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