Hello All,
I need help in explaining what I need to increase my cuts for a 1/2 in seams.
You see, Every quilt I have made in the last 2 years (using the 1/4 inch seam allowance has become unstitched.

I have used 1/2 inch seams before I joined any quilting groups and learned that Quilts should be made using 1/4 inch seams.

When I complete my quilt, I tack it every few inches to keep it together.

If I am making a 4 inch block using half square triangles do I increase my cuts to be 1/2 inch larger than the instructions call for?

Can someone please shed some light?
Thanks in advance, Laura A in Brick, NJ

Perhaps your stitch length is too long. Did you try shortening that to see if it creates a stronger seam?
Also, what is the quality of the fabric you're using? If it's very thin, with a light weave, that could be part of the problem.

I'd be really surprised if increasing the seam allowance size (and therefore EVERY single measurement for everything you're going to sew quiltwise) is the ONLY solution.

like mts said, you may need to shorten your stitch length. also try backstiching the beginning and end of each seam. That said, If your piece is to finish at 4 inches with a quarter inch seam you add a half inch (2 times 1/4). If you want to use half inch seams you would add 1 inch (2 times 1/2). When you increase the seam depth you add extra weight and bulk to your quilt. this will make it more difficult to hand quilt, and could cause problems even machine quilting.

go back and try to discover why your seams are coming apart. I don't believe making 1/2"{ seams is the solution. You will have real problems when putting different shapes together However, If I were doing it I would draw the finished size of the shapes on graf paper and then add the seam allowance and then measure to determine cutting. as long ss you are making squares and rectangles there should be no problem. the problem is when doing triangles and diamonds.

on another note. If they don't hold at 1/4" they won't hold at 1/2" Sounds like it is your stitch length or the quality of the stitching.

Agree with everyone above, the time I use 1/2"is. On flannel.

Seams coming undone?

Before enlarging your seam allowance, check:
1. stitch length, make it shorter

2. tension is off on your machine stitch

3. thread quality, older thread often weakens especially if exposed to light and air

4. fabric easily frays (not quality100% cotton)

5. quilt is not quilted close enough together when finished, use the width-of-your-hand rule

Jan in VA

how old is the thread you're using? IF it breaks easily by hand, it's not good to use for stitching. Also, what is the weave of the fabric you're using? Loosely woven fabrics may well fray out if only a quarter inch seam is used. Tighter weaves should hold stitching with quarter inch.

i also agree with finding the problem But to answer the question i think if you add 1/2 inch to all measurements that should give you the extra for seam allowance exmpl 2 inch square would be cut 2 1/2

Another thought is, are you chain piecing? If you are snipping each time you add a piece of fabric or not starting from the very beginning possibly with leaders and enders you could be weakening your pieces.

Checking your stitch length sounds like a good idea, and also when it comes time to quilt, dense quilting will help to strengthen your quilts.

is you bobbin thread catching with the top threads. No reason for the seams to come undone. Do you backstitch? If you don't do you perhaps clip the threads too short before attaching to the other rows/pieces?

If not, then I have to agree with the others

Sewing at 1/2 inch isn't going to be any better then at 1/4. If it's coming apart it will come apart, no matter how big your seam

The only time my stitching comes apart is when I didn't keep the seams straight so the rows slip apart and I've learned to backstitch at the beginning & end of my rows before starting the final assembly into a quilt.

Chain piecing with no little tail left between the patches will also quickly unravel. My machine doesn't like the couple empty stitches between the patches so I've just quit trying to do it that way.

I would definitely change the way you are doing something else before changing all my patterns to 1/2 inch seams. Fabric is too expensive to eat up with seams.

Flannel can also be sewn with 1/4 seam allowances without fear of it coming apart if it is prewashed, pressed with a very hot iron and you are very consistent with your 1/4 inch. The prewashing, drying and pressing should shrink/draw it up enough to hold even the looser weaved (usually cheaper but not always) flannel together. Less than 1/4 inch anywhere in the seams and it will unravel enough to reach into the seam line and come undone.

Another idea is, Are you pressing your seams open? If your tension is loose and you are pressing your seams open, that could easily weaken the thread enough to pop seams.

Post a photo of the back & front sides of one of your finished blocks after you have pressed them so we can see what's going on.

Thank you all for your input. I am using a Babylock machine and my stitch length is 2.5. I will attempt your suggestions and will try and use a smaller stitch length. Must I also stitch in the ditch on the quilt top to set the seams? Again, thanks to all. Laura A in Brick, NJ

No, you don't have to. The seams should be stable on their own before you get to the quilting. So FMQ to your heart's content. And you should see the difference in the unquilted top.

Now, don't go making the stitch so small you can't "unsew" it if needed. I have no idea what a 2.5 means on a Babylock. I sew on a 2.2-ish on my Bernina.

Let us know how the smaller stitch works out for you.

My mother always used a seam greater than 1/4", the end result was simply a smaller block. I never could get her to go to a smaller seam. Doesn't solve anything for you unless you are willing to have smaller blocks and work with that. She always said she felt more comfortable with the larger seams.

Is it the thread that is breaking? Is it the fabric coming out of the seam? I would first look at the thread, then the stitch length. I piece with my machine set at 2.0 and have not had seams come apart. I do chain piece, sometimes with leaders and enders. I also strip piece, so backstitching at the beginning and end would not help. Also, quilts that are tacked or tied have more stress on the seams, during use and washing, than a quilt that is machine quilted all over.