Teardrop Travel Trailer (added VIDEOS!)

NOTE: This trailer is now for sale!  Contact me if you are interested!!  Thanks!!

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.

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. 

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.  

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.

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. 

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.

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. 

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.

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. 

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!

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.

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.

Next add on the tongue.  I knew 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.

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.

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.

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.

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. 

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.

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).  

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. 

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!!

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.

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.

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.

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. 

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. 

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.

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.

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. 

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. 

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. 

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.

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. 

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.

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.

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.

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.

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.

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.  

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.

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.

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. 

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.

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.

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.

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.

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!

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.

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.

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.

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.

I'm gonna add fenders.

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

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

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

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.

Look closely at fan.


Look closely at LEDs


Look at porch light.


Hatch in floor.


Red felt glued on to shelf.

Look again at battery disconnect and battery tender.


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


View underneath trailer.

Up close of latch and doors.



Another view of closed hatch.