One thing that can put people off purchasing a vintage item is if the zip is old, rusty or even broken. However, this should never be a deterrent from buying that perfect vintage dress and I’m going to show you how to replace an old zip with a brand new invisible zip in 10 easy steps.
1. Unpick zip and remove all loose threads
The first thing to do is remove the offending zip. I needed to remove one from a beautiful vintage dress I bought from a Clerkenwell Vintage Fashion Fair a couple of years ago because it broke after a couple of uses and I also wanted to let it out slightly.
I have a couple of tools I use to unpick stitching, one being the obvious seam ripper or unpicker, depending on what you want to call it, which has a sharp point and a tiny blade in the curve. However, what I tend to use the most is a tiny pair of really sharp scissors. I have these hooked onto a long ribbon so I can hang it around my neck and access it at any time.
2. Prepare the fabric
It is always best to press the seams out, even if you are keeping the zip in exactly the same place. This ensures the fabric is absolutely flat before pinning, otherwise you may end up catching a fold of fabric in your stitching and you would have to unpick it all again.
3. Prepare the zip
Turn the dress inside out and lie the zip flat against the opening to check its length.
If the zip is too long you have two choices, either open up the seam a little further (remember to run over the end of the seam with the sewing machine to secure it before continuing) or shorten the zip (don’t try this method if you are using a metal zip). I could only get a really long zip in my local shop, and I didn’t want to wait for one to arrive if I ordered it online, so I decided to cut it off to make it fit.
To do this properly, place the zip so that the top of the slider is just below the stitching line of the armhole or neck seam; this is normally about 15mm from the edge. Then lay it flat down the seam where you will sew it in to. Mark where the join of the two seams is on the zip and cut it off so that the zip is about 3 or 4cm longer than this mark.
Cut a long strip from the off-cut and wrap it around the bottom of the zip, tucking the ends in on themselves and pin securely. With the sewing machine, sew around all four edges twice and finish off by going back and forth over the last few stitches. This will secure the end of the zip so the slider doesn’t run off it when opening.
4. Pin the zip in place on the first seam
Lay the zip face down onto one seam so that the whole zip sits on top of the fabric as shown in the picture below. No part of the zip should overlap the edge of the fabric. Insert the pins in the direction that is easiest to remove them when sewing the zip on, otherwise you’ll find yourself fighting to pull them out.
Remember to align the slider just below the stitching line so that it leaves a gap at the top for the arm or neck seam. Mark with a pin at the bottom of the zip where the two seams join together so you have a guide of where to sew to.
5. Choose your sewing foot
Before sewing, you will need to open the zip fully, otherwise you won’t be able to get the needle close enough to the teeth for a clean finish. You will also need to use one of two sewing feet to achieve this.
The best foot to use is one designed especially for inserting an invisible zip and is, obviously, called an invisible zip foot. You can buy one the same style as the one on the left at G.U.R. Sewing Superstore. If you don’t have one of these then you can use an adjustable zip foot, although I don’t find it is as neat.
6. Sew the first side of the zip
Place the garment into the sewing machine with the fabric on the left so that you are sewing to the right hand side of the teeth. Push the teeth away from the zip fabric and lower your foot into place. If you are using the invisible zip foot, the teeth will slot into the groove.
Sew a few stitches and then go back over it to secure the start of the stitch line. Then slowly sew down the zip, continually pushing the teeth away from the foot so you don’t sew straight through the teeth. You will need to hold the zip firmly in place on the fabric as you remove your pins as it will fight against you.
When you reach the slider stop sewing and finish off the stitches by going back and forth over the same stitch line to secure it. Cut the thread and remove the garment from the machine.
7. Secure the end of the zip to the garment
If you are using an invisible zip foot you will need to change to a standard narrow foot to secure the end of the zip to the fabric. You don’t need to do this if you are using a standard zip foot.
Close the zip and insert the garment back into the sewing machine at the point where you previously finished sewing (you may need to turn your dress around and sew in the opposite direction depending on which side of the foot is narrowest). Secure your stitch line by running back and forth and then sew down to the end of the zip and finish.
Run the slider up and down the zip a couple of times to check that it closes okay, and doesn’t catch on any stitches, before moving onto the other side.
8. Pin the zip in place on the second seam
Whilst the zip is still closed pin the other side of the zip to the second seam, making sure you don’t create any puckering. Again, remember to insert the pins in the direction that is easiest to remove them whilst you are sewing. If the zip runs over a waistline or any other seam, double check this will line up once the zip is closed.
9. Sew the second side of the zip
Once the zip is pinned in place, open the zip up fully again.Using the invisible zip foot, sew down the zip in exactly the same way as before, making sure the teeth are pushed away from the zip fabric.
Sew down as far down as the zip slider and finish off. Change to the standard narrow foot and sew the rest of the zip to the seam, securing it to the fabric.
10. Finishing off
Cut off any loose threads and turn the garment back so it isn’t inside out and you should have a perfectly installed invisible zip.
Tidy up the arm or neck seam by hand to make sure you sew it as neat as possible and press everything flat, including the seam with the zip in it.
And, voilà, you’re done!
If you have any questions or any pointers you think I may have missed, just leave a comment below.