You will be happier in the end with marine grade.
One thing I learned when building a wooden kayak a few years ago was "drill-fill-drill".
Pre drill any holes then fill with epoxy, then drill it out again before inserting the screw. When I did a through hole, I drilled it out bigger than needed, taped up one side, mixed wood flour with epoxy filled the hole, taped the other side. After it dries drill the size you need and you have a fully encapsulated hole.
If you are mounting hardware, drill the hole fill with epoxy, put the hardware in place and drive the screw, let it sit for a bit and take the screw out and remove the hardware. Now you have a threaded mostly waterproof hole.
|