You don't state the make and model, but this is common on older models of binoculars, cameras and all other kinds of optical devices with rubberised coatings. Basically the coating is not as chemically stable as the manufacturers originally intended and has started to break down into a sticky mess. In most cases it only happens once the product has ceased production and when spare parts have become as rare as fresh **** **** . If this applies to your binoculars then there's nothing you can do to arrest the decay of the coating. All you can do is to carefully remove what's left, and sparingly use a solvent to remove what remains. Be careful what you use as many common solvents may attack other materials used in the binocular construction as well. If in doubt, careful use of a little vegetable oil is safe and works by preventing the rubbed off goo sticking back to the binos or to itself. To replace the coatings you may need to think laterally. I've used textured vinyl, blown vinyl, leathers (including sharkskin and fake crocodile) and various textiles, preferably those which are water resistant or which can be treated to become water resistant.. I've also used sections cut from old discarded truck inner tubes (much thicker than car or bike inner tubes). I've also had success by buying new bicycle tyres and cutting them up: the gaps between the tread blocks provide a good way of hiding **** joints between adjacent pieces. Usually I use those contact adhesives which allow a little bit of repositioning before they fully grab hold of the parts to be joined. Recently I've also been experimenting with silicone baking sheets; they come in lots of interesting colours, are really durable and relatively cheap, but it took me a while to find a suitable adhesive. I settled on clear silicone sealant, but it must be the type which does not release acetic acid (vinegar) as it cures other wise your binoculars will corrode. It's also vital to fully ensure that both surfaces are totally grease-free and that the rear surface of the silicone is roughened. I hope that my reply has been of some assistance, please return the favour by rating my answer.
Answers & Comments
You don't state the make and model, but this is common on older models of binoculars, cameras and all other kinds of optical devices with rubberised coatings. Basically the coating is not as chemically stable as the manufacturers originally intended and has started to break down into a sticky mess. In most cases it only happens once the product has ceased production and when spare parts have become as rare as fresh **** **** . If this applies to your binoculars then there's nothing you can do to arrest the decay of the coating. All you can do is to carefully remove what's left, and sparingly use a solvent to remove what remains. Be careful what you use as many common solvents may attack other materials used in the binocular construction as well. If in doubt, careful use of a little vegetable oil is safe and works by preventing the rubbed off goo sticking back to the binos or to itself. To replace the coatings you may need to think laterally. I've used textured vinyl, blown vinyl, leathers (including sharkskin and fake crocodile) and various textiles, preferably those which are water resistant or which can be treated to become water resistant.. I've also used sections cut from old discarded truck inner tubes (much thicker than car or bike inner tubes). I've also had success by buying new bicycle tyres and cutting them up: the gaps between the tread blocks provide a good way of hiding **** joints between adjacent pieces. Usually I use those contact adhesives which allow a little bit of repositioning before they fully grab hold of the parts to be joined. Recently I've also been experimenting with silicone baking sheets; they come in lots of interesting colours, are really durable and relatively cheap, but it took me a while to find a suitable adhesive. I settled on clear silicone sealant, but it must be the type which does not release acetic acid (vinegar) as it cures other wise your binoculars will corrode. It's also vital to fully ensure that both surfaces are totally grease-free and that the rear surface of the silicone is roughened. I hope that my reply has been of some assistance, please return the favour by rating my answer.