Lesson 1A - Comparing a Theoretical and a Real-World Feldspar

While comparing a real-world and theoretical feldspar learn to enter, edit, save, normalize recipes and the materials dialog. Glaze chemistry concepts.

D. Desktop Insight

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Video 1C - Comparing a Theoretical and a Real-World Feldspar
Entering recipes, materials and the materials database, theoretical materials, formulas, oxides,analyses, unity and non-unity, normalization

The Basics
In this lesson we are going to learn about starting, entering and saving recipes and calculating and comparing their formulas,
some theory about oxides, formulas and analyses, Unity vs. non-unity, Theoretical vs. actual materials, Normalization and the materials database.
If you are new to INSIGHT you should watch the overview lesson before this one.

Select correct materials database
I have launched INSIGHT and the main window has appeared.
I have selected LESSONS from the Materials Table popup menu on the lower left. INSIGHT will reopen this one each time I launch in future. This static materials database is mostly theoretical and not up-to-date however we use it to demonstrate INSIGHT so your calculated numbers will match mine
INSIGHT supports side-by-side recipes here and indicates which is selected by highlighting the column header.

Selecting a recipe, create new recipe
Let’s review a little:
To select a recipe area:
• Use the Recipe 1 and Recipe 2 items in the Utility menu or their keyboard shortcuts
• Click the desired column title button in the Recipe or Formula List.
There are several ways to start a new recipe. The first is do nothing. As you can see in the Recipe detail panel, we already have two new recipes.
INSIGHT deems a recipe as new if it has not yet created a connection to a file or database record. The first time I save it will create a connection.

Closing recipes, database and recipe mode
If I already have a recipe open and want to create a new one then I can:
• Click either of the recipe Close buttons.
• Select New Recipe in the File menu, it simply closes any open recipes.
While I have this menu open I want to point this out. INSIGHT can be configured in Preferences to maintain recipes in files or in an SQL database. The main open item maintains recipes in the current mode, this opens them in the other mode. Thus we must be in database mode.
To confirm that I will choose Open. Yes, this is the Recipe Database window.

Quick recipe entry at startup
When you first start INSIGHT the cursor should automatically be here, so to enter a recipe line just start typing.
I have typed potash, pressed the tab key, type 23 and I am about to press the Enter key.
Here it is. Notice that INSIGHT searched its materials database and found the material for me even though I just typed part of the name.
Not only that, notice the line cursor has advanced to the next line and it has greyed because focus has moved back here waiting for me to type the next line.

Selecting recipe lines
There is something else interesting. Even though focus is here, if I press the up and down arrow keys the recipe line cursor will go up and down! This also works for these two blanks.
Of course you can click on a recipe line to select it also but when you do you will notice that focus will only stay on the recipe list for an instant and then revert back over here.
Now, lets name this recipe. It will click the Recipe Details tab.

Naming and saving a recipe
I have typed in the name here.
Now, lets save the recipe. I could choose Save in the File menu we have already seen, but this little button does the same.
It is split into two, one for each recipe. INSIGHT displays either half if that recipe has been changed and needs saving.
When I click it look what happens. It disappears and INSIGHT has assigned a new database record for the recipe.

We now have a one-material recipe
We now have a one-material recipe with a name and INSIGHT has calculated its chemistry. By implication this is of course the chemistry of that one material. As you might notice, this is a theoretical material, no feldspar in nature has this perfect formula.

Why two recipe material names
Now, I have clicked the first recipe line, notice this.
Why is the name here twice. The Line Label is shown on recipe reports. The Materials List Lookup is used to search for chemistry info in the materials database.
Users of foreign language versions of INSIGHT often need to label lines in their own language while using English materials table. Or, you may need to label a recipe line generically but make INSIGHT use the chemistry for a name brand material or vice versa.

When you save a line INSIGHT uses the Line Label for lookup if you do not enter anything for it. If it finds a material it completes the Lookup blank and fills in the label if it was not specified.

Be careful when editing lines
The one thing to watch here is if you are changing the material for a line: Make sure to change both the label and lookup or INSIGHT might be looking up the wrong chemistry for a line.
The best policy when changing a material line is to erase the Line Label and let INSIGHT fill it in with the new name it finds in the database.

Configuring chemistry calculation
I want to make sure INSIGHT is calculating the chemistry the way I want. I want a unity formula, where the oxides total one, so notice that I have the RO Unity Calculation Type selected for Recipe 1.
I want to see the potassium and sodium amounts explicitly rather than combined, so I have unchecked this box.

What is an oxide? An oxide category?
Before continuing, lets talk about oxides.
-An oxide is a molecule like K2O or Al2O3, it is a combination of oxygen and another element that naturally combines with it.
-Each has a symbol, a short and full name. There are only about 10 oxides that you need to learn about.
-Each has specific contributions to the fired properties of glazes.
For calculation purposes, all ceramic materials and fired glazes are made of oxides. Oxides are divided into fluxes or melters, intermediates and glass formers.
Like any common glaze this formula happens to have members in each category.

What is a formula? An analysis?
I have set INSIGHT up to display the equivalent analysis in the right most column of the formula list.
This is a formula. It catalogs each oxide and its relative number of molecules. For every 1 K2O there is 1 Al2O3 and 6 SiO2 molecules.
This is an analysis. It compares their percentages by weight.
Analyses are used when describing materials because we want to see what is in them.
Formulas are used when describing fired glazes because we want to extrapolate fired properties from the presence, amounts and interplays of oxides.

What is RO? R2O3? RO2?
Silica can make a good glaze all by itself, however you need a cone 25 capable kiln and super low expansion clay body to work with it!
To make it melt at much lower temperatures we combine it with fluxing oxides. These have higher thermal expansions, differing fluxing powers and respond differently to coloring oxides.
To give the melted glaze some body so it does not run off the ware and to give the fired glaze more strength, hardness and leach resistance we need this, alumina. Put in too much of this and the glaze fires matte.
What is this? It is boron, it is magic, it is both a flux and a glass, it comes in frits. Most of the traditional ceramics industry is built on this wonderful oxide. Only high temperature glazes do not need it.
We do not normally include these in calculations, but we do compensate for them. Everyone knows how much cobalt, for example, to put in a glaze to get the shade of blue they want.
These do not participate in the melt, their source materials suspend in the glass and make a glaze opaque. It does not require calculation to figure out how much of these are needed.

What is unity?
A “unity formula” is simply a raw formula whose amounts have been scaled so that one group totals one. Glazes are set to RO unity, materials lacking fluxes to R2O3 unity. This is an arbitrary standard in the ceramic industry.
INSIGHT displays an asterisk beside oxides that are part of unity.
Notice these formulas the same even though one is flux unity and the other alumina unity? Because theoretical potash spar has equal numbers of RO and R2O3 molecules.

Recipe total does not affect unity formula
Now I am going to change the amount of Feldspar to see what happens with the formula.
I will click this up arrow. Each time I click it the amount of feldspar increases by 4.
But nothing changes in the formula List. This is a characteristic of unity formulas because they compare relative numbers of oxide molecules. As long as material amounts in a recipe do not change in relation to each other, the calculated unity formula remains static.

Recipe total does affect non-unity formula
Non-unity formulas are different, they do change when you change the recipe total.
I made sure the first line of the recipe was selected and switched to recipe 2 and then entered “250” in the Amount field and clicked Update.
Then I set recipe 2 to No Unity.
Notice the asterisks disappeared and the formula numbers are different but their proportions to each other have not changed.
Notice the RO unity formula weight. I am going to change the recipe 2 amount from 250 to that.

Non-unity formula 2 is now the same as unity formula 1. Why? Because “556.8” is the formula weight of flux unity potash feldspar.
Notice the formula weight calculates to 556.58 for formula 2, why? Because INSIGHT does three decimal math, this is a recognition of the fact the ceramic chemistry is an inexact science. Most technicians would agree that even two decimals of precision in a formula is not realistic.
The process of re totaling a formula so that no recalculation is necessary to unify it is called 'normalization'. This concept is important in doing formula to recipe derivations.
I will open the Materials dialog to show you. To do this I will double-click the first recipe line (I could also select Edit Materials in the Utility menu).

Materials dialog
The Materials dialog acts as a window into the active materials database. This is the information INSIGHT knows about potash feldspar.
You can see the full list of materials here.
The name, alternate names, type, cost, formula weight and LOI here.
These controls are used to find, add, remove and edit materials.
This is the chemistry.
Use this to open your web browser on our materials site to get more information about this material.

Other materials dialog details
Although this formula has the same unity as the one in the recipe window INSIGHT does not force any kind of unity on material formulas in its MDT and choice of unity does not impact calculations.
You can use this dialog as a material pick-list when creating recipe lines by locating the desired material and clicking this button to insert it into the recipe.
Also notice this. The formula weight of this is not exactly 556.8, it is 557.02. Again, INSIGHT does three decimal calculation, that is enough to assure two decimals of accuracy in formulas and analyses.
Before continuing I want to point out that this dialog has menus, there are items here to import material data and the results of the current calculation.
I will click the Done button.

Preparing to compare another feldspar
Now I am going to zero line 1 in recipe 2 and add a different feldspar in line 2 to compare.
I have selected recipe 2 and line 1 and then clicked the delete line button (notice that it just removes the amount for recipe 2, it does not remove the whole line because recipe 1 uses this material).
I could also simply remove the number here and click Update.
I have set the calculation type for Recipe 2 to RO Unity.
Before continuing, note the formula for potash feldspar again. It is ‘generic’ in that it has a simple formula with whole numbers that match a perfect theoretical molecular structure.

Enter a name-brand feldspar in recipe 2
I haved done two things here. I have changed the amount of Potash Feldspar in recipe 1 to 49.
I have selected line 2 and Recipe 2 in the Recipe List and entered 49 of custer feldspar. When I did it I just entered the word custer because I know there is no other material in the list having that word.
INSIGHT has updated the line in the Recipe List, moved the line cursor down and reset focus to Material Lookup in anticipation of me entering another material.

How two recipes cohabit the recipe list
As noted already, there are two columns of numbers in the Recipe List, but just one column of material names. Normally, you will be comparing two recipes that are very similar (e.g. one will be an adjustment of the other). Normally a material that appears in both recipes will show amounts in both columns of the same line. You can enter the same material more than once in the list, however when you save and then reopen a recipe INSIGHT will combine like lines.
The calculated formulas here might be a bit of a shocker for you. The one on the right is a real-world material, not a theoretical one. Lets look closer.

Comparing the feldspars
Notice the SiO2. This highlights how different theoretical materials that textbooks talk about can be from actual ones. They are also different from each other of course.
If these were two name-brand feldspars and I was substituting the one on the right for the one the left, I would be able to use INSIGHT to determine how much to reduce the silica powder in the recipe to compensate for the extra SiO2 that this material brings.
Notice this number. This is the calculated thermal expansion, notice how much lower it is in the this one compared to the other.

Moving recipe lines, inserting blank lines
Now is a good time to consider for a moment how to change the order of lines in a recipe:
• Click on a line and drag it to the new position.
• You can also move blank lines up into the recipe.
When lines are moved, the order of both recipes is affected. We recommend ordering recipes with the flux sourcing materials first, then clays, silica, and then additives for opacity, suspension, color, texture, etc.

Out Bound Links

  • (Glossary) Analysis

    Conceptually we consider fired glazes as being composed of 'oxides'. Materials supply those oxides to the melt. The ten major oxides likely make up 99% of all base glazes (and materials we use). The oxide formula of a glaze "explains" many details about the way the glaze fires. Thus we can view m...

  • (Materials) Feldspar
  • (Glossary) Formula

    Conceptually we consider fired ceramic glazes as being composed of 'oxides' (materials contribute these). The ten major oxides likely make up 99% of all base glazes (and materials we use). The oxide formula of a glaze "explains" many details about the way the glaze fires (provided all the materials ...

  • (Glossary) Oxide

    An oxide is a combination of oxygen and another element. There are only about ten common oxides that we need to learn about (most glazes have half that number). CaO (a flux), SiO2 (a glass former) and Al2O3 (an intermediate) are examples of oxides. CaO (calcium oxide or calcia), for example, is cont...

  • (Glossary) Non Oxide Ceramics

    Fired ceramic that contains no oxygen in the crystal structure. Examples are boron nitride (BN) and silicon barbide (SiC). Hundreds of different types of these materials exist (dozens of boron derivatives alone). These products exhibit a range of amazing properties including hardness, resistance to ...

  • (Glossary) Oxide System

    In ceramic glaze calculation, a 'system' refers to a collection of glaze recipes that share a common set of oxides and material types (e.g. cone 10 dolomite mattes, cone 06 fritted boron glossies, cone 6 alumina matte, cone 8-10 crystalline) and preparation, application and firing methods. Also, a '...

  • (Glossary) Theoretical Material

    A material the way it would be if its crystal structure perfectly matches the unit-cell drawings you find in textbooks. In nature, materials are always contaminated to some degree. Calcium carbonate is never pure, feldspar never has an ideal 1:1:6 relationship between fluxes:alumina:silica, kaolin p...

In Bound Links

  • (Videos - Related) Substituting Nepheline Syenite for Soda Feldspar

    Issues surrounding substitution with complex materials that supply many oxides, KNaO vs. K2O/Na2O evaluation, substitution rules vs. in-recipe substitution calculation, non-chemistry reasons for glaze...

  • (Glossary) Digitalfire Insight

    A desktop application for Windows, Linux, Macintosh that you download and install. Insight is a classic glaze chemistry calculator. -It interactively converts recipes to formulas and back. The main Insight window shows side-by-side recipes and their formulas, you can make chemistry changes to one...

  • (Glossary) Normalization

    The process of recalculating a recipe total to effect a unity formula. This is needed for formula to batch calculations because the desktop Insight Supply dialog requires a non-unity calculation type.

By Tony Hansen

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