The acrylic around the laser exhaust was cracked and all the tape seals had pretty much given up the ghost so I put in a new panel and taped everything up again. This took a couple of hours.
Old cracked acrylic
Peeling tape on outside
New panel installed on vent beside the old one.
Installed and taped up with weatherproof duct tape.
Joint wrapped with proper duct foil tape.
Pressure differential tube reattached