Convoy metal switch discussion

I just got back to this and I love all the ideas, questions and concepts being thrown around. I honestly don’t have the time or brain capacity to put into it right now but I see intelligent people kicking this around and for that I say thank you! I am quite curious to see the results. I talked to Richard (RMM) a bit about this and he seemed to agree that most of the metal switches are more splash-proof than waterproof. I questioned this one myself as it’s the same switch used as a side switch on the BD01 which is shown here either giving false hope or proving that it IS indeed waterproof…

I look forward to hearing the results.

Ran two S2+ waterproofing tests tonight. For the first test I used a temperature differential as was suggested a couple of comments ago, but I did it the opposite direction. I chilled the light with the barrel open, then closed it while still inside the freezer. Now I’ve got a very cold light full of very cold air, which is dense. Then I dunked it into lukewarm water. The water warms the light causing the air inside to expand, forcing the air out of the weakest points. A good IPX8 light will barely bubble at all and will hold most of that pressure inside.

I found very little bubbling, much less than I expected to. One or two very tiny bubbles formed around the outside edge of the “sleeve” so there is some leakage around that oring. I think it could probably be greased and it would seal right up. I think we all know how important it is to keep orings greased and that one probably isn’t. Most of the leakage came from between the piston and the sleeve, so it was getting around that black rubber seal inside. I saw a bubble form and float up about once every 4 seconds, so not especially fast. Here’s a photo of how that looked:

Really this light leaked very little. I wouldn’t be afraid to get it quite wet, so that’s what I did next. For the next test I let the light come back up to room temperature, equal to the water. Then I just dropped it in the bowl and walked away. Its only a few inches deep, but I left it in for 15 minutes. After 15 minutes I retrieved it from the bowl. Inside the battery tube was completely dry. So I disassembled the switch assembly and it was completely dry too. ZERO water seeped past the black rubber seal during a 15 minute soak in a few inches of water. There was just a tiny drop or two above the black rubber so the nylon bushing by itself isn’t waterproof, but I don’t think we ever expected it to be.

I do have one thought about the air leakage I saw around that black rubber seal. I posted a photo earlier of the entire switch assembly stack from this light but it never occurred to be to look at how the head is machined. There’s a large shelf or “lip” inside the head that the silver washer sits on. That makes sense because it has to have something to put pressure against. I do see that the lip sits just a fraction of a mm lower than the rubber seal on the bottom of the “piston”. Not sure if you can see it in this photo, but it looks like this:

That means that the metal washer isn’t putting tight pressure on the bottom of the rubber seal, so I’m sure that’s where the highest potential for leakage is. If I were to make a suggestion to Simon it would be to machine just a bit more off of that shelf so that its completely flush with the rubber boot. I realize those are tight tolerances but for this design to seal up much more I think it would be necessary.

I’d like to take these tests a bit further and do some deeper water tests along with some jet spray/pressurized tests and see what happens, but not tonight. So far though, I’m really very impressed with Simon’s switch.

Or extend the edges of the rubber boot to overlap more of that edge and more of the washer, like TK’s pics

Good tests

I think the problem is that it might be technically waterproof but it’s relying on compression of a very tiny ledge to make the seal.

Hope you guys don’t mind me borrowing your pictures.

That’s what I think it really needs. The rubber gasket should extend to cover the whole surface there.

By the way, how is the rubber gasket attached to the metal button / “piston”?

I think that you guys are right: the very thin seal area is definitely a weak point, especially when dealing with mass produced parts and assembly processes that aren't perfect.

The solution would seem to be to make the rubber overlap more, and possibly machine the tailcap a bit differently if a switch change alone can't be made to work.

I like the way this is headed. It would be really nice if the solution is just making that lip of rubber bigger so it makes a better seal and while he’s at it switch the material to clear or translucent instead of black so a light up switch will shine through. I actually like the idea of just a glow coming from the gap in the switch. That would look pretty sweet. You could easily color match the LED for the red, blue and green versions. Thanks all for your input. Keep it coming. In the mean time I’m probably going to be brave and take my switch apart so I can see and understand better if it would be that easy. If there is enough space it seems that rubber lip or whatever else you want to call it should be extended out to the same diameter as the washer so that it seals against the inner ledge inside the tail. If there isn’t room right now Simon could just take the inner shelf of the tail maybe 0.5mm or so deeper and then there would be room to compress that gasket (which will now hopefully be made from translucent silicone) and make a proper seal. Does that sound right?

Good question. Like this:

I had gently pulled at that join before but didn’t really investigate it closely yet. I should have. The top edge of that gasket is going to be another weak point for water ingress I think. Wonder if it could be sealed/glued using some sort of adhesive. I’m sure something like an rtv silicone would work well for the job but I’m not sure it can be done at the factory in a cost-effective manner.

Hmm, well that seems less than ideal for waterproofing. :~
I suppose if it’s tight it could be good enough. But I’m thinking Simon should consider switching to a design like TK posted?

I do have some concern about long term wear with the design she posted. Could there be a risk of edges of the white clicky switch actuator cutting into the rubber gasket over time?

I think gasket should have a little nub inside which could keep the edges of the clicky actuator away. Like the nub inside our standard rubber tailcaps.

The BLF Ti light that Rey designed also has a waterproof metal clicky design. There have been problems with getting it assembled, but that is because the dimensions are not tweeked to perfection, the principle design is good. it uses a common 14mm silicon boot cap under the metal part that is screwed down, not unlike the CNQG brass 18650 light above. I got my BLF-Ti tail assembled alright and it works very well now.

From what I understand of metal switches there is always more concern over eventual breakdown because of the additional number of rubber against metal moving parts. That said, I think if properly executed you could expect at least close to the lifespan of a traditional rubber switch. I think you have to make at least a small concession there if you want the pretty metal switch…

Getting back to the concern about water getting in at the top where the rubber gasket rests in the innermost diameter, does it really matter if it is properly sealed at the bottom which is the main trouble spot for water getting into the light? My thought on that is the upper portion of the”seal” is basically just cosmetic as far as waterproofing (secondary function being to help add springiness to push the switch piston back up) and it’s the lower seal point we should be concerned about. Yes? No?

I haven’t used one of the brass lights, but just looking at it that design doesn’t seem like it would give as nice of a feel as the current convoy design does. It seems having the metal nub part just loose would feel wobbly. TK, can you (or anyone else) comment on that?

I haven’t used the brass light either although I do have one on order from CNQG. Tracking is already working but it still reads like the package is still in China. Still should be well enough ahead of the holiday that I can avoid that delay, I hope.

I do have the Rey Ti host that djozz mentioned. Here’s a photo of that tailcap from the outside:

I can disassemble it again and get some interior pictures if you all think it would help, but that thing was very fiddly to get all lined up properly. It definitely doesn’t just go together like this Convoy switch does and I had to work at it to make it operate smoothly. Its nice once its right, but getting it right was not easy.

Like djozz says, it’s got a full rubber boot under the metal switch so it would probably be a lot more waterproof, but I really can’t remember at the moment how well that rubber boot is sealed to the host. I do know the host itself was just an empty tube with some threaded sections. This photo was made from the head but you can see all the way through:

The silicon boot of the BLF-Ti is pressed tight between the stock switch (or the switch washer if you changed the switch out for a standard Omten on a 16mm switch board) and the (from the outside) screwed-in metal button-sleeve. In principle water could seep along the inner threading of the battery tube but I expect that the compressed silicon is pushed to the side sufficiently to obtain a proper seal.

Just gonna share some ideas on how Thrunite T10 can get better than ipx8 waterproof standards with thin “easy to tear” silicone boot

Just simple sandwich is enough to get things tight





the thin boot is sandwiched between the body’s lip and a washer for the retainer ring to press on.

hope it helps

The CNQG design actually feels pretty nice. It all depends on how you do it though. Overall I’d say the S2+ design feels nicest, followed by the CNQG brass light, then the Thrunite T10T, then the Rey Ti (which can bind, unfortunately), then the Sinner Cypreus (only because it’s kind of loose), then the BLF-348 (extra-loose).

It seems to depend on tolerances, mostly.

I used my Rey Ti in the rain once, and it spazzed out. I had to take it apart and let it dry before using it again.

Then again, I also had to cut the rubber boot to fit.

First post, but been a lurker for some years. Excellent forum you all have here.
If the bottom of the piston below the boot attachment point were threaded, probably smaller than diameter of boot seal opening to protect seal surface from the threads, then the piston could have a sealing lip/flange screwed on to the bottom to tighten down the boot seal against the bottom of the piston button from the inside of the boot.

That’s a great suggestion. Welcome to the forum!