What could cause a stain on the INSIDE of the sight glass on a scope? It has never been taken apart and the scope is about 30 years old, but has not been mounted on a rifle in at least 20 years. What would remove such a stain or is it possibly the optic coating distorted?
I'm thinking that the scope's seal(s) went bad and released the gas, which allowed outside air to seep in and it attacked the optic coating. If the scope is a good one, and you can still see thru scope(but stain is just an annoance) you can probably mount on old 22 and still shoot it. If however the stain prevents any sighting through, sometimes, depending on scope make, you could send it to manufacturer and have it repaired, or sell on Ebay or Craigslist as an antique for parts. If scope is a little cheap model, all's left to do is toss in trash. You could have lots of options if we knew what make and model this scope is.
Del
What could cause a stain on the INSIDE of the sight glass on a scope? It has never been taken apart and the scope is about 30 years old, but has not been mounted on a rifle in at least 20 years. What would remove such a stain or is it possibly the optic coating distorted?
You didn`t say what kind/name of this scope was so can`t assess value,if any. "If" it had some value. might be worth getting it repaired. If that`s even possible.
Sounds like it`s an old soldier and might have just given up the ghost.
Why not put that old boy back up on the shelf and look for a new one ?
Save your money.........
Most likely the seal has been broken. If you have a leupold....send it in and they will fix it for no charge. Otherwise, use it on a beater rifle (if it still holds zero) or use it as the perfect excuse for a NEW scope.
It sounds like you may have lense seperation on an internal lense. This can be caused from not using lense covers on the scope when not in use or prolonged sunlight shining in throgh the scope.what happens is that direct sunlight shining through the scope is magnified through the lensesjust like a magnifying glass that you would use to start a flame. The internal portion of the scope is heated to very high tempretures. Thus lenses can seperate seals fail ...ect. Source iron sight inc. 918-445-2001
Nitrogen gas has nothing to do with scope clarrity. It simply keeps moist air out of the scope so that the scopes resists fogging internally.the same coating that is on the outside of the lense is the same as on the inside to allow better light transmission.
