Sorry for this belated reply. I’m days behind in emails (first
grandchild was born Feb 13th and he and his mom live with us).
In Metalsmith (Tim McCreight) I was just reading that sometimes
bubbles appear (though he mentioned it with regards to granulation in
a side-bar). He says they will stay unless you go over then with
either a feather or a cloth-stringed mop. I imagine the mop is easier
to use. It said nothing about temp to do it at, etc.
he does not, however, mention much else about them. I’m sure someone
has the book handier than I do. Or, more likely, someone else
answered the question more fully. I’m pretty new to this world, and
some of my hasn’t been ‘tested’ yet. The bubbles I think
I could do without.