I am having that problem with my DM's quilts. She hand quilted and never used anything to stick the the pieces down. she just pinned then down and did the blanket stitch by hand. I hate to wash them now as each time I do some of them fray more. She did mostly applique in her last years and did beautiful work. I use wonder under on mine and have done my blanket stitch by hand and have not had that problem. I did one baby car seat quilt on the machine and it is still not fraying.