TENAX-7R is a product used by model railroaders for attaching styrene pieces, but works with acrylics. Hubby said it's not very expensive, so try a model railroad supplier. He has several little bottles of it. It works as PaperPrincess says. You apply with a cheap throw-away little brush. It works in 11 seconds, so it does not damage the material.
Maybe you've already done it, but if anyone else has this problem, try going out of the quilt world to find a solution.