L4 gasket install and leakiness

I rec'd my two gaskets from SF today and happily set about installing them. Unfortunately, after five tries the joint is still leaking bubbles. It looks like the gaskets aren't seating correctly, like they're bunching up and twisting and stuff.


I also tried using only one instead of two and it seated right, but obviously still leaked.

Anyone have some tips on getting this thing screwed together without messing up the gaskets?

Last week I sent an email to Surefire requesting the two gaskets. I was slightly perturbed that I did not get a response, but I got two small black rubber bands in the mail today, I assume these are the infamous gaskets [Actions speak louder than words].

In addition to daveidmx's question above, I would also like to know if anyone has mastered a technique for getting the head opened. Bare hands did not work, bare hands with rubber grips did not work, pliers over the rubber grips ripped the rubber and started to scratch the head so I gave up on that too.

davidmix,

Have you tried using a tooth pick to untwist the gaskets? You will likely need both of them. You might also have some residue thread sealant that is messing up the sealing area.

FlashlightOCD,

I had one L4 that required some serious torque. I have some of the rubber strap wrenches and they wouldn't work. I eventually wrapped the straps on the two areas and used chanel locks gripping through the thick rubber to break the bond. Good Luck but you may find the pathe of least resistance now in returning the L4 to SF.

- Don

After seeing these gaskets (mine arrived today), I'm even more happy I installed an O-Ring instead. I'm telling you guys, throw those piece of junk gaskets in the trash and put a single O-Ring in its place. I don't recall the size I used (got it from the Sandwich Shoppe), but it works great. No twisting and it squishes out just enough to form a great seal.

I have a question concerning the blow/suck test. My light did allow a very small amount of air through, and I mean very small [my face was turning colors]. I suspect it would be OK in the rain which is all I really care about, does that seem plausible?

I really like the beam and color, so I'd prefer to not return it and gamble on the Luxeon Lotto giving me another winner.

My gaskets looked like gaskets and not rubber bands.

The I.D. is smaller than the O.D. of the threaded portion so laying the gasket on the thread and then using a small tweezer to slide or "screw" the gasket down the thread worked for me.
I repeated this for the second gasket and had both lying flat and untwisted against the flat shoulder.
Easy peezy!

My friend simply stretched his (like a rubber band) over the threads and ended up with a stretched and ill-fitting gasket.
His still passed the B/S test but I hated watching him stretch the gaskets.

I sent SF an email on 06/30 and got the gaskets today as well.

I installed them with a bit of lube & loctite. Tighten by hands and it seem does the trick.

I might do double duty, I received my gaskets on saturday, but they are so thin I might as well add a gasket in there too. Anyone know if Home Depot has these gaskets?

i wonder why surefire doesn't just use a more simple and straightforward way to seal their bezels. all diving lights use oversized O-rings to form a tight seal, and i haven't had any problems with the O-ring seals on any of my maglites (except for the switch area).

[ QUOTE ]
V8TOYOTATRK said:
I might do double duty, I received my gaskets on saturday, but they are so thin I might as well add a gasket in there too. Anyone know if Home Depot has these gaskets?

[/ QUOTE ]
I got O-rings from Home Depot for my L4. If all Home Depots have their products situated in the same place, you'll find a whole rack of different sized O-rings in the same section where you'd find replacement hand spouts for your kitchen sink. I got a #35 O-ring pack of 6. Works fine. I retrofitted 3 KL4s. No leaks.

I'm in over my head here but I believe O-rings are the accepted solution for bore seals and adequate for face seals but gaskets are more common for compression face seal applications. Had all of the L4's shipped with properly installed gaskets, we might not be having this discussion.

From my experience with dive gear, I too like user accessable O-rings. One issue that has not been discussed is the material selection for the O-rings. Many of us are using neoprene which is fine if it is protected from Ozone with some type of lube or grease but will crack and harden if dry and exposed. EDPM might be a better choice in some applications. I digress and don't have the right info ready at hand.........

Anyway, I suspect that SF's design and material selection is sound and if we chose a different solution, the onus is on us to monitor the viability of our solution over time.

- Don