List of Materials Used in Beth’s Studio
Fired
Materials:
Soldate
60 from Aardvark Clay Co.
This is an
incredibly plastic clay body with a heavy amount of ball clay and 60 mesh sand
instead of grog. You can get Soldate 60 from Aardvark Clay Co. or Laguna, but
the Laguna mix is slightly different and seems to have a greater penchant for
cracking during the drying and firing of larger sculptural pieces.
The Aardvark Soldate is better for building, but has a real problem with
forming salty deposits on the surface of your drying work, making it problematic
for glaze and slip applications. I
have also noticed the Aardvark clay have a problem with lime-contamination-
which is extremely annoying and can cause spontaneous tiny pieces of your clay
to pop off weeks or months after it has been fired.
Beth’s
Cone 5- 6 Porcelain Slip:
50
Grolleg
40
Nepheline Syenite
10
Silica (350 Mesh is best)
add
3% to 12% Mason Stain for colored slips
1,000
g. of dry material will require 2 tsp. CMC gum mixed dry, and then
800g of Water mixed with two tsp. sodium silicate to deflocculated the
mixture.
**Mix
as a deflocculated casting slip and then add a drop or two of gum or glycerin to
help with brushability. Apply to
low-fired bisque ware with a white nylon watercolor brush for best results.
Usually 3-5 coats applied in thin layers works best.
Will crack or pop off if applied unevenly or thickly.
Color:
I
add anywhere from 3%-12% Mason stain to color the slip. TEST, TEST, TEST!
The color and amount of mason stain you add to the slip will
change its firing temperature. After adding mason stain, the slip should be
run wet through an 80 mesh sieve twice to make sure the color is distributed
evenly. You may have to add a drop
or two more Darvan (deflocculant) to keep the mixture from getting too thick.
For
a fantastic article about making slips and applications, check out this article
written by Pete Pinnell:
http://www.claytimes.com/articles/glazeadjusting.html
For
repairing non-structural cracks:
My
general advice is to leave the cracks or breaks for post-firing repair.
However, as long as the crack is not structural, I have had great success
in healing them by packing them with bisqued clay dust and some sort of flux.
*With every piece* I place a small amount of sieved powdered clay next to
it in the kiln. After the bisque
firing, the clay powder may be mixed with the glaze or vitreous slip and packed
into the crack. After it has dried,
wipe smooth and apply the normal surface treatment over the whole piece.
I also fire the remaining bisqued powder with the piece through the
second firing and use it again to mix with epoxy for post-firing repairs.
Unfired
Materials:
For
gluing joints together or strength bonds:
Devcon
5- Minute Epoxie Gel.
This
is some of the toughest stuff I have used. There
are tons of other high strength epoxies out there, but I like to use one that I
can easily find locally. Check to make sure it hasn't been sitting on the shelf
of the hardware store for more than a year.
Most glues have a shelf life and should be purchased as needed.
Stronger
than your clay, little to no yellowing, and no dripping.
Make sure you mix it to death! I
use Popsicle sticks and squares of tinfoil for mixing.
If I need to
join large sections together, I sometimes use the one hour slow setting epoxy
mix on the inside edge of the seam, and then tack it in place with the five
minute gel on the outside edge of the seam.
The slow setting epoxy will have a bit more bonding strength since it
penetrates the pores of the clay more thoroughly.
For
filling seams or cracks:
Apoxie Sculpt two part kneadable Epoxy.
I usually
purchase the white so that I am able to tint it myself by kneading in mason
stains and fired clay powder. This
stuff is great for mimicking texture and color.
Long working time- sets in 2-3 hours, with full strength in 12-24 hours.
I order it from WASCO taxidermy supply at: www.taxidermy.com
If I am in a hurry, I have
two other faster setting kneadable epoxies:
East
Valley
kneadable Epoxy.
Just like the
material above, this is a two part epoxy mixed with clay, so that it is less
likely to yellow or change color over time.
It sets rock-hard in one hour and can be sanded,
drilled, or painted. The company who
sells this, also sells pigments you may mix with the epoxy to change the color
to match your clay, glaze, or slip surface:
http://www.eastvalleyepoxy.com/
In
an emergency, I also use the ACE
Hardware Brand grey plumber’s kneadable epoxy.
It sets in five minutes, which is great, but it barely leaves me enough
time to knead in the mason stains and mix thoroughly before applying it to my
surface. I usually use this on the
bottoms of my pieces as ‘bumpers’ to level them off.
Wax paper on the table helps to keep it from sticking.
For
painted finishes:
Sherman
Williams Superpaint Flat Interior Latex and
PrepRiteBonding Primer
Although
I use the Sherman Williams primer and base, I use Martha Stewart’s Signature
color line (you can puruse the display in any Sheramn Williams store, or you can
view it on the store’s website). I
like this paint because it is composed almost entirely of calcined clays and
glaze materials…so it has the look and feel of a fired surface.
It is basically an unfired slip with a bit of acrylic binder to hold it
together. Both the paint and the primer should be watered down and applied by
brush in many thin layers to the vitrified clay surface for best results.
I sometimes use Trewax or a matte spray to seal the surface of these
pieces, but they are still prone to being scratched or soiled from handling.
In
order to add depth to these painted surfaces, I occasionally use pastel dust,
rubbed into the surface and then gently wiped off.
This treatment is then sealed with a matte spray fixative.