In Port Light Work II I mentioned that I left the trim ring dry fit because I wanted to check out the Dow Corning 795 seal around the spigot. I did go out there about a week later to check it out and all seemed well. The 795 takes forever to cure so it was still very elastic but held the port in place by its self even so. This gave me enough confidence to proceed and seal the trim ring in place.
For the trim ring I used a liberal amount of Bed It Butyl tape. I really laid it on thick around the female threaded holes so that there would be enough to fill the gaps.
Once in place I lubed up the stainless steel machine screws with Ultra Tef-Gel to prevent galling.
With the Tef-Gel in place I slowly tightened down the bolts over the course of a few days. This slowly squeezes out the excess butyl and creates an excellent seal. Heres what it looks like:
I then trimmed the excess off with a knife and this port is done!