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3D Print a Test of the Beer Bottle Neck
3D Printing a Clay Cookie Cutter-Stamper
A 3-minute Mug with Plainsman Polar Ice
A Broken Glaze Meets Insight-Live and a Magic Material
Accessing Recipes from "Mid-Fire Glazes" book in Insight-Live
Adjusting the Thixotropy of an Engobe for Pottery
Analysing a Crazing, Cutlery-marking Glaze Using Insight-Live
Compare the Chemistry of Recipes Using Insight-Live
Connecting an External Image to Insight-Live Pictures
Convert a Cone 10 Glaze to Cone 6 Using Desktop Insight
Create a Synthetic Feldspar in Insight-Live
Creating a Cone 6 Oil-Spot Overglaze Effect
Creating Rules for Calcium Carbonate - Wollastonite Substitution
Design a Triangular Pottery Plate Block Mold in Fusion 360
Desktop Insight - Difficult Formula to Batch Calcuations
Desktop Insight 1A - Compare Theoretical and Real-World Feldspars
Desktop Insight 1B - Turn a Feldspar Into a Glaze
Desktop Insight 1C - Substitute Wollastonite for Whiting in Glazes
Desktop Insight 2 - Creating a Matte Glaze
Desktop Insight 3 - Dealing With Crazing
Desktop Insight 4 - Add a Native Material to MDT, Build a Glaze
Desktop Insight 5A - Glaze Formula to Batch Calculations
Desktop Insight MDT: Adding a Material
Desktop Insight: Maintain an MDT as a CSV File in Excel
Digitalfire Desktop INSIGHT Overview Part 1
Digitalfire Desktop INSIGHT Overview Part 2
Enter a Recipe Into Insight-live
Entering Shrinkage/Porosity Data Into Insight-Live
Getting Frustrated With a 55% Gerstley Borate Glaze
How I Fixed a Settling Glaze Slurry Using Desktop Insight
How I Formulated a Cone 6 Silky Matte Glaze Using Insight-Live
How to Add Materials to the Desktop Insight MDT
How to Apply a White Slip to Terra Cotta Ware
How to Paste a Recipe Into Insight-live
Importing Data into Insight-live
Importing Desktop Insight Recipes to Insight-live
Importing Generic CSV Recipe Data into Insight-Live
Insight-Live Meets a Silica Deprived Glaze Recipe
Insight-Live Quick Overview
Liner Glazing a Stoneware Mug
Make a precision plaster mold for slip casting using Fusion 360 and 3D Printing
Make test bars to measure pottery clay physical properties
Making ceramic glaze flow test balls
Manually program your kiln or suffer glaze defects!
Mica and Feldspar Mine of MGK Minerals
Predicting Glaze Durability by Chemistry in Insight-Live
Preparing Pictures for Insight-live
Remove Gerstley Borate and Improve a Popular Cone 6 Clear Glaze
Replace Lithium Carbonate With Lithium Frit Using Insight-Live
Replacing 10% Gerstley Borate in a clear glaze
Signing Up at Insight-live.com
Signing-In at Insight-live.com
Slip cast a stoneware beer bottle
Subsitute Gerstley Borate in Floating Blue Using Desktop Insight
Substitute Ferro Frit 3134 For Another Frit
Substituting Custer Feldspar for Another in a Cone 10R Glaze Recipe
Substituting Materials by Weight: Why it does not work!
Substituting Nepheline Syenite for Soda Feldspar
Thixotropy and How to Gel a Ceramic Glaze
Use Insight-live to substitute materials in a recipe
Using Recipe Libraries With Desktop Insight

How I Formulated a Cone 6 Silky Matte Glaze Using Insight-Live

I will show you how found a recipe on Facebook, assessed it, substituted my own materials, tested it, adjusted it. Now it is like a cone 10 dolomite matte.

A. Insight-live


Click here to watch this at youtube.com or click here to go to our Youtube channel

Silky Mattes are more difficult at cone 6 than at cone 10. It is common to find ones that either gloss on slight over-firing, are too matte, are not durable (they cutlery mark), ones that have a poor functional surfaces (and stain easily) and ones that craze.

I found this recipe on Facebook. Let's take a look at it in Insight-live.

Gerstley borate 9
Silica 30
Dolomite 17.5
EPK 20
Nepheline syenite 33.5
Whiting 2.5

Copy it, paste into Insight-live account, # as G2928

#1: Mattes need high Al2O3
-many recipes source most of it from feldspar, that brings in too much KNaO and crazing happens
-other recipes source it from alot of clay, the glaze shrinks and cracks during drying

Open G2571A beside.

-Silky mattes happen when Al2O3 and MgO are high, SiO2 is low and the glaze melts well. Tiny surface ripples happen.
-At cone 10 it just happens. But at cone 6 it needs an extra kick with B2O3
-G2571A even has a little B2O3 (unusual but maybe a secret to why it works so well).
-At cone 6 we need more

Where do we get B2O3: GB (click it)
-This is going to have plenty of clay, we don't need GB gelling the slurry and shrinking it more (it is plastic)
Use a frit.

Open Roy Limits cone 6.
Compare limits again:
-MgO still not too high, Al2O3, SiO2 good, ratio is good

Sourcing issues again:
-The MgO is sourcing from dolomite: No good for cone 6, will use talc, melts better, no gasing
-CaO from whiting: switch to wollastonite to avoid gassing issues
-Clay: Not looking for toilet bowl white. Going to use Ravenscrag Slip to get a slurry of the best possible application properties (as much as I can)

Let's improve this recipe.
Not going to duplicate, going to start from scratch

1. Start with 50 Ravenscrag, 10 Frit
-click on RSlip to show iron

2. Add 1 talc, show it, match MgO (to 5)

3. Highlight B2O3, reduce frit to match it (to 6)

4. Highlight KNaO, need it, add 5 nepheline syenite, show it, re-hilight KNaO, match (to 7)

5. Increase frit to rematch boron (to 7)

6. Add 1 wollastonite, show it (oversupplies CaO, will leave for a moment)

7. Need Al2O3, SiO2. Add 1 silica, calcined kaolin

8. Add nepsy to 0.24, backoff (to 9)

9. Add 1 talc (to 6) to match MgO

9. Add frit (to 8) to rematch B2O3

10. Hi-light Al2O3, kaolin to 3.5

11. SiO2 to 1.5

Look at the LOI! It is much lower on this new glaze, that means less change of glaze defects.

Retotal to 100
Reduce RSlip to 60, notice formula hardly changes. Why? RSlip chemistry is much more like a glaze than any of the others.

It tested it. Too glossy. Needed to add Al2O3, increased Al2O3 to 0.5+

Calcined kaolin a good way to adjust: why? Try it.
-Cuts Al2O3 and SiO2 (increasing flux) and also increases the ratio a little.

Approximate final recipe:
Nepheline syenite 13
Ravenscrag Slip 60
Ferro Frit 3134 11
Talc 8
Wollastonite 1.5
Calcined Kaolin 9
Tin Oxide 5

Where is this going?
-Double layering
-Black matte

Mattes are fragile, glazes want to be glossy.
-It is important to have a way to adjust the degree of gloss so you can crank up the matte, then back off if it marks or stains
Frit 3134 only version also possible: show
Frit 3134/talc version: show

Links

Recipes G2928C - Ravenscrag Silky Matte for Cone 6
Plainsman Cone 6 Ravenscrag Slip based glaze. It can be found among others at http://ravenscrag.com.
URLs https://digitalfire.com/university/insight-live/overview/Insight-Live%20Overview.html
Insight-Live.com Overview Video
URLs http://m.youtube.com/user/tonywilliamhansen
YouTube channel for Tony Hansen
Glossary Matte Glaze
Random material mixes that melt well overwhelmingly want to be glossy, creating a matte glaze that is also functional is not an easy task.
Glossary Glaze Chemistry
Glaze chemistry is the study of how the oxide chemistry of glazes relate to the way they fire. It accounts for color, surface, hardness, texture, melting temperature, thermal expansion, etc.

Click here for case-studies of Insight-Live fixing problems


Insight-live help button

You will see examples of replacing unavailable materials (especially frits), fixing various issues (e.g. running, crazing, settling), making them melt more, adjusting matteness, etc. Insight-Live has an extensive help system (the round blue icon on the left) that also deals with fixing real-world problems and understanding glazes and clay bodies.

By Tony Hansen
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