Fixing vintage glass doorknobs with loose glass to brass connection
Try #2: Cyanoacrylate

This worked much better.  The local hardwood distributor recommended and carries super thin "super glue". Turn the knob in the usual direction to set it tight, then apply glue to the glass/metal junction (it will wick right inside).  Keep acetone handy in case you dribble.  Scrape excess off with a small screwdriver. Done.



What will we do when local stores no longer exist?  Sigh.