Devitrification Solution

20 Mule Team BoraxDevitrification can ruin a project.

While the best way to avoid “devit” is to avoid the conditions that cause it, this recipe is a good one for reducing devit.

Pay special attention to the mixing directions – not following them can lead to ugly spots on your fired glass.


  • 1 quart (4 cups) distilled water
  • 1/4 cup 20 “Mule Team Borax” (available at most grocery stores in the laundry detergent section)
  • 2 Tablespoons Bullseye Glastac or other clean burning glass glue


  • 2 clean, water-tight, 1 quart (or larger) containers


  • Mix all ingredients very well in one of the clean containers.  For best results, close container and shake vigorously.
  • Allow mixture to sit, undisturbed, overnight.
  • You should see some of the borax settled in the bottom of the container.  Carefully (so as not to disturb the particles on the bottom) pour the liquid (decant) into the second container.  Do not allow any of the settled borax into the second container. This leaves a small amount of liquid with the borax sediment in the first container. That’s okay.
  • Discard the contents of the first container.
  • The solution in the second container is ready for use (see below).


  • Over time additional borax will settle on to the bottom.  When this happens, repeat the decanting process above.  NEVER RE-MIX THE SOLUTION! Doing so will result in undissolved borax particles on your glass – which will almost certainly cause spots.


  • Simply brush or spray the solution evenly onto your glass.mouth atomizerThe best way to do this is with an airbrush.  A mouth atomizer (see photo) is an inexpensive alternative and available at most art stores.  Perfume atomizers can also be used.

    The best way to do this is with a haiki brush (the wide, soft brush most people use to kiln-wash their shelves).  If you use a haiki brush do not use the same one you use for kiln-wash – dedicate one for the devitrification solution.

  • Let the spray dry before firing. A hair dryer can be used to speed this up.


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