Hi all, Is it your experience that there is enough room to fit something like this under that headliner to keep the truck somewhat insulated? or maybe some 3MM Reflective Foam Insulation Shield?
'38 1.5ton; "The stuff is as tough as woodpecker lips"
You can also use 3M foil-faced fiberglass made for HVAC work. But it all depends on what you're trying to accomplish. Fiberglass is good for noise reduction and heat reduction when installed correctly. Foil coated bubble wrap is more for heat control only. Install any foil faced product (preferably with an air space between the foil and as much of the roof metal as possible). This is why your A/C ducts look shiny...the foil is there to reflect heat away from them. If you have an air space between the metal and the foil, it will act like a radiant barrier, bouncing heat back to the roof metal. If you do not have any air space between the foil and the metal it will help with noise if the insulation was intended to do that, but the foil will just get hot and transmit heat into the cab. The exact same thing as wrapping a potato in foil and baking it. If you want a vivid demonstration of this, get an old incandescent light bulb and hold your hand about 2 inches from it while the bulb is burning. Your hand will become very hot very fast. Now stick a layer of common foil about halfway between your hand and the bulb...shiny side facing the bulb and see what happens. And finally if you're still curious wrap your hand tightly with foil and stick it on the light bulb. You'll know how that potato feels Good luck. Personally I use the 3M foil-faced HVAC insulation and let it lay on top of the headliner.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Actually, the insulation works both ways. The foil should be placed away from the roof metal, or it would be less effective in reflecting the radiant heat from the roof as Jon said. If choosing between fiberglass and bubble wrap, fiberglass is more effective (has a better R-value) for the same thickness, because the individual air spaces are smaller. Another option is closed cell foam, either foil lined or unlined. For sound insulation, heavier is better, and not in contact with either the inside or outside surface. That's why leaded blankets are sometimes use in high noise situations. The sound waves have a harder time moving the heavier blanket, when something lighter gets vibrated by the sound and becomes a speaker in effect.
This concludes today's lesson in heat transfer and sound transmission engineering.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
