Apart from stitch types, one key feature on an overlocker / serger which isn’t on a sewing machine is a knife or blade. As the overlocker / serger creates the seam, the excess fabric is cut away. It is this that gives the perfect edge and saves so much time. You don’t’ have to go along the same edge twice, firstly cutting and secondly trimming.
However, there are a few aspects that you need to consider when using the overlocker / serger blade to cut as you sew.
Seam Allowance
With normal sewing machine sewing, when you are cutting out a pattern you leave an allowance for the seam. With an overlocker, some of that seam allowance is being cut away and the rest used up as stitch width. To get the seam allowance correct, you need to think precisely how much will be cut away and how big the stitch size is, and add them together.
Only One Chance! The Importance of Testing First!
Most of us using normal sewing machines have at some time or another had to unpick the stitching and re-sew it, perhaps because the stitch style was wrong, we got a “birds nest” underneath or maybe just sewed it in slightly the wrong place.
If you have created a seam with an overlocker / serger which for some reason you are not happy with, if you now unpick that overlocked / serged seam, then if you have used a knife your seam allowance is now much reduced. If you redo that seam then you have much less to cut away. You run the risk of starting to reduce the size of the garment you are making!
This is the importance of testing out the stitch and knife position on a spare piece of fabric first rather than go straight to your garment. Make sure you are completely happy with the stitch length and width and that your tensions are correct before your overlocker / serger starts to cut!!
Letting A garment Back Out Again
If you are making adjustments to a garment that at some point in the future you might want to undo or let back out again, then remember to disengage the blade and don’t cut the fabric! For example if you are turning up a child’s trousers, you may very well want to restore them to the longer length in a few months as the child grows.
Take Care Cutting Wool!
A great thing about an overlocker / serger seam is that it prevents fraying and it stretches and therefore ideal for using on wool.
If you are using am overlocker / serger to joining two pieces or a garment you have knitted, eg a body to a sleeve, think carefully about whether you will use the blade or not.
The advantage of using the blade is that excess wool is cut away and you don’t have big chunky seams. It certainly looks neater.
However, if there is a half a chance you might want to unpick the seam, perhaps because you realise the sleeve is the wrong way round (who hasn’t ever done something like that), then if you’ve cut the edge of the wool away all down the side of the piece, unpicking is a bit of a disaster!
If you’ve knitted something special to be sewn together, knit a small test square too so that you can check the settings on your overlocker / serger before you start to sew and cut the main garment.
Unpicking a Wool Garment Where the Overlocker / Serger Has Cut the Edge Away
If you do find yourself in this difficult situation, where you need to unpick a woollen item having cut the edge away, there are a few things to which might just help, although its not a great situation!
To stop the item fraying excessively as you remove the stitches, you might try putting some water soluble stabiliser on the wool before you snip the stitches. This is like a film that you can cut a strip and put it over your wool or fabric you are working on. Put this as close to the stitch line as you can to minimise the fraying that might happen as you unpick the stitches. Leave it on and then restritch the items in the correct position, but remember you have already cut away part of your seam allowance!
Once you have overlocked / serged the seam to where it should be then water solublae stabiliser is easily dissolved in water without leaving a big mark or sticky patch. You can stitch easily over the top of it, without having an effect on your stitches.
Some people use glue to stop the fraying. And while this would stop the fraying it may prevent the overlocker / serger from working properly as the needles gum up. Gumming up is even worse with an overlocker / serger because there are lots of fluff etc….
Cutting too much: Empty Stitches
Setting the distance the knife cuts is quite important but not something that people seem to understand.
If a stitch is well formed but appears to be empty (i.e. the fabric doesn’t reach the end of the stitches - See Photograph) then your problem is likely to be the knife is cutting too much away! We have seen quite a few videos where the advice is to adjust the stitches when actually the stitches are fine and the knife cut length needs shortening.
Similarly, if you notice the fabric is starting to fold over inside your stitches then you need to increase the fabric cut by the knife and not adjust the stitch length.
Blunt blades
Remember if your knife is not making very crisp cuts but is leaving threads or slightly torn fabric then it could be time to replace your blade. They don’t stay sharp forever!
For details of how to change the blade you will need to check your manual.
Safety! Of course blades are extremely sharp. If you are cleaning, oiling, repairing or threading your machine and your fingers are working near the blade remember to click the blade in the disengaged position.
If you are changing or cleaning the blade itself, always have the power off so you can’t accidentally start up the machine and cut yourself.
The blade makes an overlocker more dangerous to use than a sewing machine. Be sure the children are supervised at all times and keep small fingers away from the blade!
Comments