I didn't know an anhydrous form was available. Thanks for pointing that out. And a bit of searching showed that making it myself means heating Borax to near the melting point of steel. Wow! Or would heating it in an oven actually drive out all the water?
In a pinch you can prepare small quantities of anhydrous borax with the help of a Meker burner. The borax must be fused to drive off all the water. A Meker burner produces a flame of 1500oC which is hotter than a Bunsen burner can produce. But fortunately this form of borax is cheap.
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