Your weight and water is good, just shim it so it goes beyond straight, it will spring back slightly when you remove it after it dries. I somehow got a 1/4" twist in an uproar wing, I wet it down with glass plus and clamped it to the table. I put an 1/8" scrap piece of lite ply as a shim, it dried perfectly straight. You will get it.<div>Ed</div>