I have big gaps in my knowledge of enameling and of Argentium, but
here goes. Here's hoping someone with real answers replies to you,
I just have a feeling that the germanium layer may be the problem.
The enamel obviously is not fusing to the metal. We know enamel will
adhere to copper, fine silver, and sterling silver. This is why I'm
looking at germanium as the culprit.
I haven't worked with Argentium very much and especially have not
tried enameling it. Is there a way to harden Argentium without
raising the germanium to the surfacei If so, this would be my next
enameling test. I would also start preparing myself for going back to
regular metals for enameling if Argentium just does not work.