Take a look at -

http://soloscientific.com/aurora-fire-starter1.html

I have no connection with the company. I bought one, but have not tested it. A friend is taking mine elk hunting in the Bitterroots next month.

It looks solid, with a sturdy o-ring seal. I might add some lock-tite or some kind sealer just to make sure there is no leakage through the screw hole that hold the blade to the aluminum case.