The hardest part is deciding if the repair or restoration is going to
Looking for Marine Grade Plywood?
“When a great adventure is launched with a powerful thrust, fatigue in the muscles and doubts in the mind are swept away by a fullness that moves life along like a breath from the depths of the soul.” (Bernard Moitessier)
Many home builders have been convinced that it is possible to use
ply sealed with epoxy.
This type of plywood
is laminated with
non-waterproof glue and will have significant voids as soon as the
coating is damaged in any way it will soon start to rot and delaminate.
If you suspect that a non-marine grade of ply has been used you should
replacing the whole sheet rather than patching.
But don’t despair, it is actually quite a simple job to replace
On a small boat replacing the entire hull bottom is as easy as using a
The first objective is
to identify and cut away
all the damaged plywood.
If you mark out and cut
the offending area along
straight lines it will be easier to cut a replacement patch.
The particular shape
doesn’t really matter, however a square or rectangle will be
easier to cut and replace.
It is normal in plywood
construction for the ply
to be epoxied to any frames, stringers and bulkheads.
To repair plywood you
will have to cut around
these then remove the glued on ply later.
As it is easier to cut
from the outside the hull,
the positions of all the frames etc will have to be marked on the
From the inside drill a
few fine holes along side
the framing so thy can be seen from the outside then draw a line to
join them up.
To avoid cutting through
or damaging any frames,
stringers or bulkheads use a skilsaw or router with the depth set to
the hull thickness.
If the boat has been
skinned with fiberglass, you
will need to use a carbide bit in the router.
I am perfectly aware that the majority of Wooden Boat aficionados are sensible folk. However, I need to point out that I am an amateur wooden boat enthusiast simply writing in order to try to help other amateur wooden boat enthusiasts. And while I take every care to ensure that the information in DIY Wood Boat.com is correct, anyone acting on the information on this website does so at their own risk.