|Monthly Tech-Tip |
Dolomite is a key material for glazes, especially mattes. When you are forced to adopt a new brand it needs to be tested. Here, three tests were done to compare the old long-time-use material (IMASCO Sirdar) with a new one (LHoist Dolowhite). The first flow test is a very high dolomite cone 6 recipe formulated for this purpose; the new material runs a little more. The second is G2934 cone 6 MgO matte with 5% black stain; the new material runs a little less here. The third test is the high dolomite glaze on a dark burning clay to see the translucency and compare the surface character. They are very close. It looks like it is going to be OK. Does your supplier test new materials when they are forced to switch suppliers?
Material substitutions in ceramic glaze and body recipes must consider their chemistry, mineralogy and physical properties
An inexpensive source of MgO and CaO for ceramic glazes, also a highly refractory material when fired in the absence of reactant fluxes.
Glaze Melt Flow - Runway Test
A method of comparing the melt fluidity of two ceramic materials or glazes by racing them down an inclined runway.