Sometimes it is hard to visualize how something will work. And so it was for me getting rid of rather large, not intended bubbles in a fused glass piece. I read other’s hints (and even my husband suggested) to drill the bubble to open it up, fill the hole with frit and refire, but the skeptic in me thought that the addition of the frit would leave the glass looking cloudy in that spot and bumpy.
A quick definition of frit is small pieces of glass in different sizes: powder, fine, medium and course. Course is still somewhat small, but large enough that it would not fit through the mesh of a standard colander. If you were to fuse in a mold each different frit size, the powder and even fine size frit would look somewhat milky or opaque because each piece of frit is surrounded by air which can trap bubbles. The larger the frit sizes, the clearer the glass made from frit will appear.
But I had two bubbles in a recent coaster that I thought would make a good test case and so I drilled the bubbles to open up the glass in each area and then filled those holes with medium size frit. I put enough in to fill the hole, but did not mound it.
Then I refired the piece to a full fuse temperature and it actually worked.
As you can see in the picture, there was some copper near the hole and I think since the copper was exposed to air, it changed colors slightly, but this adds character and trueness to the leaf since rarely is a leaf all one color.