I was forwarded to this board by some links at candlepowerforums. This will be my first "water tight" project so I figured this was the place to ask questions?

I am working on a miniature underwater light for messing around in our home swimming pool which will be a little project with my youngest son. We plan to use a modified 2 AA mini maglite with a cree XPE LED hooked up to a mini can made from a short piece 1/2" ID PVC pipe which will hold the batteries and driver.

The setup needs to be water tight to about 10 foot depth or so. Looking at some of the other DIY projects on this forum I see you guys are using some bolt on glands to seal the cables off as they pass through the walls of the housings. Since I am using the very small mini maglite I don't have much room to install one of those glands. Are there any other options that can create this seal while if possible offering some relief to the cable?

So far I have only come up with using some sort of a rubber grommet sealed to the housing and wire with some 3M 5200 but there must be a better way??

I know I could just try and seal the maglite but the point of this project is to make a miniature version of a grown up canister type dive light so it needs a seperate can to make my boy and myself happy

Thanks for any and all input!

Bottom line is nothing will be as reliable as a gland. You could try drilling a hole and pass thru the cable then JB weld it up.

Packhorse, thanks for the reply...what is the smallest gland available and where can I source them? My cable is only about 2mm outside diameter and the actual overall size of the hole needs to be pretty small too because the base of the minimaglite is pretty small.

Thanks again.

I have a M12 sized cable gland here. The thread is 12mm. It nearly goes into a Maglite solitaire ( single AAA). It would probably work great in a AA Mag. It takes a 5mm cable +/-.

Its quite a cool project you have there. I am guessing my son may want something similar in the near future.

I went ahead and ordered a M12 sized gland from a local supply house. Hopefully we can start messing around with the project in the next couple days

In the mean time I had another question. I have an old 5 C cell maglite which I am thinking about making a stand alone under water flashlight with the larger o-rings etc.. My question is regarding the heatsinking. I have a approx 45mm diameter aluminum backed pcb with 3 CREE XRE Q5's which I am planning to run at 700mA each.

I am thinking of making a heatsink that would attach to the rear of the pcb with thermal adhesive about 3mm thick aluminum disc which would contact the inside of the head along it's edge. Would this be enough heatsinking for under water use or do you think the leds would over heat? I would imagine that the water would keep the temps down?

Perhaps I should start a new thread for this?