Stained porcelains for cone 6 - Three base bodies

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See Also:
Cone 6 Grolleg translucent porcelain for throwing, casting, 3D printing

Grolleg and New Zealand kaolin recipes are obviously best for bright colors. But for black we found an exciting solution.


Cone 6 Grolleg Pink/Blue Porcelains

Code #

L3778D1

Materials Amt
Grolleg Kaolin 52.000
Silica 25.000
Nepheline Syenite 20.000
VeeGum T 3.000
Additions
*Mason 6020 10.000

Total:110.00

Notes

*Stunning results. Although 6020 is a very refractory stain in glazes (not even recommended for them), in bodies it is a natural, even when the body is overfired up to cone 9, it appears totally stable.

Other stains to try: 6600 9%, 6121 9%.

Pictures

Fired bars of L3779D with 6300, 6020 blue, pink stains

These bars are fired from cone 3 to 8 oxidation (bottom-to-top). At cone 6 the pink and blue vitrify similarly. By cone 8 the blue is over-firing while the pink is stable.

The blue has 3% Mason 6300 stain.
The pink has 10% Mason 6020.

Pink L3778D pink porcelain with G2926B at cone 6

Mason 6020 is promoted as a body stain and not suitable in glazes. This certainly demonstrates the former, it produces stunning pink at cone 6.

Testdata

SHAB - Shrinkage/Absorption

DLEN FLEN FWT BWT CONE DSHR FSHR ABS
993.8586.4238.7838.779.06.2%7.9%0.0%
893.8285.8438.138.138.36.2%8.5%0.1%
794.0986.0337.8537.876.95.9%8.6%0.1%
694.1484.9837.9437.965.95.9%9.7%0.1%
594.1184.8138.6538.754.85.9%9.9%0.3%
494.3885.3537.3837.874.05.6%9.6%1.3%
394.4987.1137.2138.393.05.5%7.8%3.2%

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Cone 6 Grolleg Pink/Blue Porcelains" id="179859" key="kThKAb7C" date="2023-02-21" codenum="L3778D1"> <recipelines> <recipeline material="Grolleg Kaolin" amount="52.000" tolerance=""/> <recipeline material="Silica" amount="25.000" tolerance=""/> <recipeline material="Nepheline Syenite" amount="20.000" tolerance=""/> <recipeline material="VeeGum T" amount="3.000" tolerance=""/> <recipeline material="Mason 6020" amount="10.000" added="true"/> </recipelines> </recipe> </recipes>

Born: 2015-03-06, Modified: 2023-02-21 22:23:19

Red NZK Cone 6 Porcelain

Code #

L4588

Materials Amt
New Zealand Kaolin 42.000
Silica 20.000
Nepheline Syenite 35.000
VeeGum T 3.000
Additions
Mason 6021 10.000

Total:110.00

Auto Unity Formula + Analysis

CaO 0.03 0.44%
MgO 0.08 0.70%
K2O 0.08 1.61%
Na2O 0.25 3.52%
(KNaO) 0.33
TiO2 0.00 0.06%
Al2O3 1.00 23.09%
SiO2 4.70 63.97%
Fe2O3 0.00 0.15%

Ratios

Si:Al: 4.7:1
R2O:RO: 0.7:0.3

Expansion

6.1 (Molar:5.8)

LOI

6.5

Cost

1,243.20 per kg

Notes

*300g powder and 1000g water were blender mixed on high speed to get the best possible particle wetting (1000g is a lot of water but with less the slurry was too gelled).

6021 is not a Mason stain recommended for bodies but it does yield bright color in the tests done by Robert Barritz. It makes sense that it should work since encapsulated stains are specifically stabilized against fusion in glazes.

The New Zealand kaolin produces a whiter porcelain than Grolleg. That also means it produces brighter colors with stains.

This amount of VeeGum is OK for hand building and forming but for wheel throwing 4% would be better.

10% stain is a lot, we should try diluting it a little to see if strong color can be achieved with a lower percentage.

Pictures

Mixing a 300g batch of L4588 red porcelain

We also made SHAB test bars to compare the firing shrinkage of this with the pink and blue versions.

L4588 Red NZK Cone 6 Porcelain at cone 6

Total shrinkage is high, about 16% at cone 6. The porcelain is very dense and strong and the color is a very dense pleasant red.

Testdata

SHAB - Shrinkage/Absorption

DLEN FLEN FWT BWT CONE DSHR FSHR ABS
692.9683.8339.7139.716.07.0%9.8%0.0%
493.1784.0339.0739.144.06.8%9.8%0.2%

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Red NZK Cone 6 Porcelain" id="223725" key="PwtPRLKK" date="2022-12-06" codenum="L4588" picturebasename=""> <recipelines> <recipeline material="New Zealand Kaolin" amount="42.000" tolerance=""/> <recipeline material="Silica" amount="20.000" tolerance=""/> <recipeline material="Nepheline Syenite" amount="35.000" tolerance=""/> <recipeline material="VeeGum T" amount="3.000" tolerance=""/> <recipeline material="Mason 6021" amount="10.000" added="true"/> </recipelines> </recipe> </recipes>

Born: 2001-03-02, Modified: 2022-12-06 21:59:26

2018 3B+6% 6666 at 100#

Code #

L4484D

Materials Amt
3B 95.000 93.73%
Mason 6666 Stain 6.000 5.92%
Barium Carbonate 0.350 0.35%

Total:101.35

Notes

*3B is Plainsman Mother Nature's Porcelain, or MNP. Even though it is sold as a 42 mesh powder the natural material is extremely fine particled and easy to slurry process to 200 mesh. Using a vibrating sieve +200 mesh particles can be quickly removed (less that 5% of the material). Even +325 is workable, but for a black porcelain 200 works well.

Since MNP contains some iron it can form a black porcelain using a lower percentage of stain that what is necessary using white porcelains.

MNP has a unique property: It contains some soluble salts. While it is normal to precipitate these using a little barium carbonate, if used as-is the salts create a sheen on the surface, especially on the edges of contours, that is almost glaze-like.

Pictures

L4484D MNP 6% stain cone6 vs. Coffee Clay

L4484 3B 100# black vs. Coffee Clay

L4484D 3B + 6% stain cone 5

G3933A cone 5 on L4484D black porcelain

Using the C5DHSC firing schedule.

L4484,84A,84B,84D,84F 2018 3B+6666 fired bars

These were other tests done to vary the amount and type of stain.

Testdata

SHAB - Shrinkage/Absorption

DLEN FLEN FWT BWT CONE DSHR FSHR ABS
793.4286.7139.0939.097.06.6%7.2%0.0%
693.5687.0141.9341.936.06.4%7.0%0.0%
593.7387.5842.3442.365.06.3%6.6%0.0%
493.8788.4840.8141.864.06.1%5.7%2.6%

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="2018 3B+6% 6666 at 100#" id="212115" key="8NeK6ujd" date="2023-02-21" codenum="L4484D"> <recipelines> <recipeline material="3B" amount="95.000" tolerance=""/> <recipeline material="Mason 6666 Stain" amount="6.000" tolerance=""/> <recipeline material="Barium Carbonate" amount="0.350" tolerance=""/> </recipelines> </recipe> </recipes>

Born: 2021-12-28, Modified: 2023-02-21 22:20:14