Creating and sealing a hole into camper from below.

[1973Bronco]

I am upgrading my 12-volt power from the original battery to 2 Lithium batteries. I'm going to relocate the batteries and solar controller to the pass-through storage area in the front of the trailer. This will require creating a hole for the battery cables and the incoming solar wires. I've looked at a lot of info on working with the coroplast to get an idea of how to do it, but I would like any suggestions that may be helpful to my plan.

Many sources mention that the coroplast is attached with screws or rivet-type fasteners. I haven't seen any type of fasteners on my Puma in the area that I'm looking at, so I suppose I'll have to cut that material. I've seen the cuts as either two sides cut to create a triangle opening or a three sides cuts to to make a rectangular flap. Any thoughts on one being better then the other?

Since I will be putting wires through that opening it will not seal up completely when the flap is closed, so should I use some type of foam to seal around the wires, or just do a heavy tape job with something like Gorilla Tape? This incoming solar wire is from the "Solar on the Side" but I plan on adding solar panels on the roof next year, so I will need to reaccess this opening then for wiring to go through.

Any comments or suggestions would be greatly appreciated.

 

[glen1971]

FWIW, I had to make a couple of openings underneath our trailer to trace out some plumbing. I cut 3 sides of a rectangle and folded it down to look. The fold was on the edge at the front of the trailer. To close the hole up, I wiped the area down with a damp cloth, let it dry, and used black Gorilla tape. I grabbed a can of black monofoam to seal any openings, but never used it. The stuff I've used in the past was like a landscape monofoam.

 

[Aussieguy]

On my trailer it was easy as the hard plastic colorplast did not extend all the way under the pass through... there was a thin film of flexible plastic under that section

I had to measure / estimate where hole would be drilled then used a small 1/4 inch drill bit to do a exploratory hole.... gently drilled it out and stopped as soon as the bit went through the floor ... lessen the chance of hitting a hidden wire etc
Once happy with location hole... used a larger drill bit just big enough for a single cable/lug

drilled two holes close together one for each cable
did NOT use a holesaw so filling the hole with a caulking was easier after passing wires through.

The small solar wires actually fitted into one of the holes too.

 

[Bob K4TAX]

I use black duct tape to close any openings in the colorplast. For holes, I use moderately expanding foam insulation.

Bob

 

[1973Bronco]

The good advice here gave me the confidence to proceed. Got things cut, drilled, moved, and everything is working. Heading to Smokemont on the NC side of the Smokey Mountains on Monday. It will be a good test of the new batteries and solar, and give me an idea of how I want to expand in the future.

One thing that was interesting to me during this was everything that I have read about going up from the bottom of the trailer talked about Coroplast, but that is not what was on mine. The material on my Puma was a thin, fabric-type material. It almost reminded me of the old-style roofing shingle underlayment, but much tougher. It was easy to work with. Cut nicely and sealed back up.
Thank you again.