I cut an opening in the sound deadening material and use foil tape to seal the edges. I then cut another piece of sound deadening material to fit into the hole, thus plugging the hole, and again use foil tape to seal the edges of the plug. Then when you need access to the access panel you simply pull out the "plug" of deadening material.
Hope that makes sense
Originally Posted by DavidF
...Test shows the Onyx stays put at a much higher heat than any of the asphalt based roofing materials and just slightly lower temp than Dynamat. But, a very high temp never-the-less.
Got any links to that test?
Here's one on You Tube from July 2011 that has Peel-N-Seal, Dynamat and Fat Mat (Onyx not included):
