Glueing Eye Cups Back

[BCsteve]

Got a par of use Pentax binos for a good price for the kids. The glue holding rubber eye cups is pretty dried up and one of them just twisted off. Any recommendations on what kind of glue to glue the rubber eye cups back on the metal twisting part?

 

[Little Church Mouse]

Got a par of use Pentax binos for a good price for the kids. The glue holding rubber eye cups is pretty dried up and one of them just twisted off. Any recommendations on what kind of glue to glue the rubber eye cups back on the metal twisting part?

I would use clear silicone. Small tubes are available for aquarium repair, instead of purchasing a much easier to find caulking tubes worth.

 

[4th_point]

Clear silicone sounds like a good idea, especially if the fit is loose. I would just avoid any that are acetoxy curing, or that release acetic acid. If it smells like vinegar, it can be corrosive to metal. Silicone approved for electrical connections will be labelled as such, and don't smell like vinegar. You can usually find a black RTV in hardware stores that is neutral curing, and doesn't release acetic acid.

I'd give standard super glue a shot, if the fit is fairly tight. You probably have some already, and if it doesn't work there's not much time or money wasted. Just keep it away from the helical slot!

That's what I used during a hunt with a compact binoc where the rubber eyepiece came off. I figured that it would be temporary, especially since it was really inexpensive glue from a multipack (tiny metal tubes - I stash in repair kits and med kits for cuts) but it's still holding many years later. They sit in my glovebox now, have been exposed to heat/cold, and don't get babied.

I only did a few spots of glue too, but the compacts are a lot smaller than those Pentax. So you might need something a bit tougher like a rubber toughened super glue. Or even vane adhesive, if you fletch arrows?

More than likely I would go from super glue to automotive emblem glue! Handy stuff to have around and you can get it at hardware and autoparts stores. I would just test on a tiny spot first.

 

[brianwagan]

This is how vortex support told me how to fix mine that we're loose.

To fix a loose eye cup, please follow the instructions below:

Using a paper towel, gently apply a small amount of rubbing alcohol around the inside of the eye cup to remove any adhesive residue. Once the alcohol has dried, glue the rubber eye cup to the outer ring by using a toothpick to lightly run a thin layer of super glue (non-expanding) around the inside of the eye cup. Make sure the eye cup assembly (ECA) is in the down position and apply light pressure around the outer ring of the ECA for 30 seconds. Once complete, twist the eye cup up and allow to dry for 20 minutes.