Cleaning lenses

Ok I have several Surefire lights, the lenses are disgusting, Nyogel, hair, dust...

one lens is metal glass, the other is nitrolon Plastic

I was going to use Ethyl alcohol and TP and qtips.

will this damage the plastic lens?

why do i hear cleaning plastic lenses hurts them

whats the best way to clean out a surefire head, a metal one...and nitrolon...both have nyogel in the threads too.

an alcohol bath?

Cleaning glass always leaves micro scratches. For optics this can be a big deal so people approach cleaning very carefully. Flashlight lenses will scratch too, but I doubt they'll every see a significant change in performance even if you're not being careful.
If you want to be careful, use cleaning material approved for photographic equipment. Blow off any dust first. Never wipe with portions of your cleaning cloth that are dirty.
For plastic you want to use something mild like Windex.
Mineral spirits should do a good job removing Nyogel from the threads. A bath would be overkill, just dampen an old toothbrush and run though the threads, don't use on painted or plastic parts, just bare threads.

Use a microfiber cloth.

Never clean dry.

Blow off the dust, and or wash it off.

+1 on the Microfiber. I use them on Binoculars, Camera lenses and my Flashlights. I have never once had a problem. I now use them to remove the wax from my car.

Bill

On the outside a microfiber will usually take care of everything but sticky residues. Dust and grime will wipe right off. On the inside it's a bit trickier, you could try to wad up a microfiber cloth and spin it around inside, or maybe use a mild cleaning solution and then rinse and use compressed air to get rid of the moisture. This is only really necessary if you have an AR coated lens. If you know it doesn't have an AR coating then you can get away with stronger cleaners, just don't go overboard. I wouldn't use alcohol near a lexan lens. I'm not sure that it would cause problems but it's safer to use something like eyeglass lens cleaner or simple green/dish soap and water. Once you get the grit off with the liquid cleaning then you can lightly clean off any waterspots with a microfiber cloth.

I got some some eyeglass cleaning fluid that says "anti-reflective cleaning fluid" on the bottle.

If I apply this to my Surefires' lenses, will it take the AR coating off the lens? Would it be safe to use this particular fluid?

Perfectly safe, cleaners marked like that mean they're designed to be used with AR coated lenses.

I use cotton q-tips, isopropyl alcohol and gently wipe in a circular pattern... Is that too harsh?

I stopped using isopropyl alcohol because I feared it might rub the AR coating off or otherwise damage the dens.

Whether that's true or not I don't know.

kramer5150 said:

I use cotton q-tips, isopropyl alcohol and gently wipe in a circular pattern... Is that too harsh?

Click to expand...

What's harsh is the dirt, not necessarily the Q-Tip itself. Say there's a tiny piece of sand stuck in some grease residue on your lens. If it gets lodged on the tip of your Q-Tip, you could end up with a circular scratch in the glass. Considering the shape of a Q-Tip, you are exerting tremendous force using one compared to a balled up tissue. Tissues are much safer than Q-Tips. Also alcohol will only dissolve certain types of dirt. It is very good with grease residue as a final cleaning effort. But has almost no effect on water based stains.

I have worked repairing cameras and binoculars for over 30 years. Not to be gross, but it's natural for people to spit as they talk. It's normal to see optics covered with tiny spots that are actually dried spit. To say nothing of what happens when you sneeze. You could clean all day with alcohol and have no effect on this type of spot.

My cleaning procedure at work is to first blow off loose dirt. A duster from a computer or camera store is excellent for this. Then some type of lens cleaner on an ordinary tissue rolled up in a ball. Ordinary Windex is fine for this. Don't use so much lens cleaner that it gets on the edge of the glass and bleeds in between the metal mount and the glass. More of an issue with camera lenses than flashlights that usually have rubber O-rings at the edge. O-rings tend to cause their own problems as far as grease they are covered with to prevent drying will bleed onto the glass during cleaning. The first cleaning should be done with as little pressure as possible. Once you get off the initial dirt that might contain abrasive particles, in a second cleaning with lens cleaner you can scrub stubborn spots if necessary. A final cleaning with alcohol will remove the residual grease from the lens cleaner. The trick here is to follow the alcohol cleaning with a dry wipe to get the residue before it dries on the glass. We have a reagent grade of isopropyl at work that's 99.999% pure. It's almost impossible to get glass spotless with it. It dries so fast it always leaves a grease trail where it dried. I always ask myself if it's so pure, what is the residue it leaves behind. I dilute it with ≈25% distilled water. At home I use Walmart rubbing alcohol for cleaning. I use the one that's 70% isopropyl alcohol and the rest is 30% is distilled water. Obviously if you have the type of rubbing alcohol that contains lanolin to replace skin oils, it will be useless for lens cleaning. The water slows the drying just enough to be able to use the dry end of the same tissue to wipe up the residue before it dries on the glass. If the tissue is folded over in several layers, it will help prevent grease from your fingers bleeding through the tissue. Washing your hands first will help.

Windex and Walmart rubbing alcohol on the same tissue you might blow your nose in... Yeah I know it sounds like I'm joking. Believe me when I say cleaning glass is 90% technique and 10% materials. There really is an entire science devoted to this subject. We have special disposable Micro-Wipes at work we use for their low lint content. At home I get just as good results using ordinary Puffs. The ones without the grease in them. In my experience, when a camera store sells a lens cleaner and says, "This is the only thing you need", well not so much. No one single product can do the whole job as well or as easily as several products used together.

Also my technique is strictly for cleaning glass. Anything you use to rub on plastic is going to leave micro-scratches or sleeks. The same holds true for aluminized plastic or coated metal reflectors. Reflectors being on the inside of the light won't need cleaning that often. Just blow off the loose stuff with a duster and call it a day.

Till said:

I stopped using isopropyl alcohol because I feared it might rub the AR coating off or otherwise damage the dens.

Whether that's true or not I don't know.

Click to expand...

The original magnesium fluoride coated lenses they made around the time of WWII (circa 1940) were what they call soft coated. They quickly discovered if the glass was heated to ≈400°F prior to deposition, the coating became hard. Since then there really is no such thing as a soft coating. It's true multi-layered coatings are softer than glass, but the same as in the cleaning glass case, it's dirt you smear around while cleaning that does most of the damage. If there's a scratch, it's your technique's fault.

In rare cases the vacuum chamber might not be down to the proper level or the glass wasn't cleaned properly before being placed in the chamber. Cleaning defective coated glass of that type can cause the coating to come off in small spots or even streaks. But that is a manufacturing defect and very rare.

To clean the front end I use duster spray to remove major debris, then I use a disposable cleaning cloth used to clean camera lenses and glasses. I usually do the same on the inside, though nothing really gets trapped under there except dust particles. I wipe the threads with tissue.

Microfiber is much softer than cotton and also scratch less, they don't push dirt around and instead encapsulate it in the fibers. All of the current lens cloths are microfiber. I should know I also am on a car detailing forum and those guys are paranoid about scratching paint finishes which is way softer than AR coated lenses. I've been using them on my AR coated glasses for years and there's not a scratch on them. Microfibers are leaps and bounds ahead of cotton, as much as the old schoolers extoll cotton, there's a reason all the top quality detailers have relegated cotton cloths to shop rags and scrubbing duty.

under the sink with a sponge and dishwashing liquid.:shrug:

Use a lens cleaning solution made for AR coatings and a microfiber cloth. Not much more expensive and you know it's going to be OK. Trying to save a few pennies and ending up scratching a lens isn't really saving much. Also, if you need to clean in the edges where the cloth might not reach, just use a swab to gently push the microfiber cloth into the spot.

I like Rexton. Here's a thread with a little discussion.
-Winston