I hand zigzag mine together but don't know if it would hold for a large quilt, but have used that method on table runners or something small like that. There is a new product out - not sure what it's called - and I think MSQC sells it - something that bonds the two pieces of batting together somehow. Maybe its in their misc. section. I haven't tried that. I'm sure others have put their pieces together so I'm sure you'll hear from them.

Hugs,