We received a recent report of crazing with Mayco Clear One Brushing when bisque fired to 01 and glaze fired to 05 with batch 26APR023. We will be pulling that sample and an array of other batches to test for replication and will also repeat our previous tests with Spectrum 700 (which we found to be the best fit) Mayco Crystal Clear brushing, and other assorted glazes from within the following brands: AMACO, Spectrum, Mayco, Western. Please note this body has not been tested with regionally available glaze lines. Feel free to add comments here about what you have found that has worked well or has crazed so that we can work on a more comprehsive list of expectations with various glazes. Include bisque & glaze temperature along with picture of witness cones used.
*********************Update August 8, 2023*********************
We ran tests on a Spectrum & Mayco glazes (AMACO Teacher’s Palette Glazes previously tested and did not craze in our testing)
3 Mayco Fundamentals were tested – none showed any crazing
2 Mayco Elements were tested – neither showed crazing
2 Spectrum 700 series were tested – neither showed crazing, spectrum 700 clear also has the best an most consistent performance of clear glazes
2 Spectrum 900 series were tested (one matte and one gloss) – neither showed crazing
We also tested AMACO, Spectrum & Mayco clear glazes and had mixed results with those. We are repeating those tests.