I rebuilt the portlights on our 1986 Dana 24, way back when before the age of digital cameras (I was a late adopter
). So I don't have any good photos to show you.
But I can say that rebuilding them is well within the capability of most boat owners. It actually makes for a nice winter project if you have a good work bench where you can set-up.
Our portlights were still mounted in the boat. There were no problems with the frames -- only the sashes needed work. So I removed the sashes two at a time (one large and one small), covered the portlight with a plywood clamp contraption, brought them home, rebuilt the pair then brought them back to the boat and swapped them for the next pair.
You are in some ways fortunate that you can take them all home at once and set-up a production line. But just make sure the exposed portlight openings are well sealed against the elements.
Yes, acrylic is the way to go. Just get one large and one small portlight lens out, then bring them to your local glass shop and they can cut new ones for you at a very reasonable price if you don't need it tomorrow.
To get at the portlight lenses, you will need to remove the flange from the sash. First remove the old gasket, which will expose a series of machine screws. Expect many of these little brass machine screws to crumble when you attempt to extract them. You will have to drill them out carefully
. Get yourself a little tap and die kit if you don't have one, and be sure to use loctite or similar when you install the new machine screws into the flange.
I ended up rebedding the portlight lenses with a non-acidic
silicone sealant, which actually worked quite well. But there are probably better lens-bedding materials -- Mainsail might have a good suggestion.
I obtained replacement sash gaskets from the OEM, Whitewater Marine. They fit perfectly and were easy to install.
I buffed out the bronze portlights using the little B&D Mouse polishing kit -- they looked like gold when I was done. Very pretty.
After re-installing the portlight sashes, there is one final crucial step: Within the hinge mechanism is a tiny set screw which must be adjusted such that the portlight sash seats evenly around the portlight frame when it is closed. Some trial and error is necessary. Over time, as the new gaskets compress some, you will need to readjust the set screw.