Project Name
Create a clay similar to Bizen from Japan
Project Codenumber
UnAssigned
Notes
This work is based on two samples from Glen Lewis. We are assuming these samples are representative of Bizen type clay.
I am first evaluating the physical properties of the two Bizen bodies and will then propose mixes of our materials to produce a similar working and firing material.
I also did research on Shino glazes to try to define what they are in their most basic and original form, then constructed a recipe and formula profile.
At first it appears that Plainsman high carbon plastic, sticky and refractory PR#3C clay will be the base for the body. We also have grogs and sands that are similar to those found in these bodies. It may be possible to emulate the plus 200 mesh particle size distribution fairly accurately.
Bizen Clay
|
Code # L3911 |
Notes
*This was brought from Japan by Glen Lewis. It has 10% mountain clay and 5% sand added. But that sand is not evident in the particle size distribution and only a few quartz particles can be seen in the photo. The body is in fact very fine particled and slick.
Very plastic (as good as, for example, Laguna BMix). No splitting during working. Stickier than our bodies are even though this was not soft. Slakes very well. Pugged color is very dark brown (likely it contains high carbon clays).
Dry strength is not as high as expected for this degree of dry shrinkage. Drying shrinkage is higher than expected (we would get frequent cracking in ware that was not dried carefully if our bodies had 7.5%+ shrinkage).
If feels smooth (the PSD picture is highly magnified and a little misleading).
Fired bar shrinkage indicates the body has reach maximum density at cone 8 or before. Above that it is expanding and beginning to melt.
Pictures
Original Dried sample we recieved
I got around 300 grams (enough to do 4 test bars, LOI test and sieve analysis).
This label appears to indicate Bizen with 10% mountain clay and %% sand.
Plastic bars for both Japan clays
Bizen particle size distribution
Top left to bottom right (mesh):
35, 48, 65, 100, 150, 200
About 1/3 of the particles appear to be quartz (rounded), the rest are a variety of minerals.
Bizen clay and Shino glaze development
G3840 Shino on L3912 Bizen body
The wax resist brushstrokes (done right after glazing) and clearly defined. This indicates that soda migration to the surface during drying is an important mechanism of the effect.
Some carbon trapping is also visible on the lower section of the large bowl. This is where the body is thickest. That means that thicker ware would likely carbon-trap more. It also means I could increase the spodumene a little to start melting even earlier. Or incorporate a little frit.
Testdata
SHAB - Shrinkage/Absorption
| DLEN | FLEN | FWT | BWT | CONE | DSHR | FSHR | ABS | |
| 4 | 92.6 | 87 | 21.71 | 21.72 | 10R | 7.4% | 6.0% | 0.0% |
| 3 | 92.39 | 86.47 | 22.35 | Bloating | 9.9 | 7.6% | 6.4% | |
| 2 | 92.51 | 86.11 | 21.4 | 21.41 | 9.0 | 7.5% | 6.9% | 0.0% |
| 1 | 92.11 | 85.47 | 22.03 | 22.04 | 8.0 | 7.9% | 7.2% | 0.0% |
SIEV - Sieve Analysis 35-325 Wet
| TOT | 35M | 48M | 65M | 100M | 150M | 200M | |
| 1 | 100 | 1.4 | .5 | .4 | .5 | .7 | 3.0 |
LDW - LOI/Density/Water Content
| WWGT | DWGT | FWGT | H2O | LOI | DENS | |
| 1 | 9.92 | 7.56 | 6.99 | 23.8% | 7.5% |
XML (to paste into Insight)
Born: 2016-09-21, Modified: 2016-10-17 13:27:49
Bizen Duplicate using Plainsman Materials
|
Code # L3916 |
| Materials | Amt |
|---|---|
| *3C | 80.000 |
| *M2 | 5.000 |
| Nepheline Syenite | 15.000 |
Total:100.00
Notes
*Plainsman 3C clay has a very similar character to the Bizen clay tested (very plastic, high carbon). However it is refractory and high in quartz. That is actually good since the high expansion Shino glaze should craze less. But to get the lower porosity of the Bizen body I added 15% nepheline syenite. Also added 5% M2 to up the iron content to react with the Shino glaze (without it the 3C would fire quite white).
Texture: The plasticity of this body is excellent. But the Bizen is much more (even though it was stiffer it drying shrinkage is approaching 8%, no standard clay body in North America is more than about 7%).
The fired bars show that, like the Bizen body, this has reach maximum maturity by cone 8, above cone 9 it is expanding and over fired. The color is also too light (although the Shino glaze develops good color on it). The nepheline should be reduce and the M2 increased to more closely resemble the Bizen clay.
Pictures
L3916 Bizen duplicate with G3840 Shino Glaze - Cone 10R
These glaze were applied fairly thin.
The bubble pattern appears to be a remnant of the bubbles created during the glazing process.
Some carbon trapping is happening on the thicker rim of the larger bowl.
G3840 Shino on L3912 Bizen body
The wax resist brushstrokes (done right after glazing) and clearly defined. This indicates that soda migration to the surface during drying is an important mechanism of the effect.
Some carbon trapping is also visible on the lower section of the large bowl. This is where the body is thickest. That means that thicker ware would likely carbon-trap more. It also means I could increase the spodumene a little to start melting even earlier. Or incorporate a little frit.
Bizen clay and Shino glaze development
Bizen clay duplicate bars - iPhone 6
Bizen clay bars - iPhone 4
Testdata
SHAB - Shrinkage/Absorption
| DLEN | FLEN | FWT | BWT | CONE | DSHR | FSHR | ABS | |
| 12 | 93.14 | 84.58 | 33.51 | 33.53 | 10R | 6.9% | 9.2% | 0.1% |
| 10 | 92.1 | 84.77 | 34.38 | 34.4 | 9.9 | 7.9% | 8.0% | 0.1% |
| 9 | 92.97 | 84.74 | 34.51 | 34.63 | 9.0 | 7.0% | 8.9% | 0.3% |
| 8 | 92.92 | 84.61 | 33.82 | 33.92 | 8.0 | 7.1% | 8.9% | 0.3% |
| 7 | 92.91 | 84.61 | 32.86 | 33.48 | 7.0 | 7.1% | 8.9% | 1.9% |
XML (to paste into Insight)
<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Bizen Duplicate using Plainsman Materials" id="94477" key="xge2gxk2" date="2016-12-01" codenum="L3916"> <recipelines> <recipeline material="3C" amount="80.000"/> <recipeline material="M2" amount="5.000"/> <recipeline material="Nepheline Syenite" amount="15.000"/> </recipelines> </recipe> </recipes>
Born: 2016-09-28, Modified: 2016-12-01 14:16:34
Shino Trial Number 1
|
Code # G3840 |
| Materials | Amt |
|---|---|
| Nepheline Syenite | 50.000 |
| EPK | 20.000 |
| Soda Ash | 10.000 |
| Redart | 5.000 |
| Spodumene | 15.000 |
Total:100.00
Auto Unity Formula
|
Si:Al: 3.7:1 7.3 (Molar:7.1) 3.6 Cost 0.19 per kg |
Notes
*This is the first attempt at creating a Shino glaze. The rationalization for its recipe can be found on the Digitalfire Reference Database glossary page for Shino glazes (like below).
This was made for testing on the Bizen-like body L3916.
For interest sake Malcom Davis Shino:
Nepheline Syenite 45
EPK 10
Soda Ash 19
Red Art 6
Soda Feldspar 10
OM4 Ball Clay 15
Pictures
Shino glaze dried
Shino glaze slurry
Notice the bubbles. These are a product of the spodumene, but also likely the soda ash. They create the blisters on the surface of the dried glaze.
L3916 Bizen duplicate with G3840 Shino Glaze - Cone 10R
These glaze were applied fairly thin.
The bubble pattern appears to be a remnant of the bubbles created during the glazing process.
Some carbon trapping is happening on the thicker rim of the larger bowl.
Shino glazes on google.com
The color and character of my glaze seems quite similar to many of the ones I see on google.
G3840 Shino on L3912 Bizen body
The wax resist brushstrokes (done right after glazing) and clearly defined. This indicates that soda migration to the surface during drying is an important mechanism of the effect.
Some carbon trapping is also visible on the lower section of the large bowl. This is where the body is thickest. That means that thicker ware would likely carbon-trap more. It also means I could increase the spodumene a little to start melting even earlier. Or incorporate a little frit.
G3840 Shino on PolarIce/CrystalIce Mix
URLs
Shino Glazes at Di..Reference Database
XML (to paste into Insight)
<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Shino Trial Number 1" id="94385" key="skGeNoTS" date="2019-02-19" codenum="G3840"> <recipelines> <recipeline material="Nepheline Syenite" amount="50.000"/> <recipeline material="EPK" amount="20.000"/> <recipeline material="Soda Ash" amount="10.000"/> <recipeline material="Redart" amount="5.000"/> <recipeline material="Spodumene" amount="15.000"/> </recipelines> </recipe> </recipes>
Born: 2016-09-25, Modified: 2019-02-19 14:21:14
