Palf's Little Blue Jimmy

[LT7A]

Originally Posted by N2TRUX

What Bill is using is good for reducing resonance. It dampens the sound waves that are amplified by the bare sheet metal. It does offer a small amount of thermal protection, but its minimal. You need a composite barrier to reduce both resonance and thermal transfer.

In addition to the sound dampening, the bituminous layer provides a thermal break and is also somewhat of an insulator. The foil backing works like the expensive stuff and reflects the radiant heat. So it is effective and does what the more expensive stuff does, just not quite as well. It's a matter of degrees...

So to speak.