In message , Andy
Burns writes
HellyB wrote:

We have a nice pair of "rubberised" binoculars, but the "rubber" has
recently become quite sticky to the touch.

Dunno if it always happens with age, or just to items handled by
certain people with a particular composition of sweat/grease on their
skin ... my old mice wheels go that way if left for a year or two.

My wife has 'lost' several pairs of shoes (some absolutely unworn)
because the rubber soles have become sticky - a bit like chewing gum.

I think all of the shoes had been put away for several years, and kept
in their original shoeboxes, which while certainly not air-tight, would
have had very little flow of air through them.

I have a similar problem with a pair of PMR446 walkie-talkies, which now
have sticky rubber cases.

The conclusion I have come to is that the solvent in the rubber has
probably gradually evaporated, and being trapped in the box and unable
to disperse, has reacted with the rubber (partially dissolving its
surface).

I've since kept the walkie-talkies in a box with an ill-fitting lid, and
I reckon the stickiness is slowly beginning to disappear. Maybe the
binoculars would respond similarly.
--
Ian