Building Tongue Boxes

[lfhoward]

Hello everyone,

I've come to a point in my build where I've decided I would rather have the batteries in a tongue box than inside the trailer. Here's where they are currently, but I'd like to move them out front before I construct the trailer's interior.



The front of the trailer looks like this currently. The tongue is short and I will likely need to fabricate a sturdy frame to hold the tongue box in place.



I've been kicking around the idea of whether I want to purchase a ready made aluminum tongue box (like this 30-inch one from Walmart for $130) or make my own.



I will likely have some aluminum sheeting left over from skinning the trailer, so I could probably build a custom wood frame tongue box and skin it to match. How difficult is it to get a good seal on a home-made tongue box? Can anyone point me to some good threads or photos of tongue box designs? Mine will need to be large enough to hold 3, group 24 deep cycle batteries.

Thanks, all!
Lauren

[desertmoose]

Here's a recent thread.
Try a search for tongue box... there's a lot out there already.

http://tnttt.com/viewtopic.php?f=42&t=60996&start=15

Sam

[lfhoward]

Thanks, Desertmoose. That's the kind of thing I was looking for.

[tony.latham]

I've got a 1/4" plywood lip (and double-d rubber seals) around the inside of mine. It stays dry.





I built the box solid. (Top, bottom, and sides glued and screwed.) Then I laid it on edge on the table saw and cut the top off. Probably about 2" or so. I then ripped the back wall off the lid, added some wood (1/8"?) where the kerf was, and glued and dowled it back to the rest of the box. Then I added the internal lip and attached the hinge. I needed that hinge a couple of inches forward so the lid would have room to open without contacting the front of the 'drop.

I'm still scratching my head on how long this little beast took to build. But it was a winter project so what the heck!

Three batteries?

Tony

[lfhoward]

Tony, that's a very sharp, well made tongue box. Wow. The attention to detail of the folded aluminum over the box opening and the bottom of the lid is impressive. Looks like it was not a weekend project!

How did you get the electrical wires to traverse the gap between the box and the teardrop? Did you use conduit, or some other method? I'm interested in how you waterproofed that, especially since the box and the teardrop probably vibrate and react to bumps in the road slightly differently, which might stress out the seals where the conduit enters the teardrop or box.

[noseoil]

For my solar panel wires I used cable glands to go through the roof & into the cabin. They work well, are easy to install (if you remember that your hands have to tighten the nuts) & seal water-tight, no leaks.

If you want to do more wires at one time, the flexible gray plastic conduit & fittings are good. Available at home center stores or an electrical supply house, if you need a better selection of fittings & ends. Always use a larger diameter than you need (don't ask)!

[lfhoward]

Hi Tim!
Thanks for the ideas. I have cable glands for where the solar panel cables go into the roof, similar to yours. I was thinking about how I would get thick power cables from the tongue box to the utility cabinet inside the trailer where my inverter lives. I hadn't thought about flexible plastic conduit, though. That's a great idea! I was picturing trying to use aluminum conduit and having the seals leak because it doesn't flex.
--Lauren