I recently got an otterbox drybox for my phone. I was sitting and thinking that its waterproof, crushproof, and big enough to fit what I need as well protective foam. I realized this would make an amazing project enclosure…
My only problem is that I can't get the wires out of the box without negating the waterproof aspect of the box. I was thinking to drill appropriately sized holes in the box, insert bolt style contacts, and seal it with a mix of silicone caulk and gorilla glue but im not sure if the mixture would be conductive…
normally I would just go with the idea but I figured I would ask if anyone has had this problem and solved it. I want it to still be water proof up to 100ft and crush proof up to 1000lbs (as the product is advertised to withstand) and I'm not sure if I have the right idea…
Question: How do I seal a project enclosure to be water and air tight using a non-conductive seal that can withstand greater forces than a grommet?
EDIT
A more specific description of what i am getting at seems to be in order… I want to use an Android device and an open source project called "IOIO" (a link to the landing page can be found here) to construct really any kind of unmanned, WIFI/Bluetooth/3G/4G/LTE/USB enabled, waterproof, and crush proof vehicle. Since submersibles are not out of the question, I got curious about maintaining the water resistance of the aforementioned product. With land vehicles being a possibility, crush proof sounds nice.
To answer a question from the comments which was what exactly I would need outside of the submersible to be connected. Everything expensive is exactly that, expensive. I will be using a relatively expensive android device, as well as the IOIO for each one of the products. Motors and frames and even overkill waterproofing can be made to happen cheaply if done correctly, but a $700 android phone is $700. So my desire is to protect the majority of the expense in a single well protected unit. (Just imagine the insurance package i can sell on my products if I know for a fact that there has been no significant damage to the real expense). So to answer the question directly, I would want to run circuitry from the box to all forms of input and output that may or may not be applicable to the intended circumstance.
Best Answer
As already mentioned, 100 ft is a lot. IEC 60529, which is a standard for ingress protection, tests their IP67 rating at 1 meter depth for 1 hour. IP67 is generally considered to be equivalent to a NEMA 6 enclosure, I think.
There are a number of companies that make multi-hole, water-tight cord grips. Two examples that come to mind are Heyco (IP68) and Sealcon (IP66/IP68). There are other companies that make similar things, too, so look around.
One thing to keep in mind is that if your lead wire exiting the box is stranded, you have a leak path through the wire (between the insulation and the copper strands). One solution to this is lead wire manufacturers can fill that space between the insulation and copper to prevent leaking. Another option is to have a water-tight connector on the other end of your lead wires, too.