How do you get wiring from cab to tongue box?

Hey guys,
I've been thinking about how I'm going to get my 12V system wires from the front of my trailer into the tongue box? I've been trying to think of ways to attach a flanged tube around them and then let the aluminum skin cover over the flange or something but still keep it all sealed so there's no chance of moisture getting in there. The tongue box will only be about an 1" or so away from the trailer body. What have you guys done and how have you got your wiring into the tongue box?
Here's the front of my trailer, you can see where the wires come out of the front wall...


Robbie
I've been thinking about how I'm going to get my 12V system wires from the front of my trailer into the tongue box? I've been trying to think of ways to attach a flanged tube around them and then let the aluminum skin cover over the flange or something but still keep it all sealed so there's no chance of moisture getting in there. The tongue box will only be about an 1" or so away from the trailer body. What have you guys done and how have you got your wiring into the tongue box?
Here's the front of my trailer, you can see where the wires come out of the front wall...


Robbie