Easy 3-thread Flatlocking - in DL

[jcsews]

Some sergers have the ability to do a 2-thread, or "natural", flatlock. If your serger is not able to do that, you can do a 3-thread flatlock instead, and it is really easy! In flatlocking the idea is to make the needle thread tension so loose that the stitching pulls apart flat. This makes a really nice stitch with a flat seam allowance, which is great for things like boys swim shirts or for fleece socks.

1. Set your machine up for 3 thread serging. For me, this meant removing the right needle. With normal, balanced tensions, sew on scrap piece of fabric just to verify that your machine is set up and threaded correctly for a 3-thread stitch.


2. Now, turn your needle thread tension all the way down to its lowest setting.


3. Turn your lower looper thread tension all the way up to its highest setting.


4. Now, with wrong sides together serge while cutting off a small amount with your knife. It will look like the top line of stitching shown in this picture:

Can you see how it forms V's? That is because the needle thread tension is so loose that the needle thread is being pulled all the way to the edge of the fabric. The bottom line of stitching is just a regular, balanced 3-thread stitch, so you can see the difference.

5. Next, you will pull apart the stitching. So hold it with the seam allowance up like this:

And just tug on the two pieces of fabric.

6. It will flatten out to look like this on the right side:


And here is how it will look on the wrong side:


Some hints:
- Because of the extreme difference in tension between the needle thread and the lower looper thread, you should go slow or your threads might break.
- Depending on the thickness of your fabric and your exact serger, it might be possible to be less extreme in the tension settings and still get a good flatlock. I can keep my needle tension at 2 or 3 (instead of 1) and my lower looper at 7 (instead of 9) and still get a flatlock.
- It is not necessary to use the knife and cut off fabric if you don't want to. You could put your knife in the non-cutting position and flatlock on a fold of fabric for decorative topstitching.
- If you want the "ladder" side of the topstitching on the right side of the garment, you should flatlock with the fabric right sides together.
- If the "ladder" is on the right side of the fabric, it makes a nice sort of channel through which you can weave decorative, narrow ribbon.

[cinnamama]

Awesome thanks!

[Bobolots]

that's cool Jenn! thanks for that.

[Buggalena]

Thanks so much. I can't wait to try this out!

[davi23]

Thanks so much!! That was really simPle and straightforward.

[suprneko]

Great tute!

[limegreenvw]

that looks neat....might try this for trying out a new technique for the challenges...Thanks! !

[Cheryann]

Thanks so much Jenn.........I just tried it out and it worked perfectly!!! I'm thrilled!! Your instructions were so straightforward and easy to understand!

[kas]

Thanks for posting this! I've been wanting to do it forever but have been too scared to try.

[jcsews]

Thanks so much Jenn.........I just tried it out and it worked perfectly!!! I'm thrilled!! Your instructions were so straightforward and easy to understand!

Yay! I am glad that it worked for you. I can do a 2-thread flatlock on my machine, but frankly, it is just easier to just change the tensions and do a 3-thread flatlock, rather than converting the machine to 2 thread.

[mom2a2z]

I flatlock my fleece socks, too! But I do them right sides together so the stitching that you have marked as being on the inside is on the outside. They've held up just as well that way, so if you want to try a different look, that works, too! Fleece socks have been a big hit here!

[Cheryann]

Yay! I am glad that it worked for you. I can do a 2-thread flatlock on my machine, but frankly, it is just easier to just change the tensions and do a 3-thread flatlock, rather than converting the machine to 2 thread.

I'm pretty sure I can do a 2-thread on my machine too. LOL Just have never tried it. I'm thrilled with your tutorial. I made some boxers for my 5 year old and they look awesome. I'll s&s them tomorrow. Hey, I was thinking....is this stitch just as strong and sturdy as a regular serged stitch?? I can see myself getting carried away and start flatlocking everything in sight. I was making some a raglan pj top today and thought how cool the sleeves would look with constrasting thread, but then wondering how the stitch would hold up. It looks like it would be fine....but I don't know. My kids can be pretty rough and tumble. LOL

Thanks again Jenn!!

[jcsews]

I do not believe it is a strong because there is so much tension on the needle thread that it does not stretch as much. That makes it more likely to pop under stress. If I were doing the raglan tee, I would probably serge the seam and then do a decorative flatlock over it (by disengaging the knife and flatlocking over a fold of fabric). Mel has a good tutorial in the downloads (I think the techniques section) that shows flatlocking on underwear and a few different options.

[sewingmel]

I wouldn't get super carried away and flatlock everything. I did a flatlock trial a while back, and almost everything that I just straight flatlocked has popped. I mostly made nightgowns and underwear. None of the underwear held up with straight flatlocking, and the nightgown that I didn't serge first didn't hold up either. I have a few pieces in the mending pile as we speak. The nightgown that was serged and flatlocked has held up beautifully!

I think the fleece might stand a better chance of holding up mostly because you don't put the same stress on those seams. I can't wait to hear how it holds! I think I will go update the other thread.

[sewingmel]

Oops! I forgot to say that this is a great tutorial! I LOVE the idea of feeding ribbon through the ladder. I hadn't thought of that!

[Cheryann]

I wouldn't get super carried away and flatlock everything. I did a flatlock trial a while back, and almost everything that I just straight flatlocked has popped. I mostly made nightgowns and underwear. None of the underwear held up with straight flatlocking, and the nightgown that I didn't serge first didn't hold up either. I have a few pieces in the mending pile as we speak. The nightgown that was serged and flatlocked has held up beautifully!

I think the fleece might stand a better chance of holding up mostly because you don't put the same stress on those seams. I can't wait to hear how it holds! I think I will go update the other thread.

Oops! I forgot to say that this is a great tutorial! I LOVE the idea of feeding ribbon through the ladder. I hadn't thought of that!

I do not believe it is a strong because there is so much tension on the needle thread that it does not stretch as much. That makes it more likely to pop under stress. If I were doing the raglan tee, I would probably serge the seam and then do a decorative flatlock over it (by disengaging the knife and flatlocking over a fold of fabric). Mel has a good tutorial in the downloads (I think the techniques section) that shows flatlocking on underwear and a few different options.

Thank you so much Jenn and Mel. I'll try the decorative flatlocking over a serged seam. I guess we'll see how Matthew's underwear holds up with the straight flatlocking.....I'm sure it'll be in my mending pile sooner than later. LOL

Thanks again ladies.

[mom2a2z]

The socks I've done have survived a few years, but yes, different kinds of stress on an elastic undies seam and shoulder than socks!