FSK Insulation Tape (3" x 150')

Awesome. Sticks to wood, foil and clean metal like...ridiculousness. Seams a bit less adhesion on surfaces where latex duct sealant was applied prior, not sure. It is wax paper lined so stick the tip of a sharp knife through the backing to "prod" the backing loose. Fast, easy, you'll get the hang of it. Reinforced with string so it doesn't tear unexpectedly like regular foil tape. I've included an image showing what unsealed air returns look like after 50 years and the dust required a wire brush to remove. So far, I've used this mostly for sealing joints between floor joist. In 1971, they ran our "fresh air" return and capped it with sheetmetal straddling the undersides and no sealant what so ever. The system actually sucked in dirt from the crawl space for over 50 years.

It can take 10 to 20 seconds to get the backing to separate from the tape. This is just too long and frustrating to do. I cut off the length needed and then apply it. It is too time consuming to get the backing off on each piece. The manufacturer says to use a thin blade knife, but even with the knife blade, the backing is so thin as well as the tape, that it takes too long to get it to seperate for you. Too much time is wasted trying to get the backing off. Time is money. I will go back to the old brand I was using.