Project: Mast rack

The Problem

The biggest issue encountered while transporting the Puddle Duck is the mast. It’s just shy of 16 feet long, and while in transit, generally has the sail wrapped around it. In the past, I’d used several ratcheting straps to lash it to the roof rack of the Subaru. However, it never really felt stable up there. If lashed improperly, the mast could come loose and swing free. (Yikes!) On top of that obvious safety concern, there was the less important issue of chafe wear on the sail from strapping it down.

What I needed was a way to keep the mast in a straight line with the car, while minimizing the compression on the sail. What I needed was a specialized rack. I drew my inspiration from various work vehicles, and decided to make something like a pipe or conduit carrier for the Subaru.

The Planning

Initially, I wanted a solid tube that the mast could slide into, with some sort of friction-based locking system to keep it secure. The benefit of a solid tube, rather than two rings is that a solid tube cannot shift diagonally on the crossmembers. (Remember your Pythagoras!) However, since I was a starving college student, I couldn’t afford to spend money on a 10 foot length of 4 inch diameter PVC pipe. So, rings it was…

I ended up buying some aluminum flat stock, a long threaded rod, some nylon lock nuts, and two 4″ PVC couplers.

The Project

So first, I measured the rack crossmembers, and bent the threaded rod to span them. Once i had bent them into square U shapes, I made the brackets from the flat stock by cutting it to length and drilling holes.

Threaded rod and aluminum bracket

Threaded rod, bracket, and coupler drilled.

I neglected to account for the inner ring of the coupler, and how it would affect the threaded rod once tightened down. It would act as a fulcrum, and cause undue stress where the rod bends. To remedy that, I filed and sawed down the inner ring. Also, lest you think my metal bending skills are perfect, I made sure to capture an image of a failed bend. Oops.

Nearly finished couplers, threaded rods, brackets. Failed bracket for honesty’s sake.

Once everything was affixed to the rack, I slid the mast/sail into position. With the friction provided by the cover, the mast/sail likely would stay put even at freeway speeds without any additional support. In practice, I still use a single ratchet strap (not pictured) to give just enough downward pressure to keep it from wiggling loose.

Mast in the hoops. Ready for a trip to the lake.

At some point, I would still prefer to have a full length tube that spans the two rack crossmembers. While this system is holding and feels stable, I would have better peace of mind with a more robust system in place.

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