There are a few reasons why I am using Phenoseal for this project in addition to a flexible sealant. Unlike the quick setting flexible sealant or epoxy, Phenoseal dries more slowly. This is perfect for attaching, aligning and adjusting the exits. Plus Phenoseal is a caulk which is used to create a weatherproof seal between objects, like windows (portholes) on boats.
The alignment on this project is important, seal the pipe one side at a time (front then back) to give yourself time to adjust when needed.
In order to verify that the alignment is correct, do not seal both sides of the pipe (interior and exterior) at the same time. Create the seal for the interior of the pipe first and finish the seal on the exterior after the interior has dried.
Look for the excess Phenoseal on the interior wall of the cooler and use a damp paper towel, or your finger, to form a seal between the wall of the cooler and the exterior of the pipe.
If there are any cracks in the seal or not enough Phenoseal to form a complete bond, add more.
Let the interior Air Dry for at least 24 hours. Do not add heat to speed up the process, this will weaken the lifespan and weatherproofing of the Phenoseal.