Clay Studio Guidelines and Procedures

Clay goes through a number of stages, including two kiln firings. The stages are important to how you manipulate the clay. The essential stages from wettest to driest are:

• Slip: Slip is clay with added water to make it into a paste or liquid. Slip is most commonly used to join pieces of wet or leather hard clay together. It can also be used decoratively. Colour can be added to slip to make a decorating medium which can be painted on to wet or leather hard clay.
• Plastic or Wet Clay: Fresh out of the bag, wet clay that is easy to work with. It must be kept wrapped in plastic at this stage to keep it in a usable state. This is the consistency you want for wheel throwing as to not hurt your wrists. If hand building, this is good for pinch pots, coiling, and rolling out slabs.
  Work at this stage should be stored on your shelf under plastic.
• Leather Hard: This is when clay sets up slightly, and has some give still (like leather). It is no longer sticky or able to change its shape. Here is when you would trim the bottoms of your pots and add any attachments. It is very important that when joining things together the clay is at the same stage. Leather hard is often the state when flat slabs of clay are joined together to make 3D structures.
  At this stage, you will want to add your unique maker’s mark to the bottom and store it on your shelf partly covered in plastic.
• Chocolate Hard: At this phase, clay is too hard to attach anything else onto it. It is done the building stage, but not yet dry enough for firing. This is the stage most people do any fine tuning, like going over the surface for imperfections, smoothing rims, etc. Any sharp edges that are not smoothed at this stage will become solid in the bisque firing.
• Greenware, Bone Dry, or Dry Clay: The most fragile state of clay! There is no moisture left in the clay, and needs careful handling to prevent breakages.
  At this point you can now transfer your work to the Greenware cart to be fired.
• Bisque: ‘Bisque’ refers to clay which has been fired once – permanently changing the chemical and physical nature of the clay. In our studio, we fire bisque at Cone 06. Clay at this stage is hard but still porous enough to absorb glaze.
  Once your work has been bisqued, you will want to collect it from the cart and move it to your shelf until you are ready to glaze.
  When glazing, work can be dipped into glaze or glaze can be poured over the bisque pot. Water is absorbed into the clay making the glaze stick to the surface of the pot.
  Please be sure to read the glazing section of this page carefully, as this is the step that is most likely to result in issues with the work.
  Once you’ve ensured your work is glazed correctly, it can be moved to the Glaze Ware cart for it’s final firing.
• Glaze Ware: After a second firing to Cone 6, the clay and glaze have fused making a non porous surface. This is the final, finished stage. You can now pick up your finished ceramics from the fired cart, and take them home.

Our instructors create lesson plans that aim for you to have work at specific stages by certain classes. Please keep the schedule and stages in mind throughout the course:

• By class 2 or 3: Have at least one piece ready for bisque, and on the cart to be fired.
• By class 5 or 6: Glaze at least one piece, and place it on the cart to be fired. This gives you an opportunity to understand how the glaze process works, prior to glazing the majority of the pieces you’ll make.
  • If you would like to make a platter, you will also need to finish it by the 6th class, as slabs need to be dried slowly to prevent cracking. Platters and slabs are prone to cracking if they’re not made correctly. Check out these YouTube videos for tips on using a slab roller, and how to avoid warping as it dries.
• Class 7: Students should be finished making any work using wet clay.
• Class 8: Students should only be working with clay in the leather hard or chocolate hard stage. Pieces then need to be placed on the carts to be fired. Remember to put your makers mark on your piece, and take photos/records of your pieces before putting them on the cart.
  • The following week, pottery students do not attend class. We do this to ensure the pieces reach the bone dry stage, and are able to be bisqued prior to your final class.
• The final class is spent glazing all remaining bisque pieces. This takes more time than you might think. Set yourself up for success, and plan out how you’ll be glazing your pieces ahead of time! Make sure you’ve glazed your pieces correctly before putting them on the cart (see the Glaze section below for tips on how to do this), as any work with glaze issues will not be fired. All glaze work needs to be on the cart by the end of class.

• Our facilities are for learning skills and challenging yourself creatively. We do not have the capacity to support production pottery.
  • Students making multiples of anything (ornaments, dishes, dominos, etc.) may make no more than 6.
• Only touch your own work. Picking up other student’s work may damage it, break it, or wipe the glaze off.
  
• Keep a record of your work with drawings, notes or photos.
• Mark all work with your initials or an identifying mark before placing it on the greenware cart.
• DO NOT take work that is not yours, if unsure ask your instructor for assistance.
• The studio is not responsible for lost, damaged, or stolen work.
• When using extension cords for tools, be sure to make others aware of the cord on the floor.  Wrap up the cord when finished and return the tool to the designated area (i.e. mixer and hair dryer).
• We cannot fire work made outside of class. Pieces made in class, that you wish to add extra detail to may be done at home. If you would like to have it fired at the studio, it will need to be placed on the carts by the last class.
• There are no make-up classes. If you are unable to attend the final glaze class, we suggest planning with your instructor to glaze your work in advance. Please contact the Studio Technician at studiotech@wag.ca as soon as possible to request for your work to be bisqued earlier. If it’s not possible, you may need to glaze and fire your work at another local studio such as The Sounding Stone, Pottery Bug Studio, The Edge, or Just For Fun Craft Studio.

• Take note of where your class shelf is located and where the firing carts are located (where to put your greenware and glaze ware when it is ready to have it fired).
• Label works in progress with masking tape on the ware board or a piece of paper under the piece.  Do not use masking tape on the plastic as this rips the plastic.
• Any clay left in the studio after the last class will be reclaimed and used for other studio programs.
• Following the end of classes, students will be contacted by email with the ceramics pick up days and times (typically 2-3 weeks after the last class).  If you are unable to attend the Pick-Up day you will need to arrange another time with the Studio Administrator. It is imperative that students come with a photo or written log of what was created. Any work remaining in the studio must be retrieved within two weeks of the provided pick-up deadline.

A clean studio is a healthy studio!
Clay and glaze contains silica and over time, breathing in this dust can lead to serious health risks, including silicosis – a preventable but irreversible lung condition. In wet form, silica poses no health problems. Wiping down your work area after a class, damp-mopping floors (never dry sweeping!), and keeping tools and scraps neatly stored isn’t just about tidiness – they are essential steps in keeping silica dust out of the air we breathe.
Cleaning prevents clay dust exposure, keeps tools in good shape, and fosters a safe, respectful shared environment!

• Begin cleaning up 30 minutes before the class is scheduled to end. 
• Prevent airborne clay particles by wet mopping and wet wiping down all surfaces that have come into contact with clay, or glaze:
  • Floors
    • Students should take turns mopping throughout the course.
  • Tables
  • Ware boards and/or bats
  • Tools
  • Brushes
    • Please do not leave tools or equipment in the sink area. After washing, return them to the appropriate container.
      Ware boards can be left to dry in the drying rack after washing.
• Wash/wipe down the wheel if used in class:
  • Make sure wheel is turned off, and unplugged
  • Wipe down the wheel
  • Put any large chunks of clay into your clay bag
  • Remove the tray, and put any slurry into the slop bucket under the sink
  • Wash the tray, and place it back on the wheel
  • Wipe down the pedal, along with any other areas that may have clay on it
• Never put chunks of clay in the sink or drains. Clay trimmings, scraps, slurry, etc. should be put int slop bucket, or back in your bag to be recycled.
• Rinse your hands off in the studio before going to use washrooms. Large chunks of clay and slurry can clog our sinks.
• Practice sustainability! Consider bringing a small towel with you to dry your hands.

• Each student enrolled in a full term course receives one, 10kg bag of clay (Plainsman M340)
  • If a student uses up their entire bag (including any bits that need to be wedged), they may request a second bag, that will be shared amongst the class.
• Clay bags must be labeled with the student name and class (ex. Crystal, Tue, Fall 2019), and stored in the designated area.
• Your clay is your responsibility. Please label your bag, make sure it is sealed tightly and put away.
• Only students in the Intermediate Pottery class are permitted to bring in 1 additional bag of cone 5/6 clay. Please contact the Studio Technician at studiotech@wag.ca, and indicate which clay you are interested in using so they can verify that it is safe to use in our studio. If a clay has been approved during a previous class, you will still need to contact the Studio Technicians to make sure they’re aware of any outside clay being used.

1. Fettling Knife: A cutting tool used for trimming, smoothing and leveling out uneven surfaces on dry clay.
2. Wood Trimming Tool: Used for shaping the base of a pot on the wheel during the throwing process.
3. Pin Tool: Used for poking air bubbles, or leveling the top of a pot on the wheel.
4. Loop Trimming Tools: Used for trimming the base of a pot. Takes off a larger amount of the surface area.
5. Metal Rib: A finishing tool used for scraping and smoothing a surface.
6. Wood Rib: A shaping tool used when throwing. This tool can be helpful for manipulating the shape of a pot on the wheel or compressing the base.
7. Wire Tool: Used for cutting clay off the block and removing pots from the wheel head.
8. Throwing Sponge: Used while throwing, or for general finishing work.

• Above is a collection of some of the various tools the studio has for students to use during class. These tools are to be shared, and should be handled with care.
• If you bring in your own tools, ensure they are all labelled with your name, and stored in labelled container to avoid being mixed up with the studio tools.
• Students may wish to bring their own apron and/or towel.

Glaze Standards

Each piece must pass a set of standards in order to be fired. The Studio Technicians reserve the right to reject work that is unsuitable for firing. If your piece has a problem that needs to be addressed before it is fired, it will be placed on a black cart near the kiln room, with a note explaining what you need to fix.
Please note, if work is rejected after your last class, there will not be another opportunity to correct the issue, and have the work fired at the WAG Studio. Consult your instructor if you’re unsure if your piece meets any of the below standards.
The most common reasons work is rejected are:

• Glaze on the bottom, or any surface that might touch the shelf. Even a small amount of glaze is too much, as it will fuse to the kiln shelf. If the glaze is a similar colour to the clay body it may be hard to notice. There is a lamp near the carts you can use to fully inspect the bottom for glaze.
  Wax resist can be used to protect the bottoms of your forms from getting covered in glaze, but you will still need to check the bottom as you still may have to wipe it.
• Glaze that has been applied too thick, or layered too quickly. When this happens, the glaze will begin to crack and flake off the piece as it dries. You may not notice this happening during your glaze class, as it only begins to appear as the glaze dries. Be sure to do quick dunks, no more than 2 layers of glaze, and wait for the glaze to appear matte and dry before adding a second layer (typically about 10 minutes).
• Glaze too close to the bottom. Glaze must be applied leaving 4mm free of glaze at the bottom of the piece. If you’re using wax, you have to apply wax 4mm up from the bottom on the side of your pieces.
  If you have trimmed a deep enough foot, you can use the ‘foot line’ as a guide for your wax, or as a guide to use when you wipe glaze off the bottom of your piece using a sponge.
  • If your foot is shallow, it might not elevate your pot enough to keep the glaze that is beside the foot from touching the kiln shelf. In this case you will have to wipe the glaze off the part of the pot that is past the foot.
• Cracks and defects in pieces will not be loaded into the kilns (unfortunately, this issue is rarely fixable)

When Glazing

• Use the stainless steel tables, to expedite studio clean up and protect the canvas area from getting stained.
• Each glaze will need to be mixed prior to using it. You can mix it with the drill mixer, or sticks.
• Take notes of the glaze(s) you’re using on each piece.
• Be sure to put lids back on the correct glaze bucket right after use.
• Wash the mixer, sticks, brushes, and measuring cups off between each glaze, as you work. There is a ‘glaze rinse’ bucket for this purpose.
• Only put brushes or smaller containers into the glazes if they have been thoroughly rinsed
• Use smaller containers and portion out glazes if layering.
• Do not return the glaze back to a bucket if it has been contaminated with other materials.
• Inform the ceramics tech if you notice we are running low on any glazes.

Studio Glazes

The studio provides a selection of dunking glazes, created in house by the Studio Technicians. These glazes are displayed on the lower left side of our glaze test tile board. The back of each tile indicates the name of the glaze, and what (if anything) it’s been layered with. The right side shows examples of glazes that can be purchased at The Sounding Stone, and have already been approved to use in the studio.
The test tiles also have a white underglaze on one side, as an example of what the glaze would look like on a lighter clay body.

Outside Glaze

Outside glaze is permitted to be used, if the following conditions have been met:

• The purchased glaze is rated to ‘cone 5/6’. Not cone 06.
• You will need to apply the glaze to a test tile (available in a bucket on the shelf to the right of the sink), place the glazed tile on the glaze ware cart to be fired, along with a note that indicates what it has been glazed with.
  • It is recommended that you make test tiles early on in class so you can get glaze results back before you have to glaze all your pieces.
• Once your test tile has been fired, the Studio Technician will be able to confirm it’s safe to use in our kilns. This is how all potters/ceramic artists practice the craft. Test test test! This will also give you information on how the glaze behaves so you can make informed decisions when applying it to your pieces.
• After glazing your pieces with an approved glaze, place them on the glaze ware cart to be fired, along with the test tile and a note that indicates the pieces have been glazed with the glaze shown on the approved test tile.

Below is a list of links that will take you to the mid range glazes from our local clay supplier, The Sounding Stone. Each glaze on the Sounding Stone website has a write up. Please read it as it contains special instructions about the glaze, and how to apply it. If the description states that the glaze runs on vertical pieces, it likely will not be approved to use in our kiln.

• Mayco Stoneware Glazes
• Mayco Stoneware Crystal Glazes
• Mayco Stoneware Ice Glazes
• Mayco Stoneware Opal Glazes
• Mayco Stoneware Mattes
• Mayco Stoneware Washes
• Mayco Stoneware Glaze Kits
• Amaco Potter’s Choice Cone 5/6 Glazes
• Shino Gloss and Matte Cone 5/6 Glazes
• Amaco Celadon cone 5/6 Glazes
• Amaco Satin Matte Cone 5/6 Glazes
• Amaco Watercolor Underglazes
• Coyote Cone 5/6 Glazes
• Laguna Cone 5/6 Glazes

• When your piece is ready to be fired, you will need to place it on the appropriate labelled cart. Work left on the class shelf will not be fired. Prior to placing your work on the shelf, please:
  • Ensure your piece has your unique makers mark somewhere on it
  • Remove it from the ware board, wash the board, and return it to the cupboard
  • Remove all newspaper from it
  • Remove it from the mold
  • Ensure your piece meets the glaze standards noted in the previous section
• Kilns are fired according to the needs of the entire studio, and can vary from 1-3 weeks. The turnaround time is dependent on:
  • There being enough work to fill a kiln
  • The size of the work
  • If the work is flat
  • If the work is dry enough
  • If we are having any kiln issues (hopefully rare)
• Requests for work to be expedited may be considered, but it is the prerogative of the Studio Technicians to determine the kiln firing schedule. You may contact the technicians by email at studiotech@wag.ca.
  • If you are unable to attend the final glaze class, we suggest planning with your instructor to glaze your work in advance. Please contact the Studio Technician as soon as possible to request for your work to be bisqued earlier. If it’s not possible, you may need to glaze and fire your work at another local studio.
• If a piece has special firing requirements, please leave a note for the Studio Technicians.
• Making work for gift giving (especially around holidays) is not advised, as work may not be fired in time.
• Stilts are only allowed if approved by the Studio Technicians.
• Please be aware that kiln firings and glazes can have unpredictable results and, as such, we cannot guarantee the final product. Damage and/or unwanted results during the entire loading, firing, and unloading process are not the responsibility of the studio.

• Bat: A slab or platform on which clay is handled; a circular device attached to the wheel-head.
• Clay Body: A mixture of different types of clays and minerals for a specific ceramic purpose.
• Coils/Coil Construction: Ropes of clay that are stacked to form a wall. This technique is one of the most commonly used hand-building methods.
• Fire: To bake in a kiln. Firing is a term used for cooking the clay.
• Form: Three-dimensional shape and structure of an object.
• Glaze: A glassy coating that has been melted onto a ceramic surface.
• Handbuilding: One of the oldest craft techniques in which objects are constructed entirely by hand.
• Kiln: Enclosed containers of various sizes – built of refractor brick and heated by electricity, gas, oil, or wood to temperatures from extremely high temperature, in which ceramic ware is fired. Also called the oven for firing the clay.
• Plasticity: Quality of clay that allows it to be manipulated and still maintain its shape without cracking or sagging.
• Press mold: A plaster form which clay is compressed into, resulting in a repeatable shape or texture.
• Slump mold: A plaster form which is used to support wet clay in the early stages of construction.
• Underglaze: Coloured decoration applied to greenware or bisqued clay, then coated with a clear glaze. Typically made of clay slip and raw pigment.
• Wedging: Method of kneading clay to make it homogeneous; ridding the clay of all air pockets.