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.