Hello sewing gang, are you ready for your next installment of the Jessa sewalong? Yeah you are! It's Nikki here, Product Manager at Tilly and the Buttons, and today I'm going to cover something very exciting - how to sew the zip fly on your Jessa trousers or shorts.
OK, here comes a pep talk. If you've never sewn a zip fly before, the process can seem a bit intimidating. There are a few different steps involved in constructing a zip fly and I can totally relate to the feeling of flicking through a pattern booklet and looking at all the instructions thinking it looks a bit scary.
The good news, however, is that it really isn't as fiddly as it seems! Constructing a zip fly is like sewing anything - completing a series of small steps until you end up with something amazing, that looks different from the pieces and notions you started with. You can do this!
The Jessa zip fly construction is very similar to the steps in Ness skirt instructions, so you can mostly follow along using the brilliant 'How to sew a zip fly' video Tilly and Jenny made last year. Yay! There are a couple of differences between the video and the Jessa construction which I'll talk you through below, but the middle section follows the same steps.
To make the Jessa trousers and shorts you will need an 18cm (7in) jeans zip. If your zip is on the long side we have a great blog post which talks through how to shorten a metal zip.
Need to get up to speed on the previous Jessa sewalong posts? Check out the dedciated sewalong page to catch up on all posts.
Ready to sew a zip fly? Let's do this!
First things first, we need to finish the curved edge of the zip facing with an overlocker (serger) or zigzag stitch on the sewing machine. The video tells you to finish the centre front opening of the skirt at the same time but we don't have to worry about that for now with Jessa as we'll finish those edges later.
Pin the zip facing to the centre front of the left front leg, right sides together, lining up the zip notches. Stitch with a 14mm (just under 5/8in) seam allowance - this extra fabric will provide a teeny overlap once the fly is finished.
Trim the zip facing seam allowance (not the front leg!) and press the facing and seam allowances away from the leg. Understitch the seam allowances to the facing. Fold the facing back towards the wrong side and give it a good press with the iron to create a crease.
Fold the zip facing away from the leg and pin the front legs together, right sides together, from the zip notch to the bottom of the curved centre front seam. Starting in line with the zip notch (15mm / 5/8in above the bottom of the facing), stitch, starting about 1mm (1/16in) to the left of the existing stitching line.
Fold the zip guard together, right sides together, bringing together the longest edges. In the Ness skirt video the long edges are finished at this point but again we are going to skip this bit as we'll be doing this at the end. So all you need to do here is pin the short curved edge together and stitch. Trim the seam allowances - it helps to trim the curve very narrowly or to notch little triangles into the seam allowance. Turn it through and smooth the curve with a point turner - or you can use a butter knife or your finger. You don't need any fancy tools to get a nice smooth curve here!
For the next few steps the process is exactly the same as the video - you can follow the zip fly tutorial from here to the step where you sew the bar tacks - hooray! The zip guard in the video is a rectangle whilst the one for Jessa has a curved edge, but the steps are exactly the same :)
Lay the zip guard out with the long raw edge on the left and the unstitched short edge at the top. Lay the closed zip on top, the zip facing up, with the teeth 15mm (5/8in) from the raw edge, and the bottom of the bottom stop (the thick metal/plastic bit at the bottom of the teeth) just above the zip notch. Switch to a zip foot and stitch the zip to the guard down the centre of the tape that's on the left. We'll be sewing the next few steps using a zip foot so tell your regular machine foot to put its feet up (hehe) and have a rest.
Open the zip and lay the guard, zip facing down, against the right side of the fabric of the right leg (as you'd wear it). Pin the long raw edges of the zip guard to the centre front seam, matching the zip notches. The left leg doesn't need to be involved in this bit, as much as it might protest, so fold it out of the way. Stitch directly on top of the existing stitching which joined the zip to the guard. Once you've stitched around halfway down the guard, leave the needle in the fabric, raise the presser foot and close the zip. This bit can be a bit tricky but so you might need to wiggle the zip pull a little :)
The fiddliest part in this step is edgestitching below the zip bottom stop. Make sure the left leg is folded out the way so you can see the back of the centre front seam and keep sewing until you reach the bottom of the zip tape. If there isn't enough fabric to edgestitch below the start of the seam/bottom stop, unpick a few stitches that join zip tape and facing to right leg (below bottom stop of zip), roll fabric over, and restitch. Once you've sewn this bit give yourself a big pat on the back because you did it :)
Put the fabric on a table or flat surface for the next bit. Close the zip and cover it with the left leg and zip facing. Makes sure the fold is just covering the edgestitching. Pin through all the layers just to the right of the zip teeth. Smooth down the fabric with your fingers as you are pinning and make sure everything is lovely and smooth.
Flip the front legs over to the wrong side and fold the zip guard back. Grab the facing and unstitched zip tape only between your fingers and thumb. Pin the facing and unstitched zip tape together along the centre of the zip tape, taking out the pins from the previous step as you go. Make sure you are pinning the facing and zip tape together only and nothing else - I can't tell you how many times I've done this only to discover I've pinned the facing to the left leg again!
We don't need the zip guard for this bit so pin it to the right leg so it's out of the way. Using a different colour thread (we're going to unpick this stitching later so use something in a contrasting colour if you have it to hand as this will make it easier to see), tack (baste) around the finished, curved edge of the zip fly 15mm (5/8n) from the edge, using a 4mm stitch length - make sure you are only sewing the facing and not the left leg! You can switch back to a regular presser foot for this bit.
The seam allowance guides on the needle plate will be hidden by the fabric so measure 15mm (5/8in) from the edge of the facing and make a mental note of the distance and try to follow this line when you're sewing. You want to avoid hitting the zip bottom stop with your needle at all costs, so sew just below it. I like to sew this part very slowly and usually sew those last few stitches by taking my foot off the pedal and using the hand wheel on the side of the machine so I have more control with my stitching.
Flip the front legs over so the right side is facing up. We're going to use that tacking as a guide line for topstitching the fly. If you want to tidy up the stitching line, smooth it out with a chalk pencil or washable pen on the right side of the legs. Change back to matching thread, or topstitching thread if you are using it, and sew over the tacking line with a regular stitch length (about 2.4mm) for regular thread or 3mm for topstitching thread. Sew the topstitching really close to the tacking (1mm away if you can) so it doesn't lock in the tacking threads. Don't worry if you do go over the tacking stitching, it just means it's a little more effort to unpick those tacking lines but it's not the end of the world.
When you get close to bottom stop, switch to hand wheel again and slowly sew those final stitches, stopping about 3-4mm away from the centre front seam. Grab that seam ripper and carefully unpick the tacking stitches. Unpin the guard from the leg.
Eeeep we are so nearly at the end of the zip fly! Next up is sewing two bar tacks to strengthen and reinforce the stitching and anchor the zip guard to the left leg.
Set the machine to a zigzag stitch about 2.5mm wide by 0.5mm long. From the right side, sew a bar tack around 10mm (3/8in) long from the bottom of the zip opening to the bottom of the zip facing, overlapping it slightly. As this bit is a bit lumpy because of all the layers, fold up a scrap of fabric to make a stitch starter to help you with those first few stitches (the above pic shows a stitch starter on the pocket to show you what I mean!).
Sew a second bar tack along the curve part of the topstitching to anchor the zip guard to the leg.
If you've been following along with the video, this next step won't appear as it's just for the Jessa trousers. Now the zip fly has been totally sewn (hooray!) we need to finish the seam allowances. Turn the legs over with the wrong side facing up, and trim the centre front seam allowances. Clip into the left seam allowance just below the zip facing and fold the seam allowances of the curved crotch to the right so they are together. Finish the seam allowances together, starting at the waistline and finishing at the bottom of the centre front (the curved part). Press the seam allowances towards the right leg.
If you're still with me then congratulations, you have successfully sewn a zip fly! Don't worry if the stitching is a bit wonky in places or if it's not perfect - nobody will notice and these 'imperfections' make your sewing even more unique and special ;)
As always, please share your in progress photos on Instagram using the hashtag #SewingJessa so we can see what you are making. Sewing a zip fly is such a proud moment it really is something that needs to be announced to the world! Join me back here next time where I'll be covering sewing the legs together. In the meantime good luck, and don't forget, you've got this!
*****
Photos: Jane Looker
Models: Suzanna Hopkins and Alice Irvine
Pink and white denim: Gifted from Higgs and Higgs
Teal corduroy: Gifted from Like Sew Amazing
