Lubrication, not these threads!

Greetings, can LITHIUM WHITE GREASE be harmful to O-rings? What are the benefits of using NYOGEL 760P? After trying a number of different lubricants, I found that Lithium on the threads made them super smooth.
As yet I haven't put anything on the O-rings. Since I have over 30 lights and quite a few are the big Mags, those expensive little tubes of NYOGEL won't go very far.
Also, just under the serial number on my SURE FIRE L1 CE CREE are the letters "PC CE", can someone tell me what that means?
Thanks very much, friends.

White lithium grease is an excellent, very common and inexpensive general purpose lubricant. It is widely used in industry and in consumer applications. Recommended for metal to metal and metal to plastic contact.

I would guess that many people are using it on flashlights. I don't see any chemical components that would be harmful to the nitrile o-rings that are most commonly used in our flashlights.

I have never been able to get solid information on the its electrical properties. Found one statement that said "recommended for wiping contacts". This is not the type of contact we are typically dealing with in our lights.

Unlike a car door hinge or other purely mechanical use, the threads in most flashlights are the path for electrical current flow. If white lithium grease is not conducive to this flow, it could cause a problem.

I do not think that any harm will be done by trying it. If you notice any flickering, dimming or seemingly early failure of batteries it might be an indication that this is an issue.

Mark

Flash_Gordon said:

White lithium grease is an excellent, very common and inexpensive general purpose lubricant. It is widely used in industry and in consumer applications. Recommended for metal to metal and metal to plastic contact.

I would guess that many people are using it on flashlights. I don't see any chemical components that would be harmful to the nitrile o-rings that are most commonly used in our flashlights.

I have never been able to get solid information on the its electrical properties. Found one statement that said "recommended for wiping contacts". This is not the type of contact we are typically dealing with in our lights.

Unlike a car door hinge or other purely mechanical use, the threads in most flashlights are the path for electrical current flow. If white lithium grease is not conducive to this flow, it could cause a problem.

I do not think that any harm will be done by trying it. If you notice any flickering, dimming or seemingly early failure of batteries it might be an indication that this is an issue.

Mark

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First of all, you won't find any grease that's electrically conductive enough for carrying flashlight current except as an unusual and very expensive specialty. And even if you did, it would be a bad idea to conduct current through it. Nearly all "conductive" greases are something like a billion times less conductive than metal -- their purpose is to drain off static electricity, not to conduct an amp of current. Flashlight current should be conducted through metal, not grease.

Fortunately, we can grease threads and contacts with ordinary grease and still conduct current through metal. Contact pressure for most contacts is adequate to squeeze grease or oil out of the contact area, allowing the metal contacts to directly touch. Grease or oil provides the very important function of preventing oxidation of the parts of the contacts not directly mating at the time. Without the grease or oil, aluminum or tin contacts instantly form a hard oxide coating as soon as they're exposed to air. The next time contact is made, the coating is shattered into hard pieces which are embedded into the relatively soft metal. This process repeats each time contact is made or broken, and before long the contact surfaces look like a battlefield of non-conductive embedded shards. In a loose or vibrating contact, this result can occur in a very short time.

In most flashlights, current is conducted via threads at the flashlight base, head, or both. These are "wiping contacts" because contact is made via a wiping motion as opposed to a straight-on contact. Wiping cleans the contact area. Connector and switch contacts are virtually always designed to provide a wiping motion for this reason. About the only non-wiping contact in a flashlight is a battery terminal that doesn't have a spring. But even those, in all the lights I have, provide enough pressure to move an oil like Pro Gold or a light grease like NyoGel out of the way, making a good metal-to-metal contact.

c_c

Spence said:

Also, just under the serial number on my SURE FIRE L1 CE CREE are the letters "PC CE", can someone tell me what that means?

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I suggest you may want to look more closely...

CE = European Conformity (CE) Marking

FCC = Federal Communications Commission (FCC)

See here:
http://www.ni.com/support/cert/prod_cert_details.htm

Nowhere in my previous post did I suggest using a conductive grease. Also, I did not intend to imply that this is necessary or even desirable. It is not. Conductive materials can have a nasty habit of migrating to an area where this conductivity is not desired. For example, there have been a few posts by members who have tried graphite based lubricants with undesirable results and a nasty mess as a bonus.

I did say that what you do not want is any material that will interfere with the conductivity of mated parts.

The majority of all flashlight manufacturers that specify a lubricant, recommend silicone grease. (I believe Mag still recommends petroleum jelly.)

Why? Because silicone grease accomplishes the four major functions that any lubricant would need to provide.

1. Lubricate and condition o-rings to limit cross-sectional distortion, eccentricity and surface abrasion.
2. Lubricate the threaded parts to limit galling and oxidation.
3. Provide a physical barrier against the intrusion of water, dust and other contaminants.
4. Accomplish 1-3 without compromising mechanical or electrical operation.

I appreciate that CPF members in general are a curious and experimental group. It is one of the main reasons that many of us are here. The are many hundreds of lubricating products available for us to try. Some will do serious damage to plastic and rubber parts. Some will perform the necessary functions marginally. Some, no doubt, will function perfectly. Which are which? Who knows. Experimentation and anecdotal reporting of results is all that we will have to go on.

Maybe, sometimes it is better to not reinvent the wheel. NyoGel may seem rather expensive. I am three years into my 50 gram jar, and have at least as long to go. I feel that I am getting the function and protection that is required, and that my flashlights are being properly maintained and preserved.

As always there are other avenues and opinions. That is just the road I have chosen.

Mark

Flash_Gordon said:

Maybe, sometimes it is better to not reinvent the wheel. NyoGel may seem rather expensive. I am three years into my 50 gram jar, and have at least as long to go. I feel that I am getting the function and protection that is required, and that my flashlights are being properly maintained and preserved.

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I still have plenty NyoGel left as well!

Yep ,that Nyogel goes a looooong way, I love the stuff....

One thing to keep in mind is if the O ring is rubber, don't use any lube that contains petroleum products. Many lubes contain "petroleum distillates" in the carrier, even "silicone" lubes.

i've been using white lithium grease without problem for awhile. i do notice it gets dryer later on. then i just reapply.

Me too. I've been using white lithium grease on firearms for 20 years and flashlight threads for 10 years without any problems. I use clear silicone grease on o-rings and I don't think I'll be changing things up anytime soon as I've been happy with the results.

white lithium grease contains petroleum distillates, therefore not good for o-rings!!! Guys, read on the container before posting.

The problem I notice in general with white lithium is it dries over time. I think technically that means whatever lubricant is mixed in with the lithium soap base complex evaporates. I've never had a silicone grease evaporate.