"THE way" it's done professionally is with closed cell polyurethane foam, an expensive alternative that needs to be done professionally and isn't very 'forgiving'
the important points: fully isolate the exterior skin from the interior so there is NO metal that makes continuous contact between the 2 'shells' ... seal the backside of the skin to prevent condensation in the insulated space
I'm in the process of gathering materials for the same job this spring/summer - plan is to cover the inside of the metal skin with
Sealgard, a sticky back roll roofing similar to 'peel n seal', to eliminate condensation and add some sound proofing - I'll put cut-to-fit 2x in the metal ribs, isolated from them by the stick on foil backed pipe wrap, and that'll be the attachment point for the interior wood paneling
the insulation material you use can be a variety of things, but the pink fiberglas bats will collect and hold any moisture, so not the ideal, rigid pink is better but fiddly to fit the curved spaces .... what I'll be using is
sheeps wool bats [from Alberta], as good an R value as any for about the same price, and good for making sweaters after the bus rots away from around it
swing by if you're on the Island
Bill
