CaptVR here:
Get terminology correct.
1. Lights are fixed to frames and are solid with the
hull or
cabin.
2. Port Lights are a glass or plastic normally set in a metal or plastic frames. These are
set on hinges and have
dogs to lock them. Hence port - lights being transparent
3.
Ports are solid door or
hatch, normally a metallic that is secured with
dogs. Vent only
From your picture, you are replacing Lights, not port / lights. With building boats for more than 55 years, I always used Butyl Rubber
sealant, it stays pliable for decades, never
leaks and can easily replace glass,
lexan,
acrylic, etc. easily in the future.
Never want to use products like 5200, will they
work, yes. Can you replace the glass, no.
Dow 795 does
work quite well for a bedding
sealant, especially on large lights like those side lights on trawlers and
motorsailer pilot house windows. Main thing with 795, check the date, if it is expired, don't use it. It seams to never harden just stays as it came out, don't set. As far as getting yours apart, I've found a sharpened edge on a flexible putty knife works most of the time.
Happy sailing all.
Capt. Vince Rakstis, Ret. MS St.Petersburg, Fl.