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 atomizer 

    The 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.


excellent recipe!! my

excellent recipe!! my question is... which is the lower temperature do I have ti fire my glass with this formula? I´m asking because i slump glas at very low temperatures (580* C- 1076* Farenheit). May I use with this temperature?



devit solution question

I made my mixture according to your directions - easy.  I brushed the solution (used one of the sponge brushes) on a green wine bottle I am slumping.  It ended up sitting on my table a couple of days before I could get back to it.  After slumping the glass looked really spotty.  It wasn't a smooth surface at all.  I was able to hide it by doing a design with etching cream.  Did I mess up by waiting a couple of days before I put it in the kiln?  I fired it up to 1460-too high or low?  Also, will this solution work after I have fused the glass and the devit shows up then?

Thanks for any information you can give me,  K

The mixture only works at

The mixture only works at full fuse temps - not slumping.

Helios Kiln Glass Studio


devit spray

I will be using a brush to apply the devit spray but if I understand it right, I don't shake the contents of the jar before each this correct ?

Thank you


recipe question

Thanks for this recipe!!  I've been struggling with devit on some pieces that I full fuse. I'm fairly new to fusing and still learning a lot as I go....I usually fuse my pieces at a soft fuse so there's still some texture (1350-1365 F). Will this recipe work at that temp?  Should I etch or sand blast the pieces first?  Or, is etching or sandblasting enough to remove the devit before fire polishing?  I know the best defense is a good offense and I need to do as much as I can to prevent the problem in the first place, so I'll be taking steps on that end too.

Thank you!!!


Using with Bottle Glass Frit

I work primarily with frit and "donuts" I create from bottle glass. Vitrification is a huge problem. Can I spray this on frit? Will the moisture affect the kiln wash I use on my molds to make finished pieces easy to release? I don't want to try this and ruin a mold by having glass stick to it.

Photo shows "donut" with vitrification. Glass was clean; problem seems to correspond with cut edge.

Vitrification on a bottle neck "donut"


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