sloppy g2 tailcap fix it

Mudd Magnet

Newly Enlightened
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Nov 13, 2006
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102
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ontario canada ehh!
Got a sloppy tailcap on you're torch get some teflon tape/plumbers tape and do a couple wraps around the threads. I just did mine up I got 2.5 wraps around the head and I managed 4 wraps on the tail cap. Now their is not the slightest amount of play and it feels better whilst twisting off and on. This cheap trick should also increase the water resistance of the torch to what extent I'm not sure though I've done this to mini mags and used them underwater and not had one leak yet.
 
Does the tape wear out or start to unravel from the constant twisting of the tailcap when you turn the light on and off?
 
Another solution is a second O-ring in the empty groove, gives much less play and a better feel too. I've done that with three G2's, works great.
 
Adding another o-ring would also help increase the feel and water resistance But I think the tape makes a big difference in terms of water resistance. for starters The tape's purpose is to seal pipe threads to prevent leak's by eliminating the gap between threads, The same thing we are trying to acheive on our flashlights. It is however designed to be used in a fixed pipe thread so it will wear over time with the twisting and taking the tailcap on and off for battery changes. I find with the mini mags it is good for a long time I just changed the tape on my mini magled yesterday when I did my g2 It has been taped for at least 6 months now and was still holding together fine. Even with constant use it was definatly worn but still servicable just gunked up not unravled or anything that is on the head and it was not removed in this time though. I would say it was compressed more and I could have got another new wrap around the old tape without any issue. I would say adding both the extra o-ring and wraping with tape would provide the most assurance if you plan to use the light in or around water it's cheap insurance anyways plus you get a much sturdyer tailcap :thumbsup:
 
I've just installed extra o-rings on several of my lights, a 6P, 2 Solarforce L2's, a Nextorch and my Jetbeam III m, after reading a post by Sgt.LED. It's very effective! I plan on ordering some decent o-rings, but for now I bought a box of assorted o-rings and tap washers from an 'everything £1 shop'. Non were a natural fit, and the ones that were the right diametre were much too thick, so I stretched on ones that were about half the correct diametre and they work perfectly. The tailcaps now feel very solid with no noticable play at all. They're stiffer to turn, but still smooth (I smeared them with silicone grease first). I always prefer twisties to be on the stiff side, as I once accidentally turned one on (which had a loose tailcap) while rummaging in my bag, which had been locked out by half a turn.
 
I mic'ed o-rings and grooves in a new G2 and a FiveMega 1x18650 body and measured the following:

Tail
Second o-ring groove diameter = 19.7mm
Existing o-ring OD installed in the first o-ring groove = 23mm

Neck
Second o-ring groove diameter = 26.8mm (G2), 26.9mm (FiveMega)
Existing o-ring OD installed in the first o-ring groove = 29mm

Basically, it looks like you need a 23mm OD o-ring for the tail, with o-ring thickness of 1.5mm. In fact, those are the measurements I get for a cannibalized SureFire o-ring I'm using in the second o-ring groove in the tail of a G2.

For the neck, you need a 29mm OD o-ring, with thickness of 1mm (if you can't find a 29mm OD o-ring, probably a 28mm OD ring will work, as long as it is 1mm thick -- you'd just stretch it to fit into the second o-ring groove in the neck).
 
For the neck, you need a 29mm OD o-ring, with thickness of 1mm (if you can't find a 29mm OD o-ring, probably a 28mm OD ring will work, as long as it is 1mm thick -- you'd just stretch it to fit into the second o-ring groove in the neck).
I was able to find duplicate O-rings for the tail after much searching, but the head, that seems much harder to match and I haven't had any success.
 
Deal Extreme lists a 28mm OD o-ring, but the thickness is not given. They also have a 26mm x 1mm o-ring listed. Based on the given dimensions, the ID ~ 24mm. Thus, you'd have to be able to stretch the o-ring 3mm in diameter to fit into the second o-ring groove in the neck. Seems doable.
 
I had some random GITD o-rings that fit perfectly in the second o-ring groove on my G2s. I put them on all my G2s, and now their twisties have the same turning resistance as my single o-ring'd 6P, C2, and G2Z tail caps. It wasn't really an issue, but the consistency between the lights is nice.
 
Still can't get over the fact that SF doesn't install two O-rings in the first place :thinking:.

A second O-ring makes it feel 10000000 x better.
 
We use thicker O-rings after the threads to improve water resistance and to improve the feel of the switch. Choose the right O-ring thickness to get the "twist to switch ON" resistance you want.
 
Got a sloppy tailcap on you're torch get some teflon tape/plumbers tape and do a couple wraps around the threads. I just did mine up I got 2.5 wraps around the head and I managed 4 wraps on the tail cap. Now their is not the slightest amount of play and it feels better whilst twisting off and on. This cheap trick should also increase the water resistance of the torch to what extent I'm not sure though I've done this to mini mags and used them underwater and not had one leak yet.
Actually, teflon tape's purpose in life is to cut down on thread to thread resistance so that the fitting may be screwed on tighter. Metal against metal will start to seize up as soon as friction starts occurring between the two thread surfaces. Teflon tape stops this seizing and allows the two threaded pieces to be tightened to the point that there is good thread surface to thread surface contact and deformation throughout the joint. This thread surface deformation is what actually seals the connection. Pipe dope serves the same function, and is just teflon in a liquid suspension instead of tape form.

In the case of our lights, the need to withstand the pressures involved in normal plumbing is not present. It is much simpler to simply use one or more o-rings to provide the sealing rather than thread deformation under pressure.
 
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