hole and place it firmly on the previously marked center as shown in figure 3. While holding it there with one hand, draw two circles on the hardboard square. The outer circle is the cutting line and the inner circle is for the pin holes. Draw a straight line from one side to the other, making sure it goes through the center of the square as shown by the dashed line in figure 3. Where this line crosses the inner circle is where the pin holes will be drilled. (I tried making a bat tem­plate out of cardboard, but I spent too much time centering it and keeping it from slipping on the hardboard’s smooth surface.)

Step 6. Cut the hardboard along the outer circle of each square. A band saw does the job best, but a hand­held saber saw also works. Sand the edges just enough to remove the roughness. Beauty is unimportant since the bat’s destiny is immersion in muddy water.Step 7. Before drilling, make a few test pin holes in scrap hardboard to ensure using the proper drill-bit size. Pins are usually ¾-inch diameter, but it pays to be sure. You don’t want to discover you’ve chosen the wrong drill bit after making the holes in all 32 bats. Drill test holes only in hardboard because a drill will bite differently in different woods. Before you drill, place a nail at the spot where you’ll be drilling and whack it with a hammer to create a small starter hole so the bit won’t drift off center when you start drill­ing. Tip: Place a piece of scrap wood behind the hardboard when you drill to prevent the drill from tearing the hole as it drills through.Step 8. After drilling the first bat, check its fit on your wheel. If the holes are only a hair off, see if scraping on one or the other side of the hole with a craft knife or small curved file allows the bat to slide down over the pins (see figure 4). If that’s all it takes, then proceed drilling the remaining bats. No matter how precise you are, a certain amount of scraping or filing will probably be necessary on each bat.Step 9. Lastly, find a well-ventilated area where you can spread out the bats on newspaper.Varnish one side of the bats, let them dry, then varnish the other side.

Figure 3Create a wood or metal template with pencil holes to mark critical measurements on each bat.

Pottery Making illustrated

Figure 4Use a craft knife to trim and scrape pin holes for a final adjustment.

27

Wedging Boards and Tablesith few exceptions, all studio pottery equipment used to be homemade. Building one’s basic equipment

offers considerable savings, as many “ingredients” can be salvaged from demolition dumpsters, bought at junk dealers, or found among the odds and ends of any woodworking shop. The wedging board and wedging table are projects that readily lend themselves to being made out of scrap materials. Here are a few plans on how to build your own.

W E D G I N G T A B L E HOW-TO INSTRUCTIONSA wedging table is easily built

because it’s basically a sturdy box bolted to legs.The box’s lid can be clothed in canvas, or filled with brick or plaster. I’ve read of its be­ing filled with smooth, well-floated concrete, but concrete has a big drawback—bricks can be taken out, plaster chipped or cut out, but concrete, well, is as heavy as con­crete, and a big slab is hard to lift. Note:There is much confusion about “plaster in the studio.” It’s not plaster in powder form that’s the threat. The problem is chips of plaster from bats, molds or the wedging tabletop getting into the clay and causing lime pops, those notorious destroyers of great pots. The same danger is introduced with cement. Smoothing the table- top very well prevents little bumps that would be the first to chip off.

To build a wedging table, any scrap wood does nicely, provided it is heavy enough. Use 4x4s for legs, and avoid using treated wood where your body will rub against it—as on the front edge of your wedging table.

CAUTION: Examine old wood thoroughly for breaks and rot as well as “hidden” nails, screws or foreign material stuck in the wood, which might snap a drill bit or make a saw kick back. New wood must also be checked for defects— preferably at the time it is being bought or delivered.

When constructing a wedging table, use dadoed or half-lapped joints to add strength. And don’t use nails for any part of the con­struction—use lag bolts and/or

wood screws instead. Wedging loosens a table, but lag bolts and screws can be retightened as needed.

Figures 2 and 3 show two varia­tions of wedging tables you can build. Another variation (not shown) is to fill the box with plas­ter or concrete to within about 1 inch from the top. A plywood board is cut to fit the frame; the board is covered with canvas and used for wedging. Boards are made for each color clay, or to permit the proper drying of the canvas after washing. The canvas-covered board should stick up above the frame about ½ inch, so your wrists avoid hitting the frame.

W E D G I N G B O A R D HOW-TO INSTRUCTION^A wedging board can replace a

wedging table. One can wedge excellently on a piece of ¾-inch outdoor plywood or chipboard, 24 to 36 inches long and 18 to 24 inches wide and covered with canvas. Better not attach the canvas with staples, because they rust and work themselves out. Attach the canvas with strips of lath secured by recessed flat-head brass wood screws. The lath goes on the underside of the board, and can double as a rolling and wire guide when the board is flipped.

An alternative covering method is to use a sewing machine to make a canvas pillow case for the board. The long open end is folded under and held in place by your knees as you wedge.

Remnants of canvas can some­times be bought from awning or sail makers. White denim replaces canvas adequately. Dye or ink reduces absorption, but rarely so much as to make colored canvas unacceptable.

When wedging, place the board on the floor and kneel on one of the edges, protecting your knees with a folded burlap bag or a thick piece of foam rubber. Many (including myself) prefer to wedge kneeling, because it’s easier on the back, shoulders and wrists. My own board is about 18x24 inches—for ease in lifting and moving. The board takes up no room to speak of when not in use.

28 Summer 1998

by Lili Krakowski How to Build Your Ownw

W E D G I N G T A B L E HOW-TO ILLUSTRATIONS

Figure 1To establish the best height of a wedging table, stand with one foot slightly in front of the other, and rest the palms of your hands on the table. Arms and back must be straight, without any hunching of the shoulders. Rock your weight back and forth from foot to foot, checking that at no time you hunch your shoulders. Test sev­eral times, placing books under your hands if the table is too low, boards un­der your feet if it’s too high. While wear­ing the shoes you work in, check your measurements several times. If the table is used by several people, build to suit the tallest. Then, build some “wedging platforms” of 2-inch-thick scrap (e.g., 2x6s or 2x8s) for short people to stand on. These platforms should be at least 15x18 inches.

Figure 2

A wedging table may be made as a simple box, with ¾-inch sides (A) attached to a ¾-inch-thick exterior-grade plywood bot­tom (B); 2x4s (C) support the bottom, and 4x4s are used for the legs (D). The box is filled with new (i.e., “perfect”) red brick pavers laid flat. This is a good table for red clays, but not recommended for light- colored bodies.

Figure 3

To make a wedging table that doubles as a clay storage bin, make the basic box (A) from 2x8s. The bottom of the box (B) is ¾-inch exterior-grade plywood or chip­board, with several 1 -inch holes drilled in for ventilation. The top (C) is ¾-inch ex­terior-grade plywood covered with can­vas. Note the 1x1 cleats (D) that hold the lid in the box. (You can also hinge the lid, but the strips keep the lid from jiggling.) The legs (E) are made from 4x4s. 2x4 braces (F) are attached to only three sides so buckets can be stored under­neath. Using lag bolts to build the box al­lows you at some point to fill it with plas­ter or concrete. If you decide on plaster or concrete, a 6-inch-deep box is deep enough. Make no holes in the bottom of the box, fill with whatever material you choose and smooth the top surface per­fectly. Lag bolting allows you to easily take the box apart if you need to move it or to replace the “filling.”

W E D G I N G B O A R D HOW-TO ILLUSTRATIONS

Figure 1

Wedging boards can be placed on the floor so you can kneel while you wedge.

Figure 2

For a wedging board, canvas is stretched over a piece of ¾-inch exterior-grade ply­wood or chipboard.

Figure 3

Canvas is held in place by strips of lath fastened by brass flat-head wood screws on the underside of the board. The lath doubles as a rolling and wire guide.

Pottery Making illustrated 29

The Preforming and Inversion Technique

Bowls are ritual vessels. They contribute to the heritage of many races, creeds and cultures. At their simplest, bowls are used to contain and serve food. Their use in the tea ceremony contributes to an appreciation of aesthetic delight and spiritual ecstasy. Bowls are fundamental functional forms. With food served in them, they become items of great intimacy as we hold them and eat from them. Bowls help us overcome thirst and hunger—rice bowls, soup bowls, serving bowls, finger bowls, mixing bowls, tea bowls— the list is long.Basic Considerations

Creating a bowl should be a spontaneous act. As potters, our products, whether made by simple hand pinching or using the mechanics of the wheel, should exhibit economy through intelligent use of mind, eye and hand. This effort should be reflected both in form and decoration. Bowls for holding should nestle in the hand and invite caress. For mixing, they should be robust. For serving, light and easy to carry.Old Lessons

I was taught to make bowls many years ago using a method where a centered ball of clay was opened, then spread to give a concave inner contour from the base outward, squeezed from inside and out using both hands and stretched as a rising wall upward to the rim. Several pulls were needed to achieve both diameter and height, but it was a regular event for the wall to slump, leaving a humped ring at the foot of the wall inside near the bottom.

For a beginner, correcting this defect was a struggle. It was a difficult task to make a matching set. Quality was inconsistent with variations of height, diameter and contour.

Studying the ProblemAll bowls are basically a hemisphere, and the

strength of a bowl during fabrication is dependent on our approach to, or departure from, that ideal hemi­spherical form. When the foot ring is narrow with an overhanging base that is almost horizontal so that there is a marked change in profile to achieve a near vertical wall, there is always potential for the form to slump over the foot. This gives rise to a hump around the inside at the bottom of the pot.

To correct this defect, it’s not unusual to model the rising contour earlier, closer to the center of rotation and reduce the inflection between the base and the wall, or alternatively, increase the diameter of the foot ring. However, if these changes are taken to either extreme, that desirable volume of a hemispherical shape is lost. The wall and the floor may merge to give a cone or the base spreads to create a dish. The result­ant effect is to reduce the working volume of the vessel.

Although a conic shape may have aesthetic merit, it negates the function of generous containment through eliminating the fullness of the original conceptual form. The fullness of the bowl, the ceramic shell, should appear suspended from the rim, like a curtain.Understanding the Materials

To become successful at throwing, it s necessary to understand the strengths and weaknesses of plastic clay. Throwing clay contains enough moisture to provide adequate lubrication. Beyond that required for center­ing and opening the ball of clay, little more is needed. Even then, it s preferable to use slip rather than water, since slip is a better lubricant (thin slip is composed of platelets of clay, which slide over each other). Clay can

Now retired, Ivor Lewis works as a writer and artist at his home in Redhill, South Australia. He taught for Colleges ofTAFE and continues to give demonstrations. Contact Ivor at Box 10 CMA, Redhill, South Australia 5521, or by telephone 08-8636-7083 for further information.

30 Summer 1998

by Ivor Lewis

then remain slippery without absorbing moisture. ALso, thick clay is stronger than thin clay and can resist more stress without deforming.

When a potter following common practice starts working to shape a full bowl form, the first effect is to make the clay thin and therefore weaker at the base of the wall, where it will bear the most stress. Stresses arise from the torque, from friction and from gravity. At the throwing point, gravity, acting on the heavier mass extending and overhanging the foot, will cause the clay particles to shear and slide past each other, and slumping occurs.A Different Approach

To avoid slumping clay when making a bowl, expanding the profile to give the full volume should be the last action, not the first. I’ve developed and used a preforming and inversion technique for several years. It takes a lot longer to describe and illustrate than it does to accomplish. It’s a versatile method that can be used for small or large bowls, deep or shallow, wide or narrow Once the method is understood and practiced consistently, bowls that are uniform in size and shape can be achieved.You’ll soon find you can change the profile to give broader interiors and steeper walls by varying the direction of your hand movement at the inversion stage. With practice, it’s possible to throw specific weights and get consistency of size and contour without measuring.You’ll also find your production rate goes up as fast as your reject rate goes down, and you’ll get more pot from your clay.

I use this method for making tall mugs and short cups that have hemispherical bottoms; to create teapots that are generous in volume; and as an early intermedi­ate stage when I throw bulbous vases, jugs, pitchers and jars. Wherever there will be a significant overhang from a wide belly sitting on an narrow foot ring, then this technique can be applied. Less turning is needed to

achieve lightness and bigger volumes are developed from smaller weights of clay. Furthermore, height, which enhances aesthetic elegance, is maintained.

To begin, your clay should be plastic, smooth, uniform in texture, color and consistency; and until the sequence of actions is understood, it should be soft rather than firm. (Firm clay has reduced plasticity and is difficult to center.) Refrain from taking too much clay—between a pound and a pound and a half is sufficient. Work on bats if possible. Lightly moisten the clay as required for lubrication at the start of each stage.

Your immediate aim when learning isn’t to make very light, thin bowls, but to master the process.Your skill will develop as your confidence grows, and eventually you’ll make larger bowls with thinner walls. In the following description, the wheel is revolving counterclockwise and throwing occurs on the right side of the pot. In the diagrams, a circle on the arrow shows fingertip movements.

Figure 1

Center about a pound of clay on the wheel head, then reform it into a flat-topped cylinder, which is slightly higher than it is wide. Because bowls are fragile and difficult to lift from the wheel without causing distortion, work on a bat (1 A).

Pottery Making illustrated 31

Figure 2Try to make the diameter at the rim measure twice the height, with the foot about one-third the diameter of the rim. Open the cylinder by pressing a cavity into the center of the revolving clay (2A) to leave the floor about ¾-inch thick (2B). Though some potters use their thumbs, I prefer to sink my middle and ring finger, held tightly together, into the clay. These glide over the notch between thumb and forefinger of my left hand, which gives rigid but supple support against the force of the spinning clay. This technique has two advantages—your fingers can reach farther into the clay than can your thumb, so it’s equally useful with large or small masses of clay; and there’s no need to change hand positions for the next stage. Complete this step by pressing your left thumb (2C) against the base outside your rotating pot. This brings the foot ring back to the diameter you’ve chosen, and it compresses clay inside the base, helping to pre­vent future “S” crack problems.

Figure 3Having created a rudimentary form, it’s now necessary to change its shape to an open cylinder that’s slightly higher than the in­tended bowl, with enough clay in the base from which a foot ring can be turned. Continue using your left hand ring- and middle-fingertips (3A) to stretch the clay at the base of the cav­ity outward until the inside opening (3B) is about four times the thickness of the wall (3C). Raise the wall. Have your left hand inside the pot and your right hand outside so that the fingertips of each are directly opposed. Keep this distance (3C) constant as you move your hands upward to the rim. As you lift thick clay, thin clay extrudes backwards (3D). This will give a circular wall of even thickness from bottom to top. Because the thin clay is concentric with the thick clay, pressure from the latter does not cause slumping through the cantilever effect. Firm the rim, which should be level, to consolidate the clay and ensure that it runs true and concentric with the spin of the wheel (3E). If the rim waves up and down, do not try to trim it. Remember this irregularity and make corrections to your centering tech­nique. (Note: For future pieces, ensure you have prepared your clay to give it fully uniform properties and give more attention to coning the clay as you center it.) Consolidate clay in the base (3F) to prevent “S” cracks. The measurement between the rim and the bat (3G) should be slightly higher than the intended height of the bowl. If your pot is shallow, draw the wall higher from the bottom, but keep its wall thickness uniform. If too wide, compress and collar from the outside, working the clay upward from the bat. Your cylinder should be slightly higher than it is wide. This completes the first phase of throwing your bowl.

Figure 4The next phase is to preform a trumpet bell shape from this initial uniform cylinder. Supporting the outside with your right hand (4A), use your left hand (4B) to push the revolving clay outward. As the clay deforms under this force, both hands are lifted so they move upward and outward together to the rim in response to the changing shape of the clay. Your right hand will resist this force, but should support rather than work the clay. You’re not squeezing the clay, you’re stretching it. Do not try to increase the height of the wall. As your fingertips continue shaping the clay, both hands move in an arc (4C). This stretches your clay horizontally, causing the wall to thin without being lifted higher. Your movement leaves clay relatively thick, firm and strong at the base of the wall so that it supports thinner, weaker clay near the rim. This rein­forcement prevents slumping. Cantilever forces don’t cause slumping. Two or more passes may be needed to draw the clay out to its intended rim diameter. At this stage, the preshaped clay should have the funnel form of an inverted trumpet bell as shown in Figure 5.

32 Spring 1998

Figure 5

When you gain confidence, you’ll be able to achieve this shape in one pull. If you have to repeat the process several times, always keep your intention clear—to achieve predetermined heights, diameters and a smoothly defined trumpet bell. Mop excess water from the interior, then use your fingers to apply pressure to the base inside the pot. This consolidates the clay and is effective in preventing “S” cracks after the foot ring is turned. Use a round rib (5A) to clean excess slurry from out­side the trumpet bell, then true and firm the lip of the rim with your fingers. Tip: Trim the fillet of clay (5B) from the foot at the wheel head, and leave a slight undercut for wiring off, since it will be difficult later to gain access to the underside, especially on low-profile shapes. The second stage in making your bowl is now complete. You have achieved a mechanically strong structure, which resists slumping. Strength is enhanced because a minimum amount of moisture has been absorbed by your clay as you worked it. You are also making use of the mechani­cal advantage of a tapered cantilever beam.

Figure 6Moisten the inner surface of the preformed bowl so that it has a uniform coating of slip, but keep the outside free from excess lubricant. Recall that as clay is thrown it absorbs water, which reduces its strength. Again, your left hand will work the inside of the bowl while your right hand gives support on the outside. Support without pressure means less friction so less lubrica­tion is needed. Your right-hand fingers don’t apply pressure to deform the clay. Place your right-hand fingertips outside the bowl against the clay near the wheel head (6A) and your left- hand fingers inside at the base of the bell (6B). Have the wheel turning at less than half speed.

Figure 7Confidence is needed to move your hands decisively and strongly because you may believe that the clay will collapse since there appears to be nothing to support it. Remember that you’re using a technique that exploits the positive characteris­tics of microstructures within your clay. While the wheel turns at a moderate speed, push your left-hand (inner) fingers out­ward in a horizontal direction (7A). Use your outer (right) hand for support, but don’t use it to thin your clay. Resist any im­pulse to press back with your right hand. This would squeeze the clay, which isn’t your intention. As your inner fingers stretch the clay, they will be slowly raised in a long arc (7B). The differ­ential movement of stretching and lifting changes. To begin with, the “stretch out” is fast and the “lift” is slow, then as you reach the halfway point, the “lift up” becomes quicker than the “stretch.” Your final movements should be slow and should give a verti­cal wall with a thin rim. Your outer fingers support the clay but do not work it; there is no slip to lubricate this process.

Pottery Making illustrated 33

Figure 8You have now successfully created a hemispherical basin. Recall that the sequence of shapes that preceded this achieve­ment avoided the obvious and direct route and interposed a stage that exploited the properties of plastic clay. As you gain skill through repeated practice, you’ll find it becomes easier to achieve a good smooth curve with one pass when making small bowls— and no more than two passes when making larger bowls. With the wheel spinning slowly, use a round-profile rib (8A) to skim slurry from inside the bowl. This also helps to refine and adjust the curve andlor remove irregularities. Work your rib from rim to base, but give only light supporting pressure from your right hand on the outside. If there’s an excess of slurry in the bottom, mop it out with a sponge, but finish with the rib laid over at an angle to make the clay smooth. If you desire an accent for decoration, now is the time to add a swirling spiral by drawing your finger or the rib inward over the solid clay of the foot to the center of rota­tion, being careful not to push the wall down outside the foot. With your chamois, finish the rim (8B) by molding a smooth, curved lip, then cut under the foot close to the bat.

Lifting your bowl may distort it, so leave it on the bat and take that from the wheel head. If you’re throwing without a bat, lift the bowl from the wheel with dry hands and make sure the wire gives a clean dry cut. When the clay is leather hard, excess clay can be trimmed and a foot ring formed (9A). Finish the foot with your damp, smooth strap. Since the clay is malleable, it’s possible to get a polished finish, even with coarse clays. Rounding the sharp edges (9B) with the rubber strap adds a note of quality to a pot. It also helps to prevent tabletops from being scratched and it feels good in the hand. Before the clay hardens further, impress your mark in or near the foot ring. Except for necessary decoration, allow your pot to dry hard before touching it again or taking it from the bat. It will then be ready for inspection and firing.

Figure 9

34 Summer 1998

Pottery Making illustrated 35

36 Summer 1998

Sun City, Florida, wall mural, 5 feet in height by 10 feet in length. Low-fire glazes on 6-inch-square bisqued tiles, bordered by handmade high-fired unglazed tiles. Made by members of the Sun City Potter’s Wheel Club.

$ was the semiannual Potter’s Wheel Club luncheon—some say “the best buffet in Sun City (Florida) Center”—and presi­dent Martha Christensen asked for suggestions for a group project to spur fresh enthusiasm going into the fall and winter months. This is the time of year when those half-time residents, the “snowbirds,” close up their summer homes and make the an­nual return to sunny Florida.And it’s at this time that partici­pation in the numerous creative organizations in Sun City virtu­ally doubles.

In response to Christensen’s call for ideas was an ambitious suggestion from Helen Huntley, a long-time member and prolific potter. She proposed that the Potter’s Wheel Club create a siz­able ceramic mural, a project that would involve the participa­tion of as many members as wished to contribute. She noted that the campus area surround­ing the community’s outdoor swimming pool contained nu­merous exterior brick and stucco walls, any of which could pro­vide an ideal surface on which to display such a mural. This in­cluded the entrance to the pot­tery studio itself.

The initial response was a bit tentative, with no one having had any serious involvement in such a venture as this. However, Christen-sen persuaded me—a new Sun City resident—to ac­cept the chal-lenge of designing and coordinating the project.

Finally, the club was fortunate to locate a professional tile setter, Phil Griffin, whose years of ex­perience installing outdoor ce­ramic murals for the Publix su­permarket chain made him the ideal choice for putting the final touch to a satisfying and success­ful project.

Pottery Making illustrated 37

Figure 1The final design incorporated both commercial bisque tile for the main graphics and individually created slab-rolled tile to form a decorative border. A color layout was drawn small scale and submitted to the community’s governing board for their approval. Figure 2

After the preliminary drawing was approved, a larger, one-half scale detailed drawing was made on a grid, with each square (tile) numbered for control and placement later on. Coding tiles was essential since there were as many as 20 or so members applying glazes to 144 bisque tiles.

Figure 3Landis redrew the main graphic onto the bisque tiles in groupings. Matt glazes of several different colors were applied with a squeeze bottle applicator so different glazes could abut one another without “bleeding” into each other. For the commercial bisque tiles, low-fire glazes and under­glazes were selected to correspond in color to the original layout, and each area on every tile was numbered with its proper glaze number—similar to a paint-by-number painting

FigureWhile some members diligently brushed the glazes onto the main graphic, others set out to make 6-inch-square slab- rolled tiles of their own creative designs—some in red clay, others in a light beige, both high-fire. Members ran tests on the two clays to determine shrinkage and establish an accurate working size for the tiles.

38 Summer 1998

Figure 5

Where a gradation in color and tone was desired, the area was masked off.

Figure 7

Glazed tiles were carefully stacked in a tile setter for the glaze fire.

Figure 6

Underglazes were airbrushed, then covered with clear overglazes and fired a second or third time.

Pottery Making illustrated 39

Figure 8When all 200 tiles were finished and fired (the central graphic low-fire and the unglazed border high-fire), the entire mural was laid out and assembled for the first time, allowing for arranging the border tiles according to color and graphics, and to make any slight changes or corrections in the main design.

40 Summer 1998

Jeff Landis is a retired illustrator and avid potter living in Sun City, Florida.

Figure 9Detail of handmade tile border around Sun City mural.

Pottery Making illustrated 41

S t u d i o S a f e t y :

Assessing Risks

tudio safety is a major con­cern of all potters. No one know­ingly wants to work in a poten­tially dangerous environment or expose others to uncertain materi­als. However, some studio potters are unfamiliar with the safe meth­ods of storing and handling raw materials that form the basis of their clay bodies and glazes.

In any pottery-making situation, there are procedures that, once known, will produce a clean, safe ceramics studio. Many of these pro­cedures are very simple and thor­oughly effective in removing po­tential material-related hazards in the workplace. Most of the recom­mendations involve regular imple­mentation of low-cost cleanup equipment. The best tool for a safe studio is a basic knowledge of the materials and how to handle them sensibly.Danger in the Kitchen

Weve all walked into our kitchen and prepared dinner; how­ever, this common activity does have serious potential risk factors. Using knives to cut vegetables, properly cleaning food-preparation surfaces and lighting the oven all expose us to risks from cuts, food poisoning and burns.Yet we’re careful using a sharp knife, cleaning the meat-cutting table, and not touching our fingers to a hot oven.

Inherent in all these low-risk daily activities is the assumption that we’ve learned what the hazards are and have taken precautions to prevent a serious injury. Knowl­edge and education in understand­ing the processes and tools of cooking a dinner reduce this activ­ity to a safe and mundane level.

Danger in the StudioWhat separates the household

kitchen from the ceramics studio in terms of risks to your health? It’s the base of knowledge acquired on how to use each set of materials and tools correctly.

Any activity involves some de­gree of risk. Equipping yourself with the correct information about a situation either reduces the risk level or enables you to decide if the risk is too great for the reward.

At some point in our lives, most of us have determined that the re­ward of obtaining a meal in our own kitchen is worth the risk. We’ve made this calculation by learning about safe food prepara­tion and the dangers of hot ovens and sharp knives.The same learn­ing techniques can be applied to working in our pottery studios, with equally satisfying results.Assessing Your Studio

Assume that the greatest danger in the studio comes from inhaling airborne dust particles released from the movement of dry clay. While some dry clay occurs to varying degrees in the air of any studio (depending on how consis­tently the work areas are cleaned with the proper equipment), it isn't the only dangerous situation en­countered in the daily activity of making pots. Often the emotion­ally charged issues such as lung dis­ease (silicosis, kaolinosis, or any res­piratory distress) are major areas of concern. Nevertheless, other areas of serious risk, though less dra­matic, are sometimes given almost no thought.

Since time and energy are a fi­nite quantity, you must protect

yourself against the most hazardous events likely to happen in daily stu­dio activities. Identifying and cor­recting health hazards in order of their prevalence is a low-cost effec­tive way to make your studio safer.

Listed here are the leading health hazards in order of their prevalence in the average ceramics studio.Back Pain

The major health risk potters face is back injuries resulting from the improper handling and lifting of clay bags and kiln shelves.

Always lift heavy objects with a straight back and avoid leaning over to place shelves in the kiln. When picking up heavy glaze buckets, large containers or a full box of pots, place your feet near the object and lift while bending the knees. Try not to twist your body when lifting and have a clear path where the object can be set down carefully. Taking a few extra minutes to get help will save many weeks of pain from a back injury.

Back pain is often caused by the improper height of the wedging table. If the table is too low, the potter has to bend over to wedge the mass of clay. Conversely, if the table is too high, more back strain and muscle energy have to be ex­pended to move the clay. The cor­rect wedging table height should be level with where your hands fall at your sides.This height will allow the potter to use his or her upper body weight rather than pure muscle power to move the clay.

The height of the potter’s wheel in relation to the wheel seat is also critical in preventing back pain. Try to have the wheel head and throw­

42 Summer 1998

by Jeff Zamek

Most of us have determined that the reward of obtain­ing a meal in our own kitchen is worth the risk. The same learning techniques can be applied to working in our pottery studios, with equally satisfying results.

Sc

ing surface level with the height of the seat. Centering the clay is also easier, as the upper body weight di­rected through the arms applies more leverage than muscle in mov­ing the clay into the center of the bat. Sometimes moving the seat an inch up or down will place undue strain on the back tendons and ligaments.Carpal Tunnel Syndrome

Another leading cause of studio injury is carpal tunnel syndrome (CTS). It develops when too much pressure is exerted on the nerve that runs through the carpal bone in the wrist. When the nerve is compressed against the bone, the hand and fingers can be affected. Symptoms of viselike pressure and tingling can frequently progress to permanent nerve damage. It can be caused by any type of repetitive hand motion.

Factory workers on a produc­tion line, typists, dentists, roofers, auto-body-shop mechanics or any person involved in any repetitive hand motion over a prolonged

time can experience CTS. Carpal tunnel syndrome can be success­fully treated if diagnosed early.Repetitive Motion Syndrome

Potters can also damage nerves in their hand from the repetitive motion of wedging clay or throw­ing pots. The best way to prevent this type of injury is to break up the work activities associated with making pots into small segments, minimize repetition, reduce speed and rest your hands in all shop ac­tivities.

Do not wedge 100 pounds of clay at once or sit at the potter’s wheel making pots for hours on end. Throwing 12 pots on the wheel should not be followed by making another 12, but by trim­ming pots that are leather hard, or loading the bisque kiln for the next firing cycle. Since working in clay is made up of a series of separate tasks to complete ceramic objects, shifting from one task to another avoids prolonged repetitive motion situations.

CutsWhen unloading the kiln, wear

protective gloves. Many potters do not realize the edges of fired clay, glazed surfaces and shards can be extremely sharp. It’s possible to cut yourself without feeling any pain due to the razor edges of broken pots. Always examine any glazed surface for dangerous areas. When­ever a pot has fused to the kiln shelf, always wear safety goggles and gloves before attempting to chisel or remove the shards. Often, small chips of glaze and shelf will fly off the chisel. Do not attempt to pick them up with your bare hands, as they can easily puncture unpro­tected skin.Allergies and Molds

To a much lesser degree, other skin problems are encountered in the average ceramics studio. Some potters have an allergic reaction to moist clay. Small bumps or ir­ritation on the hands and fore­arms are noted after working with the clay. Applying hand lo­tion to the arms before working

Pottery Making illustrated 43

with moist clay often eliminates a sensitive skin reaction.

Under the right conditions, mold can occur in moist clay (which can increase the clay’s plas­ticity), and mold can also grow in stored wet-glaze containers. A few drops of household bleach per gal­lon of glaze eliminates mold growth. Potters should use a dust mask when handling dry clay con­taining mold.

The processing and washing of highly alkaline wood ash (used as a glaze raw material), along with soda ash, pearl ash and potassium dichromate can also cause skin irri­tation to unprotected hands.Kiln Safety

Wear the proper shade goggles or eyeglasses when looking into any kiln during the firing. Sun­glasses will not stop exposure from infrared or ultraviolet light damage to the eyes. It’s essential to wear shaded goggles even at relatively low bisque-firing temperatures.

After the firing, do not unload the kiln until the pots are cool to the touch. In their rush to see the fired results, many potters receive burns from hot pots, kiln shelves, and kiln posts.

It isn’t unusual for potters to have their studios in the basement. This popular type of work space can present several potential health concerns. Good cross ventilation is important when firing any kiln in an enclosed area. Opening win­dows and doors during the first part of a bisque or glaze firing can allow the potter to work in the basement. It’s strongly recom­mended that venting systems be in­stalled in all electric kilns. During the firing, electric-kiln-venting sys­tems directly remove fumes from organic and carbonaceous materials and sulfur found in clay, wax resist, and organic gums in glazes.Radon

Another factor that can affect the environmental atmosphere in some basements is the presence of radon gas. Radon below the base­ment floor can drift into the studio. In high levels over prolonged peri­ods, this colorless and odorless gas can cause damage to the lungs. At

44 Summer 1998

extremely high levels, it’s the equivalent of smoking one or two packs of cigarettes a day. If you work in a basement studio, you would be wise to purchase a simple radon test kit available at the local hardware store. The test results in­dicate if there is any radon gas present in the basement, and the kit usually contains a list of steps that can be taken to reduce or eliminate the gas.Safely Handling Raw Materials

Any raw materials used in the ceramics studio should be handled with common sense and care. A clean studio with materials stored in properly labeled containers is a substantial step in developing a safe studio condition.

When it’s time to order raw ma­terials for clay bodies or glazes, the ceramics supplier can furnish a Material Safety Data Sheet (MSDS) with each material they sell. The MSDS lists the chemical product, company identification, composi­tion information on ingredients, hazard identification, first-aid mea­sures, toxicological information and other safety considerations when handling the material. Read each MSDS sheet carefully, as it gives storage and cleanup guidelines for that specific material.

Some raw materials, such as lead or lead frits, cadmium, selenium, beryllium, uranium oxide, zinc chromate, zinc yellow, antimony oxide, chrome yellow and vana­dium compounds, require extensive knowledge and safety procedures. Except in highly specialized situa­tions, they shouldn’t be considered for use in ceramics studios.

Under the U.S. Labeling of Haz­ardous Art Materials Act (LHAMA), commercial glazes must be evalu­ated for chronic toxicity and the label must supply information on how to use the glaze safely. The la­bel must also indicate if the glaze is food safe. Always read all the infor­mation supplied with the product.If you’re uncertain about a glaze, call the ceramics supplier for de­tails. The supplier can often offer specific practices and techniques in the proper use of the glaze.

Clay Dust in the StudioThe most often asked question

about studio safety is, “What amount of clay dust in the air will cause a harmful effect on the hu­man body?”The practical answer is to keep all work areas free from any airborne materials.

It’s not the clay floating around the studio that’s potentially harm­ful. The nose and lungs filter most of these large particles. It’s the mi- cron-size invisible particles that can get past our natural filtering mechanisms that can cause lung

and respiratory irritation and pos­sible permanent damage.

The best policy is to keep all levels of airborne material as low as possible. Some potters invest in room air-filtration systems, which can run into hundreds of dollars. Such units are a low price to pay for a higher degree of protection. However, following proper clean­ing procedures in the studio and a common-sense approach to work­ing with dry materials are also very effective in maintaining a safe workplace.

Pottery Making illustrated 45

Unfortunately, most current health and safety information is based on industry or mining opera­tions, where high concentrations and long exposure rates can be present in the workplace. It’s im­possible to calculate if similar con­ditions exist in any given potter’s studio. But we do know that inhal­ing large quantities of free silica found in some clays can cause sili­cosis after extended exposure. Therefore, the cleaner the studio, the safer the studio.What the Experts Say

Varying views are held on the potentially dangerous effects on any given ceramic material. Some experts speculate, based on a few tests, that the average amount of silica in the air when working with clay is roughly equivalent to play­ing baseball on a dirt field. Other authorities are advising not to go into the studio unless it’s main­tained at “clean room” laboratory levels of purity.

Somewhere between these two extremes, potters must educate themselves to a level where they feel secure and safe when using ce­ramic materials in their studio.They must research the available safety information from many sources to gain an informed view­point. Then they must go into their own studios prepared to enact and maintain procedures that will cre­ate a healthy workplace.

Jeff Zamek provides ceramics consulting services and resides in Southampton, Massachusetts. He can be contacted at 6 Glendale Woods Dr., Southampton, MA 01703; e-mail fixpots@aol.com; or visit his web site at www.westmass.com/fixpots.

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Pottery Making illustrated 47

48 Summer 1998