13 June 2018

Troubleshooting Overlocker Stitches

How to fix overlocker or serger stitch problems - Tilly and the Buttons

Overlockers (AKA "sergers") are wonderful machines... most of the time! Great for stitching knit fabrics or finishing the seams on woven garments, once you get the hang of them they're super speedy to use.

However, they do need adjusting so the settings match the fabric and seam that you're sewing. Whenever you start a new project, take some time to sew a test swatch and adjust the knobs if you need to.

How to fix overlocker or serger stitch problems - Tilly and the Buttons

This is what you're aiming for - perfectly balanced stitches. (This picture shows four threads - you may have three instead if you're sewing lightweight fabric or seams that aren't going to come under too much strain.) I've used different coloured thread for each looper and needles so you can easily see how the stitches link together.

If your seam doesn't look quite right, here's a quick reference guide for seven common issues and how to fix them...

How to fix overlocker or serger stitch problems - Tilly and the Buttons

The loops from the right side are peeping out on the wrong side!
If the upper looper thread loops are visible on the wrong side, they’re either too loose or the lower looper thread is pulling them too tight. So you can either turn the lower looper tension dial down or turn the upper looper tension dial up. Adjust them one at a time, a little at a time, sewing a test swatch each time until the loops are staying on their own side.

How to fix overlocker or serger stitch problems - Tilly and the Buttons

The loops from the wrong side are pulling over to the right side!
If the lower looper thread loops are visible on the right side, they’re either too loose or the upper looper thread is pulling them too tight. So you can either turn the upper looper tension dial down or turn the lower looper tension dial up. Adjust them one at a time, a little at a time, sewing a test swatch each time until the loops are staying on their own side.

How to fix overlocker or serger stitch problems - Tilly and the Buttons


I can see the stitches from the right side when I pull the fabric pieces apart!
If you can see the straight needle stitches from the right side of the seam, the needle tension may be too loose. Turn the needle tension dial up, little by little, until the stitches are no longer visible from the right side of the seam.

How to fix overlocker or serger stitch problems - Tilly and the Buttons

The seam looks stretched out!
If your overlocker (serger) has a differential feed lever, turn it up to stop the back teeth pulling the fabric out from under the presser foot faster than it’s being pulled in. Or a stretched seam could indicate that the presser foot ispressing down too hard on the fabric – turn down the presser foot pressure dial if your machine has one.

How to fix overlocker or serger stitch problems - Tilly and the Buttons


The seam looks gathered!
If your machine has a differential feed lever, turn it down to stop the front teeth pulling the fabric under the presser foot so quickly. Or it could be because the presser foot isn’t holding the fabric down firmly enough – turn the presser foot pressure dial up if your machine has this feature.

How to fix overlocker or serger stitch problems - Tilly and the Buttons

The threads snapped when I started sewing!
Check that you’ve threaded the machine up correctly and in the right order – remember the lower looper thread should sit on top of the upper looper. If it’s threaded properly, try loosening the thread tension dials so the thread isn’t being gripped so tightly as it goes through the machine.

How to fix overlocker or serger stitch problems - Tilly and the Buttons

When I stretched the finished seam, the stitches popped!
If the needle thread breaks when you stretch the seam, the needle thread tension may be too tight. Loosen it slightly by turning the tension dial down. Sew a test swatch, and loosen it slightly more if needed. Also check you’re using good quality thread – you get what you pay for!

I hope this helps you fix any issues you're having so you can get on with your sewing :)

This is an extract from my book Stretch! Make Yourself Comfortable Sewing with Knit Fabrics, which includes loads more tips for using overlockers, as well as patterns and fabric tips for sewing clothes with stretch knit fabrics.

Published by Quadrille (Hardie Grant)
Photos by Fanni Williams