ggadwa wrote:
Couldn't find anywhere to buy the 2 inch or 2 1/2 inch Blue board other than a sheet of it so still trying to resolve that issue as its 130 plus miles to Boise and carrying a 4x8 sheet is out of the question right now.GARY
You can make the 2" to 2-1/2" rigid insulation thickness that you need by building up layers of thinner foam board, gluing them together and sealing the edges of the expanded polystrene and the isocyanate foam with tape as they absorb moisture (not needed for extruded polystyrene). The thinner foam board is easier to cut, or score / break, and fit into your vehicle.
You can use solvent based contact cement on the aluminum/paper faced polyisocyante foam board (Rmax) or the plastic faced white expanded polystyrene board. Keep the glue away from the unprotected edges or it will dissolve the polystyrene. For this reason you need to use nonflammable contact cement (Dap Weldwood brand at Ace Hardware) on the pink corning or blue dow extruded polystyrene foam.
In another thread
thread Buzzcut1 used the slightly compressible, closed cell polyethylene foam (same type of foam as the pipe wrap at building center / hardware stores) that he got in flat 4x8 sheets. Great stuff, but expensive to get via the net. Not locally available unless you have 7-8 million people living nearby like he does:D.
The clear/white version of closed cell polyethylene foam can sometimes be found in fabric stores, although it is only 1/2" thick (same stuff you find as shock absorbing blocks in shipping cartons). Building up layers is easy. Heat up the surface with a heat gun and the softened (barely melted) polyethylene will bond to itself when pressed together. No edge treatment necessary.