has a water
tank that is built into the hull
under the v-berth. The top of the tank is mostly 1/2" balsa core
except where Beneteau
installed the sender, fill port and vent. I am installing one or maybe two 6" inspection ports
in the top to access for cleaning
and possibly to install some baffles to reduce sloshing. I'm planning on using a Beckson, or maybe West Marine
equivalent, screw in deck
plate. These all say to use only a pure silicone sealant
to not damage the plastic.
First, after cutting out the hole I plan to cut back 1/8" or so of balsa, not as far as the fastening screws. Then seal with epoxy
, probably two coats, and finally fill back to the edge of the GRP with thickened epoxy
For the fasteners I am considering 1/2" #8 screws, instead of through bolting, drilling only through the top/outer skin. My thought is that this will eliminate a source of leaking through the inner skin. The tanks
are all inside the boat
so there should be no water
on the outside of this deck
plate. Will putting silicone in the hole in addition to under the flange before screwing it down protect the balsa in this installation
, or should I use epoxy in some way? My secondary concern is the pressure on the seal and screws from the water when the tank is full or any flexing when underway.
If I through bolt I'll oversize the holes, seal with regular epoxy followed by thickened epoxy, and re-drill the holes to the final size for the through bolts. I will fill the bolt holes with the silicone sealant
for final assembly.
I am interested in feedback on my approach to this project
, including other deck plates or access ports
to consider. I've looked at some like the Vetus solution, but it and others seem to be geared towards single