Removing the old instruments
The old instruments unbolted from the bulkhead easily to reveal a bit of a mess. We decided to site the instruments on the hatch garage to make them more visible. The plotter would then go where the old instruments had been sited. However, its footprint was smaller than the old instruments, and the gelcoat had many holes and was badly discoloured in this area. We decided to re-gelcoat the area.
First, I masked up the area that we wanted to re-gelcoat before sanding it back harshly with an 80-grit disc in a random-orbit sander. We filled the redundant holes with epoxy and glass cloth in the same way as used to fill the old transducer hole (see page 77) so they were flush with the bulkhead.
We then sanded back the repairs and area to be re-gelcoated. Polly’s gelcoat had a slightly yellow hue after 30 years, so we tinted some white gelcoat with a dab of cream from a Blue Gee Colormatch pigment pack (inset) which matched the colour well after some trial and error.
This done, I added catalyst to the mix and painted on the gelcoat with a brush. Once each coat became tacky, we applied another, up to four thin coats. For the final coat, I added 2% wax-in-styrene to allow the gelcoat to cure by excluding air. When cured, it could be sanded back with progressively finer grades of sandpaper. The end result looked much better – a blank canvas ready for the new 5in chart plotter.