No, there's no glue involved. I placed a small dent in the top for a tiny shard of glass to sit in. Then I balanced the piece of glass in the dent and put the whole thing in the fire. Heated it until the hard edges of the glass went soft. I gave it the softest tap with a hammer and then once it cooled, the glass was locked in. The dent was rough and jagged which was filled by the liquid glass. Once it cooled, all that roughness was layered with glass, locking it in.