Problem with Zebralight o-rings

[Virginian]

I bought five H51's and five H502's (mostly for gifts), and half of the lights would not turn on unless I removed the o-rings. I have not seen comments from anyone else experiencing this so I have to wonder if I just got very unlucky, or if there is a trick I am not aware of. I positioned the o-rings at the top of the threads -- just as they were positioned in the lights that worked -- and I tightened the end caps as tight as they could go, but no luck.

I really like the lights but it is frustrating that some work fine with an o-ring and others don't. I would appreciate any advice if someone else has experienced this and has a solution.

 

[srfreddy]

Dirty tailcap threads, causing bad contact.

 

[varuscelli]

Try thoroughly cleaning and then lubricating the threads and o-rings. I think isopropyl alcohol and a clean bit of clean cloth for cleaning the threads, and I personally use Super Lube (available at many hardware stores or online) to lubricate the threads and o-rings. That helped immensely when my first ZebraLight (an H501) exhibited very similar difficulties to what you are describing.

This is what I use for the threads (quite a few people here like this product for flashlight thread lubrication):

 

[CamoNinja]

varuscelli is ok for the o-rings also.

 

[Virginian]

Thanks, I will try cleaning the threads and lubricating with Super Lube, can't hurt. My impression from examining the lights is that it looks like contact should be between the end of the threads and the bottom of the cap, not via the threads themselves -- and the o-ring prevents the cap from screwing on far enough to make that contact. Looks like a pretty tight tolerance, considering that even without the o-rings just a smidgen of a turn locks out the light. I will order the lube and let you know if it works.

 

[varuscelli]

You might try another decent lubricant in the mean time just to see if it helps. I recommend the Super Lube for long term, but another lubricant (after a good cleaning of the threads) might tell you if that's the problem. You might be surprised at the results. Then again, it might not help. But if you do buy some Super Lube, it's handy to have for your flashlight threads/o-rings in general, and certainly has other uses. One tube might last you several years.

 

[CamoNinja]

Thanks heading to home depot tomorrow to get some.

You might try another decent lubricant in the mean time just to see if it helps. I recommend the Super Lube for long term, but another lubricant (after a good cleaning of the threads) might tell you if that's the problem. You might be surprised at the results. Then again, it might not help. But if you do buy some Super Lube, it's handy to have for your flashlight threads/o-rings in general, and certainly has other uses. One tube might last you several years.

 

[varuscelli]

If you can't find it at Home Depot (seems like some folks said they couldn't find it there), you can also try any Ace Hardware if you've got one locally. Both of the Ace Hardwares in my area carry it at a bit less than $5 for a 3-oz tube.

 

[Esko]

My impression from examining the lights is that it looks like contact should be between the end of the threads and the bottom of the cap, not via the threads themselves -- and the o-ring prevents the cap from screwing on far enough to make that contact. Looks like a pretty tight tolerance, considering that even without the o-rings just a smidgen of a turn locks out the light. I will order the lube and let you know if it works.

It is the bottom of the cap and the end of the light body. If O-ring is preventing you from closing the cap fully, I don't think that lubrication will help.

Are you sure you are using the O-rings correctly? They are not supposed to be tightened between the cap rim edge and body, they are supposed to go under the cap edge and seal them that way.

 

[Virginian]

It is the bottom of the cap and the end of the light body. If O-ring is preventing you from closing the cap fully, I don't think that lubrication will help.

Are you sure you are using the O-rings correctly? They are not supposed to be tightened between the cap rim edge and body, they are supposed to go under the cap edge and seal them that way.

I realize that -- I even tried to insert the o-ring inside the cap first, but it was impossible to screw the cap on that way. The lube may help make the o-ring slick enough to slide under the cap instead of getting caught between the cap and body. The problem, I think, is that the o-rings provided are a bit larger than needed.

 

[rojos]

Maybe this is a stupid suggestion, but have you tried contacting Zebralight about it? If you ask, they might send you some extra o-rings that actually work. That seems like the least they could do considering how many lights you bought.

 

[ico]

Wait! You're putting the o ring inside the cap? No no no. The orings mostly never move. The provided o rings are extra and not to be used unless the one that is already included in the light is broken.

 

[Virginian]

Wait! You're putting the o ring inside the cap? No no no. The orings mostly never move. The provided o rings are extra and not to be used unless the one that is already included in the light is broken.

It didn't work out of the box with the o-ring as installed at the factory, which is why I experimented. I have close to 100 lights and understand how o-rings are supposed to be installed.

 

[Virginian]

Try thoroughly cleaning and then lubricating the threads and o-rings. I think isopropyl alcohol and a clean bit of clean cloth for cleaning the threads, and I personally use Super Lube (available at many hardware stores or online) to lubricate the threads and o-rings. That helped immensely when my first ZebraLight (an H501) exhibited very similar difficulties to what you are describing.

Thank you, varuscelli -- I purchased some Super Lube and 99% Isopropyl alcohol from Amazon and lubricated the threads and o-rings. It was still a bit tight the first time I screwed the cap back on but it solved the problem!

 

[varuscelli]

Thank you, varuscelli -- I purchased some Super Lube and 99% Isopropyl alcohol from Amazon and lubricated the threads and o-rings. It was still a bit tight the first time I screwed the cap back on but it solved the problem!

Pretty odd, huh? As a sort of follow-on procedure with mine after cleaning an lubing, I went through the process of tightening and loosening the tailcap about 15 or 20 times, cranking it down pretty hard when tightening. I went through that exercise a couple of times and the tailcap got easer and easier to work with. Then I did the cleaning a lubing one more time just to remove any extra grit that might have accumulated after all that tightening down of the tailcap. After a short time it got to the point where I never would have known there was any initial problem. The only ZebraLight I ever had a problem with was the first one I got (an H501w).

 

[Virginian]

Pretty odd, huh? As a sort of follow-on procedure with mine after cleaning an lubing, I went through the process of tightening and loosening the tailcap about 15 or 20 times, cranking it down pretty hard when tightening. I went through that exercise a couple of times and the tailcap got easer and easier to work with. Then I did the cleaning a lubing one more time just to remove any extra grit that might have accumulated after all that tightening down of the tailcap. After a short time it got to the point where I never would have known there was any initial problem. The only ZebraLight I ever had a problem with was the first one I got (an H501w).

Yes, I noticed the same thing after repeated tightenings. From now on this will be standard procedure, especially on lights intended as gifts.

 

[varuscelli]

Yes, I noticed the same thing after repeated tightenings. From now on this will be standard procedure, especially on lights intended as gifts.

Yeah, I think that's a great idea, especially the cleaning and lubing for gift lights to give the recipient a good start.