Troubleshooting Serger Problems

Sergers are incredibly useful tools for anyone who sews, offering a range of capabilities from finishing seams to creating decorative edges. However, when they start to misbehave, they can become a source of frustration. Serger issues can be intimidating due to the complexity of these machines. There are multiple potential causes which can make it challenging to identify the root of the problem. Instead of tackling each potential issue individually, I prefer a more comprehensive approach — a "nuclear" strategy where I address all possible issues. 

This approach is especially useful for sergers that were functioning properly before but have recently started to show issues. This guide is not for new machines that might have their own set of initial setup challenges.

1) Take all the thread off the machine. Completely unthread it, remove the spools.

2) Clean the machine. Remove that metal plate under the sewing foot and clean in there too. You don't need to open the machine case, just clean what you can get to. I like to use a dry bristle brush - the ones that come with reusable straws are great! 

3) Oil the machine.  Follow your manual instructions for oiling, but generally you lightly oil all the friction points, which are the moving parts.  Move the handwheel to help visualize what needs to be oiled. Use sewing machine oil only - machines usually come with a sample bottle. 

3) Replace the upper knife.  Usually your machine comes with an extra and it's very easy to change.  Just one screw, replace, and you're done!  Save your old knife - most sewing shops can sharpen it for you.  If you don't have an extra, eBay has a good selection of upper knives for around $15 a pair.

4) Blow out the tension disks with canned air. Gently pull the tension knob towards you to separate the disks (where the thread goes) and blow out any dust or threads.

5) Replace the needles. Make sure they are the right needles for your machine and project.  Also make sure they are in correctly - there's a front and back to needles. eBay is handy for needles too!  I usually buy them in packs of 100. 

6) Rethread the machine. Use the manual to thread, because some sergers are very picky about threading order. And if you miss a step, your hard work will be for naught. Use a different brand of thread, because sometimes it's your spool of thread causing issues - particularly if you're close to the end of the spool.  Some brands of thread get extra twisty and knot at the end of the spool.

7) Reset tensions and differential to neutral. This is usually a 4 for thread tensions, and 0 or N for differential. 

8) Sew a test seam on a scrap of fabric.  Always use two layers of fabric when testing.

9) Adjust the serger settings. Since you've fixed all the common possible issues, you can adjust tensions and differential with confidence.  If you still can't get the seam to look correct, then your machine likely needs a service.