Teardrop Travel Trailer (added VIDEOS!)

Fair warning!  This is going to be a biggie Instructable.  Fair warning!  I suggest you read the WHOLE THING before you start building.  You may also want to obtain some more detailed plans that include more detailed drawings and dimensions.

Over the past year I've built a 'teardrop travel trailer.'  It's been an adventure for sure.  It's very much been worth it.  I aim to introduce you to the idea of a teardrop trailer and the steps involved in building one.  You WILL need more info to complete a build.  I strongly recommend the forum below. 

I stumbled across this idea because my wife and I were thinking about buying an old airstream trailer to fix up.  Then I stumbled across this web forum: http://www.mikenchell.com/forums/
It turns out that these teardrop (named for their shape) travel trailers were once very common.  Especially after WWII in the states.  Often built of materials at hand and ranged from minimal to elaborate.  Check out this link here: http://www.mikenchell.com/VintagePlans/vintageplans.html.

Well I was hooked.  I considered various designs and what I wanted in a trailer.  You can track down a TON of resources through that forum above, as well as many gracious and helpful and wonderful people.  There are a variety of FREE plans and a few at modest cost.  Note: be wary buying plans on Ebay.  Evidently, there is a fellow who pops up selling the free plans available from the above forum.

I decided to build a 'Cubbie' type trailer, based on plans from a company called Kuffle Creek.  http://www.kuffelcreek.com/  But with LOTS of modifications.  You must understand  that no two trailers are remotely alike!  One reason I picked these Cubbie plans is that there was NO WELDING.  Certainly there are designs where you can weld your own trailer to spec, but mine started out with a bolt-together utility trailer from Harbor Freight.  So without further ado....

P.S. At the time of initial publication (July 2011) I've got the trailer roadworthy, but it's by no means finished.  As I complete further finish work I'd further steps.  Please feel free to ask Qs in the comments and I'll respond as best I can.

Step 1: Buying the utility trailer - piecing it together.

Per the plans I was using I bought a 4x8 utility trailer from Harbor Freight.  It has a weight capacity of 1800 lbs.  Which should be plenty for my trailer.  In fact I took out the smallest leaf spring plates bc of the light weight.   (Step 11)  You can buy essentially identical trailers from other sources, or even fab your own.

I spread out a big piece of cardboard on my garage floor and fitted the thing together.  This particular trailer is designed to fold in half.  The plans call to modify it so it has a solid body.  This involves making an additional spar of wood to put in the middle (I painted it black).

Another mod is to build out the axle ABOVE the leaf springs instead of below it, as the factory plans call.  This allows your tailer to ride lower.  But to do this, you have to cut a notch in the axle brackets.  Hence the angle grinder. 

Step 2: Building the subfloor - preparing plywood floor

I bought some 2x2s to build a subfloor that rests on the trailer.  The purpose here isnt really structural, but more to create frame that a floor can be built on and give you something strong to bolt to the frame.  I used a piece of 2x6 at the back because I knew I'd be adding supports there. 

I also added a piece between the front two spars to hold the spare tire.  I used a piece of oak for this, leftover from a pallet I tore apart.  It's hard as nails.  I also added some blocking that will frame out the hatch.

You will also need to pre-drill holes so you can bolt the deck to the frame.  There are existing holes in the metal trailer.  Line up the frame, mark the holes and pre-drill now.  

Step 3: Preparing the plywood subfloor

At this stage, I'm working on the 4x8 ply sheet that will be the actual floor. Note, the trailer itself is 4x8. To accomodate the walls that I will build, my subfloor and floor are actually 47" wide - I cut off a 1" strip from the ply.

I used the space I framed out to trace the size of the hatch door (see Step 4).  I added 1/2 inch all around to get the total size.  I used the circ saw to cut out the hatch door.  I temporarily screwed a slat of wood to the hatch to hold the piece while I made the last cuts.  So it wouldnt tear out.

Step 4: Planning ahead for cargo compartment

These trailers are small, even tiny.  So any addtional cargo area helps.  A frequent addition is a cargo compartment nestled under the floor, between the crosspeices on the trailer. 

To accomodate this, I added a metal strap under the second crosspiece.  This required drilling holes into the strap as well as the underside of the metal crosspiece.

Side note: I had never drilled in metal much prior to this.  I was talking to an old guy at ACE Hardware and suggested using plain new motor oil, instead of any fancy cutting fluid, to lube and cool the bit.  As I was drilling so few and so small holes.  Kudos to ACE.

The other side of the compartment was the wooden crosspiece I made, so I just used some angle brackets (from the deck supply section at hardware store).

The actual material to make the bottom of the compartment is just 1/2" ply, I painted it several times with exterior latex to try to protect from moisture. I also sheathed the underside with aluminum flashing.

To install I laid a bead of exterior caulk along that metal strap and around edge where the board met up with the frame.  (I had dryfit before I did this step!!)  Then drilled through strap and backets to make it all hold fast.  Extra caulk where necessary to keep water out.

I also cut a correspnding hole in the 1/2 ply floor for access to the compartment. 

Step 5: Stick this to that

Once the subfloor frame is complete and the ply floor is complete, you can glue and screw the thing together.  I used construction adhesive and decking screws here.  I countersunk everything.  I used a chalk line to plot out where I needed to place my screws. 

After I was all glued and screwed, I used bondo to fill in over the screwheads.  Then sanded it all smoove.  Once smoove I primed it a couple of times and then painted it green with floor/porch paint.

Step 6: More about the floor: tar

Step 7: More about the floor: insulation

Once the tar has congealed after a day or two, then its time to insulate. Why insulate? Depending on your climate, you can have serious condensation issues on the inside of your trailer. It's also more comfortable. Check out that forum for further discussion.

I used 3/4 solid pink foam insulation. I cut to fit. there is a plastic membrane that peels off, I made sure to remove that membrane.  I made the pieces as snug as possible. Then used construction adhesive, screws and fender washers to attach. 

The tar was still slightly tacky, and my pieces were pretty snug fits.  I kind of wedged them in there and they stuck to the tar. 

Step 8: Spray Painting the Frame

I did kind of a crummy job here.  A lot of folks leave their trailer red.  I wanted to make mine black.  I used black spray paint and it took several coats to cover the red...  

You DON'T have to paint the frame.  The red powder coating is certainly sufficient.  If you cut or drill, you certainly want to cover the bare metal. 

Once the trailer is finished I'll go back with another can of spray paint and touch up the visible parts.

Step 9: Attaching floor to frame

In my case I primed the floor, screwed it all together, and bolted it to the frame. One side note - there will be a gap between the metal crosspeices of the frame and the wooden subfloor. I used paint stir-sticks and construction adhesive to fill in that gap.  

I countersunk holes in the top of the floor where carriage bolts pass through the floor to match up with the existing holes in the trailer. 

Then I went back and bondo-ed the holes to get a smooth floor.   Once that was done I used floor paint to paint the floor green.  Some folks use linoleum, plastic tiles, etc.  You can use pretty much whatever you want, being mindful of the weight. 

Step 10: Dealing w Harbor Freight Hub

Now the axles on this particular trailer need some special attention.  Don't be scared.  Once you figger it out it'll be no problem. 

The axle is shipped with some cosmoline type gunk in the hubs.  It's NOT grease.  You have to clean it out and pack the hub with grease before you actually get on the road.  I don't have too many pics of this bc it is messy business. 

You will need some particular tools to do this right.  First of all, you will need new seals.  These can be a pain to get ahold of.  You can order them from HF.  You can also typically find them at a decent auto parts store.  You will need this size seal: 30-52-10.  I finally got mine from Red Trailer (part #SJ8510-18B).  Order extra!  These turned out to be a LOT beefier and well-built than the HF versions. 

You'll need some type of solvent to clean off the cosmoline crud from bearings and the inside of the hubs.  I don't recommend using one of your wife's holiday candy tins as a wash basin - she'll get majorly pissed at you.

Now put it back together.  I watched some vids online on repacking bearings before I did this.  I bought a small size grease gun and bearing packer from Harbor Freight and that seemed to make things much easier.  No pics from those steps - my hands were dirty!

Step 11: Dealing w Harbor Freight Axle

I knew the specs on this trailer were for a max capacity of 1800 lbs or so.  I guessed my finished trailer would be about half that. So I decided to take a leaf out of the leaf springs to relax the ride.  This turned out to be surprisingly easy with vise grips and a crescent wrench.  There is just one bolt holding it all together.

One mod for this plan, from the factory plans to hang the axle ABOVE the leaf springs instead of below.  I discovered when I did that the axle didnt want to mate up cleanly with the bracket on the axle.  So took the leaf springs apart AGAIN, flipped the little bolt over and it worked fine.  It turns out one end of the little bolt is designed to mate up with a hole in the bracket on the axle.

Tightened it all down and we are good to go.  Added the hubs and bolted on the wheels.

Step 12: Envision your Profile

I modded the profile that was in the plans I bought from Kuffel Creek..  Which is not uncommon.  I wanted a more classic teardrop type shape.  I mocked up the profile on a piece of cardboard (you could use anything handy) to see what it would look like. 

original plans call for a profile that is exactly 8 feet long - so you can use a 8 foot sheet of plywood.  my mod added nine inches to that.  so I had to 'stretch' the plywood.  i did this by adding to the tail end.  you'll see in step 19.

Step 13: Add the tongue

Next add on the tongue.  I new my design would not be anywhere close to the max capacity of the trailer (1800 lbs or so).  So I just used the stock tongue setup.  

There are ways to beef up the tongue if you think you might need to.  You can also add crosspeices to the tongue to carry additional cargo or cargo boxes. 

Consider your options.  Just make sure your tongue is strong enough. 

You can also add the tongue jack now too.  I got mine at Harbor Freight.  Now it'll be a lot easier to move this sucker around.

Step 14: Adding jack stands

These stands come in a variety of shapes and sizes.  I liked these because they are attached to the trailer.  You just have to remember to retract them before you drive off. 

I got conflicting advice whether to have them extend to the side or straight back.  I choose to go to the side so they would be more out of the way.  We'll see how that works in real life.

Step 15: Working on Profile, Walls I

Now we can set aside the trailer for a while now and focus on the walls.  I sandwiched two 1/2inch plywood sheets together and screwed in several places.  Now any cuts I make are identical (more or less) on each piece of ply.  I wanted to make sure I had IDENTICAL walls to work from. 

I used a square and tape measure to plot out the points of my front curve.  I designed the curve myself.  I did it in google sketchup to find something pleasing.  Then id' the points I could use to transfer the shape to the ply.  I used a piece of flexible molding as a batten to create the curve for me, then traced with a pencil.  Then used a jigsaw to cut the curve.  Midway through the cut, I screwed in a brace to prevent the piece from ripping off at the end of the cut.

Do the same thing for the rear half of the profile.  DO NOT separate the sheets yet.

Step 16: Working on Profile, Walls II

Inside the trailer, folks frequently have a variety of shelves and cabinetry.  Not to mention there is a door (typically on each side) as well.  I mocked up with blue painters tape where I thought I would like everything to go. 

That helped me figure out where my 1/3 spars needed to be inside the walls.  It also helped me figure out where the spars will need to be across the top of the trailer.    I drilled a bunch of small holes completely through both sheets of ply so I knew I'd have perfect registration on each wall.  This was ENORMOUSLY helpful. 

I also painted all the way around the edge of each piece of ply wood with exterior latex or primer (whatever I had handy).  I wanted to impregnate the edges of each piece, impregnate teh fibers so water would not soak in easily.  Water should never get into this part of the trailer, but I wanted to be careful. 

SIDE NOTE:  At this point I knew I was going to skin my trailer with something.  I was NOT going to leave the wood visible on the side, so I was comfortable screwing through the sidewalls to mount spars and whatnot.  If you want to have the wood visible, you can do it, but it'll make things more complicated.

Step 17: Cut the door.

Step 18: Cut & Lay out the spars, attach spars

The walls on my trailer are insulated as well.  To create that space, and to strengthen the walls I  used 1x3 spars.  This is also important to block out around the door as well. 

Once the spars were all cut to size, I glued and screwed to the sidewall.  The registration holes I drilled were an enormous help so I was sure the spars were exactly where I wanted them AND matching on each wall.

Now is the time to make sure you'll have blocking in place to support any cabinetry, lighting or fixtures you plan to have inside the sleeping compartment.

For the curved door top, I used a 1x6.  I'll use a router to remove the extra material. 

Step 19: Quirky Profile - The discussion and the solution

The standard plans use 4x8 sheets of ply as the basic size of the floor and walls.  But that means you sacrifice a little floor space.  I also felt the curve at the front of the trailer wasnt aesthetically pleasing for me.  I wanted a more pronounced curve. 

BUT I was still limited by the 4x8 size of the floor of the trailer. 

My solution was to "stretch" the side wall by 9".  That allowed the front curve (again, of my own design) to overhang the front of the trailer by 9".  It also meant I had to stretch the tailend of the profile by 9". 

I used a lap joint and a bunch of construction adhesive to build this.  For the tailend, I used the same exact points of the standard cubbie plans.  Using a piece of flexible molding as a batten to trace the curve.    Again screwing both pieces together so they are mirror images and drilling registration holes for reference later.

Step 20: Insulate the walls - Discuss the LIP

Time for more of the pink foam.  I cut to fit solid pink foam, 3/4inch.  Used Titebond II glue to attach to walls. 

One of the features of this build is that you add the headliner from the outside, instead of trying to hold it above your head from the inside.  The approach calls for a pronounced lip all the way around the cabin.  It's essentially the tops of all the spars and insulation cut a pre-determined distance from teh edge of the ply.

What is this distance?  Will it is the thickness of the headliner, plus the spars.  Such that, when the headline r and spars are added, it will create a flat surface for the exterior skin. 

I created a little jig from a razor blade, a piece of headliner (5MM plywood) and a piece of spar.  I deliberately went too high with the spars and pink insulation.  Then I went back and  I used this jig  to score a line where I needed to trim back.  See the pics. 

THERE IS ALSO a lip along the bottom of the side wall.  The spars and insulation also stop a certain depth from the bottom of the wall.  That depth is the depth of the 2x2 subfloor plus the 3/4 inch floor ply.    This lip allows the wall to rest on both the trailer frame (where the outer ply touches) and on the floor (where the spars touch).  

Step 21: Finish the Sandwich: the inside surface of the walls

I decided to use 5MM plywood as the inside layer of the wall sandwich (1/2 ply, 1x3 spars & insulation, 5MM ply).  Again I screwed the two pieces together.  I proceed to trim down the piece so it matched up with the main plywood walls.  This is just a first step, as the inner walls now match the exterior wall size.  We'll still need to cut it down one more time.

NEXT I used that same razor blade jig to score a line where the edge of the inner lip should be.   Carefully cut these off next.  It'll be about a two inch difference that accomodate teh thickness of the roof & insulation.  See the pics.  Ultimately the interior wall matches up with spars and insulation. This creates a lip for the headliner to rest on.

NEXT I traced where the door opening should be.  And cut that out.  Again, if you are careful you should be able to use this material for your door.  Set this aside in a safe & dry place.

I used a polyurethane mixed with stain, two coats on the inside of the inner walls AND all around the outside cuts.  I wanted to impregnate the ends of the walls so they won't absorb moisture. 

Step 22: Paint the floor. Attach the walls.

First thing I did was to put several coats of porch paint (green) on my floor.  Some folks use linoleum or  adhesive tile or whatever.  I was fine with a couple coats of primer and a couple coats of paint.  I knew that I would rarely see the floor bc the mattress would be there. 

Next I attached the walls.  I screwed in through the base of the wall into the 2x2 subfloor.  This created a really sturdy joint.  I used some pieces of ply as braces to hold the walls  up.

I temporarily braced each wall with a couple of spars across the top.   The tiny registration holes I drilled through BOTH sheets of ply while they were still sandwiched were a HUGE help here to get things lined up.

Next step was to attach the inner skins.  I line them up and glued and brad nailed to the spars. 

Its starting to look like a trailer!!

Step 23: Overhead Cabinet, Velvet, Outlets

This is a smaller cabinet that will be overhead of the sleepers.  I added some blocking on the walls.  Then crosspieces.  I used more of the 5MM ply to build the floor and face.  I poly'd the pieces after they were cut to fit and dry fit.  Then glued and bradded to the cross pieces.  I did NOT build doors, that was a personal preference because I didn't want doors or have to deal with making them.  I think I'm in the minority there. 

I also added to 12 volt outlets and chased that wire into the walls and out the top.

Almost as an afterthought I thought it would be cool add some type of liner inside the cubbie.   My wife had some red velvet leftover from a project, so I hot glue gunned that into place.

Lastly, I added some dividers, removable if I wanted.  Psyched.

Step 24: LED lights I

I wanted to have some sort of lighting inside the cabinet. I struck upon adding LEDs to the overhead crosspiece, with a switch to turn them on.

I made sure to wire them so I could pull them out and have enough wire to work with for a different solution if they ever got jacked up.

I also added a second pair of wires with about 3 feet of extra length, just in case I later decided to add any other electrical items. I simply folded the extra wire and tucked it into a corner.

Step 25: Starting Main & Galley Cabinetry

Working off the ends of the sidewall sammich.  I began to add crosspieces and more sections of the 5MM ply and insulation to build up the walls.  I used 1/2 ply for horizontal (load-bearing, shelving) pieces and 5MM for vertical walls.  I sandwiched more rigid foam insulation in the vertical walls.  I probably ought to have done that in the horizontal walls, too, but I didnt.  See pics. 

I screwed through the outer sidewall into the blocking and crosspieces.  I would determine where I wanted a piece, trace in pencil, then drill a pilot hole FROM the inside TO  the outside.  That way when I screwed into the wall, through that pilot hole, from the outside I knew I was hitting my blocking/spars precisely where I wanted to.  It made things very very strong. 

The drawback is that I would not be able to leave the outside of my sidewalls natural, as some designs indicate.

I decided to just use a piece of ply with many coatings of poly as my countertop.  I may come back and cover it with another surface later.

Also, at some point I'll use a router and cut out the frame at the top of each side door.  SAVE THAT PIECE for when you build your door.

Wiring Note:  I knew I was going to run various electrical through the roof, so I used a fat piece of conduit to create a run from the roof down to where my electrical box be.

Step 26: Electric Box

Now there are many many ways to set up your electrical service.  See the main forum ( ) for those discussions.  You can either or both 12volt or 110 service.  I opted for both BUT very basic with the 110 service.

I opted for a longer sleeping area which meant I could NOT put the electrical box under the countertop.  So I built a box on top of the countertop and to the side.  I ran a piece of conduit up the inside of the wall to catch wires that run through the ceiling.  I used 12 gauge for the 12volt outlets and 16 guage for everything else.  I used a fuseboard I got from Bass Pro.  It's meant for boats but worked fine for my purposes.

I also used a "shore power inlet" to bring in 110 service.  It's basically a gasket with a very thin face.  You can plug an extension cord or power strip through the back of it, and the prongs will appear on the face.  The plug is then held in place by a bracket.  Then you can simply plug an extension cord to the outside.  Flap-type lid seals from moisture.  Pretty nifty. 

Step 27: Main Cabinet, LED II, Wiring

In the main cabinet in the cabin, I added 2 more 12 volt outlets.  Then ran those wires in flexible black conduit.  I also added LED lights in the crosspiece with a switch. 

Here is a lot more detail on how I built the LED features:

I bought individual LEDs, LED holders, resisters, from Radio Shack.  I used my regular spar material.  I cut a channel along the side to hold the wiring.  Then I drilled a 1/4 inch hole allthe way through the piece ~ this will hold the LED bulb.  I glued a LED bbulb holder to mount the bulb. 

I then drilled an intersecting hole 3/4" (I think) sideways through the piece.  This gave me access to place the bulb, solder, etc.   Then link up all the bulbs, with the proper resistor.  Go here for help with calculating the proper resistor.  I couldnt have done this part without this calculator.

It's critically important to keep track of the polarity of yer bulbs.  Don't forget!

See pics ~ they can describe better than I can. 

Step 28: Tripled Spar for Hurricane Hinge; Battery Box

Now that I have the 'attic' all built, I can put in a heavy duty spar.  This is a tripled-up piece of wood that will be the base for the hurricane hinge.  This is where the real hatch will attach to the trailer. 

I also added the batter box and battery disconnect.

Step 29: Porch Lights

On either side of the trailer I added an exterior light next to the door.  I had left a channel inside the wall sandwich to run that wiring. 

I'm fortunate there is a very good RV supply place in KC that carries a ton of RV parts and supplies.  They don't have a website.  You can find similar lighting on the intertubes.  I added a switch on the interior for the lights.

Step 30: Install Headliner

This is essentially the ceiling inside the trailer.  I used more 5mm plywood, painted with the poly stain mix.  I was worried about bending the ply after I applied the poly.  So I bent the ply into an approximate shape to apply the poly.  I was expecting a battle but really had no problems attaching.

I then placed my structural spars over the headliner, starting with the very lowest in the front.  This "pinched" the ply between the lip on the walls and the spar.  I also chased the varies electric wires into the roof space, then through holes in each spar. 

I wound up not putting _any_ material fasteners through the headliner!!  It was pinched into place under the spars and on the lip.  I did add a stripe of Titebond II glue along each spar. 

On the roof you will want to add any blocking you may require for lighting or a vent/fan.  If you plan on a roof rack or storage or roof-mounted solar panel, you'll need to start planning how to mount those items.

One last note, the 8 foot long piece of headliner was not long enough to reach all the way back the triple spar.  I had to fashion another 18inch piece of headliner to make up the difference.  This range included the spot where I have that conduit chase, so I cut a notch for that.  I also wanted to add some lighting in the back of this cabinet, so I hot-glued a LED strip in the back. 

Step 31: Insulate the roof

After the headliner is installed, you can start to glue in your insulation.  I used about a 2 inch of rigid foam. 

On the curves I used a base of 3/4 inch foam, kerfed with a utility knife so it would fold.  I used Titebond II to glue it down.  I then used 1/4 sheets (usually three) to fill in the rest of the space.  Also glued with TB II. 

I used a variety of nails and strips of material to hold it all into place. 

Step 32: Blocking for Light, Vent; Notes on VENT FAN

At the appropriate point, you'll have to cut a hole for a vent.  I wired separate vent fans that were actually 12 volt PC fans. 

Step 33: Finishing Wiring

With the headliner in, the vent and ceiling light installed, the insulation can be finished and the wiring can move along. 

I ran the wiring through the roof, drilling horizontal holes through spars to run the wires.  I chased the wires down through the conduit tube and started to connect to the fuseboard.  I found it critically important to label your wires.  If you plan to use LEDs you also want to keep track of polarity too!!

Like I mentioned earlier, I used 12 gauge wire for my outlets.  But I used 16 gauge for everything else.  In my case, I don't expect a heavy amp-load.  You can google and read about max amp loads for different wire guages.  Also read about the 'amp-draw' that various fixtures may have.  That will influence your wiring decisions.

In my case, I'm only going to use 15amp fuses for my outlets and 10amp fuses for everything else.  Why?  I'm going to want to know (and stop) any heavy amp-draws off my battery.  It'll blow out an automotive glass tube type fuse, but those are cheap and I'll carry many spares.   Radio shack has em by the bag.

Between the fuse box and the deep cycle 12 volt battery are a couple of safety precautions.  One is a 30 amp circuit breaker on the positive line from the battery to the board.  The other is a mechanical cutoff switch. 

You can see how I fleshed out the 110 service too.  I used a power box with a true circuit breaker in it.  I plugged that on the back side of the 'shore power inlet'.  I have a portable GFCI unit that will go into the outlet I draw shore power from, thru extension cord to inlet.  For inside the cabin, I'll plug in a small power strip into my circuit breaker box.  It's kind of rigged but it satisfies my need for simplicity and not dealing with making any 110 connections myself.

Step 34: Book Shelf

So it sounds weird but I wanted a bookshelf in my cubbie.  Of course a bookshelf in a moving vehicle presents some concerns.  So I wanted to create a way to hold the books in place.

I started with a 1x6 board, cut to fit the entirely across the cabin.  I routed two channels, about a foot long at each end.  (see pics). 

I used a milk crate and foam insulation pieces to find the right height.  I made sure it was level and square then traced the end of the board on the wall.    I drilled from the inside out to give me the exact point to screw in from the outside.  In general I used this approach for most of my walls and cabinets. 

This approach is different than most plans.  Most plans do NOT have you screw through the walls.  I figured it was a hell of a lot easier.  I can bondo and smooth and still sheathe in aluminum, paint, etc. 

Step 35: Attach exterior layer of roof.

This was kind of tricky.  I actually glued the front half down first, with some aluminum nails at key points.  Once the glue cured, then I glued down the second half/roof.  You'll need lots of clamps and blocking. 

Again one piece won't stretch the entire distance.  Trim the first sheet so it ends midway on one of the spars.   Then cut another piece to fit from the spar back to the tripled up spar where the hurricaine hinge will go. 

I had some trouble getting the sheet to lay right along the tripled up spar so I ended up using a lot of little nails to keep it in place until the hinge was screwed in place.  See the next step.

Step 36: Attach roof side of hurricane hinge

Now that outer roof is down, we can attach body side of hurricane hinge.  I special ordered this hinge online.  It comes in a beefly plastic tube, so no worries about it getting damaged in transit. 

Simply follow instructions on how to affix it.  Initially I used a 2x2 and clamps to hold skin in place as glue cured.   I had slight problems with the lip of the 5mm plywood staying down, so used a ton of tiny nails.  I'm a little anal retentive sometimes. 

I drilled pilot holes ( again using the hinge drill bit tool) and squirted some silicone caulk in each hole before final assembly.  You probably cannot do final attachment at this point.  Just do a dry fit.  I think I attached and removed mine 3 or 4 times.

Step 37: Hatch Part 1 - Hurricane Hinge

I'm using a special water-resistant type hinge for the galley hatch.  Its designed so that water cannot run inside through the hinge.  Available only online that I know of. 

To support that weight I needed a beefy cross piece.  So I sistered up three crosspieces here.

The back of the main cabinet leans up against this piece.  I put some TBII in there to seal it.   I used some pencil lines so I knew where the screws were.

The outer roof covers this spar to very edge.

Step 38: Hatch Part 2 - Build the Hatch Frame

I used a piece of cardboard to trace the actual curve of the hatch.  Then I transferred this to 3/8 ply, bc that is what I had on hand. 

I cut out 10 pieces.  I sistered them up in two pairs of 2 and two pairs of 3.  Using TB II.

Once the ribs were built, I carefully put them in situ on the trailer.  I used a 1/4 inch spacer at top of spar, 1/2 inch space along walls and 1/16 at base of spar.

I positioned some cross pieces and notched out the spars where appropriate.  Then I assembled everyting together, glues and screws, but LOOSELY.  I then put the frame back on the trailer, made sure all my spacing was correct.  ONLY THEN did it cinch down the screws.  Then left it to dry in place.

Note: some folks complain/warn that their hatch springs out after it is built.  Those hatches seem to be built with the ribs going horizontal instead of vertical.  Such that the plywood overpowers everything and pushes the hatch out of shape.  I'd suggest running your ribs vertically.  YMMV.

Step 39: Hatch Part 3 - Skin the Hatch; Lights and Electric

So I have my framework ready.  Now I attach the skin.  I'm using the same 5mm plywood from Lowes.  Made in USA.  I measured the distance I'll need and cut to fit.  I did NOT enclose the frame because I thought it looked cool.  Once I'm finish sealing the whole thing w CPES I'll paint the underside white.

I plan to use a minimum number of fasteners to attach the sheet to the frame.  I used construction adhesive and glue and lots of clamps.  See pics. 

One element to address is the overlap of the side lips over the side walls.  I had a 1 inch overlap on the two side edges of the hatch.

Next I used rattle can of primer to paint the inside white.  It wasn't enough, so I ultimately used a paint brush and some Kilz to get better coverage.

Step 40: Hatch Part 4 - CPES, spray paint & hardware

Once the hatch was assembled.  I coated the whole thing, inside and out, w CPES.  I then painted the underside with white primer.  I used a spray can for the initial coat bc I knew it'd be tough to reach all the spots on the ribs with a brush or roller.  I'm going to leave it white to it helps keep the workspace bright. 

I ran the wires for the running lights.  Affixed bracket for tags.  I added switched overhead light.  I don't like how that overhead light works, but it's fine for now. 

Eventually I'll cover the inside of the hatch for a neater look.

ONE NOTE:  I put a trailer wire connection between the main body of the trailer and the hatch.  That way if I want to remove the hatch, I can simply disconnect the wires versus having to cut them.  

Step 41: Hatch Part 5 - attach hatch side of hinge

Now we can attach the hatch side of the hurricane hinge. 

I clamped the hatch in place, then clamped the hinge to the hatch.  I drilled pilot holes with the hinge tool.  Again this tool is makes it super easy.  Then removed the hinge and finished the pilot holes with a regular drill bit. 

Once these are complete, you'll be able to slide on the hatch and check it out!!  I used a 2x4 to prop up the hatch initially.  Be careful as wind can catch your hatch!!

I drilled pilot holes ( again using the hinge drill bit tool) and squirted some silicone caulk in each hole before final assembly.  Again this is probably not the final attachment, just do a dry fit and be prepared to pull it back off for further work.

Step 42: Wire the brake, marker, turn lights

I deliberately kept the trailer running lights completely separate.  They are run from a plug into the tow vehicle like any trailer.  In this case it's a four prong connector.  The wires are routed under the trailer.  Then they snake up along the inside of the driver's side wall through and out the top of my electrical box.   I added an additional connection at the hatch so I could simply unplug instead of having to cut wires if I need to remove the hatch. 

I wanted to make sure my brake lights were super obvious so I placed them on the hatch AND placed a third light at eye level.  It's LED, super bright and super annoying to anyone following me.

Step 43: Epoxy everything!

Once the hatch is built and the roof is attached and cured. And you have the hole cut for the vent fan (although you could probably wait and do at a later step if you wanted) it's time to seal the outside of the trailer. 

I used Clear Penetrating Epoxy Sealer (CPES) from The Rot Doctor.  He seems to be a good guy to work with, responded super-quick to my email questions.   This stuff penetrates and encapsulates wood so that it resists rot and deterioration.  It cures rock hard.   It will still need some sort of UV protection.

I applied the CPES per the directions.  I ended up with three coats in quick succession.  I used a total of two 2-quart batches to cover everything (trailer sides & roof, hatch, doors) and I have a little bit left over.

I used an epoxy based filler to patch cracks & seams and hide screw holes.  That is the white dots and stripes you see on the raw-looking wood.

Other options would be to use some other type of sealer or even exterior house paint. 

Step 44: Build the Doors - Part 1

Now it is time to turn attention to the side doors.  You should already have some door blanks cut from when you made the openings in the side wall.  You should also have the curved pieces you trimmed out of the top of the door frame.

Build up the doors like you built up the walls with 3/4 inch spars and rigid foam insluation.  Trace the window trim pieces where you wnat then and cut them out with the a skil saw.  I found it immensely helpful to use pencil and sharpie to mark my pieces so I didnt get them confused. 

Assemble and dry fit the window, but DO NOT permanently attached yet.   Apply CPES to exterior side and let dry.

Step 45: Build the Doors - Part 2

So now we have two door blanks to work with.  Make sure you keep track which is passneger side and which is drivers side!!

Before we can affix the hinge and latch mechanisms, we need to see how the door will fit in the opening.  To do that, we FIRST have to fit all the trim. 

I did my trim a little bit unorthodox.  Most folks use a T-shaped aluminum trim that creates a natural cover of the door seam.  I was itching to get this done so I just used 1/2 inch angle from Lowes and ACE.  I used lathe screws with oversized heads to attach.  I used a simple jig on my drill press to hold the al angle while I pre-drilled holes.  Try to make sure your holes don't overlap with adjacent bits of trim.  I had a couple spots where the screws crossed paths.  That is a pain in the neck!!

A CRITICAL PART OF placing the trim was using a hinge drill bit set from Harbor freight. This is an attachment that centers a pilot hole in the middle of an opening.  Then you can come back drill out the hole knowing it is exactly in place.  Super easy to use (altho they needed a little bit of powdered graphite at first). See here: http://www.harborfreight.com/3-piece-hinge-drill-bit-set-41907.html.  I strongly recommend this type of tool.

I also used a 1-3/8 inch door bottom as my threshhold.  I ended up having to trim down the rubber gasket, but it worked great.  See pics.  behind the hinge  I used a piece of inner tube rubber to fill the gap.  I also used some flashing that I had to cover the door jambs.

I used a wide piece of aluminum along the top of the door frame.  The lip of the aluminum extended proud of the wall.  I used this ledge as a base for my drip edge.   The drip edge is just a piece of molding, w CPES.  I predrilled  nail holes. 

To get the molding to bend easily I fixed a piece of conduit vertically.  Covered the bottom end with duct tape.  Put the molding inside, then pouring in boiling water from teapot.  (Don't tell my wife I used her teapot.)  After about 5 minutes I poured it out and it was much more pliable.  Then I affixed it to trailer. 

Once all the trim is in place, I could put the doors in place and finaly see how they fit.

Step 46: Build the Doors - Part 3

Once the opening was all trimmed out AND the door was all trimmed out, we could fit it together and see where to attach the hinge.  I used a stainless steel piano hinge and the lath screws. 

A CRITICAL PART OF placing the hinge was using a hinge drill bit set from Harbor freight.  This is an attachment that centers a pilot hole in the middle of an opening.  Then you can come back drill out the hole knowing it is exactly in place.  Super easy to use (altho they needed a little bit of powdered graphite at first).  See here: http://www.harborfreight.com/3-piece-hinge-drill-bit-set-41907.html.

Once the hinge was in place, I taped it down and drilled my perfectly-spaced starter pilot holes with the hinge drill bit.  Then came back and finished them with a regular drill bit.  Then I attached with lath screws.

Then I went to work on the latch.  Same deal: start pilot holes with hinge drill bit, drilled them out, then attached with lath screws.  I ended up using some pieces of aluminum to build up under the handle.  You'll have to fabricate something that works for you.  At some point you'll cut down the square rod that fits through the internal mechanism.  I left mine long for now - I'll take care of it down the road.

Step 47: PAINT

Our initial plan was to sheath this thing in aluminum but we ran into two snags.  1.  Aluminum was really expensive.  And 2 we really wanted to start using this thing.  So my wife and I decided to just paint it.  Which we we ended up loving.  And if we change our mind we can skin it with aluminum later.

The first step to paint it was to take off EVERYTHING.  Take off the trim around the doors, take off the hurricane hinge.  I had not attached the vent yet so that was fine. 

I used a high quaility exterior latex paint.  Two coats.  I used a cream color and I'll later paint on a fat green stripe.

Once that is good and dry, reattach all the trim and hinges.  I used a squirt of silicone caulk on all the screws to make sure everything was sealed.

Step 48: Build the doors - Part 4: the return of the windows

Now that we are all painted and reassembled, we can do some final attachment. 

I used some standard windows I ordered online.  They sandwich together into a hole that I pre-cut in the door.  My door was just a hair thicker than the trim piece, so I had to use some slightly longer machine screws than what were supplied.  I also drilled some pilot holes just to make things go quicker. 

Check it!

Step 49: Vent Fan

I used a vent that is smaller than the standard size.  It did NOT come with a fans.  So I used some simple PC puck fans and small pieces of metal angle.  Used simply bolts with wingnuts to attach. 

I wired them to include a plug/socket connection in case one craps out.  I can swap out the fan without having to cut a wire.

Look at Step 32 for more info.

Step 50: Road worthy - more or less!!

So now that it's painted, the windows are on, the doors reattached... it's time to take some pics.  There is still some work to do, but we can get this thing out on the highway. 

Make sure your trailer lights are working correctly.  I used a bungie to hold the hatch closed. 

At this stage I took my first peramubulations around the neighborhood, and then onto the highway.  It towed like a dream.  I had it up to 70 mph with no problems.  I could barely tell it was there.

Note: in most other states, you'll have to get a license tag from your DMV.  In Kansas, for trailers under 2,000 pounds you don't need a license plate issued to you.  You only need to display a sign indicating trailer us under 2,000 lbs.  You'll have to investigate laws for your area.

Step 51: Trimming out the hatch

Work isn't done.  Now I'll need to add some trim along the sidewalls of the hatch to keep out water. 

First I'll use some 1/2 inch aluminum channel from the box store.  A lot of places can give you instructions on annealing the aluminum to make it soft enough to bend.  I was just toying with it and simply gently bent it on my knee!!  I couldnt believe it.  I slowly bent the channel and dry fit it into place until I was satisfied.

I used a jig that I created to hold the channel sideways so I could drill pilot holes to fix the channel to the wall.

I also cut a little notch at the bottom end of the channel where the wall meets the floor.  See pics for details.

I also added a strap of 1inch by 1/8 aluminum alongside the underside of the hatch edge.  I used large pop rivets to hold in place. 

I'll eventually add some rubber molding onto the hatch itself, that will compress against the al channel to seal the hatch.

Step 52: Bedding

There are lots of different approaches to bedding.  We got a great deal on a 2 inch thermopedic mattress topper. 

I measured the distance from inside wall to inside wall, and then cut the mattress about a inch wider than that.  I wanted it snug in place.  It worked out really well.

Two inches might be a little thin for some.  When I sit on it, I can feel the floor, but when I stretch out I don't.  If it becomes a problem, we can add a second layer of closed cell foam.  My wife is going to sew up some special sized sheets and whatnot.

Step 53: Fenders

I'm gonna add fenders.

Step 54: Fittings

I'm gonna add hooks, lights, iPad bracket.

Step 55: Bookshelves

I'm gonna finish out the bookshelves in the sleeping compartment.

Step 56: Diamond plate gravel shield

I'm gonna add a metal gravel shield to bottom half of the leading edge of the trailer.

Step 57: VIDEO MADNESS I

A few folks have asked for videos.  So here you go!

Cubbie Intro (fixed now).
http://youtu.be/OpyLXvquRLQ

Cubbie battery & wiring box.

Closer look at shore power.

First look inside the cubbie.
http://youtu.be/opkwnN7oScU


More inside, hook fixture.

Laying down inside.

Step 58: VIDEO MADNESS II

Look closely at fan.

Look closely at LEDs

Look at porch light.

Hatch in floor.

Red felt glued on to shelf.

Step 59: VIDEO MADNESS III

Look again at battery disconnect and battery tender.

Closeup of taillights, hatch seal and edge of trailer body.

View underneath trailer.

Step 60: VIDEO MADNESS IV

Up close of latch and doors.

Another view of closed hatch.

Comments

[Rob O]

Hey everyone, per requests I've added a few videos at the end. It's the last 4 steps. Please consider voting for this 'ible in the Summer Contest. Thanks!

[MakeItWithJason]

Thanks for the great Instructable. Hope you'll check out my teardrop, too!

[schmitta]

Looked up and watched your instructable tonight. You obviously thought twice and cut once. I think I saw you had some plans at some point. What were they? Thanks. Alvin...

[Rob O]

Hey there. I got my plans from here: http://www.kuffelcreek.com/8'_cubby.htm
I found them very helpful. I customized a lot or did things differently. You can follow them to the letter or incorporate your own changes. I don't think any two trailers are alike!! Also check out the teardrop trailer forum; lots of good info there. Good luck.

[bryan3141]

I'm not sure I understand. Why did you want the axle above rather than below the leaf springs?

[DeathMagnet]

With the axle above the leaf springs it lowers the deck of the trailer by 3 - 6 inches (depending on thickness of axle and spring).

[bryan3141]

ah, thus removing the need for a ladder to get to bed....makes sense. :) Thanks! I REALLY want to do this, but I think I'll want to add a 12v heat pump to the party...once I figure out how many batteries I need, I'll probably go ahead with the vent like you have.

[rowerwet]

unless you are camping in the tundra somewhere these trailers are rather warm in cold weather as the interior is small, put a second person or dog in with you and you will need the windows open to let the heat out.
you could also try this idea http://www.instructables.com/id/The-Hotmail-Heater/

[coachmachado]

For someone who lives in California (me!), how would you get this registered with the Department of Motor Vehicle?

[Rob O]

Hey coach. I wouldnt have the foggiest idea. Fortunately in KS it is super simple. BUT I can tell you where you can do some research: http://www.mikenchell.com/forums/

Search those forums. I recommend using google advanced search. The search function within the forums is very buggy. Or even just post and ask. There are many many teardrops and other small camper trailers in CA, someone will know. Good luck!

[rowerwet]

if you live in a hard state, look up the DMV in Maine, they are very easy to get plates from even out of state. Then take your Maine registration and plate to whatever state you live in and ask to transfer registration. There is a sticky thread on t&tt.com (formerly mikenchell.com that explains the process better, as well as more than one horror story about certain states. One guy in PA spent nearly as much on registering/weighing/inspecting his trailer as the frame cost. Not to mention the time lost in the whole process. Using the ME shortcut another walked in and out with his plate that day.
Just look at the registrations on the 18 wheeler trailers next time you are on the road, many will be registered in ME, and not because they were bought or operated by a ME based company.

[gmajane]

Hi...I enjoyed your instructable. I have a homemade teardrop that I bought from a friend. How did you get that plate for Kansas? I was told I didn't need one here in Kansas for a trailer that small. I carry the regs at the recommendation of the DMV. Did you make your plate? Thanks!!

[Rob O]

I didn't make it. I bought it at KC Home Trailer Co. They don't have a website.
[phone], 1115 Merriam Ln, Kansas City, KS 66103

[Rob O]

It turns out to be pretty common to buy utility trailers like this. I didnt know that either. A lot of hardware stores have them, or can order them. I got mine at good ol' Harbor Freight.

The trailer has a spec weight limit of 1,800 pounds. Sometimes called a '2,000 lb' trailer but that is definitely rounding up. My finished trailer weighed about 800 lbs, but that is without food/gear. I weighed it on a truck scale.

Start to finish it took me about a year and a half. But at least half of the time it was either too hot or I was too busy. So really maybe 8 or 9 months of nights and weekends. It would ultimately depend on how fast you work and how much time you could devote to it.

[reallyreally]

Man, I've been needin' a board stretcher! Does HF carry 'em?

Great trailer!

[Rob O]

Ha! I wish. My method was a pain. But I was really pleased with the result!!

[reallyreally]

My son and I plan to build a teardrop, then take 'er cross country. Yours has re-inspired us!

[Rob O]

Wow thanks. That makes my day. Check your inbox for another message!

[dr.knowitall]

lol, yeah actually, I'm a journeyman machinist and that is a trick I learned a long time ago (using motor oil). believe it or not, I've even used vegetable oil as a last resort for aluminum pieces and it works surprisingly well.

[sconner1]

I use any oil i have at hand. Veg, mineral, motor, 3-in-1, air compressor, etc.
Not WD-40 though.
Usually no problems for a few holes.
I suppose if I were working on an industrial scale, I might tell the difference in cutting oils.

[dejure]

For those who want to crank up the life of plywood and such, treat it and all wood surfaces before you apply any other protectant. You can make your own treatment using cheap poly and a hardening oil, like tung oil or boiled linseed oil.

Adding hardening oil to your poly reduces its hardness, but gives it more flex (that's how they crank up the expensive exterior finishes, by making them "long oil" (more oil) finishes. Adding about 25% hardening oil to your poly will reduce its tendency to separate from your wood.

To start treating wood, start by thinning your treatment 50% with mineral spirits, turpentine or naphtha. As long as the wood keeps soaking it in, keep adding it. I'll often leave a bucket by the wood and do other thing throughout the day and add more each time I walk by.

Give the first treatment a few days to harden (the solvent will evaporate off and the poly-oil mix will harden). Then you can drop back to a 25% mix and do the same thing.

Doing this wherever leaks might appear or where the wood would be subjected to water (e.g., around vents, doors and windows, or the underside) can greatly increase the life of your investment. Even if the siding, tar or whatever fails, it will come up against your polymerized wood, which will be protected,

I do this to particle board, such as around sink installations, and it stops it from swelling and falling apart.

[sconner1]

Great tips.

[rowerwet]

I avoided using any fasteners as much as possible on my TD, the box is bolted on with 8 stainless bolts every other joint is only glued with PLPremium construction adhesive, as I build small plywood boats with it and it is water tight and if the joints are made correctly (chine log) it doesn't fail. the only screws I have in my whole build are to hold the walls to the deck and they are special coated deck screws, as the heads face down they will rarely see water.

[rowerwet]

one guy actually has a hole in the bottom of his "cargo" box, by placing the hatch on the ground he can stand up inside his trailer to get dressed etc.

[rowerwet]

I went as light weight on the hatch as I could, I made the ribs and spars the real strength then skinned the hatch with FRP (shower wall liner) held on by channels around the outer edge, I figure the hatch is just a fairing, so no strength is needed, even in snow the curve is enough to just let snow slide off.

[rowerwet]

I made my doors rectangular as square corners are easier to match on my double walled doors and walls (two skins of 1/4" with 1x2 framing and foil faced foam board in between) after a year of using a fwd hinged door I plan on making a gull wing door set up instead, I would like to have a roof to step in and out underneath if it is raining. I plan on making the hinge up top at the roof line.

[rowerwet]

I also used paint for my TD finish, however I did a canvas/paint finish like they used on old wooden boats before epoxies. I bought cheap canvas drop cloth from Home Depot, cut to rough size of each side of the trailer, rolled on the paint thick into the canvas to fully wet it out, then rolled a heavy coat of paint onto the TD, then rolled more paint onto the canvas as I applied it to the trailer. Use porch and floor exterior paint for the final coat and it should last the life of the trailer with a few re-coats as needed. The canvas gives it some nice texture and keeps the paint tough. It also hides a few boo boos that I have in my plywood skin :-)

[rowerwet]

on my TD I used the "live plastic" hinge, much cheaper and fully water proof, Hurricane hinge is great but expensive. (just an option to consider for other builders) you just get a light aluminum strip to put on top of the hinge and screw down through it after laying rtv along the edge. One advantage is that you don't have to figure on heights (offsets), as you may have to with HH.

[fastfloyd]

I am just really puzzled about the hole in the floor. What is it for?

[Rob O]

It's a storage compartment. It's not very deep - essentially just the depth of the trailer frame. But every bit of space is helpful on this thing.

[Mower]

I thought it might be for ice fishing!

[dchall8]

Before I start coming across like a buzzkill, I first want to say that this is an amazing project and you did an amazing job!  Nicely done and nice instructable.  If you wanted to improve upon it you might put a parts list, cost, and sources to buy up front.  But that is beside my other point...

There is a reason why cars (and boats for that matter) are no longer made of wood.  Wood is normally joined together with steel fasteners.  When wood absorbs moisture, the steel fasteners are right there in prolonged, direct contact.  The screws will rust, shrink, and fall out.  Some of the modern deck screws are coated to prevent rusting.  From my experience they work very well.  I have had occasion to disassemble some old projects and the coated screws were actually reusable.  So I would caution people to use excellent hardware when trying to make a vehicle like this out of wood. 

Another issue is that wood shrinks and expands with moisture and temperature.  The joints you thought were tight could loosen without doing anything.  With that in mind I would strongly suggest a full coat of good glue on both sides of every joint.  Leave no room in the bond for moisture to enter the joint.  Wipe the excess after screwing it together. 

Regarding your glue, Tightbond II: it is a glorified Elmer's white glue.  For a project that I wanted to keep, I would use regular Gorilla Glue.  Gorilla Glue is 100% water proof, not just water resistant.  Gorilla Glue also foams and expands to fill wood grain as it sets.  Gorilla Glue joints in wood are stronger than the wood itself.  When I was in college we built a wooden airplane using the glue that is now called Gorilla Glue.  It was the only glue approved for making wooden airplanes.  It is very good stuff.  Gorilla glued joints will not loosen with moisture or temperature. 

Again, very well done project.  Thanks for posting. 

[dejure]

Just a note, or two:

Regarding fastening hardware., it really is a good time to apply that old concept of "I can't afford cheap."

Regarding the filling effect you attributed to Gorilla Glue, while it does fill gaps, the fill offers no structural integrity to your glue joint. To the contrary, glue joints must be tight, just like with Titebond, for the glue to work well. That said, Gorilla glue and similar products by other manufacturers are good glues (one side MUST be moistened, as stated in the directions).

End to end (butt) glue joints don't hold well. That's why you see things like finger joints (like both hands spread wide, then joining them by pushing fingers together to fill the gaps), lap joints, dove tail joints and so forth. Laying boards over the top of each other, then removing half the thickness of both boards, so when they over lap the joint produces the same thickness of a single board, but produces a larger glue surface.

A good glue joint beats screws and nails every day, baring deterioration from moisture or heat, which may not be an issue with most quality glues.

Treating all surfaces of your wood with hardening oil or paint, after gluing, will reduce movement of the wood from changes in humidity.

Since your surfaces are going to be covered, you can use any color paint. As such, you can go to specialty paint stores and buy mismixed oil based paint for a fraction of the retail cost. Generally, five, rather than thirty or so a gallon. One store sells its quality mismxied paint for one dollar a gallon.

Like hardening oils, oil based paints can be diluted (mineral spirits, turpentine, d-lemonine, or Naphtha, whichever is cheapest) and applied in several coats.

[Rob O]

Gee thanks for the half-hearted praise. Read steps 43 & 47.

[dchall8]

Half-hearted? You got two "amazings" and a 2 1/2 unsolicited hints for you to use next time or for people coming along after you to take advantage of.  You have done ALL the heavy lifting on this "amazing" project. 

I would discourage you from skinning it with aluminum.  The aluminum would become a dew trap and guarantee the wood inside would rot.  The epoxy outer covering is probably good.  I'm not sure if wood lasts longer being allowed to breathe or being fully enclosed in plastic.  Years ago I used a polyurethane covering on another wooden project, but eventually it delaminated to allow moisture in.  Hopefully they have advanced the technology with the epoxy. 

Here is a link to the National Woodie Club.  There is a lot to know about wooden vehicle construction.  If someone wants to learn more, the link is a good place to start.  Maybe someone will do an Instructable on building a wooden car from scratch. 

[Rob O]

You are remarkable.

[Bubbler]

Well done. I wish I had one of these little campers. Good luck on your travels.

[Mike Causton]

Hi Rob - me again, I'm afraid!

I can't find any mention of the timber size you used for the structural spars on the roof. Was it perhaps 2 x 1?

Thanks, Mike

[Rob O]

I used a variety of sizes. In the front curve mainly 2x1. I used a few 2x2 where I planned to attach some diamond plate AND where the outer skin had a seam.

I also used a couple of 2x3s across the flat of the roof in case I ever wanted to attach roof brackets or carry a load like a canoe or boat.

[Mike Causton]

Thanks Rob!

Hope not to worry you any more now. Best wishes.