Build Your Own Mast Gates

In order for any mainsail reefing system to work correctly with a mast that has a slug opening for bending on the mainsail, there should be a way to prevent the sail slugs from falling out of the opening when you reef the sail. If they fall out, somebody has to guide them back in when you let the reef out and hoist the mainsail back to full size.

One way to prevent the slugs from falling out is to have a sail loft add a jack line to the sail. These let the slugs be held above the slot by a stopper in the slot while the sail is pulled down by the reefing line. You can read more about how jack lines work elsewhere. Instead, I chose to install mast gates, which is the way to prevent the slugs from falling out without making modifications to the mainsail. Mast gates work by letting you close the mast slot after you have bent on the mainsail. Then the slugs move down through the slot when the sail is reefed and back up again when you shake out the reef and hoist the mainsail.

There are a couple of sources for manufactured sail gates for the C-22. Many owners choose the MastGater Sail Track Gates from a popular online Catalina parts retailer, which screw permanently to the mast and are fine if your boat is in a slip most of the time. They have to be unscrewed to take the mainsail off and put it on again. The clever external hinged gate kit from from is held in place with a small piece of shock cord that also acts as the hinge. That design is better for trailer sailors. For my review of both their external tethered and their internal bifurcated tube mast gates, see Product review: MastGates Sail Track Gates.

Since DIY is the name of the game onboard Summer Dance and being an armchair engineer, I made my own mast gates for the cost of a cup of coffee at Starbucks. They’re a bit of work to make, but they’re also simpler and cheaper. Way cheaper.

Mast gate overall oblique view
Oblique view

“Necessity may be the mother of invention, but play is certainly the father.” – Roger von Oech

These gates are 1-1/8″ x 6″ strips of 16 gauge 6061-T6 aluminum with a 1/8″ lip on one edge that fits inside the slug slot. The lip serves two purposes. First, it helps hold the gate in place by interlocking with the slug slot. Second, it adds stiffness to the edge of the gate. Without it, the slugs could catch on the edge and the gates would bend more easily. The gates are curved to fit the curve of the mast and each has a single slotted hole for a #10-24 thumbscrew that screws into a tapped hole in the mast. Depending on how well they work this season, I might need to modify them to use two thumbscrews. You could also make gates out of thin stainless steel or virtually any other non-corroding, malleable metal. I’ve read where other owners have fabricated theirs out of a piece of aluminum carpet edge strip.

Ironically, after I built the mast gates and was preparing this post, I discovered that I had designed my mast gates remarkably similar to the standard equipment Sail Track Gates on Catalina 320 and Catalina 350 yachts. I guess great minds do think alike!

End view showing profile

The trick to fabricating these part is making the sharp bend straight and without stress fractures on the outside of the bend. I used a propane torch to keep the metal soft during forming to prevent cracking. I used a vice to hold the part with just 1/8″ exposed and gradually and lightly hammered the bend evenly its full length into shape. There are lots of videos on YouTube that demonstrate the right technique. The most interesting ones are the guys making suits of medieval armor with hand tools. Those guys are metal artists, I am not. After all the shaping was done, I sanded and polished the gates with a buffing wheel.

The thumbscrew and slot allow the gates to be quickly loosened by hand and slid open so that you can bend on the mainsail. The gates stay attached to the mast so you don’t drop or lose any parts. After the sail is on, the gates are slid back into place with the lip filling the slug slot and the thumbscrews tightened to hold them there. The whole process only adds a few seconds to setup and takedown times for the trailer sailor, far less than it takes to go forward and replace the bottom sail slugs when you shake out a reef.

The Bottom Line

Suggested price: $44.95
$tingy Sailor cost: $5
Savings: $39.95

Have you’ve made your own mast gates?


3 Comments Add yours

  1. Karen says:

    I’m going to try to make your mast gate, can you explain how you shaped the metal to match your mast shape? I’ve only seen videos on how to bend them.

    1. I just carefully hammered the metal into shape using a piece of steel pipe or a similar shape underneath as a buck. It will take some trial and error.

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