Sealing Maglite Lens

[mts0628]

Hello All:

I am about to jump into my DIY canister light project, and I am slightly confused on the light head. I am going use a c-cell Maglite with a (lensless) MR16 bulb as the basis of my light head, but I don’t exactly know how to seal the lens.

I want to try two lenses, one stepped and one just a straight thickness. The latter I will try first because I want to try and use borosilicate glass. If that doesn’t fly then I will try cutting a stepped acrylic lens. I know that the lens needs to be about 0.25 inch thick and 2.125 inches in diameter.

Now my question: how many and where do I put the o-rings? Do I put an o-ring on either side of the lens for both lens configurations or is there one lens that will require only one o-ring to seal?

Also, I have already looked at several references: Steve Lindblom’s Divelight Companion, Homebuilt Divelights by Brent Schermerhorn, and Canlights by Scott Blair. I am still lost!

Any help would be greatly appreciated. Thank you in advance.

Kindest regards from North Carolina,
Thomas

 

[Packhorse]

If you are not going to use a stepped lens just replace the stock Maglite O rings with something slightly larger.
I think I listed the sizes in this thread

 

[350xfire]

I used the original small O-ring in its original place. Put the glass lens from Dealextreme on and then placed a large o-ring between the glass and the Maglite. I found an o-ring kit at Harbor Freight for $8 that has large enought o-rings for the head and tail. I am only using 1 lens. Anyone know if that's enough for 100+feet?
I tried down to 35' and it worked.

Oh, you can also leave the O-ring that is on the outside threads of the head on there. I used teflon tape all over as well to ensure proper seal. Cheap insurance.

 

[Packhorse]

... I am only using 1 lens. Anyone know if that's enough for 100+feet?
I tried down to 35' and it worked....

I used 2 lenses form DX in a test pot down to 60meters and it was fine. I wouldnt use 1 lens when 2 will fit easy enuf. You may have to sand down the face of the reflector and mag lite but its a easy 5 minute job.
I would like to know the limitations of the lens as I fell its the weakest like. I have some perspex lenses too that are stronger as they can flex but they get scratched easy.

 

[nwfladiver]

i used o-rings on both sides of the lens. slightly larger o-rings were used on the butt of the light and under the head where the beam is adjusted. lightly lube the o-ring with silicone grease at the head. i was able to take it to 120 feet with no problems. keep in mind the light is a AA size mini-mag light using 2 aa batteries.

 

[blurryshmo]

don't they leak at the switch? i may have missed that part somewhere.

 

[Packhorse]

I cut the switch section out on mine and put the switch on the cannister.

 

[possem]

I used the two lenses for deal extreme and then siliconed the lenses in. Teflon tape on the threads. I epoxied the head on (no twist to focus now) and used the p7 module from deal extreme for the light. I kept the switch and covered it with 10 speed innertube that is siliconed and zip tied at each end of the tube to make a decent seal. I have only had the light down to 35' so far as its just finished.

 

[Packhorse]

Interesting design.
How clear is the lens using the silicon? I tried using acrylic glue which is super clear but it didnt work on glass.
The inner tube on the switch sounds a bit dodgy. I think under pressure the switch will depress and stay like that until you ascend.

 

[JOHNCREA]

Edmond Scientific sells adhesives just for gluing glass lenses together

John