glazenerd Posted September 10, 2016 Report Share Posted September 10, 2016 A simple test of vitrification for home hobbyist, or serious hobbyists, and production potters. An easy preliminary test to check the vitrification of your clay body. (porcelain shown and #2 stoneware) The Test: Simply drop some red food dye on a un-glazed sample of the clay you are using: fired to maturity before testing. Allow to soak for two minutes: rinse clean with clear water while wiping with a sponge or rag. (wiping, not scrubbing). (clear water, no soaps). This initial test will tell you instantly if you are producing a mature body when fired. If it fails at all, then go to the traditional absorption test to verify results. Bar 1: mature body, no staining. Make sure the bar is smooth with no pits. (bar tested) Bar 2 less than 4% absorption. Small blotch not visible on camera, barely visible with the eye. Bar 3> Cone 10 clay fired to cone 6. Absorption around 10% (not tested) Bar 4. 14% absorption. (bar tested with standard absorption test). **All bars fired to 2230F (10 min. hold) Use this simple test every time you get a new clay shipment, or change clay bodies. If they fail, then you need to do the full absorption test to measure exactly what the % is. Nerd Edit: added some wording to clarify the test is done after the test bar is fired to maturity. Link to comment Share on other sites More sharing options...
Denice Posted September 11, 2016 Report Share Posted September 11, 2016 Easy peasy. Did any of your kilns survive the lightning. Denice Link to comment Share on other sites More sharing options...
Mark C. Posted September 11, 2016 Report Share Posted September 11, 2016 food color burns away completely at cone 10 so this is a midrange or low fire deal did the lighting ruin your kilns? Link to comment Share on other sites More sharing options...
glazenerd Posted September 11, 2016 Author Report Share Posted September 11, 2016 Mark: This test is performed after an unglazed test piece is fired to maturity. A mature body will absorb no, to very little dye. A body with 4-5% or more absorption will. I better reread my post, it somehow is giving the impression it is done before firing. Nerd Denice: looks like I lost an Orton 4.0 controller. Other than that, everything seems to be okay. I know one bolt hit just 50' from the studio, because I saw it. Link to comment Share on other sites More sharing options...
Mark C. Posted September 12, 2016 Report Share Posted September 12, 2016 Nerd-it was most likely me as my day was hectic and I most likely missed the details. You mean ceramics require details? I never figured that. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.