Candlelight Forums have a great
Comprehensive Grease and Lube Thread.
If there is a group more neurotic then us, it's got to be the "Flashlight Fanatics Fringe".
Cleaning:
Please wear proper safety equipment when cleaning and lubing your lights. Recommended equipment includes safety glasses and latex/nitrile gloves. Even more important than the lube you use is the prep work you do before lubing your light. If you don't have clean threads, the best lube in the world isn't going to make them feel smooth. The easiest way I have found to clean threads is with a microfiber towel and isopropyl alcohol. I also use cotton swabs for internal threads, being careful not to leave any fibers behind, as they can cause problems down the road. Do not use paper products to clean any part of your lights. Paper is more abrasive than you think.
While cleaning is important, you usually only need to do it 2-3 times per year with normal use. Of course if you're using it in the mud or sand, you'll want to clean it more often, but here's where common sense is put to good use.
Lubing:
The amount of lube you use is pretty important too. I try to stick with a less is more approach. There is usually no need to slather the threads with lube. A small bit of lube usually goes quite a long way.
The first thing I do is put a tiny amount of grease under the o-ring, and then twist the o-ring. I then spread a tiny amount of lube on the surface of the o-ring. This makes the twisting action of the light much smoother in most cases.
Next up is a small amount of grease spread evenly along the leading edge of the inside threads. I use a nitrile glove to spread the lube, but a well-washed finger usually does the trick too.
Last, but not least is to assemble the light and work the lube into the threads. Different lubes will take a different amount of working to get evenly spread.
Lubes:
Now on to the list of lubes. It will be divided into 4 sections: Very Good lubes, Good Lubes, Poor Lubes, and Bad Lubes.
Very Good Lubes will hold the best of the best, lubes you can use without hesitation on any light. A lube will only be added to this section if several members agree that it belongs there. All candidates will first be added to the Good Lubes section.
Good Lubes will hold lubes that are safe for use, and will perform well, but may not be ideal for all applications.
Poor Lubes will hold lubes that would work in a pinch, but should generally not be used on flashlights. These lubes may be lubes that are excellent for other applications, just not the ones relevant to this thread.
Bad Lubes will hold the lubes that should never be used. This section will also act as a Wall of Shame Any suggestions that get added to this section will also have the username of the poster listed with it.
O-Ring Compatibility
Use caution when using petroleum products, as they can damage some types of o-rings.
Don't use silicone lubes on silicone o-rings. The o-rings can swell and make your light almost impossible to get open.
Very Good Lubes
Krytox: One of the best lubes out there. This is a fluorinated grease that is very non-reactive and is safe for just about any application. This lube works exceptionally well on
Ti lights. It is available in many different varieties, but the two most popular here are straight grease and a mix of 50/50 GPL101 oil and GPL201 grease. The grease can be purchased from the Marketplace in small quantities, and 50/50 can be purchased from the Sandwich Shoppe. It has been discovered that the sodium nitrate additive in the anti-oxidation varieties of Krytox can reduce the wear-resistance of
Krytox on Ti and bare Al. The difference is small, but it is something to make a note of.
Krytox Re-Brands: Finish Line Extreme Flouro, Loctite PFPE Grease, Chris Reeve Knifes Flourinated Grease
Nano-Oil: A highly-recommended lube by forum members. The lube uses oil as a carrier for nano-particles that are designed to act as a bearing surface.
Nyogel: This lube is used by Surefire, and can be purchased from Lighthound. This lube tends to change color slightly, but that should not affect it's lubrication properties. 759G/760G is tuned more for threads, 779ZC is tuned more for o-rings. Here's a good review.
Super-Lube: A cost-effective teflon-based lube that provides very smooth action. Both the grease and the oil perform well. It can be purchased from many hardware stores and online retailers, such as MSC.
NO-OX-ID: A wax-based lube with excellent anti-oxidation properties. It's been around for about 50 years. Sold at the Marketplace.
Good Lubes
Pure Silicone grease: This is a very common lube that can be found just about anywhere. It is generally safe for use, with the only exception being use on silicone o-rings.
Tri-Flow Clear Synthetic Grease: Similar to Super Lube. Will be moved to the Very Good section if there are more positive responses.
Deoxit ProGold: Anti-Oxidation electrical contact conditioner. While not a lube, it can be a good addition to electrical contact points on lights.
Parker Super O Lube: Silicone oil formulated to be used on o-rings. It would be a bad idea to use it on silicone o-rings though.
Sil-Glyde: Grease designed for use on rubber or plastic seals.
Poor Lubes
Motor Oil: It may work, but it can damage o-rings. A full synthetic like AMSOil might be safe, but why take the chance when there are better lubes out there.
Petroleum Jelly/Vaseline: Contains petroleum distillates, which can damage some types of o-rings.
Moly Grease: While very useful for other applications, Molybdenum is toxic, and should not be used for handheld applications, such as flashlights.
Lithium Grease: Contains petroleum distillates, which can damage some types of o-rings.
Bad Lubes
WD-40: It is a solvent, not a lube. It actually increases friction on the threads.
Gatsby Moving Rubber Hair Wax: It's a hair wax, not a light lube.