Clay Questions and Answers
Surface Questions and Answers
Safety Questions and Answers
Purchasing Questions and Answers
Equipment Questions and Answers
Firing Questions and Answers
1. What kind of clay do I need?
What do I need to consider when choosing a clay body?
Temperature: lowfire (cone 06-04); midrange (cone 4-7); highfire
Color: This will affect your glazing choices
Texture: Groggy or smooth
Intended purpose: Handbuilding or Throwing
Scale: small, medium, large. Larger scale will require more grog
This will mainly affect throwing capabilities
2. How much clay do I need?
For a class of 25 students, you will need at least 25 pounds of
clay (1 bag) giving each student 1 lb per small project such as
cup, small figurine, pinch pot bowl, etc. 1lb ball of clay is
roughly the size of a tennis ball. For more information please
see the chart on the Teacher's Lounge Homepage.
3. What are some common terms to
use when referring to clay?
Wet Clay: Malleable, fresh workable clay ready for building
Wedging: kneading the clay to make the clay homogenous, to align
the particles, and to remove air pockets.
Handbuilding: pinching, coiling, slab building
Wheel Thowing: Throwing pots using the potter's wheel
Slip and score:
Leatherhard: clay that has died out some, but is still slightly
moveable and has not started to change colors yet. This is a
good stage for attachments.
Greenware: bone dry clay that is ready to be fired. MOST FRAGILE
state of clay
Bisque: 1st firing to drive off chemical water to make the clay
ready to accept glaze.
Glaze Fire: Firing of the clay and glaze to make a glass like
4. Can clay go down the sink?
No, it will clog the pipes. You should have a recycle bin for
scraps for reclaiming and install a
sink trap to catch the finer particles.
5. Can I recycle my clay scraps?
Rehydrate the scraps with water. If too wet, dry out on plaster
or canvas. Then wedge the clay together to make the clay all the
same consistency. This clay can also be mixed with fresh clay.
You can use a pugmill to make the reclaiming process easier.
6. What is a pugmill and how do
I use it?
A pugmill is a piece of equipment used to assist with reclaiming
clay. Different machines have different qualities. Things to
know about pugmills: mixing only or do you need de-airing?
De-airing will need a vacuum. Stainless versus Aluminum? This
will depend on the clay that you are using. If using stoneware
or porcelain you will want stainless steel. Size and space it
takes up in the studio. Tabletop model or free standing floor
model? And don't forget to make sure you have the correct power
for the machine.
7. Does clay go bad?
No, but it may grow mold. This is good bacteria and will be good
for the clay's workability. It is not harmful bacteria. It can
also dry out, so keep it covered and add water as needed.
8. How long can I keep my clay?
Indefinitely as long as you keep it hydrated. Rehydrate if it
does dry out.
9. What happens if my clay freezes?
It is still useable after it thaws out, but it will need to be
1. What is the difference between paint
Paints, such as acrylics, oils, watercolors, pastels, etc, are a
cold surface techniques and do not require firing. When using
paints, it is recommend to seal the surface with a spray sealer.
Glaze is a specially formulated material that is to be applied
to bisque and then fired to form a glass like surface.
2. Does Clay-King.com sell
paints and sealers?
Duncan makes a great line of non-fired paints and sealers
3. How many coats of glaze do I
put on the piece if I am brushing on the glaze?
2-3 flowing coats
4. What is the difference
between slip and underglaze?
Underglaze is a commercial product available in a wide array of
colors that can be applied to leatherhard, bone-dry work, or
bisqueware. Slips can only be applied to leatherhard clay.
5. How much glaze do you need
for each piece?
1 pint of glaze will cover about 8 mugs or 12 cups.
6. Does glaze keep and for how
Yes, it may need water added as time passes to keep the ideal
7. Can I rehydrate my glaze if
it is dried out?
Yes, just add water and give it a little while to hydrate and
then stir. Once mixed to smooth consistency it is ready to use
again. It is ideal to run it through a screen or sieve, but not
8. What is a wash and how do I
A wash is an oxide mixed with water and usually some sort of
suspending agent for ease of use. Washes are great to put on a
textured surface and wipe away the excess so that it is only in
the recessed areas. Then you can apply a translucent glaze or if
on an exterior of a functional item or on a sculpture you can
leave just the wash and then fire it to your target glaze
9. What are some surface
Stamping, stenciling, masking tape to mask off areas such as
stripes, slip or glaze trailing, sponging, etc.
10. Are glazes food safe?
Most are non-toxic and food safe, but it is important to read
the labels to make sure.
11. Are glazes mixable like
Some are and some are not. All underglazes are mixable like
paints. All of the AMACO Teacher's Palette Series as well as the
Mayco Stroke and Coat Series are mixable like paints.
1. Can you eat off of and drink
from the ceramic items the students make?
Yes, as long as you are using a food safe glaze. Most of the
glazes we sell are food safe, but some are not. Read the labels
2. Can ceramic dishes go in the
microwave and the dishwasher?
3. Can ceramic dishes go in the
Yes, as long as you preheat with the dish in the oven so that it
warms up slowly.
4. Is clay toxic or dangerous?
No, but clay dust is bad for your lungs. You should never sweep
it up, always wet clean your studio and wear a dust mask when
5. Are electric kilns dangerous?
Do they catch on fire?
Kilns if wired properly with the correct voltage, phase, and
breaker size, are not inherently flammable. However, if you have
flammable items near the kiln, it could cause some problems. For
instance, do not leave ware boards or newspaper on or near the
kiln when firing. These items are flammable and could catch
6. What is an MSDS sheet?
MSDS stands for Material Safety and Data Sheet. The sheets let
you know how safe your material is and what percentages of
minerals are in the product. MSDS sheets can be obtained for
most any material including clay and glazes. Go to the
manufacturers website to download a copy. It is not a bad idea
to keep a copy in the classroom to comply with Environmental
Health and Safety laws.
1. Can I purchase with a
Yes, just fax over your PO to 864-579-1756.
2. What are your terms for using
a Purchase Order?
3. Do we have to pay with
No, you can pay with any major credit card. We also accept cash
(if picking up at our location) and checks. You can place your
order online and check the appropriate payment method. Please
note that if paying with a check, your order will take longer,
as it will not be processed until payment is received.
4. Do we pay sales tax?
If you are outside the state of South Carolina, no you do not
pay sales tax. If you are in SC, then you will need to pay sales
tax. If your school is tax exempt, fax over a copy of the tax
identification sheet with your PO or email us a copy to have on
file in the store.
5. How do we obtain a W9 form from Clay-King.com?
Either give us a call or send us an email and we can email or
fax you a copy.
1. What equipment would be good to have for a classroom setting?
Kilns, wheels, extruder, slabroller, pugmill, clay, tools,
stamps, and glaze. See our teacher packages for great ideas to
fit a variety of classroom needs.
2. What do I need to do to
maintain my kiln?
Periodically vacuum out the kiln, making sure to vacuum the
elements channels. If you have the unfortunate experience of
blowing up work, be sure to vacuum out the kiln and element
channels after unloading. Wash one side of you kiln shelves with
kiln wash. If glaze gets on the kiln shelves, be sure to remove
it before the next firing. If you do not, it will continue to
fire into the kiln shelf and destroy it. To remove it scrape
with silicon carbide scraper. For stubborn areas, wear eye
protection and use a hammer and chisel. Then wash the kiln shelf
with kiln wash.
3. Can I use kiln shelf paper
instead of kiln wash?
No, shelf paper is used for glass only.
1. What temperature should I
Firing temperature will depend on your clay and glazes.
2. What is the difference
between cone 06 and cone 6?
Cone numbers with a zero in front are like negative integers.
For example cone 06 is cooler than cone 05. Imagine a horizontal
line with zero being in the center. On the right side of zero,
are increasing numbers 1,2,3....10. The progression in numbers
gets hotter with temperature. On the left side of zero, you have
01,02,03,04....021. As you get further away from zero, you get
cooler in temperature. So, there is a huge difference between
cone 06 (1836 degrees F)and cone 6 (2232 degrees Farenheight).
3. What do I need to know prior
to buying a kiln?
voltage: 240 volts or 208 volts
phase: single or 3
size desired: interior dimensions. If you do not know, we
recommend that you mock up the interior space with cardboard or
paper, so that you can visually see the stackable space.
breaker size: each kiln will need a big enough breaker to
support it. This is listed on each kiln page, but you will need
to know what your building has or can handle.
4. What is single or 3 phase
This is how the power is broken down and delivered into the
building. Check with your school's electrician.