On Tuesday, December 12, 2017 at 2:49:51 PM UTC-5, N_Cook wrote:

So you don't roughen the surfaces with glass/sandpaper?

Re elsewhere in this thread:- I'd picked up a bottle of superglue
de-bonding , for such a finger-bonding emergency.
Went to use it and the bottle was totally empty, the liquid had
completely diffused? through the glass/cap , not a trace left, hence the
procedure in the original post.

I do not, no. I want as clean a surface for bonding as possible. Soft neoprene O-Rings have enough surface texture, even when cut, to hold the glue. In my mind, the key to the process is the second dip + baking soda. Chip off the excess, then file smooth with a good jeweler's file. Nice thing about these files is that they remove hard stuff, but more-or-less don't affect soft materials, unlike sandpaper.

Peter Wieck
Melrose Park, PA