Water-resistant,dunkable,ect

For every light I purchase I test the water resistance by dunking them in 2 foot of water for 25-30 seconds. I have sent back to fenix lights that leaked at the lens o-ring as well as a DX light which leaked, I was wondering if anyone else had these problems with their lights, and if you didn't test your lights I suggest doing it before your warranty is not valid

I'm curious, what exactly are you doing to verify leakage? Obviously if there is water in the cavity it is leaking, but I would imagine most "dunkable" lights that leaked would very slowly leak and the amount of water that leaks in would be minimal.

I've considered doing some dunk tests on my P2D, especially since I replaced the tail boot cap, I'm concerned it's not dunkable as it's very slightly too large (had to put it on a pencil and poke it into place, wouldn't just push in).

Was your light tested a clicky or a twisty? I have a Fenix P1D-CE that I have held underwater for extended periods with absolute zero ingress.

This is bound to happen as "Quality Control" is non-existent in China, or given the same meaning as "Packaging". Some SFs also leak according to some CPF members. Pot luck really.

Khaytsus said:

I'm curious, what exactly are you doing to verify leakage? Obviously if there is water in the cavity it is leaking, but I would imagine most "dunkable" lights that leaked would very slowly leak and the amount of water that leaks in would be minimal.

I've considered doing some dunk tests on my P2D, especially since I replaced the tail boot cap, I'm concerned it's not dunkable as it's very slightly too large (had to put it on a pencil and poke it into place, wouldn't just push in).

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The lights will generally leak a lot more than you think, There were a few drops in about 15 seconds which were very noticeable even while submerged

ScubaSnyder said:

The lights will generally leak a lot more than you think, There were a few drops in about 15 seconds which were very noticeable even while submerged

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So you take the batteries out, slowly dunk it, leave it under for 30s, then remove it, dry the outside off, then open it up and look?

Ever a problem from this for those that did leak, or did you not care and sent them back?

I really need a oring lube for my Fenix.. I'm afraid to try it right now.

Khaytsus said:

So you take the batteries out, slowly dunk it, leave it under for 30s, then remove it, dry the outside off, then open it up and look?

Ever a problem from this for those that did leak, or did you not care and sent them back?

I really need a oring lube for my Fenix.. I'm afraid to try it right now.

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No I keep the battery in and turn on the light dunk it for approx. 30sec, take it out dry it off and look in the lens, then open the light to look for leakage at the o-ring for thread slop. For your o-ring try nyogel 760g it works well, they have some on lighthound.com as well as some others

etc. is short for et cetera

http://en.wikipedia.org/wiki/Et_cetera

Ho-hum...I wanted to upgrade my P3D to a Q5, so I needed to open up the head. I read that CPF'ers had had success boiling the head for a few minutes and then trying to screw it open.

Well I wrapped the head in aluminium foil and put it in a top with boiling water. 15 minutes later..I go and check and oops...the head was bathing in boiling water!

I took it up, screwed it open quick as hell (still took about an hour though since I needed to go buy some PVC tubing to put around the head to increase the friction). I then dried the head out completely by heating it with a hair dryer for about 15-20 mins. I waited about half an hour more...put the batteries in and..tada the light turns on as if nothing had happened

So don't worry too much if water gets in in our Fenixes..they are tough little lights

I'm more worried about the battery. Lithium does not like H2O.

Pontus, that sort of remedy will often work if it is fresh water that has got into an item, but sea-water will kill practically everything electrical/electronic in fairly short order.

Pontus.F said:

So don't worry too much if water gets in in our Fenixes..they are tough little lights

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its different when the batteries are still in as you get electrolysis stuff happening on the PCB that stays once it has dried out, no power = no problem! (so if you ever get your light / phone /laptop etc wet get the battery off ASAP!)

It's good to get the power off a wet circuit because PCB parts are highly corrosive intolerant. If you have a leaky O-ring problem i would say to find a better O-ring elsewhere and use it.

Khaytsus said:

I'm more worried about the battery. Lithium does not like H2O.

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It's not elemental lithium you're dealing with. It's also INSIDE the battery.

BTW - if you're going to do water-leak testing... or BOIL your flashlight head (heh) I highly recommend you get some distilled water, since it's not electrically conductive.

meuge said:

It's not elemental lithium you're dealing with. It's also INSIDE the battery.

BTW - if you're going to do water-leak testing... or BOIL your flashlight head (heh) I highly recommend you get some distilled water, since it's not electrically conductive.

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Right, but you're saying that the water won't get IN the battery? I've been told that 123's will 'foam' (out the top ports?) and get hot if they get wet. Never tried it.

Distilled water is a good idea.. Won't leave gunk behind. Alcohol might work too, but not good for orings.

DM51 said:

Pontus, that sort of remedy will often work if it is fresh water that has got into an item, but sea-water will kill practically everything electrical/electronic in fairly short order.

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Yup. As an electrical engineer (and hobbyist circuit builder) I know pretty well what water can do to electronics . I was just glad that the electronics actually withstood boiling water for such a long time without problems. I a few of my own circuits that have died of far less .

The way we "test" the water tight-ness of some of our products that we reassemble:

Put the product in the freezer overnight.

Then put the product in a tub of hot water.

You will see bubbles coming from a spot if there is a leak there.


The thinking goes... Freezing it will get the air inside to reduce pressure/contract. If there is a leak it *should* draw more air in. Putting the product in the hot water will cause the air to pressurize, expelling the air through the leak. And even on the occasion where during the freeze part the product contracts and doesn't let air in (like a check valve), when you put it in the hot water, it will still pressurize enough to leak if there is a leak.


In reality, most of our "water-tight" products simply won't show the bubbling when we do this test. But on occasion, when we reassemble a unit, they leak around a gasket or o-ring. These produce an unmistakable bubbling and I have yet to see a unit that barely bubbles. They either don't at all, or it's easy to see with this test.


This is a nice test. It's easy and it has proven reliable for us. If you have a leak, no water gets into the electronics. When we have a leaky unit we let it return to room temperature before opening if it's still cold! This is important so you don't get condensation all over everything once you open it.