Measure twice, mix once.
– ancient UNL Proverb
CLAY
Radasch Red Earthenware Pottery Body
Red Art- 50
Fire Clay- 15
Gold Art- 20
Talc- 10
Silica- 5
________
100
1/4 cup Barium Carbonate to prevent scumming
Grog to taste- 7%- 18% a variety of mesh sizes works best for particle packing. (depending on how large, thick and strong your work needs to be)
SLIPS
Pete Pinnell’s WHITE SLIP
OM4 Ball Clay- 40
Talc- 40
Silica- 10
Neph Sye- 10
_________
100
7% zircopax
* For thin dunking slip, use 10-15% zircopax
* mix this slip on the thick side because the neph sye and sodium creates a slight defloculation…wait 24 hrs before fine tuning.
RADASCH COLORED SLIP BASE
OM4 Ball Clay- 40
*Wollastonite- 40
Silica- 10
Neph Sye- 10
_________
100
Frit 3124 12%
Stain of Choice 12%
*This is the same slip as above except for the wollastonite substitution. This is nescessary for good color response.
*Blunge wollastonite in water first.
*This slip is a little stringy because of the Wollastonite. It takes just a bit to get use to.
TERRA SIGILATA BASE (thanks to Pete Pinnell and Meredith Brickell)
(by weight)
2 parts water
1 part clay
let clay slake down in water
mix well, 5-10 minutes; you cannot mix it too much
add sodium silicate
1/2 of 1% (0.5%) of dry weight of clay
(the amount of deflocculant may vary depending on the clay)
mix well again
set bucket off floor about 6 inches or so
let sit undisturbed, covered for 8 hours
(the amount of settling time may vary depending on the clay)
siphon off center layer
*I find that these sig’s mostly settle into just two layers not three which is often typical
Here are recipes that I use. These amounts mix up well in a 5-gallon bucket:
OM4 BASE
20 # water
10 # ball clay
22.7 grams sodium silicate
yields approx 2 gallons of terra sigilatta
settle for exactly 8 hrs
RED ART BASE:
20 # water
10 # Red Art
22.7 grams sodium silicate
settle for 6 hours
Notes on adding colorants:
Generally stick to Pete Pinnell’s rule of no more than 3 teaspoons of colorant per 1 cup of terra sigilatta base.
I have found that in most cases, some titanium dioxide in the mix helps give the sig some substance. It prevents it from being too washy, translucent or disappearing beneath glazes. That being said titanium yeilds a creamy white, so adding too much titanium to any base can be like adding yellow.
Here are some colors I use. All are based on 1 cup of terra sigilatta base plus the listed colorants.
t = teaspoon
Ball Clay Base Recipes:
Orange
3t #6028
¼ t titanium
Yellow
3t #6433
¼ t titanium
Light Blue
3t 6376 or 6315
¼ t titanium
Red
3t Bordeaux Red
¼ t titanium
Red Art Base Recipes:
Terra Cotta Red
3t Red Iron Oxide
GLAZES
*I fire most of my glazes to cone o3 in a computer kiln.
*I often add cmc gum to my glazes. This makes it a brushing glaze. If you want to dunk and/or pour make sure to skip it.
*I fire my kilns with visual cones just like one would a gas kiln.
*Some of these glazes can be quite runny at this temperature so I always leave myself a bit of wiggle room for the glaze to move…sometimes I fire on cookies.
RADASCH CLEAR BASE (originally Debs Clear)
Frit 3134- 30
Frit 3195- 45
EPK- 25
————————
Bentonite- 1.6
CMC- .6
Silica- 3
Most of the other glazes I currently use are commercial AMACO glazes
These are some of my favorites so far…….
Leaf Green LG 46
Olive Green LG 44
Canary Yellow LG 61
Brilliant Red LG 58
Light Blue LG 24
Gray LG 14
LIsted below are glazes that I have intimate knowledge of and have used very frequently at some point in time during my career.
WOODY’S BASE (from Woody Hughes)
Gerstley Borate- 26
Lithium Carb.- 4
Frit 3124- 30
Neph Sye- 20
EPK- 5
Silica- 10
Calcined EPK- 5
_________
100
*This glaze works great with mason stains.
*7% mason stain will usually produce a good transparent glaze.
*The lithium will crystalize over time, especially if the glaze gets cold or freezes.
Clear
Red iron oxide 1%
Icy Blue
Silica 3%
Copper Carb 0.4%
Grape
Lobster Red 6026 3%
Blackberry Wine 6381 3%
Manganese dioxide 1%
Pink
Shell pink 6000 7%
KARI’S BEST
Frit P-626 -25
Frit 3124- 15
Gerstley Borate- 15
Spodumene- 18
Wollastonite- 7
EPK- 20
__________
100
Emerald Green
Copper Carb 6%
Blue
Cobalt Carb 1.5%
Copper Carb 2%
Maroon
Manganese dioxide 7%
Copper Carb 0.5%
Soft Lime Green
Chrome oxide 0.125%
Vanadium Yellow 6440 0.5%
Chartreuse
Chrome oxide 0.125%
Vanadium Yellow 6440 5%
SS MOSSY GREEN (UNL Grad. Sean Scott version of Pete’ s Best)
Frit P- 626- 22
Gerstley Borate- 31
Spodumene- 18
Kaolin- 18
Silica- 11
_________
100
3.5% Red Iron Oxide
2.5% Copper Carbonate
*Depending upon your copper and RIO you may have to back off on the percentages as the glaze can get a little too metallic.
*This glaze looks good on its own and great both over and under Woody’s Icy Blue.
KARI’S YELLOW
Frit P-626- 12.5
Frit 3124- 22.5
Gerstley borate- 20.5
Spodumene- 9.0
Wollastonite- 3.5
EPK- 15.0
Lithium Carb- 2.0
Neph Sye- 10.0
Silica- 5.0
__________
100.0
Naples Mason Stain 2.0
Vanadium Yellow Mason Stain 5.0
GAIL KENDALL’S AMBER
Gerstley Borate – 35.52
Custer Feldspar- 34.58
Barium Carbonate- 13.08
Silica- 10.28
Black Iron Oxide- 6.54
___________
100.00
MERE KARI CLEAR
(aka SWO…Meredith Brickell and I revised this glaze)
Frit 3124- 59
Frit P-626- 14
Neph Sye- 11
Silica- 10
EPK- 6
_________
100
Veegum T 1.6
CMC gum 0.6
*This glaze is great with mason stains…7%-15%
DAM MAJIK MAJOLICA
Frit 3124- 57.21
EPK- 14.87
Frit 3110- 13.73
Zircopax- 13.73
Frit 5301- 0.46
____________
100.00
Veegum T- 1.6%
CMC gum- 0.6%
* You can use 7% of most any mason stain to tint this glaze.
KARI’S PLASTER NOTES (via Ian Anderson)
SUPER FORMULA
1 quart of water needs 3lbs of plaster
1) Measure width, length, and height of space. Multiply these numbers together:
This is your TOTAL VOLUME.
2) Divide TOTAL VOLUME by 80. This gives you how many quarts of water you need.
3) Multiply quarts of water by:
3lbs. plaster for normal shit.
2.85lbs. plaster for slip casting shit.
2.75lbs. plaster for really absorbent softer shit.
This gives you how much plaster you need for your water.
To find how much plaster you need for a space AND you can measure your object:
1) Measure width, length, and height of space. Multiply these numbers together:
This is your TOTAL VOLUME.
2) Measure width, length, and height of object you are casting. Multiply these numbers together:
This is your OBJECT VOLUME.
3) Subtract OBJECT VOLUME from TOTAL VOLUME:
This tells you the VOLUME OF PLASTER YOU NEED.
4) Divide VOLUME OF PLASTER YOU NEED by 80:
This gives you how many quarts of water you need.
5) Multiply quarts of water by:
3lbs. plaster for normal shit.
2.85lbs. plaster for slip casting shit.
2.75lbs. plaster for really absorbent softer shit.
This gives you how much plaster you need for your water.