It was discovered that the glass seed beads, readily available for arts and crafts, can be easily melted with a butane torch.
Initial tests, on small pieces of a copper sheetmetal grounding strip, were successful. The glass however keeps being colored red by the underlying copper oxide. The underlying metal can be heated under reducing conditions, and then the glass let to flow over the bare metal, but achieving this is not easy and the results are not consistent.
The second set of attempts was based on thicker copper sheetmetal, the kind for roofing flashing. It however turned out that the metal is too thick for the torch used, the heating was not sufficiently intense, and, the worst problem, the copper oxide layer grows too thick and then spalls off. Perhaps washing the jewel in hydrochloric acid and dissolving the oxide (and then optional chemical polishing and silver-plating) would be helpful?
Pendants from thick copper, oxide spalling visible
The next batch was made on the thinner substrate again, sacrificing mechanical stiffness for better appearance. The lower stiffness does not matter much as the glass reinforces the background and the size of the objects is small.
Small enameled pendants, thin copper. Left to right: Spiral, Orange eye, River, Lake.
Small enameled pendants, thin copper
Document the thickness of the copper sheets and the type of the torch. Attempt to build a small induction furnace.