Review on High Temperature HVAC Aluminum Foil Tape - 2 Inch By 210 Feet (70 Yards) 3.6 Mil - Ideal For Sealing & Patching Hot/Cold Air Ducts, Metal Repair, And More - Professional Grade Quality! by William Lin

A 6 inch hvac ceiling vent was moved and reduced to 4 inch when adding a corner shower to a 2nd bathroom in my home. The output was weak duct was leaking air everywhere the tape looked like a blind guy applied it. I removed everything and did it myself. I resealed all the joints the tape sticks great I used a piece of wood dowel to smooth the tape all joints. Added duct seal the 4 inch vent output is better than the 6 inch was! First time I ever did this stuff.