I am building a kegerator out of a coca cola fridge, basically it is to store my kegged beer and i have removed the glass where i intend to install some form of rigid board to mount taps on, the thickness is 25mm, whilst i can get 25mm thick MDF cut to fit i was wondering would the insulation value be better if i sandwich two pieces of 5mm thick MDF with 15mm baton then filled the void with expanding foam ?