Sail repair is where the true capabilities of the ultrafeed LZ-1 are tested. My slip neighbor has had me repair his 150% genoa twice. First along the luff where I added a piece of canvas 3" wide and 174" long, (not shown here). And then resewing the canvas material already installed to protect the sail when rolled up on the furler. The zig zag stitch sewn with a #20 needle goes through the four layers of thick material easily.