Category: Adventure Trailer

This adventure trailer was the first thing I wanted to do with TrailTop parts. I wanted something that would be a pretty straightforward build and would showcase how easy Trailtop components are to work with.

Adventure Trailer Build Plan:

• Custom 4′ x 6′ welded trailer with 17″ Jeep wheels
• ~3′ tall TrailTop shell with large rear barn door and side cargo door
• Storage space inside TrailTop shell as well as side and tongue storage
• Easy deploy rear camp kitchen
• Functional on-board water, propane and electrical
• Roof top tent

I chose to design a custom fabricated trailer for this project to get all of the features I wanted as well as to simplify the build process. Here are some highlights of the design:

The frame sits on a 3500lb axle and leaf spring with E-Z lube hubs.

The main platform that the TrailTop shell will be built on is 4′ x 6′. I went ahead and had the floor welded in and powdercoated rather than building and sealing a plywood floor.

I went with a versatile tongue platform which has tie-down loops on all 4 corners. This way I can strap anything up front, depending on what is needed for a particular adventure. Of course there will be more storage inside the TrailTop shell as well.

A close up look at the mounting tabs I had welded in to each of the 4 corners. These will be used to bolt the TrailTop shell to the trailer later in the build. More details when I get to that step!

The custom diamond plate side steps are welded in to the fenders. The inside of the fenders were boxed in with sheet metal so that the plywood walls do not have to hold up to road grit, water, etc from the tires. The wheels are a pair of stock 17″ Jeep wheels I picked up locally.

All of the trailer lighting is LED, fully enclosed in sheet metal ‘pods’. These should be bombproof!

Off the back is a 2″ hitch receiver, I expect I’ll hang some bikes off of it eventually. I grabbed some cheap bolt-on dock bumpers, I may try to find some that are the right size to mount to the outer edges of the corner steps as well. They won’t do much if I really hit something, but they will at least protect the powdercoat and my lights if I back into a tree or something at a campground.

Up next, it’s time to start preparing to build the TrailTop shell.

I am excited about how easy this phase of the build was, which is what originally inspired me to try and make these parts more available to others. The basic cutting and fitting techniques can be found on the ‘TrailTop System’ page but more details will be shown here.

I definitely spent some time at this step thinking through the plan before breaking out the epoxy. I needed to make sure I was happy with how the parts fit together, and that I could quickly lay the parts out, square them up, and clamp them together. I even made a few ‘practice runs’, which I highly recommend, just to make sure that when the epoxy is open and the clock is ticking everything came together the way I wanted.

I made an adjustable jig with galvanized strut channel, but since I am expecting to build several projects for the website I wanted something that would work again in the future. You could easily build something with some scrap lumber or plywood as well, or even just tape the dimensions out on the garage floor and ‘eyeball’ the parts to fit as you fit and clamp them together.

I used whatever scraps of wood or angle iron I had around to level the jig and clamped it on to a couple of folding tables so I didn’t have to work on the floor. Taking some time at this step definitely made actually assembling the 2 main side walls a breeze, as well as ensured they were identical to each other. Again, for a single project this is overkill, a simple box made of lumber or plywood would work great.

I decided to epoxy the corner pieces to the ‘legs’ of the shell as a first step and let those cure. There are lots of ways to do this, but I simply clamped the leg pieces onto my jig and used a couple cheap spring clamps to hold the corner pieces in place. I used some adjustable bungee cords which were perfect to put just a bit of clamping force on the joint while the epoxy cured.

The West Systems Six10 pre-thickened epoxy is awesome. I have never used it before this project, but I am glad I took the recommendation and gave it a try. I purchased a few tubes as well as a bag of the static mixer tips. It seems expensive at first, but the ease of use, the cleanliness, and the near zero waste makes it the ideal product for this application. Once I had a tube loaded in my caulking gun, I simply squeezed it where I wanted it to be and put the pieces together. I pulled each joint apart one time to check that I had proper coverage, I found a few spots where I had not laid down enough epoxy to bridge the gap between the two TrailTop parts. A few squeezes is all it took to resolve the problem. Once I was happy with the coverage, my planning paid off and I was able to just quickly clamp everything in place while the epoxy cured.

I also ran a bead of the Six10 into the seams between parts which will add strength as well as make smoothing everything out with body filler easier later on in the project. Side note: the permanent marker scribbles you see were simply how I kept track of which corner was fitted to which piece. I did not plan to use them for alignment at all, I just wanted to make sure I didn’t accidentally epoxy parts together differently than I intended.

Once the legs were done, I was able to clamp them to my jig and make sure everything was level and square so that the longer top section would drop right in place.

One small detail, for the top piece I drilled one hole in the flange so I could still use the bungee cord method for applying some clamping force to the joint. I used a little s-hook as you can see in the photo, the particular bungees I had would have required a pretty large hole which I did not want to drill out.

The second time through for the other wall was even easier, and once I had two identical side wall shells I was able to clamp them on the trailer to finally get a sense of what the build was going to look like.

During the trailer walk-around above I mentioned the mounting tabs we welded to the corners of the platform. Here you can see the intent; the 4 legs of the structure locate over these tabs, and once the entire shell is complete I will just drill some holes through the tabs and the bottoms of the legs and run a few bolts through to secure the shell onto the trailer.

Once the side walls were clamped securely on the trailer and were level and square, it made sense to just fit and epoxy the two cross pieces right there in place.

Just like that I had a complete structural skeleton to work off of for my camper project! I did not record the hours I spent exactly but this came together very quickly. For this first time through I was also spending time thinking through writing this build log, recording video/photo etc. I estimate if I built this project again I could do all of the cutting/fitting and epoxy the 4 legs to corners on day 1, epoxy the two wall tops on day 2 and epoxy the two cross sections to complete the structure on day 3. The cutting/fitting day would be a long day of effort but the other days would only require a small amount of time and then there would be a lot of waiting for epoxy to cure.

Now is the best time to get everything built, there is good access around the trailer since the walls are not in place yet. Every project will be different depending on what is needed but I needed to add wood framing for a number of reasons:

A bottom ‘sill’ around the perimeter of the shell. For this project I don’t need to tie the corners together since I bolted each leg to my trailer but this still serves several functions. It will allow me to attach other wood framing pieces to it, it will give me something to bond the bottom of edge of the skins to, and it also defines the bottom of my doors (more on those later).

Support frames around door openings. These will just add rigidity as well as give something for screws to hold on to.

Support for wall skins. The walls are just going to be 1/4″ plywood so I don’t want it to span to far a distance without something to support it.

Places to mount accessories. I tried to lay out where all of my gear would go (water pump and system components, electrical, etc.). I would like to mount things onto a solid surface so in goes odd little pieces of wood for that purpose. This wasn’t 100% pre-planned, but it was easy to add pieces of wood where I needed them as I went along getting all of my systems built.

As I worked through this stage of the build, I was always double checking that I had the wood ‘in-plane’ with the TrailTop parts so that the skins would bond to a flat framework later on. That meant sometimes needing to notch out the wood so it would fit in flush. I used a little trim router set to depth of 1/8″ (about the thickness of the fiberglass) but you could do this a number of ways.

Before the walls went on was the best time to get this camper built out the way I wanted. This post will highlight the features I chose to include but is not meant to be a step-by-step guide. There are tons of resources with more detail about fresh water systems, electrical systems… most written by people more knowledgeable than me. Feel free to contact me with specific questions!

Kitchen / Galley

The rear of this camper will open up to reveal the kitchen/galley area. The main component is a 4′ slide-out kitchen that was built using 1/2″ plywood, wood glue and pocket screw joinery. It slides on a pair of 48″ locking drawer slides with a 500lb capacity (I believe the actual capacity of these longer slides is a bit less but search for 500lb slides to find yours).

The kitchen has a work surface, a spot for my camp stove, and storage areas for pots/pans, plates/bowls/cups, and silverware/utensils.

Above the main kitchen is a 2′ long slide-out pantry built with the same methods. It has a front access compartment for everyday items like salt/pepper, oil, spices, etc. It slides out on 24″ RV slides that are designed to keep drawers closed while in motion, so a slight pull is all it takes to open the pantry. Dry storage is revealed inside for food that does not need to be chilled.

Next to the kitchen and pantry I chose to just set my cooler in the space. The original plan was to build a slide for the cooler as well but once I got to this step I felt it was unnecessary as it is really easy to just unlatch the cooler and grab whatever I need from inside.

Propane

I decided to keep the propane system super simple. I mounted a small 5lb bottle on the rear fender, I can just hook up the camp stove (or anything else) when I need it.

Water

The water system is mounted so that it is generally out of the way but still easy to get to for service.

The pump delivers to a quick-connect spray port mounted on the side of the trailer. From here I can connect the hose to the sink in the side table, hook up a basic sprayer for washing off feet or gear, etc.

The water source is not a built in RV-style tank, instead I chose to just draw water from inexpensive blue 6 gallon jugs. This setup is easier to maintain and keep clean, and I can expand the water capacity if needed by simply bringing more water containers. For a longer adventure it would be easy to add a filtration/purification system to have more options for a water source as well.

Electrical

The electrical system was kept pretty simple as well but with some room for expansion and flexibility in the future. This was originally designed around a 100ah AGM battery and a 100W solar panel but I found a great deal on a brand new 200ah battery locally so I grabbed it instead.

I have an onboard 10A smart charger set up and with the huge battery capacity I chose to skip adding solar for now (although it could be added easily in the future). From the external power center I can simply plug into the wall with an extension cord to charge the battery. There are also 2 marine grade 12v sockets for charging laptops,phones, kids devices, etc.

I made up a couple of simple switch panels with some scrap fiberglass from the TrailTop parts. There is switchable power to the water pump, as well as LED’s for the galley area and the cargo area. There also some blue ‘proximity lights’ mounted underneath the trailer for low impact area lighting.

Next up is to get the the wall skins into place. With the flanges on the TrailTop shell, 1/4″ plywood was simple to just drop into place.

I epoxied the walls to the shell and wood framing, then secured them with wood screws.

In many areas I cut a cheap piece of 1×2 furring strip to spread the clamping force out a bit along the epoxied seams. This is probably unnecessary but I had 3 or 4 cheap 1×2 pieces laying around so it was easy to setup.

I went ahead and smoothed a bead of epoxy into the gaps between the shell and the plywood as well just as I did when building the shell. These epoxy fillets will secure the edges of the plywood and should help minimize cracking of the final finish due to trailer movement. After the epoxy cured, I removed the screws one at a time, drilled a small countersink and reinstalled the screws so they were just below the surface of the walls. The body filler will just go right over and make them disappear.

This project has 3 doors, and I chose to simply order custom RV style baggage doors rather than building them from scratch. Yes, they were expensive but it was money well spent when it came time to install. I simply fit them in place with some foam weatherstrip, ran a handful of screws around the perimeter and I was done!

As I prepared for the final body prep, I needed to decide how to finish around the doors. I did not want to use body filler right to the door edge in case I ever needed to remove a door in the future. What I ended up doing is using 1/4″ square dowels to make a nice clean perimeter around the frames. I simply tacked them in place with epoxy and some spacers.

Once the epoxy set I was left with a consistent gap all the way around. The 1/8″ gap around the doors is caulked. It will look seamless but if I ever had an issue with a door I could just cut that caulking line and unscrew the door to repair or replace it.

This is my least favorite step of any project I have ever done. I like to build, I find the finishing stage to be boring and tedious but this is where the magic has to happen!

Some of my gaps were less than perfect fitting so I chose to fill them in roughly with a layer of fiberglass-reinforced body filler. This stuff is thick and difficult compared to regular body filler but it worked well for this application.

With some patience I filled in around the door frames as well while maintaining the small gap where caulking is meant to go.

After a sanding pass with 80 grit to clean up the fiber-reinforced layer, I switched to more standard ‘pink’ body filler. I ended up making multiple passes; body filler, sand, repeat until I got everything smoothed out. Many hours later I was finally at a point where I was happy with the result.

After I felt good about the body work, I went around and sealed up all the seams with paint-able exterior caulk (black).

There are plenty of ways to finish a project like this. Roll-on bed liner is a common choice and would be an excellent option. For my particular situation, I chose to just go with high quality primer and exterior paint. This may not be suitable for everyone, but I have done projects before with paint and it has held up very well. I live in a very dry climate (Utah) and have a place to store this indoors when not in use. If I ever need a re-coat or a patch it will be easy to do, and I can choose from nearly unlimited colors. This was not a cost decision but the bed liner system would have been a bit more expensive as well. Also for me it is very helpful to be able to get out paint and work for an hour when I have the time, something you can’t do with the bed liner products since once they are opened they start curing.

One thing I do like about the bed liner products however is the finished texture. After primer, I applied 2 coats of my final color with a FoamPro 58 texture roller. These rollers have an open foam-like structure so it ‘pulls’ the paint as you roll and creates that bed liner texture. It doesn’t work quite as well with paint that is designed to minimize brush and roller marks but I am happy with the result. I would recommend some test panels if you want to try this to make sure you see how the paint goes on and what techniques will give the result you want.

Below are shots of the finished product, rigged up and out in the wild. As this trailer gets put through it’s paces photos will be added here!