Cargo RV Insulation & Wall Board Stage

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RoadtripsAndCampfires

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I am very glad I took on this project of turning a 7x16 cargo trailer into an RV.  After removing all the wall boards and seeing what I see, if you don't do it yourself it isn't going to be done right.  Air gaps and spaces are plentiful and we have an Interstate LoadRunner which is built well.  Thing is, it's built for cargo and not for people being enclosed in during hot and cold weather.  I've been taking photos and videos and down the road will post those but right now the build is my high priority.  So I am just sharing these notes.

I highly encourage the removal of all boards.   Despite being a 2018 and new there is still rust to be found on the inside frame.  This will be sanded and sprayed and not left hidden to get worse, thus protecting our investment.

There are plenty of air gaps all along the bottom where the aluminum outside walls meet the bottom of the frame between screws.  I found some large gaps where mice could get through up at the front between the front walls facing inside and the outside covering.

If anyone has watched the Corning YouTube video showng how air gaps affect the temperature of insulated walls you know that these weak points are problems that should be fixed when insulating.

TIP:  There are a couple of strange screws.  Look for the "driver bit" T40 for the cargo door handle removal and other T driver bits for stange shapes.


PRIMER:  In my young adult years one of my dad's good friends was a professional painter and dad hired him at times.  I learned a few things from Phil, rest in peace.  One is the value of PRIMER.

I chose to and I highly recommend considering this if you are building your own to last.  The wall boards are plywood.  We're coating all six sides of each board (inside/outside/top/bottom/left & right edges) with  Zinssler Bullseye 123 Primer which adds a mold, mildew and rust resistant film as it seals it.  If a small leak developes the wood has some protection and hopefully the leak is found before too much damage.  I am not yet done with this but getting close.  In total for all the boards/all sides it will take 3 cans, possibly 4 (I've gone through 2 and have a new one I'll open tomorrow).

Think about how much paint is being soaked up and this stuff is thick.  Thin water pooling on the untreated wood would be absorbed as fast as it could brush up against it.  Should a pipe brake or any other large water problem this could cause serious damage.  I would never want to have to remove boards after a build is complete.  As well, any insect wanting to bury itself into what it thinks is a tree will likely choose elsewhere since it'll meet with this film which is foreign to it.  Be sure to use a brush to coat the knot holes that the roller brush misses.  Use a roller with a nap to it as the wood is rough.

The front inside corners on ours have long verticle strips of aluminum which look very nice but have huge gaps of air behind them so we removed these as well as the front boards so we can insulate behind them.  I think we will have to use fiberglass insulation behind these and not the board.  Our cargo trailer has "diamond plate" running several inches high across the bottom of the front that was put on with self-tapping screws.  Thus I used a Mult-Master to plunge cut across the top and remove the board leaving the diamond plate in place.  These are osillating blades.  I just went very slow so as to not plunge further than needed to get through the plywood.  Note that this was the area of the floor where the largest air gaps were found that I mentioned mice could easily get through.

I labeled the inside of the aluminum where panels of insulation will go this way:  "D" = Driver Side "P" = Passenger Side.  #1 is closest to the front.  D1 is area between the frame where the first insulation board will go directly behind the driver.  The next one is D2, then D3, all the way to the ramp which is next to panel D12.  I did the same for the passenger side.  Why?  I will have the information that my wires are running down panel "D8" - etc.  In 4 years I might want this information that I will no doubt have long forgotten by then unless I write it down. 

Mark all boards in pencil before they are removed.  I used letters for all my  boards and made notes on them.  Whatever it takes so that you understand where those boards are returned to.  If you are going to prime the boards, be sure to prime the BACK of the board first.  Then after dry write IN MARKER on the back side the info that is on the front.  Then primer the front of the board.  This way you always know the pencil side gets primed second and you always know the marker side faces the insulation - thus keeping your holes lined up.  Also, you won't paint over the pencil before you mark the back if you follow this system.  I forgot (er, or someone did) to mark two boards and it was a pain to figure them out.  Would not want to figure them all out!

Occasionally you will discover extra drill holes that were mistakes made when the boards were originally screwed to the wall framing so there is no screw and just the hole.  Mark a large "X" through this hole so that when you go to put the board back you won't try and put a screw thorough it.

Aluminum tape is handy for helping to seal holes along with the usual sealants.

I hope some of this info helps someone else.
 
For our ExpeditionVehicle, we wanted hooks inside to hang stuff instead of permanent cabinets.
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The other reason we prefer no cabinets above waist-level is the visual and visceral sense of openness.
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Accordingly, after our obsessive excessive insulation, we mounted our visible interior walls -- glossy Maple-face plywood -- using 3/8" eye-bolts with an inch eye, bolted through to the outside.
A yuge worsher under the eye supports the eye from collapsing into the wood, a second yuge worsher outside prevents the nylock nut from sinking into the exterior GRP of the cargo-box.
Multiply this by four bolts per four-foot section of interior wall.
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Going with our DieselPunk theme, we sanded the eye, then dunked it in vinegar to accelerate the corrosion.
Outside, the bolt extends from the exterior wall for about an inch-and-a-half... perfect for hanging our tarp for a sun- and rain-shade.
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Inside, through the one-inch eye, a 3/4" copper pipe slides nicely.
As you might imagine, plain pipe is adequate, but we prefer tarnished.
We lightly sanded the pipe, then applied Miracle Grow® liquid granular plant fertilizer to slightly etch a lovely aging patina with dazzling patches of green.
A spritz of rattle-can clear stabilizes and protects.
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At second-hand stores, we acquired wood clothes hangers.
We think they add a layer of 'retro', and complement the bright wood of the walls.
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As we get on in years, the copper pipe adds a layer of safety, a handy grab if we park on uneven terrain.
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Above the windows, a variant of the eye-bolts -- a half-eye bolt -- offers temporary over-night support for our black-out curtains.
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Bolting through the interior walls, through the layers of insulation, with the ends exposed to the outside temperature might seem as though it creates a thermal path for heat gain/loss.
Based on our experience, that influence is negligible.
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An advantage:
* if we need to access the area behind a section of wall, unscrewing four nylocks frees the paneling together with the insulation.
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Our eye-bolt system uses one product to solve three issues:
* they hold the walls
* they support our clothes hangers
* the exposed exterior ends offer a place to hang our sun- and rain-shade.
Plus... the copper pipe is a handy grab if a dog toy is unexpectedly under-foot.
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An aside:
We understand concerns about small windows placed high on the walls enclosing the living space into a cave-like tomb.
Based on our experience, we think a glossy finish on walls and ceiling -- offering places to reflect, similar to 'banking' during a game of snookers -- bounces light throughout the interior.
Interior Designers can use dark paint to set the mood of a room by using a glossy finish.
Alternatively, a zone designed for peaceful repose -- such as a bedroom -- can be painted in bright colors and still accomplish the intent with a matte or flat finish.
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One size rarely fits all.
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Link for your consideration:
www.frugalfamilytimes.com/2019/11/how-to-turn-copper-green-patina/
 
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