Making a Long Separating Zipper

We want to make a jib sock for our Pearson 10M. The luff measurement is approx 48′ so we would probably need a zipper close to that length. You don’t offer that length but do have continuous zipper material. In addition to the zipper and a pull, what else would we need? And how is this done?

Sailrite currently offers several long separating zippers (aka jacket style or finished), for example we have one that is 508″ in length. Although this zipper is not 48 feet long, please keep in mind that it is actually better to use at least two zippers for a jib sock. The shortest zipper should be used at the bottom of the sock and sized so that it ends roughly where the jib sheets would exit. In this case, it is normal to build the sock so there is about a 1 foot gap between the two zippers to allow for some movement in the sheets.

A jib sock can be created using just one continuous zipper that runs its full length. In this case, lead the sheets out to the bottom of the sock (keep in mind that you will need provisions to prevent headsail unfurling). Position the continuous zipper so that it extends about 12 inches beyond the top edge of the sock. Attach the zipper tapes to each side of the sock. At the top edge of the sock, cut only one side of the zipper off so that only 4 inches extends beyond the sock edge. To test the closure of the sock, work the zipper slider onto the long zipper tape end and then work the short tail into the slider to get the zipper teeth to mesh. Some zipper sliders (locking style) will have a locking pin that activates anytime the pull has no pressure on it, simply pull on the zipper pull when trying to mesh the teeth.

Slide the zipper slider down toward the bottom of the sock. At the bottom of the sock, install a zipper top stop on each side of the zipper tape to keep the slider from coming off the end of the zipper tape. The most common type of zipper stop is a metal shaped “U” that clamps over a tooth on the zipper tape. This completes the bottom end of the zipper.

Back at the top of the zipper, take a 2 inch section of the scrap zipper (previously cut away) and mesh the teeth with the end of the long row of zipper teeth. Start at the top cut end and tap the teeth in place using just about anything. Melt the teeth together slightly using a hotknife or soldering iron to keep the slider from coming off at the top.

There will be a 6 inch gap at the top of the zipper between one side of the zipper tape and the top stop on the other side. Once the slider reaches this gap, the zipper sides will separate. To start the zipper each time the sock is used, the short side of the zipper will need to be fed into the slider. When in use, the zipper teeth will hold fairly well on their own, but in a good blow the sides will separate. To keep this from happening, create a velcro strap or snap tie at the top to wrap around the neck of the zipper tape about 2-3 inches above the sock. The idea is to place positive pressure to the zipper sides so they cannot start to come undone until the tie is removed (which would be done each time you drop the sock).

Supplies required to do the project with continuous zipper: #10 YKK vislon zipper chain, #10 slider single pull, 2 ea top stops, thread V-69, basting tape, sock material (SurLast), webbing and velcro for wrap, webbing for halyard hoist attachment, webbing for loops for securing at bow.

Hope this helps! 

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