Tuesday, February 17, 2015

Navigating Notions: How to Shorten a Separating Zipper

Ah zippers...a necessity of the sewing world.  We've all battled with one or two in the past!  Many sewists are intimidated by zippers, especially when there is shortening involved.  Unfortunately, there are only so many lengths available.  Zipper manufacturers like Coats & Clark or YKK produce zippers in standard lengths, like 7", 9", 12", 14", 18", and so on.  Sewing patterns usually call for these standard sizes.  But ready to wear garments are not bound by these standards.  When a company mass produces a sweatshirt, for instance, they can order thousands of non-standard lengths of separating zippers specifically made for their product.

This poses a problem for home sewers who are looking to replace a worn out zipper on their beloved garments.  We often get customers in the store looking for an exact match to their broken zipper.  There are also certain patterns that require non-standard sizes.  Luckily, there is a way!

Shortening a regular, closed-bottom zipper is quite simple.  Coats & Clark zippers are even packaged with a tutorial.  It's simply a matter of sewing a "bar" at the desired length.  There are more advanced methods, but this is by far the easiest and most common.


(Look for a blog post in the future on shortening closed-bottom zippers!) 

But what about shortening separating zippers?  They are on a lot of our most worn garments, like sweatshirts, jackets, and outerwear.  It may seem more complicated at first, but trust us, it's easy!  So let's get to it!

First off, figure out how long your current zipper is and what length you'd like it to be.  This sample zipper started off as 18" and is marked with a water soluble pencil to become 15 1/2".



Next, move the slider below the mark, and cut the zipper tape above the mark.  You want to leave some tape above the stop.  We recommend cutting each tape individually to keep the lengths even.  It is very important to leave the slider below the mark during this entire process, or else you'll have to rethread the slider onto the teeth, which can be tricky.



Now to finish off these new cut ends.  We prefer to burn the edges:  it's quick, easy, and effective.  Most zipper tapes are polyester or a poly/cotton blend; when synthetics like polyester burn, they leave a hard, shiny, plastic-like finish.  This method will not work if your zipper tape is 100% cotton, which just burns up like paper.


Another option is to use glue or fray-check to stop the edges from unraveling.  We've done both here in this demo.  The upper zipper tape in the picture below was burned and the bottom tape has Fray-Block.  We have also heard hot glue works well in this situation! 


This next step is somewhat optional, but removing the excess zipper teeth makes for a nicer finish.  It's actually quite easy.  Hold the tape with one hand and grip the individual teeth with needle-nose pliers in the other hand.  If you're having trouble with this, make sure your pliers are only pulling the tooth, not the zipper tape as well.


Here is the zipper with the extra teeth removed.  Almost done!



Finally, we need to install some kind of stop to prevent the slider from coming off.  We've seen people use a small strip of fabric here, but we like to use metal stops, which are small, U-shaped pieces that just clamp down with pliers on the zipper tape.  You can see one before installation in the picture below.  Zipper stops come in a few sizes, and you'll probably want to use a bigger one for separating zippers, as the sliders tend to be larger.



And that's all there is to it!  With some pliers, a lighter, and a few minutes, you can easily shorten a separating zipper!  This skill will give you professional-looking results when installing or repairing zippers.



Have you ever shortened a separating zipper?  Or maybe you have a zipper horror story to tell–we've all been there!  If you're intimidated by zippers, check out our Fearless Zippers class!  Terry McClintock will show you different techniques for installing regular and invisible zippers with ease.  We also offer the Sew and Fit Labs, where you can bring in your personal projects and get individualized help from our wonderful teachers.

Let us know what other techniques you'd like us to cover in a future blog post, and Happy Sewing!

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