On Wed, 20 May 2009 01:30:11 -0500, cavelamb
wrote:

Ok, the big argument is this...

Does partial unrolling of a roller furling head sail cause damage to the sail?
(in terms of shape and stretch)

Yea or Nay?

Nay.

When partially furled, the forces on the sail are much lower than when
let out.

Some sailmakers make head sails specifically designed to have a better
shape when partially rolled up, but it haslittle or nothing to do with
any potential for actual damage.

Kappa Sails in Westbrook, CT makes a really nice 135% that rolls to a
100%, and maintains good shape. It is made with two different weight
sailcloths, in addition to the careful design.

Most "common" headsails, when partialled furled, have a very fat
leading edge that kills air flow, and a poorly shaped exposed area.
They still provide "some" power, but not as much as you might like.