Eagletac T10L o-rings

Mjolnir

Flashlight Enthusiast
Joined
Dec 19, 2008
Messages
1,711
First off, I would like to say hello to everyone here, as this is my first post! I've been searching through these threads a lot lately in order to find the best flashlight for my needs, and I eventually couldn't resist the urge to register any longer. I am pretty new to this whole world of flashlights, although I have become more aquainted with much of the terminology (and other miscellaneous stuff) native to flashlights in the past few weeks.

So anyways, I ended up getting an Eagletac T10L from 4-sevens (through the "eagletac-store"), and I am very pleased with it, for the most part. However, I have had some o-ring issues. It seems that the o rings keep stretching out for some reason, most likely due to inadequate/incorrect lubrication. I have been thinking about getting nyogel, which is apparently pretty good stuff, from what I have seen, which will hopefully solve that issue. My real problem, however, is getting more o-rings for the light. It came with 2 replacement o rings, but I have quickly gone through those, and I'm not really sure what o-rings to get for it that will fit correctly, work with lubricant, and won't compromise the watertight seal (that is what they are for, after all).

I measured the width of the tube that the o ring surrounds, and it seems to be 13/16 of an inch in diameter. I attempted to measure the dimensions of the o ring with a caliper, but Its pretty difficult to get an accurate diameter of something so flexible. It also seems to be about 13/16 of an inch (probably a little bit less, since it has to be tight around the tube). The outer diameter seems to be about 15/16 of an inch when on the tube, which apparently puts the width at about 1/16 of an inch. However, lighthound does not have o-rings of this size, and I couldn't really find ones with these specific dimensions (if they are even correct) through a google search.
So basically, where should I look for o-rings this size (or whatever the ideal size is for this light), and what material should they be (ideally)? Any advice would be appreciated, especially first hand experience with the eagletac t-series and o rings. I don't really know much about how tight the o-rings should fit on the light, and I don't want to compromise the watertight seal.

Thank you to anyone brave enough to read through my mildly boring first post! Any suggestions or advice would be GREATLY appreciated.
 
Bump...
I'm pretty much clueless about what o-rings to get, so I would really appreciate some help. I know there are people on this forum who have eagletac lights, so any advice from them would be great. Also, any general info about how tight they are supposed to fit, and what material they should be made out of.

I know o-rings might not be the most interesting of topics, but I would really appreciate any help.
 
I haven't contacted them, but wouldn't it be more of an eagletac issue? Its not really about the issues with the existing o rings (which are probably my fault), but more about finding out where to get extra o rings if/when i need them. Ideally i would like to get the original eagletac o rings, but they can't be bought anywhere from what i've seen.
 
I remeasured the o-ring, and the inner diameter is more like 11/16 of an inch, not 13.
In that case, would these o rings work?
http://www.amazon.com/dp/B000FMUULC/?tag=cpf0b6-20

Is silicone a good material for o-rings? Has anyone here replaced the o-rings on any eagletac light?
 
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Neat I did`t know Amazon had O rings. Now on to your problem. Do as JayHawk suggested and E-mail 4 sevens give him a full description of the problem he will take care of you. For a immediate solution take the O ring thats in the best condition and head to the plumbing department of Lowes, Home Depot, Menards, or Ace hardware and match it up. Do not go to the Auto parts you will get a blank look. Then you will know the exact size. You could also get a small container of silicone grease there. See one of the many lube threads for more info/ choices.
Oh yes :welcome: enjoy
 
Use the contact us on the web page. Its at the bottom of the little white box on the right side of Eagle tac page or on the 4 sevens page its on the top bar.
 
Any material o-ring will work, but be sure to stick with silicone, nitrile, or polyurethane; plain rubber o-rings aren't as tough and aren't compatible with some lubricants.

Make sure you completely coat the o-ring with lube, then install it.
 
It may not be a good idea using silicone grease on silicone o-rings, as it makes them swell. It's fine for other types of o-ring. The difficulty for me is not knowing for sure what the o-rings are made of. :thinking:
 
If you have a problem with your O-rings and wish to replace them you can always take the light down to the local plumbing/hardware store and buy some O-rings that fit for under a dollar.
 
I found some other o-rings on the internet that seem to be of the proper dimensions. They are made out of nitrile rubber. How good of a material is this?

Also, is Nyogel a silicone grease? If I use it on silicone o-rings, will they swell? If I got the Nitrile ones, they would not swell, would they?

It seems like the stock Eagletac o-rings are silicone. Would nyogel cause the stock rings to swell? Is nogel the best lubricant to use? If so, what kind? I understand there are a few different Nyogel compounds of different consistencies.

Sorry for all the questions, but i'm pretty new to this and don't have the slightest idea what I am doing...:thinking:
 
Mjolnir, I'm finding it a complicated subject myself. Silicone grease on nitrile is fine, if that helps.

I'm not sure how 'bad' the results of swelling silicone o-rings would be on a flashlight, but on some equipment it's an issue, which is why I'd prefer to avoid it (though it's hard without knowing what the o-rings on every light I own are made of).
 
You can usually tell the composition of the o-rings by their color; black is nitrile, red is silicone, clear/white is polyurethane. Any of these work fine for our flashlight purposes since they're all very durable, do well with most lubes, and are cheaply/easily replaced.

There's no 100% certain way to know exactly what an o-ring is made of and/or what will happen when you use a certain lube on it; trial and error is pretty much the rule. But most combinations work fine, odds are pretty slim you'll sacrifice an o-ring, and even if you do, remember that it's an expendable part of the light, similar to tires on a car or a pencil - you wear it down and then go get another one. No point in trying to stress a 25 cent component when it could kill your $50+ flashlight.

If you search the site for all the threads on lubes, you'll find it provides several hours of reading with no firm conclusions or consensus. Everyone has their own favorite lube, and very few have tried more than the one that has worked for them anyway (again reinforcing that most lube/o-ring combos work fine). The most popular choices are Nyogel 760 (http://www.lighthound.com/NyoGel-760G-10-gm-tube_p_127-1343.html), Nanolube StClair (http://www.nanolube.com/) and Sandwich Shoppe Krytox 50/50 (http://theledguy.chainreactionweb.com/product_info.php?products_id=710). Any of these lubes are far more advanced than anything you could buy at a local shop, and can handle levels of abuse your flashlight will never see.
 
If you search the site for all the threads on lubes, you'll find it provides several hours of reading with no firm conclusions or consensus.

This is what niggles me, I've read through threads here and on watch forums (re: lubing watch gaskets) and it's never clear at the end. :sigh:

It does seem quite well documented that silicone grease will cause silicone o-rings to swell and prematurely fail. There's quite a lot of information on this, but it's mostly related to cameras, where silicone o-rings are commonly used. The recommended lubricant for silicone o-rings is fluorosilicone grease. For all other types, silicone grease seems to be fine.

What I can't find anywhere is whether the o-ring will simply swell a bit making it a poor fit (possibly disaterous in an expensive camera), or whether it causes it to break down in some way. Either way, I do agree it's a cheap and replaceable part, and shouldn't be anything to worry about if you check them from time to time. Personally I use silicone grease on all of mine (I've only recently discovered silicone o-rings are used in some flashlights), and if one day I find one blown up to the size of a tractor innertube, I'll let you know. ;)
 
You guys are really over thinking this. If for some reason you should actually wear out an O-ring, than R&R and be done with it.

FWIW, the O-rings on my Fenix LD2 which is strapped to my bicycle helmet and sees daily use in sun, rain, and temps to -30c are just fine after three of abuse and no maintenance whatsoever.

With advances in technology by the time your O-rings wear out you'll be ready to upgrade the light anyway.
 
You guys are really over thinking this. If for some reason you should actually wear out an O-ring, than R&R and be done with it.

To some extent yes, but it's nice to know when you lube your o-rings you're helping them rather than killing them. I've had a waterlogged Mini Mag due to a completely perished o-ring, so you don't want to leave them 'till they're fubar before taking action (not with more expenisve lights anyway).
 
To some extent yes, but it's nice to know when you lube your o-rings you're helping them rather than killing them. I've had a waterlogged Mini Mag due to a completely perished o-ring, so you don't want to leave them 'till they're fubar before taking action (not with more expenisve lights anyway).
How old was the light with the bad O-rings?
 
MiniMags aren't waterproof - The Minimag lens doesn't really have any provision for waterproofing. It's not a big deal since the bulb is technically sealed in its socket, but it does mean that should you run one through water, you'll suddenly have a mini-aquarium in the head/reflector assembly. :p
 
How old was the light with the bad O-rings?

About a year old. It had previously been lubed with Vaseline, I'm not sure if that played a part or not.

StarHalo, I know they're not water proof, but they shoud be water resistant. I've never had water get in one before or after, just from being used in the rain.
 
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