Having campaigned the Finn in its current mode
for three years, problem areas were well established. With the rule
change to permitting a hull weight reduction (to 116kg) , the
opportunity to put the Finn on a diet plus carry out modifications
to rectify problem areas was taken. Target was to reduce the
boat weight from the existing 120kg with no corrector weights to 114
Kg to enable the use of corrector weights to achieve better weight
distribution and swing in the hull.
Problem Areas
1-.....By far the largest problem was the inability to
funnel water out of the bow. To drain the forward
compartment a small one way flutter valve was used.
That proved to be totally useless. So ended up just with
a bung and while in flat water sailing this proved not a problem,
the 2009 Nationals in Lyttleton, with rougher and at times
washing machine affect conditions, showed up the inadequacies
of the arrangement. Sailing with enough water in the bow to fill
a bucket is not ideal.
2-.....Using blocks as the position adjustment in the bottom
mast step made it easy to change mast setups on shore but much more
difficult proposition to make those adjustments out on the
water.
3-.....Longitudinal
flexing in the centrecase capping allowing the centreboard to fall
off. Even though the capping had been strengthened with a
composite carbon fibre and cedar support, the support was in the
logitudinal plane and the fabrication did not have the stiffness
desired.
The Fixes
1-....The whole of the front of the bow section was
redesigned by adding a bouyancy tank in the bow, similar to the
raised floor concept of the Devoti. A tunnel allows free flow
of water from the bow into the cockpit and out through the self
bailers. The boat only needs to be level to drain the now much
smaller bow compartment back into the cockpit.
2-....The existing mast heel bearing
slide was thrown away and a new concept of using a rockable bearing
cup (to slide in a carbon fibre slot) designed. Made
adjustable by an 8mm rigging screw. More details and purchase
opportunities here.
3-....The
original concept, to ensure the centreboard remains centralised in
the hull without any slop was sound, but the flex remained in the
centrecase capping.
Reduced the size of the centreboard
locating blocks to 50mm long and made them non adjustable. Removed
alloy and carbon supports in the capping and replaced with
fibreglass retaining plates.
Side bracing supports installed
using fibreglass and 3mm plywood sandwich.
This
stiffened the centrecase totally and had the added bonus of being
able to relocate the drink bottles away from under the
twart.
Weight savings was 1.1 kg in the bow and 0.8 kg on the
centrecase supports. Much more is to come by attacking the
decks.