Kayak trailer


Misc. Projects / Friday, June 24th, 2016

I’ve tried several ways of easily transporting kayaks over the years, and encountered several frustrations, particularly with those that involved tying them to the roof of a vehicle. For the last two years or so I’ve settled on using a small utility trailer, which has worked out reasonably well. However, the trailer isn’t quite wide enough for two kayaks to lay side by side, so tying them down securely has still been a small challenge.

The utility trailer before any modifications.
The utility trailer before any modifications.

I decided to finally tackle that problem, and after considering several options, I began work on some simple saddles that I could build using mostly scraps and some leftover hardware laying around the garage. For anyone who might be considering something similar, I documented the process as I went. The final design is probably a bit over-engineered, but I enjoy the process of tinkering with ideas and I’m relatively happy with the way it turned out.

I decided to form the primary support by heat bending some sections of plastic pipe. In this case it’s black ABS plumbing pipe, but ordinary PVC would work equally well. In fact I believe the PVC is actually a little bit easier to work with. Both are inexpensive and readily available anywhere that sells plumbing supplies. The first step was to get an idea of the correct profile, since the two kayaks have different shaped hulls.

I started by measuring the distance on the trailer from where I wanted the front of the kayaks to sit, to where I would be attaching the two supports. I then measured that same distance from the front of the kayak and used painter’s tape to mark the two spots on the hull. I used a large wire tie-down to create a sort-of mold of the hull shape, which you can see in the photo below. If you’re not familiar with what these are, think of it like a large twist-tie. Anything flexible enough to be molded, but stiff enough to retain it’s shape would work. Perhaps a coat hanger, or scrap of heavy gauge copper wire. This gave me an idea of the shape, and also an idea of how long to cut the sections of pipe.

Copying the hull profile.
Measuring the hull profile.

The first step in creating the supports was to build a quick template, using a scrap of wood. I used the tie-down to trace a rough shape on to the wood, then used a bevel gauge registered directly on the hull to trace a more exact angle. I then cut the shape out using a band saw and clamped it to the trailer bed, which substituted for a workbench.

The traced template.
The traced template.
The finished template.
The finished template.

I cut the pipes to length, based on the measurements taken earlier and then filled them with sand, sealing the ends with duct tape. Filling them with sand first helps in heating them even for bending, and more importantly, helps prevent the pipe from kinking severely at the points of the bend.

Filling the pipes with sand prior to bending helps prevent kinks.
Filling the pipes with sand prior to bending helps prevent kinks.

The next step is to heat the pipe. I’ve found the best way to do this is by holding a heat gun concentrated on just the immediate area of the bend with one hand, while slowly rotating the pipe with the other, keeping it flat on the work surface. Once the plastic begins to soften, quickly set the heating gun down and use both hands to bend it to the template. Hold it in place just long enough for the pipe to re-harden. Do this one bend at a time, working slowly.

Bending the pipe to the template.
Bending the pipe to the template.

You’ll quickly get the feel for how the plastic softens, when to initiate the bend, and how to pull it in to place. It’s easier to simply experiment with this than it is to describe the process. If you’ve never done it before, I’d suggest trying it out on a scrap piece of pipe first. I’d be remiss if I didn’t also take this time to remind you that it’s very easy to accidentally burn yourself when your trying to move quickly and a heat gun is involved. Be very careful, leave yourself plenty of room around the work area and plan in advance where to set the gun down safely.

The end result of bending.
The end result of bending.

Once you’ve made al the bends in the first support, you can empty the sand and repeat the process as needed. It worked fine in my case to use a single template per kayak, making two identical supports for each. Once finished, you can check the fit and make any adjustments as needed by re-heating the pipe.

Checking the fit of each support.
Checking the fit of each support.

Once all the supports were completed, I attached each one to a pair of wooden runners. There are probably simpler ways to accomplish the same goal, but what worked the best for me was to take two scraps of wood and cut them to the same length. I kept one edge flat, and used the bandsaw to rip the other edge at an angle to match the pipe. It took a little trail and error to find the right angle, but ultimately created a very stable surface. The pipe was then attached to the runners using metal pipe clamps.

Attaching the plastic supports to a wooden base.
Attaching the plastic supports to a wooden base.

I took each of these assemblies, and added to additional scraps of wood to act as cross bracing, reinforced with metal brackets. I then added some padding by cutting a section off a foam pool toy and zip tying it to the pipe. Lastly, I placed each assembly in it’s final position on the trailer, and the screwed on a short section of 2×4 to the side of one of the runners to sit down in the metal brackets of the trailer. Those final steps are easier to show than they are to explain, but if you look at the photo below it should be fairly self-explanatory.

One of the finished supports.
One of the finished supports.

They are easily removable, stable, and sit tightly in the metal brackets of the trailer, which assures they are aligned properly. The added height allows the two kayaks to sit above the fenders of the trailer, and comfortably fit side by side. For added security when hauling the kayaks, I strap down the supports directly to the trailer. To help hold the kayaks in the saddles, I also drilled a small hole in each side of the plastic pipe to accommodate the hooks from a rubber tarp strap, which is stretched over the hull at each support. Finally, I throw a strap over both kayaks to hold the whole contraption down.

It sounds a little complicated, but in practice it means the kayaks can be loaded or unloaded in just a few seconds. So far it seems to have worked really well.

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