A high-nepheline, zero-silica cone 8 silky matte glaze is cutlery marking and crazing. Why?
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.
How I found a recipe on Facebook, substituted a frit for the Gerstley Borate and added the extra silica it needed to fight crazing. I got a fabulous cone 6 clear.
Using Insight-live I will demonstrate the surprising amount of silica some cone 6 base glazes that appear OK will accept and still melt well.
How to spot out-of-balance indicators in the chemistry of glazes that suggest susceptibility to scratching or cutlery marking.
Raw lithium carbonate can be replaced with a lithium-containing frit if you can do the chemistry. And you can at insight-live.com.
Use Insight-Live.com to do major surgery on a feldspar saturated cone 10R glaze recipe with multiple issues: blistering, pinholing, crazing, settling, dusting and possibly leaching!
Insight-live shows recipes in tall narrow panels. They open side-by-side right-ward. They remember the type of calculation last requested. So just opening multiple recipes automatically enables comparison.
The test bars will measure fired porosity and shrinkage over a range of temperatures, drying shrinkage, LOI and pugged water content. They follow procedures defined in Insight-live.com.
How to reference a picture from an external website like flickr.com from within a recipe in Insight-live
A short annotated video of how to create an account at insight-live.com
A short annotated video of how to sign-in to a personal account at insight-live.com
How to import the Digitalfire Insight recipe database file (INSIGHTDATA.DB) and the pictures that attach to recipes therein
Using help, your account, renewal and preferences pages, the managers and panels, recipes, materials, entering a recipe, chemistry, downloading desktop Insight.
How to find them, duplicate them and develop them within your account at insight-live.com
If your recipe is on the clipboard, this shows you how to import it into Insight-live and make adjustments after.
Learn how to add a recipe, title it, add lines and change them, set lines to added status, enter notes and pictures and print a mix ticket
An example of how to enter test results from your ceramic testing into recipes in your account at insight-live.com.
How to take a picture using an iPhone, crop and resample it, save it, then upload it to a recipe.
How to import data from desktop Insight, GlazeMaster, Matrix, GlazChem, HyperGlaze, Generic Spreadsheet CSV into your account at insight-live.com.
How to add and override material data and how to do chemistry calculations in your account at insight-live.com.
How to organize your recipes into a worksheet of recipe rows and material columns, save it as a CSV file and import into Insight-Live.com
A tour around the home page. Where to start.
I will show you some secrets of making a base engobe (or slip) apply to leather hard terracotta ware in a thick, perfectly even layer.
I will show you how to glaze a mug with a liner glaze inside and a colored one outside so that they meet in a perfect line at the rim.
To do a drop-and-hold firing you must manually program your kiln controller. It is the secret to surfaces without pinholes and blisters.
I will show you why people love/hate this material and how I substituted it for Ulexite to make a much easier-to-use glaze that fires just as good or better.
Making 10 gram balls of your glaze and firing them on 2in by 2in tiles is a great way to evaluate their flow, surface and susceptibility to defects.
I will show you why thixotropy is so important. Glazes that you have never been able to suspend or apply evenly will work beautifully.
D. Desktop Insight
Part two of a complete tour. It includes using targets, setting calculation types, entering recipe notes and details, SQLite and a review the menus.
Part one of a complete tour. The anatomy of the recipe window, how to open, edit and save recipes; the materials, oxides and supply oxide dialogs, the MDT.
Learn to how to download a recipe library from your account at Insight-live and open and explore it using desktop Insight
Compare calcium carbonate (whiting) with other sources of CaO (dolomite, wollastonite, frit), learn to understand the chemistry differences between materials and then substitute wollastonite for whiting in a specific recipe.
While comparing a real-world and theoretical feldspar learn to enter, edit, save, normalize recipes and the materials dialog. Glaze chemistry concepts.
Learn to compare a target formula with the chemistry of a feldspar. See why it does not make a good glaze by itself and what materials need to be added to make it into a balanced glaze.
Learn to do difficult formula to batch conversions. Learn mole%, finding frits by chemistry, Na2O sourcing, oxide oversupply, recipe line added status, overriding in the Supply dialog, when to compromise an exact match.
Learn to add a native volcanic ash to the INSIGHT materials database (MDT) and then create a glaze from it maximizing its percentage. Learn to impose an LOI on a material and why this method is better than line blending.
Learn to convert a glossy glaze into a matte by comparing its chemistry with a target matte formula. Alter the chemistry in such a way that the thermal expansion does not rise and it maintains good physical application and suspension properties.
Learn what crazing is, how it is related to glaze chemistry, how INSIGHT calculates thermal expansion and how to substitute high expansion oxides (e.g. Na2O, K2O) with lower expansion ones (e.g. MgO, Li2O, B2O3).
Shows four different ways to add materials to the desktop Insight materials database (MDT)
Do this completely outside of Insight, it knows how to read it at each startup.
There are five ways to do it. Generate your MDT at digitalfire.com, copy and paste XML, type in the formula, enter an analysis as a recipe, handle the MDT as a CSV file in Excel.
Wollastonite is 50:50 CaO:SiO2. So why not just substitute 40 wollastonite for 20 calcium carbonate and 20 silica?
Learn to substitute Nepheline Syenite for Soda Feldspar (and vice versa) using the KNaO checkbox to. You will see the benefit of in-recipe substitution calculation rather than making substitution rules.
Learn the chemistry differences between cone 10 and 6 glazes and how to make a glaze melt at a lower temperature without introducing other problems like crazing.
Learn to reformulate a glaze that is settling in the bucket. Al2O3 and KNaO are sourced by the feldspar, we will source them from kaolin and frits instead.
How to use desktop Insight to substitute wollastonite for calcium carbonate (and vice versa) while maintaining the same SiO2 level. Create substitution rules.
Use Desktop Insight to explore ways of calculating substitutes for Gerstley Borate in the popular Floating Blue cone 6 glaze recipe while maintaining or improving the other raw and fired properties of the glaze.
How to fine-tune the thixotropy of a ceramic engobe for pottery
Tony Hansen takes you through all the steps from opening the box and wedging the clay to taking the fired mug from the kiln.
*Youtube Video, +MP4 Video, #ScreenCast, ^URL
Lesson 5A - Glaze Formula to Batch Calculations
Learn to use a non-unity calculation to convert a formula into a batch recipe using theoretical and real-world materials. Retotal, round-off and make a side-by-side report.
D. Desktop Insight
Click here to watch this at youtube.com or click here to go to our Youtube channel
Shows you how to use a non-unity calculation and the supply button to convert a formula into a batch recipe. You will find out how to match a target formula exactly using theoretical materials and how to create a best match using real-world materials and the KNaO checkbox.You will also use the retotal and round-off function and the side-by-side report. The next chapter of the book deals with a more difficult conversion that requires an online search for a frit of specific chemistry to solve the problem.
Lesson 5A: Formula to Batch
Mon-unity calculations, the language of formulas, normalization, the formula to analysis dialog, supplying and re-supplying oxides, material ordering and material oxide sourcing, KNaO vs. K2O/Na2O, side-by-side reporting
Formula to Batch Derivation
Welcome. In this lesson we are going to learn how to do a formula to batch calculation.
We will cover non-unity calculations, the language of formulas, normalization, the formula to analysis dialog, supplying and re-supplying oxides, material ordering and material oxide sourcing, KNaO vs. K2O/Na2O, side-by-side reporting.
Many textbooks present glazes as formulas, instead of recipes. Their authors speak the language of formulas when discussing glazes and relate fired properties to the presence, absence, amount and interplays of the oxides. They assume that you will select appropriate materials to source each oxide and that you know how to calculate the right amount of material. For example, what material do you want to supply CaO from and how much is needed?
Formulas don't belong in recipe list
This process can be tricky. I will first work through an example where everything works according to plan. Then I will consider a tougher one.
You cannot just type a formula into INSIGHT as a recipe. Why? Recipes express parts by weight, formulas compare numbers of molecules. INSIGHTs Recipe List can only contain parts-by-weight.
There is a special dialog to convert a formula into an analysis (which technically is a recipe of oxides).
The Formula-to-analysis dialog
I have selected recipe 1 and chosen Enter Formula in the Calc menu and have keyed the formula into the Convert Formula to Analysis dialog.
Now I am going to click Done.
Use No-unity for formula to batch
INSIGHT converts the formula into an analysis and puts it into the Recipe List and then calculates the formula and puts it here.
To set things up I want to make sure Calculation Type is RO Unity for recipe 1 and No Unity for recipe 2 where I will be building the batch.
Why No Unity for recipe 2? If INSIGHT imposes unity each time the recipe changes all the formula numbers will be bouncing around. Furthermore, the Supply button needed for this process will not be available unless the recipe is set to no unity calculation.
Determine order to add materials
I need to determine which oxides to satisfy first.
It is easy to oversupply some oxides if I introduce materials in the wrong order. I will use the most complex material (the one supplying the most oxides) first: I will use feldspar to source Na2O/K2O.
Then wollastonite & whiting to supply CaO, dolomite for MgO, kaolin for Al2O3, silica to round out the SiO2 and zinc oxide for ZnO.
Supply Na2O first
First, I want to supply sodium and potassium.
I am going to use generic soda feldspar to satisfy the Na2O, and generic potash feldspar for the K2O. Remember that generic materials do not exist in nature, but for this demonstration they are a good starting point. I will use a real world material later.
I will point out also that I am still using the lessons materials table.
I need to unselect this checkbox, I want to see K2O and Na2O listed separately.
I have selected recipe 2, I am building it there.
I have also selected the first blank line in the Recipe List.
Enter source material, click Supply
I have entered soda feldspar (I just typed soda f) in the Lookup blank and clicked Update.
Now I have soda feldspar on a line with no amount. I need to click the line also since it moves down automatically each time I add a material to the list.
Instead of keying in an amount, I am going to click the Supply button.
Supply Oxide dialog
INSIGHT displays the Supply Oxides dialog. Notice that only oxides supplied by this material are available and INSIGHT shows the relative amounts of each that the material contains.
I have clicked the Na2O option button.
INSIGHT fills in the Molecules Needed blank with the amount of Na2O in the formula of target recipe 1. The Molecules Present blank shows how much has already been supplied by other materials in the recipe under construction; currently none.
I will Click Done.
Supply K2O from potash
INSIGHT calculates the right amount of soda feldspar to supply 0.1 Na2O. Notice that the feldspar also sources Al2O3 and SiO2.
Now I will supply K2O.
Click on the next empty recipe line, key POTASH and click Supply (notice that I do not have to click the update button before the Supply button).
INSIGHT calculates the correct amount
In the Supply dialog Ill click the option button for K2O.
Then I will click Done and INSIGHT calculates the amount of potash feldspar needed to supply 0.15 molecules of K2O.
Supply MgO from Dolomite
Now I need to supply MgO from dolomite.
I will click the next blank recipe line, key DOL into the Lookup blank and click the Supply button.
In the Supply dialog I have selected the MgO option button and now I will click Done.
Three oxides are matched
Here is the result, INSIGHT has calculated the right amount of dolomite to supply 0.05 MgO.
I have three oxides matched now and part of the requirements for the others have been supplied (and thankfully not overshot).
Supply CaO from whiting
Next I will use the same process to supply CaO using Whiting. But notice the supply oxide dialog. As before INSIGHT knows how much CaO I want by looking at the target in Recipe 1. But it also knows now much has already been supplied by other materials.
I'll click done to establish the whiting amount and then supply the ZnO from zinc using the same process.
Supply Al2O3 from Kaolin
Now the formula and recipe look like this.
I have supplied all the fluxing oxides in the exact amounts needed, now we need alumina.
Kaolin is highly desirable in many types of glaze recipes because it aids suspension, dry hardening and other working and application properties. 0.4 molecules of Al2O3 are required, only 0.25 have been contributed from other materials.
I am going to click on the next available recipe line, enter KAOLIN in the Lookup blank and click supply.
Supply SiO2 from silica
In the Supply dialog I will click Al2O3 as the oxide to supply, then click Done.
I have done the same thing with SiO2 using silica as the supplier material.
The formulas now match.
Notice recipe 2 totals 379.59. This is the exact weight at which a nounity and unity formula are identical for this recipe. We call this a normalized recipe. I could now use the retotal item in the Calc menu to retotal it to 100 but I am not finished.
Using a name-brand feldspar instead
The feldspar I used was generic. I looked it up in the materials dialog, here it is. Notice the numbers are nicely rounded. Unfortunately real-world feldspars are not so simple.
Here is an example of a real feldspar. Almost all feldspars supply both K2O and Na2O and almost never in the proportions you need, so you have to be satisfied with matching the total of the two. You get other fluxes also, in this case, CaO.
I will therefore check the KNaO checkbox. This tells INSIGHT to combine the Na2O and K2O totals in the Formula List.
I will use Custer feldspar in place of potash and soda feldspars.
Replace the feldspars
First I will manually sum the total of the two feldspars. It is 136.
I will make sure recipe 2 is selected and delete the potash and soda feldspar lines by selecting each line and clicking the Delete button once to zero the amount and again to remove the line.
I will click the next blank line in the recipe and enter custer feldspar with an amount of 136.
Fine tune the new feldspar amount
If we compare these two formulas now you will see that while they are pretty similar there is a significant difference in the amount of KNaO contributed.
Now I have selected the feldspar line and I am going to fine tune the amount of Custer using the Increment and Decrement arrow buttons until the KNaO matches.
I am also going to check the three decimal button since this is a high total recipe where material amount changes do not impact formula numbers as much.
Accomodating the new feldspar
I stopped at 160 feldspar to get a perfect match on the KNaO. Or is it perfect? Notice what happens if I uncheck the KNaO checkbox for a moment. The individual amounts of K2O and Na2O do not match, but their totals do. This is the reality of using feldspars, fortunately K2O and Na2O have pretty similar effects on glazes.
Notice that the Al2O3, SiO2 and CaO are now all oversupplied because of the feldspar increase. I will resupply them now.
I'll click on the Al2O3 line in the formula list. Selecting this line does not really do anything, I just clicked it as a reference to what I am doing. If you teach INSIGHT you will want to do the same.
I'll click the kaolin in the recipe and then the Supply button. As you can see it is also a resupply button.
I have clicked the Al2O3 and notice that INSIGHT shows the Molecules already present as if there was zero kaolin.
I'll click Done.
Resupply SiO2 and CaO
Now I have the Al2O3 matched up again. Then I will do the same thing with the SiO2 from Silica and CaO from Whiting.
Retotal and round amounts
Now the formulas match again. This exercise helps us appreciate how different feldspars can be in their chemistry.
The recipe totals 379 so I will retotal it to 100 by choosing 'Retotal Recipe' in the Calc menu and then I will round it off by choosing 'Round Amounts' in the Calc menu. I am also going to uncheck the three decimal box, I don't need this accuracy anymore.
Restore RO unity
Now I have a 100 recipe total, at least almost 100. During the process of rounding to a tenth an over or undershoot of 0.1 can happen.
But there is another problem. What happened to the new formula, it does not match anymore? The problem is here, I need to set recipe 2 back to RO Unity (remember that when a recipe total changes so does its whole non unity formula). Here is the formula list again. It looks good.
Print side-by-side report
Wouldnt it be nice to print a side-by-side report of these two recipes and their chemistry? I have done it here using this item in the Report Type menu. It compares the recipes as well as the formulas, analyses and mole percents. INSIGHT has templates for its reports (in the TEMPLATES folder) so you can change the layout and content.
Now, can you follow my example with the feldspar and substitute a much more chemically complex ball clay for the kaolin. The ball clay will give a completely different character to the working properties of the glaze slurry.
You might think this process should be more automatic. But there is no way a machine can chose the best materials in every situation. INSIGHT would create batches with the correct chemistry but they might be expensive, from difficult-to-get or inconsistent materials, have poor application, drying or suspending properties, exhibit problems with high LOI and gassing, etc. These considerations are complex and beyond software, at least now.
That is the end of this lesson.
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