Yep, this is my 3rd application of filling to level out the surface. The mixture shrinks a wee bit, and with pinching really compresses below the seam edge. Each sanding gets the high areas, but those micro bubbles and low spots, take more time to fill and cure before sanding. I think I rushed a wee bit, that caused sanding to lift or become sticky. Now I am giving the mixture an extra day.Still lots of sanding to do before everything is smooth Keep up the good work!