[morzh]

I repair grid caps only if I know the tube is expensive and is good enough on the tester; what I do is I heat up the cap and simply shake the solder off, so the small hole is exposed. The hole and the wire are usually aligned so I put the cap back until the wire protrudes, and simply melt some solder on. If there is any adhesive that can glue the metal to glass and stand to high temps it can be used to hold the cap, but that's what I don't do. It holds well enough for it not to come off by itself.