E2 waterproofing tests

[Gman]

I was reading a thread over on the SF forum regarding this. I agree with F/C, the E1/E2 is quite water resistant. It may not be a dive light and hold under the pressure of several atmospheres (as I recall every 33 ft of sea water is one atm, at 33 feet you'd be under two), but it does very well otherwise.

I submerged my completely assembled E2 for 1 hour with the tail cap one turn out, it was completely dry afterwards. I then turned it on and ran it through a set of batteries underwater and watched for bubbles since I assume the heat would expand the air inside and show leaks. Again, nothing happened and it was dry after. Since I saw no bubbles, this means the light was tight and the slight positive pressure from heating may actually help to keep the H2O out.

As long as the bezel is tight and the O rings lubed, I see no water issues in normal use at all. I also noted that there is sufficent room on the tail cap end for machining another O ring groove next to the stock one, but it seems uneeded. (I may do it anyway) Btw, I don't know how the lens is sealed but it didn't leak either.

The only weak spot could possibly be where the rubber pushbutton contacts the inside of the tail cap, but as long as the batteries are loaded and exerting force to seat it, it seals fine. (This is why the first test was with the cap out one turn, tightening it down so the lamp is on really seals it.)

Just for grins, I applied a little grease to the "flanged" part of the rubber button where it meets the ID of the tail cap anyway.
Btw, I use Dupont Krytox, this is PTFE (teflon) grease. Very expensive but the best you can get for this kind of work.

Seems to me other SF with the same design (6P, 9P, ect) would perform the same.

I also submerged a Ultra 123 battery alone for 30 minutes prior to the test as I was concerned I would have to machine up some dummy batteries, but there was no reaction at all and it functioned fine afterwards.
I think people may be confusing Lithium with Sodium, which you for sure don't want to get wet, but I'm no chemist.

Any Comments? Opinions? Flames?

 

[Size15's]

When hot Lithiums get wet, they froth white smelly froth.

 

[lightlover]

Gman, glad to hear that it's fairly waterproof. Wetted Lithium batteries are a Bad Thing. It figures that SF would make their Lithium torches at least highly water resistant, and SF are noted for having a policy of conservatively stating the performance of their models.

About the chemistry, all the "Alkali Metals" are reactive with water. As you know, Sodium and Potassium in sufficient quantities will "explode" quite impressively on contact with water.
Lithium has lesser reactivity, but a 123 with a small hole in it will fizz in water for a hour or so. I don't know what the gas produced is.

I'm investigating a scheme to further waterproof my E2. According to Loctite UK, the best product is a clear silicone glue/sealant, product code 5366. This is quite low-strength in adhesive qualities, and will allow "bond to be made, then broken". It's heat resistant to 300+ degrees C. Doesn't react with rubber O rings.

The idea is to stick the tailcap rubber in place, and also apply a very little to the O ring channel in the body. Then, the O ring would be seated in a flexible liner/surround, and have a silicone grease to further waterproof it.

At the head end, the idea is to cover the body's O ring with the 5366, (while it was in place), and then screw the bezel on to expel most of it, and later, cut off the excess.
To prevent the bezel becoming glued to the body, you spray WD40 to coat the bezel's end with a very thin coat of dry lube. (First sealing the reflector off with some blu-tack and tape.) Allow at least half an hour to let the white-spirit carrier of the WD40 to evaporate before fitting it on.
This trick apparently allows a for a very close fit to seal the join, while not letting the body and bezel glue together, or interfering with the elasticity of the 5366.

The lens itself is a disc of Lexan, set into a channel, pressed outwards by a square-section ring of rubber stuff. If you press it in hard, it gives slightly, and the Lexan itself seems to dish a little. I think that it's maybe the weakest point in the water resistance.
Certainly, trying to polish out a scratch resulted in cusswords and a lot of jeweller's rouge in the channel.

It's difficult to remove the lens, though heating it might help. But then, to line the channel with sealant means that quantities of Acetic acid vapour would be released, and possibly damage the reflector finish. So, a line of sealant on the join outside would be as far as I would go.

I wanted to test this, but I'm looking for a chemical which will change colour in the presence of water, to confirm the resistance to a 1 metre depth.

Until I get my E2 back, I can't test this out, and it's all theoretical till then ......

lightlover

 

[Gman]

Interesting approach, especialy about the bezel sealing. I think a larger "spacer" O ring on the switch may help seal it also but would make it stiffer to actuate. A flat seal of some kind would also seal the head nicely, in addittion to the O ring.

As I said, I had zero reaction to soaking a 123 for 30 minutes but it was cold. As Size15s points out, they will froth when hot. I suspect the overpressure vents in the top may be opening when hot and may let the water in then.

I know the Loktite line well, I'll have to look at that sealant more closely. I doubt the O rings are "rubber", I work a lot with elastomers and more likely they're Buna (nitrile) or flurocarbon (Viton is the trade name). Viton is compatible with almost anything however.

At any rate, the E2 was far more water resistant than I would have thought and thats comforting to know.

Thanx for the chemistry lesson!

 

[Lonewolf]

Has anyone tried www.super-lube.com as a waterproofer/grease?

 

[vcal]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 5BY5:
Has anyone tried www.super-lube.com as a waterproofer/grease?<HR></BLOCKQUOTE>

The Super-Lube in a tube is the same product as the R.S. professional Lube Gel #64-2326 is non-corrosive, repels fresh and salt water, and IMO is an excellent PTFE lubricant grease. Made by Synco Chemical. Slicker than K-Y jelly

 

[**DONOTDELETE**]

Gman, where do you get dupont grease? Thanks.FC-Fire/Rescue

 

[Gman]

F/C, I have some from way back, it's very high quality stuff, not easy to locate and very expensive. Look at www.krytox.com for info. The oil in Krytox is sold by weight instead of volume so that'll give you an idea of it's cost. A kilo of it is about $1000!

It's really *way* overkill for lubing torches and shouldn't be used on highly loaded aluminum bearing surfaces. (ok for threads though.) "Dupont Teflon Bearing Grease" is essentialy Krytox also and is sold by many bike shops. It's amazing stuff under high load and corrosive applications. (search on "Krytox" to see some info and uses.)

You might consider the Super-Lube product posted above. Better still, over on the SF forum there was a post about the same stuff SF uses under the topic "Z2", the product is NYE Nyogel 759G. This might be your best bet, I used Krytox only because I had some and have past experience using it in highly corrosive semiconductor equipment. It's also used on the Boeing aircraft I operate.

If you can't find it and you're really set on using it, let me know and I'll send you some, my pleasure. But frankly, the SF stuff is supposed to be better in case it migrates to the contact surfaces as I'm told it's conductive.

 

[Lonewolf]

Where can you find the NYE Nyogel I did a Google search and just came up with product specs but nowhere to purchase it. That is why I was looking at the super-lube(that and super-lube is way cheap 3ozs. for $5).

 

[vcal]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 5BY5:
That is why I was looking at the super-lube(that and super-lube is way cheap 3ozs. for $5).<HR></BLOCKQUOTE>

That teflon Super-lube is $3. @ R.Shk.(exact same stuff)-see my post above.
-And I can't Believe how much easier "twist-on" type flashlights like the LW-2000 are to operate! ...

 

[Gman]

"Windler" over on the SF Forum said he had some Nye 759G, he'll be able to say where he got it. Btw, after reviewing it's specs, I see it is *not* conductive. I know Nye Lubricants, they make some very good stuff, including carbon or silver based greases which are conductive. They are also well known for quality "damping" greases, which is what I've used mainly used Nye for.

I'm going to bore you a bit about greases as I have a background in tribology. Greases are simply oils with a thickener added. This thickener, along with the carrier oil determines the greases properties. Oils are either hydrocarbon based or synthetic based. Common thickeners are soap, clay, and lithium based among others.

There is *alot* to know about greases, common misconception is that grease is grease and frankly, thats pretty much true for lubing torches. (Btw, SureFire's Nye choice is a good one and reflects their dedication to quality engineering in every component of their product.)

For other applications of high loading and extreme enviornmental conditions the lubricant must be very carefully chosen to achive the performence and long life of the parts involved.

A few words about "teflon". There is much hype about this stuff, used by manufactuers to make all sorts of claims in all sorts of applications. (In reality there are four types of "teflon", which is a trade name of Dupont.)

Now that I have reviewed the specs for Super Lube, I see that it is simply a snythetic carrier with PTFE in suspension. This is very common and such lubricants can be found in almost any Hardware store. ("Triflow" is another common one.) Such lubricants are relativly cheap to make in quanity (thats reflected by their prices) and they will all work fine for lubing torches.

Such suspensions are a far cry from a true flourine based lubricant such as Krytox or Fomblin. Fomblin is an Italian product and Dupont developed Krytox as a "cheaper" alternative to it. (Although in this case, "cheaper" is a relative concept.)

One thing that surpised me about Super Lube is they also market such oils for use in engines. These are also PTFE suspension lubricants and are claimed to do miraculous things in your car. Like others (Prolube and
Matrix (sp?), they make some pretty far fetched claims.

It's interesting to note that Dupont, the developer of fluorinated compounds, long ago recommended agaisnt the use of their product in motor oils and will not sell PTFE powers directly to any firm that will use them to manufacture such products.

They are banned for aviation use also. One such product (Microlon) was extensivly tested
by the FAA and found to have none of the benefits claimed. In fact, some aircraft have been brought down as a result of the PTFE particles coming out of suspension and clogging oil passages. Teflon is good for frying pans, not for engines. Be careful of the hype involved in these products. (Fwiw, I used synthetic RedLine lubricants in my engines but again, the price reflects their performance.)

Finally, I'm often asked why an electrical contact is maintained through an insulating film of lubricant. The reason is that although a surface, even a polished surface, may appear to be "smooth", it's not. Under high magnification it appear very rough, having many "peaks" and "valleys". These peaks make the actual contact surface far less then the apparent contact surface but since the load is carried on the peaks, the pressure per square inch is *much* greater than if the load were distributed over an perfectly smooth surface. It's this pressure that insures good contact in the presence of
a insulating film of lubricant.

Btw, In you want a great corrosion proofing product/lubricant, I highly recommend "ACF 50" or "Corrosion X". (These are aviation products that will actually "kill" corrosion rather than trap it with a film, like WD 40, LPS and other such products.)

Whats it all mean? Well, other than boring you nice folks, just about any quality lube will perform well for torches. Take a little more care in your selection for extreme clod weather and be sure the lubricant is compatible with the elastomers (seals and O rings)used. Tribology is a very complex engineering field and, sadly, it's full of "ooga-booga" marketing hype.

Sorry for the length.

 

[sunspot]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR> Sorry for the length. <HR></BLOCKQUOTE>Oh no Gman, not true. Thank you for furthering my knowledge of lubes.

 

[lightlover]

Gman,
thanks for the info.

If you want to post a more detailed overview, please feel free to do so in Chit Chat. The dry-film lubricants are interesting ...

Also, see "Topic: Lube & O-ring Info." by the great PK himself, @ http://discuss.surefire.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=12&t=000006

for notes/links re: the two types of lube SF recommend.

lightlover

 

[**DONOTDELETE**]

FWIW, I don't think that superior lubricating qualities are really the most important attribute of grease for flashlight O-rings. It's more important that the product seal the o-ring/metal interface against water penetration. I use Trident brand silicone grease (from local Scuba shop) with good results.

 

[Gman]

Yes, you are correct. My diatribe was only intended to offer some insight into the field
in general. I do get to typing some times and can't stop.

Some lubrication of the thread pitch is desirable, the threads are sharp when new and burnish in after being exposed to use. This removed metal and, along with any dirt picked up, mixes with the current lubricant and promotes more wear.

Best thing to do is clean and then lubricate
the threads maybe twice a year (for normal use) with any decent water resistant grease. I admit Silicone is certainly an acceptable lubricant.

lol...We Flashaholics are an anal bunch when it comes to caring for our torches, eh?.

 

[Gman]

I did forget to mention one important item.

Fluorinated and some similair greases are
not really toxic but when dealing with some of them (especially Fomblin or Krytox), they can release toxic by products when heated.
(Perusing the Nye specs reminded me of this.)

Best to wash your hands after handling this stuff, especially if you smoke. I know a guy who became quite sick because of this.

 

[lightlover]

Gman,
seriously, to me it's really worth it, if you post an "as detailed as you like" overview in a dedicated Topic. If you could run through some stuff on Elastomers and O ring behaviour, so much the better.
Where the shucks else will I find out about this kinda gear ?

lightlover

 

[Gman]

Sure, OK, if ya think it won't bore folks.
Some people eye's just roll up inside their heads when technical stuff is discussed.

But I think torch people are a savey bunch, if they didn't appreciate finely engineered things, they wouldn't have this addiction.

I'll do something in Chit Chat on elastomers, I've got some background in that also. lol...However, I'm warning you. As you have seen, I tend to be "wordy".

 

[lightlover]

Good, that's settled then.
Long discourses on Elastomers and on Lubricants to look forward to.

Gman, I forgot to say, I know that the O ring engineering and tolerances in SF's is something that is painstakingly designed. I think I'd be very cautious about alterations to the tailcap.

lightlover

 

[**DONOTDELETE**]

The only way a "wetted" lithium battery would become wet would be due to it's low-tech crimp seal instead of a hermetic seal. Lithium and water is very bad. Lithium will oxidize and sputter in the presence of water and raw lithium will ignite when immersed in water.