No i never have.

I don't double stitch or lower my stitch length and I've made well over 50 quilts and not one has come apart. I don't back tack even though my Bernina comes with that option. I override it.

I don't double stitch. I think one of the reasons store purchased quilts "come apart" is that many of the quilts made in China have so little seam allowance. Many many years ago I was given a "store/China" quilt as a gift. All it took was one wash and about 10 percent of the seams opened up , and not just a little.

No. Using good quality fabric and a normal stitch length it is not necessary to double stitch seams.

I think double stitching is a waste of time. Shortening your stitch slightly would be much more efficient.

Also, don't cut your threads too close to the edge; I always leave at least half an inch of thread hanging, sometimes more. (I have an older machine that does not have an auto cut feature. Not sure how close auto cuts would be.)

Edit: Also, check the balance of tensions for your stitch. Some older machines never achieve a good, even balance and that may be part of your problem. If upper and lower tensions are unbalanced (or if both are too loose), stitches will unravel much more easily. Still, shortening the stitch length should compensate even for that problem and save you a lot of time.

I take great care to use a consistent 1/4" seam and I have NEVER had a seam come undone. Sometimes I notice that one side slipped and I don't have a solid seam so I rip it and redo.

No, I was told to use a shorter stitch, so I stitch at 2 and have never had a problem.

Pat in MN

I agree with everything you said! I use a 201 for most of my quilting and always leave a tail hanging. Shorter stitch length is a must!

Prism. I'm sewing on a two machines from the 50s - a 15 clone and a Singer 301. I accept nothing less than perfect tension and I can get it from either machine.

The only times I double stitch are if I hand piece and discover I've made stitches larger than intended, if my fabric is fraying (satin for instance), or if I get my 1/4" too scant when machine piecing. I try to always check seams as I press so I can redo if needed.
When I was a beginning quilter I used some fabrics that frayed badly in addition to having seams too narrow and had to do repairs which I would just as soon avoid ahead of time. I'm more careful now!