6x12 Cargo Trailer Conversion

This project started in October 2022, with the purchase of a 2017 Mirage 6x12 cargo trailer.

Follow along as I convert this into a full-blown travel trailer!

First order of business was too remove all interior paneling. I also replaced all original door hardware with proper carriage bolts and nylocks, ensuring it cannot be removed by someone wanting to break in.

I sealed all joints in the original, plywood flooring, and then added another layer of 1/2" plywood.

Cut an opening for a 30x24" window on the passenger side, cut & welded-in framing for the window.

Removed every single exterior screw in the trailer, drilled-out each hole, sealed each hole with sealant, then installed a 3/16" stainless rivet. Also installed sealant between every exterior panel.

Bolted-in the window with stainless bolts and nylock nuts, through the steel framing I previously added.

Replaced roof screws with bolts and nylock nuts and covered the entire roof with several layers of Herculiner truck-bed liner. This completely waterproofs the roof, all fasteners & joints, and adds a rubber-like layer to the roof which will help dampen noise from raindrops. Sealed the edges with Sikaflex 291, a superior marine sealant.

Installed a 10'x8' awning. Welded-in steel studs as necessary to ensure all awning components are mounted into solid steel.

Made a 7'x2', folding table from 1/4" aluminum.

Opened up the structure of the rear doors, filled all empty cavities with 3/4" plywood. Sealed all components upon re-assembly. Removed original bar lock, sealed holes with new hardware and sealant. Installed new door gaskets, butyl tape, and other sealers. Rivited doors to frame with over twenty 3/16" stainless rivets.

Installed three, 4' long s-tracks on exterior of doors. Welded a storage rack that mounts on the tracks.

Had the rack sandblasted and powdercoated.

Mounted the spare tire.

Installed an RV-style door lock with dual dead-bolts. The strike plate is recessed in the exterior aluminium skin and riveted to a steel stud with 1/4", stainless rivets.

Installed a 2kw diesel heater into a waterproof hard-case, ducted heat output into trailer through rear wall, routed wiring through waterproof connectors, added extra fan for combustion air intake, mounted case to storage rack.

Tested heater and it kept the trailer (with zero insulation) at a steady 17C while it was 2C outside.

Installed 2mm, butyl-based noise-deadening on the rear wall, cavities, entire roof, and a few of the side wall panels.

Installed mass loaded vinyl (further sound deadening) on rear wall, followed by rigid insulation (R5), and fibreglass insulation (R12) in side cavities.

Framed rear wall with 2x4 studs, installed fibreglass insulation (R12) and vapour barrier. Wood suds are screwed to the original, steel studs, floor and rear doors. Sprayed expanding foam between all original studs and panels.

Added another layer of left-over mass loaded vinyl.

Installed 5/8", pine tongue & groove panels on the rear wall.

Installed a marine access-hatch on the passenger side. Hatch is bolted to welded-in steel studs.

Passenger-side wall framed, insulated (R12) and covered with vapour barrier. Wood studs screwed to original, steel studs and floor. Finished with pine panels.

Installed another 30x24 window and marine access hatch on driver's side. Everything is bolted into steel studs with stainless hardware.

Added four, 2ft long sections of s-track; rivited (1/4") into original studs. Also added a drip cap above the window.

Driver's side wall framed, insulated, covered with vapour barrier.

Cleaned up poorly done electrical work in front of the trailer. Before & after.

Finished installing panels on driver's side wall and remainder of passenger wall.

Installed an LED strip under the awning and routed wiring through a waterproof connector.

Made brackets from 1/4" aluminium and mounted a 23Zero shower enclosure.

Framed the front wall and made a recessed box for the propane water heater. Heater is bolted to 1/8", diamond-tread aluminium, which is spaced 1/4" from the wood behind it.

Also added two PVC conduits for running wiring, and left pull-ropes inside each.

Bent another piece of 1/8", aluminium diamond plate and mounted it above the heater to redirect exhaust air away from the recessed box and towards the (future) fan.

Finished insulating (R12) the front wall. Ran PEX for water heater's input/output lines.

Started installing paneling on front wall. Mounted two switch panels, three dimmers (two pictured), and Renogy battery monitor.

Made and ran wiring harnesses. Hooked up all electrical panels, controls, etc.

Made "trusses" from 1.5" plywood (2x 3/4") and screwed them into original trusses. Installed 2" (2x 1") of rigid insulation (R10) and overlapping layers of reflectix insulation (R3.7 - R7.4).

Installed ceiling paneling and twelve, 2" LED lights. Rear ten lights are connected to one dimmer, front two lights to a second dimmer; the idea is to be able to light up the front of the trailer (which will have the kitchen and washroom) without having to light up the rest of the trailer where someone may be sleeping.

Framed in the opening for the fan and started installing trim to hide seams.

Installed trim around the door.

Installed trim around the passenger side window.

Installed trim around the driver side window.

Took a quick break from working on the trim to make a zero-clearance insert for my mitre saw.

Installed trim between the ceiling and vertical wall on driver side.

Installed trim between the ceiling and vertical wall on passenger side.

Sprayed entire intrior with two coats of Varathane Diamond finish.

Installed flooring (10mm, waterproof vinyl plank).

Framed-in the water tanks. 170L fresh water (bottom) and 70L gray water. Framing is screwed to studs, walls and floor, while the tanks are sandwiched-in between the framing and walls.

Started on the plumbing using 3/4" PEX.

Made the box containing water fixtures for the driver's side access panel. Finished in Herculiner (truck-bed liner).

Plumbing progress: drains for both tanks are routed outside (bottom) of the trailer, fresh water tank intake connected, exterior shower connected. Also ran 12mm bolts through the bottom of the water tank framing, to the exterior, and secured with nylocks. Roughed-in insulation for the access panel.

Framing for the batteries. The three tie-downs are bolted through the floor with 1/4", stainless bolts.

Batteries are secured with a ratchet strap.

Started kitchen cabinet work.

More progress on the cabinetry, and routed the propane hose with various splitters. One propane line runs to the water heater, another will protrude through the kitchen countertop for a camping stove hookup, and the final line runs to the passenger's side access hatch (also for a camping stove hookup).

Made a panel to hold all electrical components and mounted it above the batteries. Panel is bolted in and secured with four M6 star-knobs, so that it can be removed without tools in a pinch. Plenty of space below for access to the batteries.

The Renogy battery monitor conveniently shows current charge, incoming/outgoing amperage, and projections for either battery depletion or full charge, depending on whether the battery is being charged or used. Great piece of kit!

Made a cable for the NOCO 10 Genius charger to work with my external Anderson connector. This connector can be used to charge the battery via a portable charger (like my NOCO), an external solar setup, a DC/DC charger, or any other source of electricity. The NOCO charger puts in 10amps as advertised.

Finished most of the plumbing and added a countertop. Material is 1.5"-thick bamboo, stained and finished before installation. Countertop is bolted and screwed down. Sink and faucet installed.

Split the pump intake line with a Wye and two valves. The second intake hose can be placed into a container of RV antifreeze for easy winterization.

Leak-tested the fittings in the external, driver-side access hatch, then insulated and finished it.

Built four drawers and two access panels (one for the pump & plumbing, other for the electrical section). Drawers are on full-extension, soft-close slides.

Painted cabinets and trim, sprayed drawers with protective finish, applied silicone inside drawers, along the cabinets, etc.

Framed the bed area using 2x4s which are half-lap jointed everywhere. The two vertical 3/4" plywood supports are recessed into their respective joints, and screwed to the floor. These will serve as the walls for the future fridge slider.

The bed area is 65 1/4" wide and 79 1/2" long; larger than a residential queen bed, and nearly king-size!

Ran pipe for the heating output; all components are glued together. The heat now comes out at the foot of the bed, below the bottom drawer. This position will allow some hot air to rise into the kitchen cabinets, ensuring that the water tanks and pipes are adequately heated.

Moved the trailer outside, installed the MaxxAir fan, installed original wheels, installed four 7500lb stabilizers.

The fan is almost imperceptible at low speed, and can move a lot of air when needed.

Added flanges and downward facing pipe for the two air intakes on the diesel heater. This will keep rain/snow out.

Built the second access panel, finished it in the same Herculiner that was used before, ran hot and cold water plus propane through it (update: propane line removed). The panel is insulated on the inside.

Finished the bed. It is composed of three carpeted pieces of 3/4" plywood, which are easily removable for access to everything below.

The two Exped Megamat 10 LXW mattresses are an absolutely perfect fit. Also temporarily mounted the heater's controller (using double-sided tape) until I figure out a more permanent location for it.

Installed roller blinds on both windows. These ensure privacy while still letting some light through.

I removed the propane lines running through the interior of the trailer, leaving only the one running to the water heater. Doing significant research into RV propane setups and appliances, I realized that my low-pressure system would not run typical camping propane stoves (as I had intended - they require high-pressure), and the best course of action was to remove the extra propane lines. The only propane line left is the one running to the water heater.

For interior cooking we'll be using our current camping stove with a regular 1lb propane tank. Simple and effective.

Added kitchen cubbies/shelves. Dividers are adjustable.

Got a base plate for the porta potty toilet, made a matching 3/4" plywood base, mounted it to the floor. The toilet clips in, and removes easily by pulling the latch at the front. It's not meant to be used inside the trailer (although it could be), so this is more for secure transport & storage.

Made a shelf above the toilet and added a 12v, 30QT refrigerator. This fridge is powered by a new 12v port behind it, runs very quietly and cools quickly.

Added drawer below the fridge.

Beneath the bed was a vertical wall which divided the area into two spaces; I decided that a single large space was going to be more useful, so I relocated that wall as far to the passenger side as possible, and enclosed the back, giving me a 48" deep and 32.5" wide space. This will be a huge storage spot to haul bins of firewood (or whatever else) on the way in to camp, and will act as a crate for my dog when we are in camp. By keeping the dog contained here it'll free a lot of floorspace.

The storage door swings open all the way, providing unobstructed access to the space, and locks via a single sliding barrel bolt.

I trimmed out everything around, painted the trim, applied silicone between the trim/walls and floor.

On the left of this space I mounted two shoe holders. They expand (outward) to hold shoes of different thickness, and work for everything from slippers to boots.

Added carpet in the storage area as well as the entry way; this will keep things cleaner, and minimize items shifting around in transit.

Built a cabinet above the fridge, and added a small hook for the fridge strap to hang on when it's not in use.

To be continued...