ok, i guess i am missing something here. if you are zig-zagging the batting together why are you using fusable too? seems like a waste...i would think one or the other would be the way to go, if you are stitching then don't waste the fusable; but i thought the original post was from someone who did not want to sew her batting pieces anymore. the problems with fusing the edges are: bulk if you overlap the pieces; stiffness along the seam; gumming up the needle when quilting (depending on what fusable was used) pressing such large pieces and getting them to stay together until you get it quilted. if you just go with the zig-zag it is done and going to hold up without lumps/bulk/stickiness/ problems with it not holding.
Originally Posted by QuiltswithConvicts
I lay W&N pieces overlapping just a little bit and trim both layers. Remove the slivers & butt the big pieces together. Lay the interfacing over the joint and press. I use steam and an applique sheet (just because I have one) but you could use a scrap of muslin to keep the glue off your iron. THEN - I take it to my machine. Turn it over so that the fusible is on the bottom and zig-zag the joint. I use as wide a zig-zag as my machine does and a fairly open length. I like to reinforce the fusible - kinda like the fusible is holding everything together so you CAN sew it together.
I use this method to put ALL my scrap W&N together into a usable size, I don't like to throw it away.