Why would a glaze turn into a jelly like this?

Wednesday 24th June 2015

This is one of the things Gerstley insight-live.com/glossary/129">Borate does to glazes (when its percentage is high enough). This slurry has a high water content and should be far more watery. It is also highly thixotropic - this can be stirred vigorously to thin it and yet within seconds it turns back to jelly again. This was deflocculated with Darvan yesterday and it was stable enough to dip bisque ware - but overnight salts have gone into solution and it is no longer dispersed. It also dries very slowly on bisque ware. What can be done with a mess like this? Replace the Gerstley Borate with something else. Gerstley Borate sources B2O3, it can be supplied using frits or Ulexite (glaze chemistry calculations are needed to juggle the recipe), this can be done in an account at insight-live.com.

Pages that reference this post in the Digitalfire Reference Library:

Gerstley Borate, Gerstley Borate 50:30:20 glaze. How could this have worked?, Glaze Gelling, Getting Frustrated With a 55% Gerstley Borate Glaze

This post is one of thousands found in the Digitalfire Reference Database. Most are part of a timeline maintained by Tony Hansen. You can search that timeline on the home page of digitalfire.com.