New to CPF, just received my ARC-P GS

Hi

I just got my first AAA flashlight and am new to this whole thing. The O-ring on my new arc seemed somewhat busted up already. When my arc is in the "on" and "off" mode, the O ring is still slightly visible. Is that a problem or is that just how it should be?? Also, overall I am pleased with arc, but I am not sophisticated enough to know if I got a good one or not or how to properly check if a got a lemon of some sort. Any suggestions?

pc

First off, remove the O-ring and grease the threads. Then reinstall the O-ring, making sure to get some grease underneath it. Then smear some more on its outer surface.

Second, the positive contact is made of solder and so it might be a little too tall, causing the O-ring to be exposed even when the head is tightened. This can be fixed by sanding it down carefully.

Third, you may want to take off the foam ring from the underside of the head, and install it in the bottom of the battery tube instead, sticky side down. This keeps the foam ring out of the way of the threads, so it doesn't get covered in grease and torn up by the threads. I came up with this brilliant idea a couple of years ago, and later discovered that all Peak flashlights are arranged this way as well.

You are awesome. That makes so much sense as already, so much shredded black foam pieces are already sticking to the threads and creating a mess. Also, I don't have any grease as of yet, but can I use olive oil to lube up the threads and o ring?

Olive oil would probably work for a short time, but I have no idea what its wear-reduction characteristics are for metal-on-metal contact. Assuming you have a car, I think a dab of oil from the dipstick would be better. My personal preference would be to simply not use it until I could get to an auto parts store tomorrorow to buy a little packet of grease. I used to use lithium wheel bearing grease on my flashlights (until I formulated a teflon grease that I like better), but on aluminum any old grease will work just fine -- it's not nearly as picky as titanium is.

Motor oil (especially USED motor oil) and olive oil both sound unwise. A tiny dot of vaseline applied with a toothpick might be ok if it doesn't degrade the O ring (depends on O ring material), otherwise lithium grease is advised, I think. And the O ring should not come up past the end of the barrel like that (since it is supposed to create a seal), and if the ring has gotten munged up it should be replaced. I'd send the light to Arc for repair/replacement/adjustment whatever.

The arc-aaa's of the past used buna-n (nitrile) o-rings and recommended petroleum jelly. I don't know if the new ones still use the same but the packaging should tell you. If you have that laying around the house that would work.

Lowes Silicone plumber's grease works well, and lasts the same...not just Lowes, but most any home center. M2C

I've used lithium wheel bearing grease on my old Arc AAA (the really old kind with the cheap anodizing) since 2001 and the O-ring hasn't suffered any damage. Silicone is not a good choice for metal-on-metal contact, and the O-ring is replaceable whereas the screw threads are not, so I consider the as-yet-unfulfilled potential for O-ring damage to be an acceptable risk to keep the threads lubricated properly.

Hey thanks for everyone ones comments and replies!! This is great. Question though, why is silicone grease not good for metal on metal contact when it seems like the general consenus on CPF is that silicone grease is good for thread and o ring lube?

Olive oil, petroleum jelly, Nano lube, Krytox, OX lube, Silicone grease, Astroglide, Bees wax, K-Y jelly, Lard, Nyogel, etc etc... The list is endless and everyone is going to have an opinion about whats good for what, and what is not. Use what you have in hand and be done with it. I personally use Nyogel , but really, use what works for you...

One advantage the foam donut has is reducing chances of reverse polarity. The flat negative side of the battery will not easily make contact with the + anode. Sort of mechanical reverse polarity protection.

Bill

pascual said:

Hey thanks for everyone ones comments and replies!! This is great. Question though, why is silicone grease not good for metal on metal contact when it seems like the general consenus on CPF is that silicone grease is good for thread and o ring lube?

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It just isn't, I don't know why. I got that info from www.silicones.net, purveyor of darn near every kind of silicone lube known to man (and maybe a few that aren't). They say it's suitable for non-metal on non-metal, or metal on non-metal, but not metal on metal.

It's certainly more than good enough to lubricate the O-ring against the metal casing of the flashlight, and in all likelihood the amount of pressure on the threads isn't enough to cause problems with the silicone lube, but since the O-ring is replaceable and the threads aren't, I'd rather use the best lube for the threads and replace the O-ring if it ever does degrade. I've never needed to, since 2001.

Bullzeyebill said:

One advantage the foam donut has is reducing chances of reverse polarity. The flat negative side of the battery will not easily make contact with the + anode. Sort of mechanical reverse polarity protection.

Bill

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This is true, but I haven't heard any horror stories about people destroying their Peak flashlights which have the foam ring at the bottom of the battery tube. Changing batteries is a common enough thing these days that I'd like to think the average person these days knows to pay attention to which way they're inserting the battery.

Cuso said:

Olive oil, petroleum jelly, Nano lube, Krytox, OX lube, Silicone grease, Astroglide, Bees wax, K-Y jelly, Lard, Nyogel, etc etc... The list is endless and everyone is going to have an opinion about whats good for what, and what is not. Use what you have in hand and be done with it. I personally use Nyogel , but really, use what works for you...

Click to expand...

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