I have a hole in my door at home. I stuffed paper in the hole and
sprayed in foam insulation. Once letting it dry for a few hours I cut
away excess and put in wood filler. Everything seemed well until
either the wood filler or insulation shrank and caused cracking and a
crater where the hole was. After 4 hours I sanded away excess of
edges and added another layer of filler and let it dry over night. Again
shrinkage happened so I bought spackel and added another layer.
The spackel went on smoother and all looked well but again it
shrank. (I had the door still on hinges..I know stupid of me. So some
of the spackel started moving down.) I took the door off the hinges
and removed the spackel that was was wet and moving down. Now I
have a hole slightly deeper than 1 cm. What do I do? Add more
spackel? Another layer of foam insulation?