Broken Finn Wing Mast Repair -- Part Three
Part Three of the Broken Finn Wing Mast Fix. View Part One. or View Part Two.
With the mast back in one piece, a trial run to
see what the mast bend numbers were was done.
Whilst the
addition of the flat edge on the back of the mast stiffened it
considerable, it was not enough however to meet the bend figures
desired.
In the past we have stiffened masts up with layers
of standard uni carbon. The number of layers required added
considerable (up to a kilo) weight to any mast.
So off to C-Tech Ltd
we send the mast to have high modulus prepreg carbon layers
added. Stiffer and lighter mast than if we had used
standard carbon
unis in a wet layup.
Assembled the mast ready for mast bend
calculations and a test sail.
These are the mast bend numbers we ended up
with.
While not achieving directly the Wilke or Hit mast
bends desired (especially low down sideways stiffness), we can ease
the sideways tip slightly to improve the "flick" that opens up the
leach in a puff. Fore and aft stiffness low down can be can be eased
slightly with removal of carbon from the front of the mast below the
deck collar.
First couple of test sails were in light air and the mast performed really well. Feels powerful but the ultimate test will be in over 12 knots of wind. Can I hold it up?
For a free quotation on yacht and spar repairs- contact us directly using the information at the top.
