Repair and Maintenance of a Drascombe Lugger
Replacing the Wooden Floor Boards
(page 1 of 5)
This set of pages reviews the options for replacing the
wooden floorboards in the Lugger and goes on to describe
in detail the DIY construction of of a new set of boards.
Looking over Sospiri at the end of the 2002
sailing season it was obvious that the two sets of wooden
floor boards (port and starboard), were in very poor
condition and either needed extensive refurbishment or
else replacement. A more detailed examination showed deep
splitting along the grain on most of the larger boards.
Consequently the decision was made to completely replace
them.
What does the standard floorboard set look like?
Sketch Plan of Lugger Floorboards, viewed from beneath to
show the bracing boards
This sketch is a representation of the Lugger
floorboards. To facilitate extraction, the floorboards
are in two sets; one set each side of the centreplate
trunking. There is a gap of about 12 mm between each
longitudinal board to enable drainage of water into the
bilge. Underneath the longitudinal boards are a series of
smaller cross or bracing boards typically fastened with a
combination of copper nails and bronze or stainless steel
screws. The sole function of these cross boards is to
hold the longitudinal boards in position. Note that with
the exception of the two port and starboard curved outer
boards, which are markedly different in size, the other
port and starboard board sets approach an exact mirror
image of each other.
Sketch of the boards in relation to the supporting GRP
bearers in the boat.
To complete the picture, this sketch shows the boards in
relation to the moulded GRP bearers in the boat (outlined
in blue), on which they are supported. It is important to
ensure, when obtaining new boards, that the bracing (or
cross) boards do not foul either the bearers, or the hull
around the outer perimeter of the boards.
Design Variations
First variation on the original floorboard design.
In this variation, the boards each side of the
centreplate casing have been divided across to give a
total of four sets of boards instead of two. With this
design it is important to ensure that the 'joints' across
the boards on each side of the centreplate casing,
coincide with the central GRP bearers, the positions of
which are shown by the blue arrows.
Second variation on the original floorboard design.
This variation is similar to the one above, the only
difference being that 12 mm plywood sheets are used
instead of longitudinal boards and cross boards to give
four sets of 'solid boards. Again it is important to
ensure that the 'joints' across the boards on each side
of the centreplate casing, coincide with the central GRP
bearers, the positions of which are shown by the blue
arrows.
Back to the Original (Two Set) Design
The design variations shown above will not be referred to
again and what follows refers exclusively to the 'Two
Set' board design.
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Photograph showing the port board set and the
starboard board bearers
This picture taken from the back of the boat,
looking down into the cockpit, shows the port set
of boards in position on their bearers. The
starboard set of boards have been removed showing
the GRP floorboard bearers. From this it can be
seen that the boards rest directly on the bearers
and the bracing or cross boards take none of the
loading, their sole function being to hold the
longitudinal boards in position.
(Click on image for larger view)
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What went wrong with the old boards?
The original floorboards should be carefully dismantled
for use as templates for the new boards. In so doing it
is worth examining them to see why they have broken and
how the design can be improved to make the new boards
more resistant to wear and tear.
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Photograph of the old boards
This picture shows part of the original set of
starboard pine boards.
All three of the larger longitudinal boards have a
series of deep splits. This is probably a result of
ageing of the softwood coupled with inadequate
maintenance or use of inferior coatings which have
allowed the wood to weather, become brittle and
split. The remedy with the new boards will be to
apply an initial multiple coating of Epoxy followed
by a regularly maintained overcoating of
marine-grade varnish.
Note also the two bracing boards which over the
years have been fastened to the longitudinal boards
with a combination of screws and copper nails in a
battle to keep them securely attached to the main
boards. A more effective combination of glue plus
screws will be used in the construction of the new
boards. Note that the fastenings had been removed
when the photograph was taken.
(Click on image for larger view)
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Another area of damage
This photograph shows a split in one of the large
boards caused by a screw driven through the bracing
board with an inadequate pilot hole in the wood of
the underlying longitudinal board. Note the sharp
end of the board and the angular edges which make
all the boards more prone to splitting and also
unpleasant to handle.
(Click on image for larger view)
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What are the options for relacement?
The first thing to decide was the method of
replacement. There are several options:
- Purchase a new set of boards from one of the two
main Lugger suppliers; Churchouse Boats or
else Honnor Marine.
This option is attractive if you haven't the time,
skills or inclination to make the boards yourself.
- Get a local timber /boatbuilder/furniture
maker/fabricator to construct the boards from some
drawings. This option requires close collaboration with
the contractor to ensure the boards fit properly and
are constructed using marine grade coatings/adhesives
and fastenings.
- Purchase the appropriate wood from a timber
merchant and construct the new boards as a DIY project.
What wood should be used?
There are several options depending on how much you are
prepared to pay:
- At the top end of the range you can have the boards
constructed of Teak either as boards or as a grating
(network of cross pieces). Teak is very expensive but
is perhaps the ultimate durable boatbuilding timber,
remaining in good condition with a minimum amount of
maintenance.
- If teak is too expensive then a cheaper hardwood
such as Mahogany or Iroko is a good and popular second
best. This is tougher than softwood, but will still
need regular protective coating and maintenance to keep
the wood in good condition.
- Another possible option is to make the boards from
sheets of marine plywood. The boards are made in four
sets instead of two.
- The cheapest option is to use softwood for the
boards. The original boards in my Lugger were made from
Western Red Cedar Thuja plicata, and Honnor
Marine still use this wood for floorboard construction.
Although a softwood, it is very durable with a high
resin content making it very resistant to rot.
So which options were chosen for replacing the boards
on Sospiri?
The original floor boards on Sospiri were made
of Western Red Cedar but, not knowing that at the time,
I opted for Redwood Pine (also known as Scot's Pine or
Pinus sylvestris). This is not as durable as
Western Red Cedar so will require a little more
maintenance. The original boards were used as a
template for the construction of the new boards.
Note that the following instructions for making new
boards can be applied to the softwood or hardwood
options but not the plywood option.
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