May be a bit bold title, but after 5 years with tricky in-mast furling
issues my current
solution is a great relief. It is all about friction.
My rig is a Zspars UK on a Prout 39 feet catamaran
. The rig design is "Prout Offshore
Rig" witch means that the mast
is far back on the boat; 6m from the bow, the boom is 3m. The production year is 1998 and I never changed any sails
or standing rigging
Even with this small mainsail
the jamming inside the mast
has been a increasing problem. I have tried all tricks in the book (web) Zspars description, easing the tensions, angling the boom, winching in with tension on the sail etc.
My first problem was that the line used for furling
the sail had swollen from salt water
and general use. When the line was furled in the plastic spiral in the mast as the sail was pulled out, the diameter of the spiral roll was bigger than the space inside the mast, increasing the friction for every turn. This was solved
(some years ago) with replacing the line with a new 10mm diameter line.
Still the sail has jammed more every year. I consulted a mechanical designer
I know (whom is not a sailor) when I started to realise that the inside of the mast where the sail was to be furled felt all corroded and similar to sanding
After explaining how a in-mast furling system works ("roller window blind" in a alu-tube with a slot) he suggested that rather doing anything to the mast to coat the sail with a dry lubricant on the "outside". It would be a much larger surface that would not wear of so easy and reduce the friction coefficient in the system.
I coated the 12 year old sail with PTFE spray-cans, and guess what...
It worked perfectly!!
After 5 years of impossible power handling of a sail that newer would cooperate I now furl the main sail with my bare hands. Now winches, no hassle, no angling of the boom, no nothing. Just furls in and out as a dream.
I guess you could use any dry lubricant on the sail as long as the friction between the sail and the mast tube is reduced. I used 8 cans of PTFE spray from a local low cost store and could not be happier.
CatSailor - Now with both Genoa
in use, even for a short leg.