Gun Cleaning Clinic: Sport Optics - Getting A Clearer View

Remarkably, that cheap rimfire scope held up to a lot of abuse on my little pneumatic airgun for five or six years before the plastic lens in the eyepiece filled up with condensation, rendering it completely useless for anything other than a carry handle. By this time, however, I'd moved-up to bigger and better – a lever action .22 rimfire with a brand new, fixed power Bushnell.

Funny how as you grow, so too does your appetite for more expensive shooting equipment! Nowadays, a good, dependable piece of glass for a long-range rig can run more than the gun itself. You simply can't afford NOT to take care of it. Despite the improved scratch-resistance of today's precision ground and coated lenses, cleaning your optical instruments is something that shouldn't be taken lightly. And, like most things in life, common sense and moderation play an important role in cleaning your premium optics.

Dusting - Not Just For Suzy Homemaker Anymore!
As you grow older, you also grow wiser, and experience has taught me not to lean my deer rifle against the trunk of a tree unless there's no alternative place to put it. Every time I do this, the objective lens ends up a tabletop for bits of bark, sap or pollen – things I really don't want to look through when I'm trying to get on target. In addition to picking up contaminants in the field, the glass-to-air surfaces on your optics are inherently susceptible to electrostatic charge. This means dust and debris sticks to the lenses like stink on a skunk – even when tucked away, safe-and-sound in your cozy gun safe.

Luckily, dust, smudges, bits of grit and grime alone won't destroy your favorite riflescope or binoculars. It's the stupid things we do in a hurry, like wiping condensation off the lenses with a glove or the sleeve of our hunting coat, or sloppy cleaning techniques that put us on the path to disaster. Every time you touch a lens surface – no matter how carefully – there's the real potential to trap tiny particles against the lenses. At best you only scratch the multi-coatings – at worst, you scar the glass itself. Polishing your lenses before each use is just bad juju and a habit you don't want to get into. You'll be better off in the long run to leave well enough alone when small accumulations of dust form on the lenses. Don't mess with it until it becomes a noticeable hindrance to the clarity and light gathering abilities of your optical device. After all, these instruments were designed for use in the wilderness, not the E.R.

Don't get me wrong; too much dust buildup isn't good either. It can promote the absorption of dew particles, especially in the more humid climates. And, although the vast majority of optics are sealed against moisture, it's never a good idea to make it any easier for H2O to penetrate the seals.

When the time does come to clean your fine, optical instrument, it must be taken seriously. This is no time to be rushed or pre-occupied with honey-dos. Wait until the kids are in bed or outside playing, then wash your hands and find yourself a good comfortable place with adequate lighting so you can see what's going on when you begin the project.

Lens pens like this one from Nikon include a super-soft, retractable lens brush on one end and a special chamois pad on the other. Inside the cap is a tiny sponge impregnated with a special, non-liquid glass-cleaning compound. Install and rotate the cap to replenish the cleaning pad.

Removing particles of dust and grit MUST be the number one step in your cleaning regimen. Remember, anything harder than the lens coating can and will scratch it once slight pressure is applied with any type of lens pen or cloth. Because static electricity and skin oils can make it difficult to dislodge tiny media from the lens surfaces, blowing on them might not do the trick. I like to use a soft-bristled brush designed specifically for optics. Camera lens brushes are perfect, as are your wife's cosmetic brushes if you're lucky enough to nab one before she uses it for beautification purposes. Better yet, you can save yourself a night in the dog house by purchasing a LensPen® or one of the many available clones from Leupold, Nikon, Burris and other name-band manufacturers of high quality, sport optics. In my opinion, lens pens work exceptionally well. They include a self-contained brush, cleaning head, and non-liquid cleaning compound formulated especially for glass. Plus, they cost only about $10 - $12 at your local scope dealer or camera shop. We'll discuss lens pens in further detail, later.

Working with a lens brush isn't rocket science, but you'll want to make sure the bristles are clean before introducing them to your delicate lens surfaces. When you think about it, starting from the center of the lens and working outward really doesn't accomplish much, other than moving particles of dust and grit into those hard-to-clean areas where glass meets housing. Conversely, working in the opposite direction drags everything from the edges of the housing to the center of your lens. I get around this by holding the firearm so the scope is above my head. It's not the most comfortable cleaning position to be in, but gravity is your friend, and I know anything dislodged by the brush will most likely fall to the floor, clear of my precious glass.

Sometimes dust really sticks to the lens surface and is not easily dusted away. With a lens pen, you can actually fine-tune the brush coarseness by retracting it partially into the body. This forces the bristles into a tighter bundle, making it much easier to dislodge that built up, stubborn debris without grinding it into the glass.

Before I cleaned my Burris 8-32x this month, I inspected the bristles on my Nikon lens pen for any visible chunks of dirt. I didn't see anything, but was both surprised and irritated to see each stroke of the brush lay down an ultra-thin film of oil onto the glass. Obviously, somewhere along the line, I'd inadvertently touched the bristles with oily pizza fingers or something, which made a dirty situation even worse. When this happens, isopropyl alcohol is a great solvent for cleaning your lens brush. Once clean, simply blow-dry the bristles with a hair dryer and you're back in business.

A can of compressed air, like that sold at the big box stores or any office supply shop, is another good choice for dusting your optics. If you do go this route, keep in mind that with any aerosol duster also comes the potential for propellant to leak onto your lenses. To help avoid this, keep the can upright and fire it in short, quick bursts with the applicator tube outside the confines of the lens housing (i.e., eyepiece or objective) in case it happens to drip or spit a little at the end of its flow.

Then, go ahead and check the turret knob setscrews to make sure they're still snug. You might need a good jeweler's screwdriver or Allen wrench to accomplish this task. And, don't over-tighten the screws; there's the real potential to strip out the threads in the knobs. Finally, brush or blow out the caps themselves to avoid re-contaminating what you've just so nicely sparkled-up.

A quick check of the turret screws can save you time and frustration next you need to "dial-in" during competition or an actual hunting situation. (By the way, doesn't my wife have pretty hands!)

Some shooters are concerned with the potential risk of ultraviolet rays and natural oxidation attacking the chemical integrity of the turret seals and other rubber parts in their optics. Personally, I haven't run into deterioration of this kind with any of my modern scopes or binoculars. Nor, have I seen evidence of it with any vintage glass I've owned (dating back as far as the early 1950s). This is not to say it can't occur, but I think much of this worry stems from confusion between the less hardy latex compounds and modern, vulcanized rubber. Seals used in optics, at least today, are made using the highest quality form of vulcanized rubber, not latex. Nonetheless, if your shooting days are long and spent in bright sunlight or extremely warm, dry climates with the seals exposed, I suspect some seal degradation is inevitable.

Unfortunately (or maybe fortunately), most of the rubber parts inside and out of your optics are in places the unprofessional repairperson shouldn't go, so I don't recommend any preventive maintenance in this area unless prescribed by the manufacturer. After all, most of your better optics nowadays come with a nifty, transferable "forever warranty" that simply can't be beat. Nonetheless, if you feel the need you have to do something, by all means use caution in your selection of rubber lubricant or preservative. Some oil-based lubes, and I've read, even some Armor-All^® products can actually accelerate the natural aging process of vulcanized rubbers. What this tells me is that there is a lot of mad chemistry going on when it comes to rubber treatments.

There has been some success using Vaseline^® and specialized, silicone-based greases to protect rubber, but keep in mind these products are designed to help prevent abrasion, not condition. They also attract dirt! If you must try to restore the natural elasticity of outer seals going bad, I would suggest one of the more low-tech, natural products recommended by some expert chemists. These include glycerin, neat's-foot oil, lanolin cream, bees wax, or a combination of these, which can be found in the Australian-produced leather conditioner called "Dubbin". These products are free of harsh solvents, ammonia, formaldehyde and other known rubber-eaters. Whatever you decide, the key to using any of these conditioners is to apply it sparingly with a cotton-tipped applicator once, maybe twice a year max.

Easy-Does-It Lens Polishing
Only after you've removed all traces of loose particles from the delicate surfaces of your ground lenses – checked them twice, and dusted again, should you take your cleaning talents to the next level – polishing. Don't forget, even the tiniest particle of grit caught between your polishing cloth or pen and the lens, can scratch through the anti-reflective coatings and into the glass. Once this happens, you either live with it or send your instrument to the factory for repairs. And, this could easily exceed the worth of your "used" sport optic.

In most circumstances, dry polishing your lenses with a camera-grade lens cloth or pen should take care of any remaining smudges or fingerprints after dusting. I've never had even a remotely successful experience using lens paper, and very little luck with those small, cheap cloths that come in the box with your new scope. Most of these products smear, and offer little benefit other than being readily available and easily disposable.

A special microfiber pad and dry, carbon-based cleaning compound make the lens pen an excellent choice for lens cleaning.

Key to using the lens pen system is to activate the microfiber tip with the special cleaning compound impregnated in a sponge located inside the lens pen cap. Because the compound is carbon based (similar to a pencil lead), it could leave excess residue on your lenses if you over-activate the cleaning head. To avoid this, install the cap and rotate it no more than one half turn over the cleaning pad. If necessary, blow off the extra cleaning compound with pressurized air or blot the tip on a clean cloth beforeuse.

I find that moving the pen in small, circular motions seems to work best to remove fingerprints and smudges. But, again, remember not to get too carried away with your polishing. The longer and firmer you rub, the more likely something can go awry.

Dust and fingerprints are a walk in the park for lens pens. Shown here is the ocular lens (or eyepiece) of a standard 3-9x variable used for hunting and target work. As you can see from the before and after shots, a quick dusting and polishing with a Nikon lens pen did the trick!

Unfortunately, there are a few downfalls to everything good when it comes to cleaning. Lens pens don't last nearly as long as cloths, you can't easily wash the cleaning head and expect it to stay intact, and once the cleaning compound is used up, well, it's time to buy a new pen. With this said, they're still my first and favorite choice for detail cleaning of all optical accessories, including shooting glasses.

Liquids & Optics - Do They Go Together?
I'm not a big fan of using water (the universal solvent) or any liquid chemical cleaners on expensive sport optics, but sometimes you need to resort to more extreme measures than simple dusting and dry polishing alone. After all, hunting guns go where things like sticky tree sap, blood, bullet and powder blowback are real elements to be contended with. When faced with really stubborn stains on lens surfaces, I usually try cleaning with pure water first. If that doesn't do the trick, I reach for my bottle of Birchwood Casey Lens Cleaner. My only suggestion when using liquids, which goes against the recommendations of Birchwood Casey – is to NOT spray the cleaner directly onto the lens surfaces. Use a cotton-tipped applicator, or bet yet, a soft, Kleenex brand tissue (without moisturizing additives, of course) to apply the liquid.

Even the mildest chemicals formulated for optics can be pretty rough on seals when used over time, so if you can avoid drenching them with spray – why not do so? Also, try to stay away from household window cleaners – you can bet Windex^® doesn't give a rat's behind about the longevity of your sport optics, and they probably won't replace your scope or binox in the event of damage caused by their product.

Birchwood's Lens Cleaner includes a defogging agent to help prevent the effects of condensation caused by breathing on the lens or moving immediately from cold to warm environments. It sort of works, but if I had to speculate, I would guess this additive is what makes it difficult to get streak-free results when using their product. Nonetheless, you can easily go back over the lens with your pen or cloth to remove any streaks. What's really important here is softening and loosening the gunk that could otherwise potentially scratch the lens surface.

Catastrophe Cleaning
Let's pretend for a moment you're afloat in a canoe in the bogs of Saskatchewan hunting trophy moose. Out of the clear blue, your skipper strikes a submerged, waterlogged stump, which results in an episode of near Armageddon proportions – your beloved, scoped .338 Winchester is pitched overboard into three feet of thick swamp muck. Assuming you haven't smashed a lens against stone or rock and the seals have done their job – you might be okay. Most of today's premium optics are built to withstand some level of punishment, or they'd have gone by the wayside from shot recoil alone. In such circumstances, you may be able to borrow the outfitters rifle or your buddy's gun if you're hunting in pairs. If not, well, you're no worse off trying to salvage what you have left than being without a shootin' stick altogether.

Since most good scopes are waterproof to some extent, you can begin by rinsing off as much mud as possible with pure water. Before doing this, make darn sure your turret caps are tight -– no sense flooding them with more dirty water when you begin the rinsing operation. If you have a spray bottle to work with, all the better. And, I'd recommend starting with it to remove the big chucks. Submerging your scope is a last resort, so without a spray bottle, do your best to find something soft and absorptive to clean with. In this case, you might need to surrender a clean handkerchief, T-shirt or a portion of your favorite pair of long johns. Soak the material in clean water, then ring it out over your scope using care to prevent water from pooling in the eyepiece, objective and around any moving parts like the parallax and variable power adjustment rings, if equipped. Once all loose gunk is gone, wipe the scope body down with the dampened cloth, and remove the turret caps so you can blow out any crud that might have seeped inside during the initial mishap.

When you've done your best to get rid of the grit and grime, dry off the body and move onto cleaning the lenses as best as possible. Look through the scope and make sure your reticle is still in one piece, then rotate the parallax and power adjustment rings. If everything seems functional – great! If not, well…you can't win 'em all.

Hi-Tech Sight Systems
With the ever-growing popularity of the AR-15 and tactical shooting, more and more folks are mounting high-tech, battery-powered sights by makers like EOTech, J.P. Enterprises, Trijicon, and Docter Optic to name a few. Like traditional sport optics, these advanced sight systems feature top-of-the-line, ground and multi-coated lens surfaces, plus a certain level of complexity, which warrants professional repair if something major goes haywire.

There are, nonetheless, a few basic cleaning and maintenance tips for those who prefer to live on the edge. Batteries wear out, terminals become crusty, and usually the environmental demands placed on tactical optics far exceed those of typical hunting and competition scopes, especially when used by our military and law enforcement professionals.

Once the positive (+) and negative (–) battery contacts are clean, it's not a bad idea to protect them with a thin film of dielectric lubricant. Loctite^® Dielectric Grease and Permatex^® Dielectric Tune-Up Grease are both excellent products designed to form a protective barrier against moisture, dirt, salt and corrosion, plus they significantly reduce the potential for voltage leakage. You can find one or the other at your local automotive center and some electronic stores. For hard-to-reach terminals, apply a dab of dielectric grease to a clean cotton applicator, or bend the end of a pipe cleaner and use it as an applicator tool.

Unsightly Dings & Ring Marks
Once you've shined-up the body of your riflescope or other optical device, some of those "not-so-noticeable" nicks and dings tend to stick out like a sore thumb. Not to worry…Brownells carries several Brownells or Birchwood Casey products, which can easily disguise and protect those unsightly character marks. I have the tendency to swap my riflescopes around from time to time, and despite lapping my rings, I'll get the occasional ring mark that drives me up the wall.

Super Black Touch-Up Pens by Birchwood Casey allow you to cover nicks and annoying ring marks in matte and gloss black scope finishes.

I prefer to cover scratches and dings with black oxide if possible, but many of the metal alloys used today don't cooperate all the time. If you don't have luck using Brownells 44/40 or the Birchwood Casey Presto® Blue Pen on steel bodied optics, you might have to experiment a bit. For example, when black oxide formulas just don't take on certain steels, I've had excellent results using Birchwood Casey Aluminum Black of all things. Generally, your best bet on aluminum is to go straight to the flat or gloss, Super Black Touch-Up Pens offered by Birchwood Casey or a tube of high quality, automotive touch-up paint. When I specify high-quality, I don't mean the kind you find in the automotive department at the big discount stores. Go to a reputable automotive parts franchise or directly to a GM, Ford, or Chrysler dealer for paint. And, remember, you aren't trying to touch up a da Vinci painting, you just need something that somewhat matches, adheres well, and dries tough as nails. Good automotive paints will do that.

Although, there are similar designs on the market today, it's of my personal experience that Butler Creek goes the extra mile to use materials that survive years of "real-life" hunting and shooting scenarios. The beauty of the Flip-Open model is the unique, spring-loaded, push-button design of the ocular cover, which provides instant opening of the hinged cover for snap shooting in inclement weather. The objective cover is also spring-loaded, but features ambidextrous push tabs that are activated by flipping them forward with the thumb.

For those who want added protection for the entire riflescope or sight body, Devron Scopecoat^® fits the bill. These stretchy, neoprene rubber covers slip over your optical instrument and are cushioned on the inside to protect against everyday bumps and scrapes caused during transport and storage. Devron manufactures a wide selection of different size covers to fit everything from small AGOG sights to some of your longer riflescopes with 50mm+ objectives. Brownells offers a large selection of their product line.

It would be nice if sport optics weren't so blasted delicate, complex and expensive. Or, better yet, if someone invented the perfect sight or scope for all shooting situations that could be easily swapped around between all our guns. Obviously these ideas simply aren't practical and certainly not advantageous to the scope companies. Until there's a better option out there, get used to cleaning and protecting your glass, and remember all good things come in moderation, including the care and maintenance of your valuable sport optics.