I also put a 2 or 3 pound hand weight on top of the clapper and let it set for a little bit. I tend to assembly-line sew....so while the seams are setting on 2 blocks (with the clappers and weights on each new seam), I am trimming another 2 squares......then, pick up the weights, the clapper, move the blocks and then press the new blocks, clapper down and weight on top. Maybe I'm getting a little muscle? If not, at least the weights add some "pressure" to the clapper and I'm using the weights!