Staple it to back up your job and you should be fine. There is a difference between the glues and the Landau Top is far better. It is preferred to be sprayed like Roger noted but can be brushed on. I did my door panels with it, using a brush, and am pleased. If you have trouble with the Masonite board warping, replace it with plastic sign material (best) and foam or plastic shower wall material (stiffer) again with foam. As you said, your job looks 400% better, keep chugging on. All the little things add up.