If you are working on a small project the bubble could be caused by you finger prints. The project wasn't cleaned properly prier to the start of your project.  You can drill it out but the chances are it will reoccur. You can refill the hole dry with a hair dryer and refire. If the bubble is just on top and doesn't penetrate to the metal, this will work, If it goes to the metal it might reoccur.  After the hole is drilled and your ready to refill, wash the hole real good and dry with a hair dryer. Then refill. Be sure the hole is filled completely, no gaps any where. good luck Charles

You can drill out he hole with what ever you want. You can use a steel putty knife and a razor blade to smooth the outer edger. I would use a knife to out the inner edges. You don't want to make the hole any larger than you have to. A chip is easer to fix, a hole is caused by impurities to improper cleaning, or finger prints. They are extremely hard to fix. As I said before always ware cotton gloves to protect from touching with bear hands. Charles 

I have a bubble on my enamel.  How do I get rid of it?  With a drill bit that I use on glass or with an instrument like a scribe?

Thank you,

Mary Rose