Waterproof cannister for a single 18650 ideas?

[gav6280]

Inspired by barbicans new cave light i am going to have a go at making a really, really simple dive light for helmet mounting.

Similar to this:

It will consist of a 1" cooper pipe end cap, an R2 Led, 1ohm 3watt resistor, ledli real spot optic, and a glug of optical grade epoxy casting resin.

So now all i need now is simple waterproof solution for a single 18650 cell any ideas?

I was originally thinking a bit of copper pipe with 2 end caps screwed on + cable gland, only one problem its metal!!

 

[Packhorse]

Why is metal a problem?

 

[gav6280]

Well the metal pipe would conduct and short out the cell? Plus electrolysis in salt water?

 

[Lynx_Arc]

copper pipe would also corrode unless treated and be a mess to keep conducting if you used the pipe as part of the circuit. If you have ever counted pennies you will see what I mean about dirty handling copper that has been oxidizing for awhile.

 

[pyro]

look for PET preforms!

 

[Packhorse]

Well the metal pipe would conduct and short out the cell? Plus electrolysis in salt water?

Well that would all depend on how you used it. There are plenty of aluminium battery tubes that dont short out the cell. And the tube does not have to be part of the circuit. As for it corroding, its not really that bad. It will certainly discolour but I think it will last. Anyway your light head will be copper, so whats the difference.

But anyway how about PVC tubing? Plenty of that available with end caps and its very easy to reshape and glue.

 

[gav6280]

But anyway how about PVC tubing? Plenty of that available with end caps and its very easy to reshape and glue.

Have never tried shaping pvc and wouldn't have a clue where to start?

 

[alphazeta]

Why not just pick up a ~$10 18650 host from a place like DX & seal out/(remove) the weak links? (i.e.- the tailcap)

With minimum work, it should work rather decently...

 

[Packhorse]

Have never tried shaping pvc and wouldn't have a clue where to start?

Put it in an oven and heat to 140deg C or so. Then shape it then cool it.

It will hold its new shape.

 

[Lynx_Arc]

I have heard they use sand when bending copper pipe maybe that would help if you were to bend PCV too

 

[Norm]

I have heard they use sand when bending copper pipe maybe that would help if you were to bend PCV too

Very important that the sand is completly dry.
Norm