The excellent work @davidbrooks did refurbishing his engine bay/bilge area got me thinking of two pieces of really important advice regarding working in those areas. I was just going to add it to the thread but thought maybe it deserved its own highlight? The advice I was given, in ascending order of importance:
1. I was told to prevent wood/fiberglass rot by sanding flush and vacuuming out any "abandoned" screw holes in those areas then filling them with a quality fiberglass filler or caulk (3M 5200 or Sikaflex) and then finishing that with a quality enamel, polyurethane etc. bilge paint. David used a West Marine enamel for his work . Abandoned screw holes can result from a rigger changing his mind or an owner moving something. Regardless, the holes must be dealt with asap to prevent costly damage.
2. One of the biggest dangers to any marine catalytic converter is fiberglass dust. I know Rinker is ocd about cleaning these areas at the factory before the engines are ever fired-up. Mercury Marine is adamant about not letting that dust into the engines (very , very hard-on them) and absolute death to the catalytic converter "bricks". When the dealer who sold me my 2014 EC 360 decided to grind the engine hatch edge a bit to make a better hatch to deck fit they put a guy in the bay with a shop vac and then had him hand wash and towel dry every surface. It took him 10 minutes with the grinder and three hours to clean the bay. I was there.