Once I had the inside of the port hatches sanded smooth, and that includes sanding back all traces of the tape edges so that running your hand all over the hatch feels smooth with no sharp shards, I will be able to finish them by painting them. If a person puts a hand in a hatch they don’t want to get their finger pricked by a razor sharp fibreglass splinter. And the best way to be sure is to run you hand all over it after sanding it smooth. This inevitably results in splinters! Better now than later. Some builders go to the effort of actually fairing the inside of their hatches including bogging the tapes out. I don’t think it necessary to go to that level of effort, but the inside of the hatch should be safe and sealed. But with a thick enough coat of paint most signs of the tapes will disappear anyway.
The paint I am using inside the hatches (I will only ever use this stuff inside hatches) is actually an epoxy floor paint used for painting concrete floors. It is a high gloss 2 pack epoxy, hard wearing and perfect for what I am using it for and much cheaper than other marine paints. The boat builders are using this on the Waller under the soles to seal the ply. I applied the paint as thick as I could get it and like most paints it is self levelling so I applied it with a roller and it then smoothed itself out. I may give it a second coat in the morning if I feel it is not quite thick enough. It will still be green so like all epoxy I will be able to apply it wet on green and once fully set it will set very hard.
As I still have to tape the decks on I have stopped the paint about 200mm short of the tops so the glass goes onto raw glass (duflex). Then once I have the tapes done (and I will peel ply them to minimise having to sand inside the hatch with the deck glued on) I will paint the rest of the hatch inside. I will paint the underside of the deck to within 200mm of the edges to save more upside down painting before I glue it on. I am hoping to glue the port inside deck on tomorrow so I will paint it first up then glue it on.
I also cut the pieces to fill the gaps under the beam that needed to be cut out to fit the deck over the beam. I used the piece I cut out and trimmed the shapes I needed to fill the gaps. Once this is all glued down it will be glassed inside and out to finish the securing of the beam and then bogged and faired back out again.
All is pretty much ready to glue the first of the deck panels on.