Wayne Parham Messages: 18751 Registered: January 2001
Illuminati (33rd Degree)
Remove the vapor barrier (paper backing) from the insulation before installing it. That goes for wall linings as well as the cross-section piece.
As for wood filler, we really want guys like Epstein to chime in here because they do more woodworking than I do. I know there are purpose-made wood fillers that I'd rather use to fill a hardwood, but I'm not sure that's the best for MDF. I can't imagine you'd go wrong with that stuff though.