Advice please on Surefire Nitrolon o-rings/threads

[Niconical]

I previously had the G2L, and now I have just bought a G2Z.
They both have a similar trait, in that the tailcap is a lot easier to rotate (either direction), needs a lot less pressure applied to move it, than the metal equivalents, 6P etc.

In fact, with the G2Z, it is so smooth/loose that a small amount of light handling, in and out of a pocket a couple of times for example, is enough to have moved the tail either way without me even knowing.

I assume (and we all know what that is the mother of.....) that having a larger/fatter o-ring will solve this, and make the tailcaps tighter. So, can anyone please tell me the size of o-ring to use? Either the fatter option, or just the measurements of the Surefire one and I'll try to find a slightly larger one.

I do actually have a few assorted o-rings which would be about the right size, but most seem thinner than the one on the G2Z which would make things worse I suppose.

Thank you

 

[FlashSpyJ]

I dont remember if the Nitrolon lights have a second groove for an oring at the tail. I had it on my 6P on which I put a second o-ring on. This was enough to make the tailcap less loose.
I bought my o-rings from Lighthound, they have most o-rings for SureFire lights!

If you want to measure the o-ring on the light, just remove it from the light and measure it with a slide caliper. (I did it for you, I got 1,9cm inner measurement, 2,2cm outer measurement, and 1,5mm thickness)

 

[Niconical]

Ah, good idea.

I checked and the G2Z does appear to have a second groove.

I'll find something Suitable to put in there, and report back if it works.

Thank you

 

[FlashSpyJ]

This is the one I measured!

 

[Niconical]

With the few o-rings I have, most combinations wouldn't work, however, I did find this.

With the Surefire one moved up to the second groove, and one of mine in the first groove, it is good and tight.

However, it's actually very tight. In fact, the last 1/8th of a turn or so to get it into constant-on requires quite a bit of pressure to turn. I'm happy with it that way, but I just want to check, is it in any way damaging for the tail or the threads to have it like that?

 

[Sgt. LED]

Nah that's fine.

But keep an eye out for a more appropriate one for the one nerest the threads so you can switch the stock one back if you are heading into wet conditions. From your description and my own experiences the o-ring closest to the gripped part of the body is now not doing any work due to the starker contrast between their thicknesses.

Not a problem unless it is going to get really really wet.

 

[Zen|th]

Ah, good idea.

I checked and the G2Z does appear to have a second groove.

I'll find something Suitable to put in there, and report back if it works.

Thank you

If SureFire had left a margine for adding an extra o-ring, why didnt they added it in themselves? Just wondering.. Is there a pro and con in this situation when adding an extra o-ring?

 

[Bullzeyebill]

I have never been sure that the extra grove is an O ring grove. It is not as deep as the grove used with the O ring, and might be just a space between the threads and the O ring grove. Not sure though. Look at the groves closely.

Bill

 

[Zen|th]

I have never been sure that the extra grove is an O ring grove. It is not as deep as the grove used with the O ring, and might be just a space between the threads and the O ring grove. Not sure though. Look at the groves closely.

Bill

Well there is an extra groove actually. I just bought a few o-rings and attached it to my G2 and 6PDL. (I added 2 more on the 6PDL actually, the smaller one is below the original o-ring if you can see it)
It feels kinda tighter now and a little bit more water resistant.

 

[TJx]

I had the same problem on a new G2Z, just by replacing the original o-ring with a new Lighthound one did the trick, much tighter.

 

[Bullzeyebill]

Well there is an extra groove actually. I just bought a few o-rings and attached it to my G2 and 6PDL. (I added 2 more on the 6PDL actually, the smaller one is below the original o-ring if you can see it)
It feels kinda tighter now and a little bit more water resistant.

I did not say it was not a grove. It is not the same depth as stock grove used for the single O ring, which is always the second grove from the threads. A stock O ring in the shallow grove will sit higher than the original grove, so if used as an O ring grove it needs a different size O ring. That was why I was thinking it is not a real O ring grove.

Bill

 

[Zen|th]

I did not say it was not a grove. It is not the same depth as stock grove used for the single O ring, which is always the second grove from the threads. A stock O ring in the shallow grove will sit higher than the original grove, so if used as an O ring grove it needs a different size O ring. That was why I was thinking it is not a real O ring grove.

Bill

Oh.. ok. But i used a similar sized o-ring to the stock ones, and it fits perfectly! But i think it might be a grove for an extra o-ring because i checked my E1B and there wasnt any extra grove there for any additional o-ring attachments.. confusing

 

[Sgt. LED]

Well whatever you want to call that groove, all my Surefires that can have 2 head and tail O-rings DO. It is worth it for my peace of (deranged) mind.

I believe Surefire designed some of them to be able to be more water resistant but since there was some sort of standard put to them as to how much effort it should take to twist them on and off only 1 o-ring is used.

I only part way remember that conversation.............:shrug:

 

[Zen|th]

Well whatever you want to call that groove, all my Surefires that can have 2 head and tail O-rings DO. It is worth it for my peace of (deranged) mind.

I believe Surefire designed some of them to be able to be more water resistant but since there was some sort of standard put to them as to how much effort it should take to twist them on and off only 1 o-ring is used.

I only part way remember that conversation.............:shrug:

Ya iget wat u mean.. my G2 is really much much tighter now with an additional o-ring.. It feels more 'solid'..

 

[Till]

I added an extra o-ring to the tailend of my G2Z. It does feel tighter and more water-resistant since.