How to: Sew a Zipper onto a Crochet/Knit Sweater

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Adding a zipper to a crochet or knit sweater makes a special garment even more special. I know I was intimidated by them at first but it really is easy. Believe me! I am horrible at anything that has to do with sewing so if I can do it, anyone can!

How to Sew a separating zipper onto a crochet/knit sweater free tutorial

What you’ll need:

A finished Sweater

  • The vest shown is my Woodland Hooded Vest. You can purchase that pattern here or use any other pattern you like.

One separating zipper

  • Make sure your zipper says “separating” on it. If it doesn’t the bottom will stay together.
  • Pick a zipper that is the exact length you need OR longer (I will show how to shorten it)

Coats: Thread & Zippers – Coil Separating Zipper

Sewing thread and needle

  • I like to use clear thread. I’m not the neatest sewer but with the clear thread you’d never know! Plus, I don’t have to worry about finding the right color thread. I will warn you, the clear thread is hard to see (it’s clear!) so if you find that just too much to handle pick a coordinating thread to match your sweater.

Coats: Thread & Zippers – Transparent Polyester Thread 400 Yards

Fray Check

  • This is to seal the raw edges of your trimmed zipper.

Dritz 674 Fray Check Liquid Seam Sealant, 0.75-Ounce

Optional: Grosgrain ribbon

  • To reinforce your zipper you can sew some ribbon over it. This will make the zipper stronger and also makes for an even more finished look. I didn’t add this to my zipper but I may later since this vest is for rough and tough 3 year old.

Lets get started!

Step 1

Open up the zipper. Starting from the bottom up (remember you will be shortening the zipper) pin the first side into place as close to the edge of the trim as you can. Periodically zip the zipper up and down as you go to make sure your stitches do not catch in the zipper.

How to Sew a separating zipper onto a crochet/knit sweater free tutorial

Step 2

Back stitch up the trim as close to the edge as you can. Again, periodically zip the zipper up and down to make sure it does not catch. Be careful not to stretch your stitches as you sew. Stop where you’d like to shorten your zipper. For the sample I stopped about 2” from the shoulder seam. You’ll want to leave some room for the shoulders.

Since I used clear thread the red lines are showing where to sew.

Step 3

Zip up your zipper and pin the other side just as you did the first side. You want to do this while the zipper is zipped up so that you can make sure your stitches on either side are lining up.

How to Sew a separating zipper onto a crochet/knit sweater free tutorial

Step 4

Back stitch the second side just as you did the first side.

Step 5

Bring the zipper pull down past where you will be shortening.

How to Sew a separating zipper onto a crochet/knit sweater free tutorial
The red lines are marking where I will be shortening the zipper to.

Step 6

Turn the vest inside out. Fold the zipper inward at about a 45 degree angle and pin in place. *Do NOT trim the zipper until you have stitched it in to place.

How to Sew a separating zipper onto a crochet/knit sweater free tutorial

Step 7

Repeat for the other side making sure both sides match.

Step 8

Back stitch across the top of the zipper and all the way down the edge. Trim off the excess of the zipper.

How to Sew a separating zipper onto a crochet/knit sweater free tutorial
The red lines are showing where I stitched. The blue line is showing where to trim the zipper.

Step 9

Repeat for the other side. Seal the raw edges of the zipper with some Fray Check.

Step 10

Turn the Sweater right side out, stand back and admire your work!

I hope this helps you tackle something you may have thought was intimidating before. If you have any questions feel free to ask!

Katy