Quote Originally Posted by Adam_Wysocki
I would do a thin wood back just for a little extra strength ... It will act like a cross member and keep the rack from twisting if you ever have the need to move it ... then, if you still want to do the insulation on top of the wood, it will certainly help keep the heat in. -adam
I second that. I don't think I mentioned that in my post a minute ago, but my 32 qt. rack like yours has a 1/4" piece of sheet wood for a back, and it works great to strengthen up the rack.