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Suddenly, ware is coming out of your production kiln warped or cracked or off color. Unless the answer is obvious, the first action should be to compare its drying and firing test data with past runs. If you are doing that as a routine, then SHAB test bars (and the test result data they bring) will already be available. These bars are tests of slip casting bodies, they can be made in a plaster mold and length-marked as shown. That data is a characterization of the clay body. The value of this kind of data-gathering becomes evident when a disaster happens (or better yet, is prevented). Clay bodies have plasticity, dry performance, dry strength, fired density, fired shrinkage, fired strength, etc. If you have historical data (accompanied by firing schedules, recipes, etc), you have an invaluable tool. Where does one gather the data? In spreadsheets? No, in a database. An account at Insight-live.com is specifically intended for this.
Available on the Downloads page
This picture has its own page with more detail, click here to see it.
Use this to make length marks in standard SHAB test bars (for testing clay body or clay material drying shrinkage, firing shrinkage and fired porosity). This can be 3D printed. The markers are 10cm apart (outside edges). Most printers can achieve this measurement accurately. To be sure check yours using a caliper, if it is not close to 10cm adjust using sand paper or reprint using an adjusted dimension.
Available on the Downloads page
This picture has its own page with more detail, click here to see it.
This is for making test bars of slip casting clays bodies for use in the SHAB test (to measure drying shrinkage, firing shrinkage and fired porosity). I designed it in Fusion 360 and 3D printed the light-duty rails and case mold. I poured plaster into that to make the two plaster working mold halves (top right). The funnels provide a reservoir so the bars be cast solid. This mold can produce a set of three bars in less than an hour.
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Entering TestData Into Insight-Live
How to enter physical testing results into your group account at insight-live.com. We will enter data from shrinkage/absorption bars, the drying factor disk and an LOI/water content tester. |
Articles |
Setting up a Clay Testing Program in Your Company
Set up a routine testing pipeline and start generating historical data that will enable your staff to understand your source materials and maintain, adjust and troubleshoot your clay body recipes. |
Glossary |
Physical Testing
In ceramics, glazes, engobes and bodies have chemistries and physics. To fix, formulate and adjust their relative importances in each situation need to be understood. |
Glossary |
Characterization
In ceramics, this normally refers to the process of doing physical or chemical testing on a raw material to accurately describe it in terms of similar ones. |
Tests |
Shrinkage/Absorption Test
SHAB Shrinkage and absorption test procedure for plastic clay bodies and materials |
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