I'm having a bash at making terrain for the first time. I have used air-dry clay on the board and whilst drying it has cracked and released from the board in some spots. I plan to glue it back onto the board where it has come loose and was going to try one tip of adding more wet clay to fill the gaps and add another thin coating. Does anyone have any other possible ideas? Is it a terrible medium to use or can it be fixed? It will only provide structure which will then be coated so aesthetically it makes no difference.