Shaking Furlex

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moonshine

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At the boat yesterday winds gusting up to 33 knots, busy below fixing new heat sensor to bowthruster when disturbed by load 'rattle/shaking' which originated from the Furlex doing an imitation of the Tacoma Narrows Bridge !!

No sail on the Furlex turning it 180 deg with the grooves downwind stops the vibration. Now concerned that the whole foil can go into resonance. I did not see other boats seemed to be suffering this issue :-(

I noticed on boats ashore that have set small triangle pieces, which are slide up the Furlex groove to approx mid point and tied off to the mast. I assume this is effectively a damper to any vibration.

Does anyone know where I can buy one of these devices, or any other soultion that I can impliment ?

Moonshine
 
I have found bungee cords to the pulpit work on mine. It's just a matter of getting the damping factor right. A longer line and bungee higher up the luff should work better.
 
Actually, its the insubstantial mast they fit to those Nauticats, and the coachroof elastomeric damping block. That coupled with the very weak forestay fitting in the bow will combine to create a mutil resonative area, which gives the illusion of the Furlex foil resonating. If left unchecked, this will workharden and stress the rigging rivet fixings causing structural failure
I can only suggest that you upgrade the mast and rigging to something more substantial, and get the bow fitting reinforced.

Alternatively, ring Mick at Wilkinson Sails in Burnham on 01621 786770, and he will have you one done in the morning.
 
It must be the Engineer in you Jim !!

Insubstantial is not one of the words I would use about the 2" SS tubing used on a Nauticat bowsprit ? Perhaps I will have to source a 4x2 RSJ to bolt underneath ?

A call to Wilkinson will be the route to take, thanks.

Moonshine
 
I cope with it this way -
When the sail is on, simply ensure the sheets are left quite tight back to the winches.
If the furler is bare, hoist the top furler fitting about a third the way up, with a line attached to pull it down again (!) and another line from it that is led across to the mast - the spi pole attachment ring is handy for this - and given some tension.
 
FullCircle - what on earth are you talking about? "weak forestay" "insubstantial mast" "upgrade mast and rigging" Are you taking the p**s? What do you think an "elastomeric damping block" is?
Nauticats are amongst the sturdiest built boats anywhere.
 
Malo37 said:
FullCircle - what on earth are you talking about? "weak forestay" "insubstantial mast" "upgrade mast and rigging" Are you taking the p**s? What do you think an "elastomeric damping block" is?
Nauticats are amongst the sturdiest built boats anywhere.
Click to expand...

Ah. SOHF.

I have known moonshine for a good number of years......
 
moonshine said:
At the boat yesterday winds gusting up to 33 knots, busy below fixing new heat sensor to bowthruster when disturbed by load 'rattle/shaking' which originated from the Furlex doing an imitation of the Tacoma Narrows Bridge !!

No sail on the Furlex turning it 180 deg with the grooves downwind stops the vibration. Now concerned that the whole foil can go into resonance. I did not see other boats seemed to be suffering this issue :-(

I noticed on boats ashore that have set small triangle pieces, which are slide up the Furlex groove to approx mid point and tied off to the mast. I assume this is effectively a damper to any vibration.

Does anyone know where I can buy one of these devices, or any other soultion that I can impliment ?

Moonshine
Click to expand...

I have triangley thing you can have if you want it. PM me.
 
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