Can't find 2" so I'm going to have to use 2 sheets of 1" thick insulation. Making a silk purse out of a sow's ear, I'm thinking of "over-lapping" all the corners - so that the left side will have a 20" x 26" piece glued to a 18" x 24" piece, etc. Maybe it will provide a "better" joint? However, I'm concerned about holding it together when closed. This will be up on a table and only the front will be removable. I read something about someone using dowels to hold theirs together - but can't find any other references. Can anyone help?