How many people have worked on their rifle scope?

[WNTFW]

The main points that would keep me from trying to fix a scope would be:
1. MFG has warranty.
2. Is it really worth my time and effort for a low percentage task. Either the scope is worth fixing & send it back or not & I toss it.
3. I am already good at a lot of things I would be better off doing.

I don't think making a reticle would be all that easy.

From what I understand lenses also need to be aligned optically. I have seen where some guys reset the parallax in scope. Some say it works, others say it messes up the optical alignment. So does any body know what the deal on that is.

 

[788Ham]

That must be why I trashed my Redfield 3 X 9 scope after they left Denver. Oh well, have better scopes now anyway!

 

[BLACKHAWKNJ]

One of my Iron Rules is that BEFORE I work on anything I have a COMPLETE schematic, factory manuals-if available, plus any books, plus proper tools.
I found the nitrogen purge machine interesting, though I wonder if for most of us the cost of that setup is worth it. Like buying a proper barrel vise to change the barrel on a revolver-is it really worth it?

 

[Mr transformer]

Building something like that is dependent on you already owning the stuff to make the filling rig. Buying all that stuff to fix one scope would not be economical.

Nitrogen purging is not the only way to keep the scope from fogging. The only thing that maters is that the air/gas in the scope is dry. If you fill it with normal dried air, then it will be fine.

The other way you can do it is wait until it gets real freaking cold outside then put the final lenses in place outside. That will allow the cold dry air to fill the scope and you know it will be above the dew point for all other weather.

If you don’t plan on taking it out in sub zero weather, then purging is pointless.

I never really worried about the purging thing myself, and I have never had a problem.

 

[zfk55]

Not exactly, Mr.Transformer. Are you thinking that "normal dried air" will not allow condenstion to form when there's an outside winter temp difference?
And you're also thinking that putting a room temp scope outside in cold temps for a while will somehow acclimate it without condensation forming?

 

[russ69]

Optics are a specialized field. A hobbyist would have a hard time collecting the equipment he needed to do a full evaluation of a damaged scope. Just having the right tools would be impossible.
Guys that specialize in scope modifications and repair usually only work with one or two brands, mostly because tooling is an issue. Sure it can be done by a hobbyist...sometimes. But the expert already knows which scopes he can work on and which he can't. They learn this the hard way, by loosing a scope during an attempted repair. Not something for the faint hearted.

 

[Mr transformer]

If the humidity content is low enough that the saturation level stays below the dew point, then no water will condense on the inside of the scope.

If you take the lenses out where air can move freely into the scope, and take it outside in cold conditions, the heat of the scope will drive off any moisture that may be on the surface of the metal. Once everything cools down, then you can put the lenses in to trap the air. If the outside temp is -20, you know that the moisture content is below the dew point at that temp, and that as long as the scope is warmer than -20, you will not get any condensation. The only way the moisture will condense in the scope if you take it outside, is if you have the lenses on it, which will trap the air and force the air to cool down while it’s trapped in the scope. That will cause the moisture load to dump in the scope.

As the air in the scope warms up, then the relative humidity will drop. That is because as the air warms up, it can hold more moisture. That is what causes condensation. You take air that has a lot of moisture in it. When the air cools, it drops past the point where the air can no longer hold the moisture it has. It goes past 100% humidity. That is the dew point.

That is how industrial air driers work. They run the air through a refrigerated baffle system to cool it down to the point that it drops it’s moisture load.

If you know the relative humidity, and the temp of the air in the room when you work on your scope, then you will know how cold it will have to get to have condensation on the inside of the scope. They have psychrometric charts for that.

If I was filling a scope with dried air, I would use a desiccant drier for the dry air source. You won’t have any condensation even if you go down below -40F

Or you could get some air from a filling station that uses the membrane style nitrogen concentration units. You will get dry nitrogen that if far drier than anything you will need.

 

[FROGO207]

I built a small vacuum chamber with an old refrigerator compressor and it worked to almost 27 inches of vacuum according to my R-12 gauge set and it is still around here in the garage somewhere I think. I will have to try this when I am playing around with optics. The chamber would need to be schedule 80 PVC I would think to stand the vacuum used. I have a Millett red dot that has a cracked lens but was thinking that getting the parts would be a problem.

 

[KW37]

It seems nitrogen is the gas of choice, but I would like to suggest argon, if you know anyone with a MIG system that welds aluminum that would be a possible source. Argon is used in the food industry because it is a heavy gas and can be "poured" into open sacks of like potato chips to displace the air and stays there until the bag is sealed. Not having noticed anyone mentioning it, a dry room, that is without a high level of humidity would be helpful I would think. I have a Weaver V7 that doesn't zero well and is suffering from age that I intend to disassemble and repair. It could have loose optics as we use nothing under .30 and mostly .338 rifles.

I am most interested in finding a schematic view of the scope tube, I don't fear damage to the scope as it is pretty useless unless it works. I noticed an O-ring on one spot on the scope tube so far, it is over a threaded portion of the tube, that by itself is a poor design flaw for sealing the unit. O rings can be found at reasonable prices with good delivery from Hydrapack Seals in Salt Lake City, Utah, I found them when needing to repair equipment I use on the place here. They have a lot of sizes and I tend to find I can use them for many purposes other than the hydraulic cylinders or valves they were ordered for.

Most of the posts reflect reality, it is easier to buy something rather than to fix it, and I like not too be bone headed, but the lessons you learn, and the subjects you research often serve you well.

 

[Elkins45]

One of the reasons all of my serious rifles have Leupold scopes is so I don't have to worry about repairing them. If one ever goes bad I will just send it back home to Oregon.

Life is too short to waste it on cheap scopes.

 

[243winxb]

Had this on a Weaver years ago. Pinned it, worked fine.

If the reticle starts to rotate, it is an obvious and easy fix for most scopes. Unscrew the eyepiece and the reticle will be front and center. Realign the reticle and retighten the retaining ring.

 

[Arizona_Mike]

I have an out of warranty magnifier that actually has water in it. I'm not sure what tool is needed to remove the retaining rings. The slots look smaller than grip ring pliers.

Mike

 

[Arizona_Mike]

Duplicate post removed

 

[Arizona_Mike]

That is because as the air warms up, it can hold more moisture. That is what causes condensation. You take air that has a lot of moisture in it. When the air cools, it drops past the point where the air can no longer hold the moisture it has. It goes past 100% humidity. That is the dew point.

Not to nit pick but air does not "hold" anything. The dew point would be the same for the same partial pressure of water vapor in 2 atmospheres of air pressure or in vacuum. It is the equilibrium temperature and pressure between condensation and evaporation of the water vapor itself. This would be different with a polar gas but oxygen and nitrogen are non-polar and only start deviating from ideal gas behavior at very high pressures and temperatures.

Mike

 

[230RN]

If the reticle starts to rotate, it is an obvious and easy fix for most scopes. Unscrew the eyepiece and the reticle will be front and center. Realign the reticle and retighten the retaining ring. Other ones that have the reticle deeper in the scope will have to be fixed by removing the objective lens.

Yes, you may lose the nitrogen filling, but the couple scopes I have worked on, have never given me a problem. If you had access to nitrogen then you could repurge if you want to be a perfectionist.

I got a bunch of used scopes from a local LGS and one of them had that problem, Son2 did exactly that, no N2 re-fill, no problem anyhow... but then again, it's pretty dry hereabouts most of the time.

 

[jmr40]

Most any decent quality scope should be good for 30ish years. The glass may still be OK, but I'd not trust the rubber seals on a 30 year old scope on an expensive out of state hunt. Meat hunting locally maybe. Another thing; a $200 mid grade scope made today is going to be far better than a top end scope that sold for $300 thirty years ago due to advancements in optics.

I don't buy cheap scopes, if it goes bad within 20 years or so I'd just send it back and let the manufacturer either repair or replace it. Much older than that and I'll just buy another to get a better scope.

 

[denton]

The nitrogen purge is not so hard, if you have a bottle of nitrogen handy. You just put the pieces (and necessary tools) in a plastic bag, flood the bag with nitrogen, seal it up, and do the final assembly steps through the bag.

There is nothing magic about the inside of a camera or a rifle scope. It just takes time and patience.

But I think that all my scopes have lifetime warranties. If one fails, it's off to the manufacturer.