Zero4 - A Porcelain That Vitrifies Translucent at Cone 04

Share from Insight-live.com (Lab Documentation and Calculation System) by Digitalfire. https://digitalfire.com

See Also:
Zero3 Porcelain, engobe, glaze, firing schedule
L4170 Cone 04 Terra Cotta Casting Body, Glaze, Firing Schedule
Low expansion super white fritware body

Would you like to make translucent porcelain at terra cotta firing temperatures and use bright colored low fire glazes? Make this.


Project Name

Zero4 Porcelain

Project Codenumber

UnAssigned

Notes

This project adjusts the Zero3 fritware porcelain to mature at cone 04 (instead of cone 03). Zero4 porcelain enables making translucent and ultra-strong ware at terra cotta and talc body temperatures. Like them, it can also be fired fast, very fast.

The motivation for moving beyond our Zero3 recipe is to make it more compatible with commercial low fire glazes (e.g. Spectrum). Even more important, for dipping we are switching to the G1916Q recipe, it is more adjustable, better tested and melts better at cone 04 than the recipe we were using for Zero3.

Note that the G1916Q recipe is enabling the addition of up to 10% silica and yet is still melting well (because it has high boron). This enables Al2O3 and SiO2 levels that are typical at far higher temperatures, these two oxides are the key to glaze durability. That feeds the dream of making super-duty functional ware at cone 04!

Like Zero3, this is the plastic version for use on the potter's wheel. For slip casting, try dropping the Veegum to 1% (if it does not shrink enough and pull away from the mold well, increase the it, if it casts too slowly, drop it).

Pictures

Zero4 porcelain broken and cross section close-up

The body is highly plastic and can be thrown very thin. At cone 04 this thin-walled mug did not warp even though it fired to a near-glasslike cross-section. The strength is amazing, it took about 30 hits with a hammer to break this mug, hitting it as hard as I dared without risking cutting the hand I was holding it with. The whiter flecks are agglomerates of New Zealand kaolin (because of improper mixing of the slurry).

Zero4 Plastic Porcelain

Code #

L3924J

Materials Amt Units
New Zealand Kaolin 200.000 KG 0.08%
Ferro Frit 3110 325.000 LB 61.85%
Silica 200.000 LB 38.06%
Additions Units
VeeGum T 35.000 LB 6.66%
*Mason 6336 Blue Stain 250.000 GM 0.10%

Total:254,466.00 (R)

Auto Unity Formula

CaO 0.27
MgO 0.13
K2O 0.05
Na2O 0.55
(KNaO) 0.60
B2O3 0.08
Al2O3 0.08
SiO2 4.96

Ratios

Si:Al: 60.7:1
SiB:Al: 61.7:1
R2O:RO: 0.6:0.4

Expansion

7.6 (Molar:7.4)

LOI

0.9

Cost

0.00 per kg

Notes

*Fantastic throwing, very thin walls. This should not be used when too soft or drying cracks will occur. Dry pieces evenly. Make ware having walls of even thickness.

The plastic material stiffens dramatically when left to sit (in minutes), but softens when wedged.

We encountered no warp on the rims of thrown ware despite vertical cylindrical shapes, thin walls and the weight of the handle on mugs. However the firing shrinkage is very high, that means at least some warping is likely on susceptible shapes.

Thus far it seems the 325 mesh silica (45 micron) is important. It is maintaining glaze fit (no glazes have crazed so far, none have shivered either).

This is a production batch mix, retotal it as needed based on the percentage column.

Mixing thoroughly is vital to break up the agglomerates of NZK and Veegum, blender mixing is likely the only way to do it properly.

Kiln shelves must be well sanded to prevent plucking.

You must have a clean plaster bat for dewatering otherwise fired surfaces will be marred by specks.

If 1500F is too hot for bisque. Try 1450F.

Pictures

L3924J Zero4 Porcelain

Use G1916Q and G3879C. Very similar.
Tiny white flecks in the body, must mix it very thoroughly.

Zero4 porcelain cross section of mug

Zero4 porcelain cross section

3924J1 Zero4 Porcelain at cone 04

left: G1916Q3 glaze
right: Two coats of Spectrum 700
Amaco underglazes.

L3924J Zero4 fired bars - vs. Polar Ice

These Zero4 test bars (left) are fired from cone 02 (top) down to cone 06. These contain 0.06% Mason 6336 blue stain. The bars are on the right are Plainsman Polar Ice (fired from cone 8 down to 5).

L3924J, L3924J1 Zero4 porcelain at cone 06, 04

L3924J uses New Zealand kaolin, L3924J1 uses Grolleg. A fritware body showcases even the small difference in iron these two have.

L3924J and L3924K Cone 04 with clear glazes

These bars are 3mm thick and the glaze was applied in three coats. Since the bodies fire very vitreous it is expected the bars should easily bend toward or away from the glaze if it is under tension or compression (as a result of mismatch in thermal expansions). However, the bars are straight and there is no crazing.

Spectrum 700, front, is not bending.
Duncan PB001 is bending more with J, much less with K.
Mayco S2101 is bending most with J, less with K.
In another test our G1916Q3 did not bend the bars either.
After many months none of these were crazed.

L3924J Zero4 Casting translucency at cone 02

Untitled

Testdata

SHAB - Shrinkage/Absorption

DLEN FLEN FWT BWT CONE DSHR FSHR ABS
692.68336.18-1.07.4%10.4%
293.0183.3634.8534.84-2.07.0%10.4%0.0%
192.7883.123736.99-3.07.2%10.4%0.0%
392.9482.9335.5735.57-4.07.1%10.8%0.0%
492.8682.8235.3735.38-5.07.1%10.8%0.0%
592.8682.935.8235.85-6.07.1%10.7%0.1%

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Zero4 Plastic Porcelain" id="212869" key="9b7ELJro" date="2023-03-08" codenum="L3924J"> <recipelines> <recipeline material="New Zealand Kaolin" amount="200.000" tolerance="" unitabbr="KG"/> <recipeline material="Ferro Frit 3110" amount="325.000" tolerance="" unitabbr="LB"/> <recipeline material="Silica" amount="200.000" tolerance="" unitabbr="LB"/> <recipeline material="VeeGum T" amount="35.000" unitabbr="LB" added="true"/> <recipeline material="Mason 6336 Blue Stain" amount="250.000" unitabbr="GM" added="true"/> </recipelines> </recipe> </recipes>

Born: 2014-09-19, Modified: 2023-03-08 13:20:00

Zero4 Casting Porcelain

Code #

L3924L

Materials Amt Units
New Zealand Kaolin 200.000 KG 0.08%
Ferro Frit 3110 325.000 LB 61.85%
*Silica 45 micron 200.000 LB 38.06%
Additions Units
VeeGum T 10.000 LB 1.90%

Total:242,876.00 (R)

Notes

*The casting version only needs 1% veegum. Like the plastic version, NZK agglomerates. During initial testing we were unable to mix thoroughly enough to break them all up, this will be an issue for anyone: You must have a really good propeller mixer and make enough slurry in a big enough bucket that your mixer can run at full speed for an extended period. Even better, blender mixing will guarantee that all agglomerates are broken down.

For our test mixes we start with 1000 water and 22 Darvan and add 2000 powder to that. This gels on the first day but on the next day it casts quickly, in 8 minutes we can drain and get a piece with walls between 2 and 3mm. Pieces extract from the mold pretty well (but it would benefit from a little more drying shrinkage). We can cast pieces later afternoon and have them in the kiln two hours later and out of the kiln early the next morning.

It is vital to thoroughly mix the powdered ingredients before adding them to the water. 2000g makes about 1.6 liters of slurry.

Cone 04, 03 and 02 total shrinkages are all 14.3%.

Pictures

Zero4 Casting fired to cone 04

Walls are 2-3mm thick. Fired at cone 02. Very translucent.

Testdata

SHAB - Shrinkage/Absorption

DSHR FSHR ABS
1

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="Zero4 Casting Porcelain" id="215896" key="hh7vs6Hz" date="2022-10-04" codenum="L3924L"> <recipelines> <recipeline material="New Zealand Kaolin" amount="200.000" tolerance="" unitabbr="KG"/> <recipeline material="Ferro Frit 3110" amount="325.000" tolerance="" unitabbr="LB"/> <recipeline material="Silica 45 micron" amount="200.000" tolerance="" unitabbr="LB"/> <recipeline material="VeeGum T" amount="10.000" unitabbr="LB" added="true"/> </recipelines> </recipe> </recipes>

Born: 2014-09-19, Modified: 2022-10-04 13:04:13

G1916Q glaze + 10% silica

Code #

G1916Q3

Materials Amt
Ferro Frit 3195 64.000 56.14%
Ferro Frit 3110 11.000 9.65%
Ferro Frit 3249 14.000 12.28%
New Zealand Kaolin 15.000 13.16%
Silica (45 micron Silica) 10.000 8.77%

Total:114.00

Auto Unity Formula

CaO 0.54
MgO 0.15
Na2O 0.30
(KNaO) 0.30
B2O3 0.96
Al2O3 0.53
SiO2 3.67

Ratios

Si:Al: 6.9:1
SiB:Al: 8.7:1
R2O:RO: 0.3:0.7

Expansion

6.4 (Molar:6.4)

LOI

1.8

Cost

0.39 per kg

Notes

*This adds 10% 45-micron silica to the G1916Q cone 04 glaze recipe. The glaze has absorbed this 10% (as well as the 5% in G1916Q2) yet still melts just as well! This will certainly reduce the thermal expansion, Better yet, it increases the hardness and durability (the objective, we want to best glaze surface possible for Zero4 porcelain).

One of the big benefits of this recipe is that it is possible to adjust thermal expansion by trading Frit 3110 for 3249 (for shivering), or vice versa for crazing. With further testing we will discover whether there are any glaze fit issues on Zero4 porcelain.

After several months this is still fitting L213 talc:ballclay body (applied thickly it fires ultragloss).

We mixed a batch of dipping glaze using 3040 water, 4000 powder. A little thin so added 0.8 epsom salts. The consistency is more challenging for achieving an even layer during dip (because of gelling). But with practice, it is working.

For a brushing glaze version we make a 1 pint jar using 340 powder, 440 water, 5 VeeGum and 5 CMC gum. This will adhere to any surface and dry without cracking. It will hang on without running.

Pictures

G1916Q3 glaze on L4170B terra cotta at cone 04

After a several months this had not shivered or crazed.
However where thick on thrown pieces it does craze after months.

3924J1 Zero4 Porcelain at cone 04

left: G1916Q3 glaze
right: Two coats of Spectrum 700
Amaco underglazes.

G1916Q3 on L215 at cone 04 - Shivering at rim

Even with an addition of 10% silica it is just as glossy and runs when thick. However it is shivering on the rim of this mug, so the thermal expansion is too low for L215 (better to use G1916Q).

M370 cone 6 vs cone 04

Clear glaze at cone 6: G2926B
Clear glaze at cone 04: G1916Q3
Notice the color is much whiter at the low fire. While it did not craze out of the kiln, crazing did begin a few hours later after the cone 04 cup had been used to drink coffee.

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="G1916Q glaze + 10% silica" id="213847" key="tdA7LouZ" date="2022-11-24" codenum="G1916Q3"> <recipelines> <recipeline material="Ferro Frit 3195" amount="64.000" tolerance=""/> <recipeline material="Ferro Frit 3110" amount="11.000" tolerance=""/> <recipeline material="Ferro Frit 3249" amount="14.000" tolerance=""/> <recipeline material="New Zealand Kaolin" amount="15.000" tolerance=""/> <recipeline material="Silica" lookup="45 micron Silica" amount="10.000" tolerance=""/> </recipelines> </recipe> </recipes>

Born: 2014-03-04, Modified: 2022-11-24 20:29:50

G1916Q glaze + 5% silica

Code #

G1916Q2

Materials Amt
Ferro Frit 3195 64.000 60.38%
Ferro Frit 3110 11.000 10.38%
Ferro Frit 3249 14.000 13.21%
New Zealand Kaolin 12.000 11.32%
Silica (45 micron Silica) 5.000 4.72%

Total:106.00

Auto Unity Formula

CaO 0.54
MgO 0.15
Na2O 0.30
(KNaO) 0.30
B2O3 0.96
Al2O3 0.49
SiO2 3.28

Ratios

Si:Al: 6.6:1
SiB:Al: 8.6:1
R2O:RO: 0.3:0.7

Expansion

6.6 (Molar:6.6)

LOI

1.6

Cost

0.34 per kg

Notes

*This exchanges ball clay for kaolin in the standard G1916Q recipe (to lower the iron content for use on super white bodies). That means that slurry properties are not as good. That being said, NZK is very sticky and works well to suspend glazes. If needed, a little Veegum can be added.

Additionally, this adds 5% 325 mesh silica. G1916Q is melting well at cone 04 and we suspected it would tolerate this. The more silica it will take the harder and more durable the fired product will be.

The glaze is still melting well and running enough that it should take more silica.

We mixed a batch of 3040 water, 4000 powder. A little thin so added 0.8 epsom salts.

Pictures

G1916Q2 On L215 and L210 at cone 06

Applied fairly thick, enough to run and collect at the base, yet still transparent.

G1916Q2 On Zero4 porcelain at cone 04

G1916Q2 on L210, L215 at cone 04

The NZK is aglomerated because this was not screened.

XML (to paste into Insight)

<?xml version="1.0"?> <recipes version="1.0" encoding="UTF-8"> <recipe name="G1916Q glaze + 5% silica" id="213504" key="E545z3yz" date="2022-05-26" codenum="G1916Q2"> <recipelines> <recipeline material="Ferro Frit 3195" amount="64.000" tolerance=""/> <recipeline material="Ferro Frit 3110" amount="11.000" tolerance=""/> <recipeline material="Ferro Frit 3249" amount="14.000" tolerance=""/> <recipeline material="New Zealand Kaolin" amount="12.000" tolerance=""/> <recipeline material="Silica" lookup="45 micron Silica" amount="5.000" tolerance=""/> </recipelines> </recipe> </recipes>

Born: 2014-03-04, Modified: 2022-05-26 18:56:34