[Rhodes22-list] IMF "Reefing"

[TN Rhodey]

Joe, GB's IMF is a great design. I did have to replace a screw.....very easy 
just tapped a new hole. In 5 plus years it has never failed me.

Wally


>From: Joseph Hadzima <josef508 at yahoo.com>
>Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>Subject: RE: [Rhodes22-list] IMF "Reefing"
>Date: Sat, 17 Feb 2007 08:08:35 -0800 (PST)
>
>Hi Gang:
>
>I assume no one on this list has ever had any major
>problems with their Rhodes IMF. Is there any special
>maintence required?  I was on a boat where the furling on
>the head sail failed as the 160 was fully out.  I recall it
>was a little dicey going foward and fixing the problem,
>under the no so calm conditions.
>
>the down side any time you add complexity to something, you
>introduce another point of possible failure (plus
>maintenance issues, cost, etc.).  I'm assuming Stan's
>choice of materials, and his teams' workmanship minumize
>risks, but I'd still like to know of any sea stories
>involving IMF systems.
>
>
>
>
>--- Jim Connolly <jbconnolly at comcast.net> wrote:
>
> > It seems to me that the difference between IMF and
> > conventional from a
> > weight distribution standpoint is two fold:
> >
> > 1.  The furling tube which is negligible and the weight
> > of the mast
> > extrusion, heavier than standard.  Both of these are
> > fixed weights (fixed
> > height above deck with the mast raised in sailing
> > position) and can be
> > approximated by a weight "x" at the midpoint of the mast
> > (i.e., center of
> > gravity or CG).
> >
> > 2.  The weight of the sail (less than conventional,
> > because it is smaller).
> > Since it reefs and furls on a vertical roller, the CG of
> > the sail also stays
> > at the same height above the deck.  The center of effort
> > (CE) of the furling
> > sail will move down and forward as the sail rolls into
> > the mast.
> >
> > Net effect, furling the IMF lowers the center of effort
> > and not the center
> > of gravity of the mast and sail combination, while
> > furling the conventional
> > sail lowers both the CG and CE.  The CG of the
> > conventional mast/sail
> > assembly is lowered by the weight of the sail, which is
> > not likely a
> > significant part of the whole.
> >
> > It seems then to come down to the additional weight of
> > the IMF assembly with
> > sail vs. the conventional mast and sail.  I don't know
> > this, but I am sure
> > somebody here does.  Likely windage of the thicker mast
> > extrusion might be a
> > factor in some wind conditions.
> >
> > For me, convenience trumps all.
> >
> > Jim Connolly
> > s/v Inisheer
> > '85 recycled '03
> >
> > -----Original Message-----
> > From: rhodes22-list-bounces at rhodes22.org
> > [mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of
> > Bill Effros
> > Sent: Saturday, February 17, 2007 9:55 AM
> > To: The Rhodes 22 mail list
> > Subject: [Rhodes22-list] IMF "Reefing"
> >
> > Wally,
> >
> > Comparing "reefing" on standard sails vs. IMF sails is
> > very hard to do when
> > discussing among sailors some of whom have never even
> > seen an IMF.
> >
> > "Reef Points" result in noticeable changes in sail size.
> > The IMF is
> > infinitely adjustable. I often adjust my sail in
> > increments of 5% of total
> > sail size. I suspect most IMF sailors change the size of
> > their sails instead
> > of using the traveler. We don't think of it as "reefing"
> > -- it is an adjustment the sailor can quickly make in
> > response to changing
> > conditions.
> >
> > The extra weight of the mast is insignificant. Remember
> > that your sail is
> > larger, adding weight aloft compared to the smaller IMF
> > sail. But, since the
> > boat is designed to be sailed upright, and can easily be
> > trimmed to sail
> > upright, the difference in performance due to weight is
> > probably no greater
> > in an IMF boat than the difference of carrying an extra
> > bottle of rum. Or
> > not.
> >
> > I carry my extra sail on the Genoa instead of the main
> > sail. Both are
> > infinitely adjustable while single handing. When
> > conditions change, I change
> > the set of my sails, all by myself, so easily that even a
> > lazy sailor will
> > do it.
> >
> > I think the biggest surprise about the IMF is how well it
> > works
> > mechanically. The sail and mast are made for each other.
> > There is no
> > compromise here, and it is easy to extend and retract the
> > sail under any
> > conditions. My wife enjoys doing it.
> >
> > Our harbor is busy on weekends with a very narrow neck,
> > rocks all over the
> > place, and a 10 foot tidal variation every 6 hours. It is
> > irresponsible to
> > sail into the harbor if you've got a motor, and most
> > experienced larger boat
> > sailors take their sails down just outside the neck, and
> > motor to their
> > moorings. We turn on the motor and don't even stop while
> > we retract our
> > sails. When my wife sees other wives trying to control
> > flopping sails inside
> > lazy jacks she shakes her head in disbelief. When other
> > wives see my wife
> > roll up our sail they ask their husbands why they don't
> > have sails like
> > ours.
> >
> > Bill Effros
> >
> >
> >
> >
> >
> > TN Rhodey wrote:
> > > Bill,
> > >
> > > Well I may be wrong here .....I guess it would depend
> > upon how much
> > > smaller the sail is verses the extra weight of mast.
> > Way back when (on
> > > the sailnet list) there was discussion about this. In
> > my opinion even
> > > if the mast weighed the same you still might need to
> > reef sooner with
> > > IMF. Pure speculation on my part and I will admit I may
> > be totally wrong.
> > >
> > > The R22 is small enough to be quite sensitive to subtle
> > changes in
> > > weight and trim adjustments. You pay a price with IMF
> > in mast weight,
> > > sail cut, no downhaul, no cunnungham, no battens
> > (except for the new
> > > rev). If you know how to use all these controls you can
> > create a much
> > > flatter sail. You would be surprised at the difference
> > adding a vang
> > > made even with IMF. I could still flatten the sail
> > enough to make a
> > > big difference ...sailing much flatter, fast, and
> > higher into the wind.
> > >
> > > Everything is a trade off and for me the pros for IMF
> > are well worth
> > > any cons.
> > >
> > >
> > > Wally
> > >
> > >
> > >> From: Bill Effros <bill at effros.com>
> > >> Reply-To: The Rhodes 22 mail list
> > <rhodes22-list at rhodes22.org>
> > >> To: The Rhodes 22 mail list
> > <rhodes22-list at rhodes22.org>
> > >> Subject: Re: [Rhodes22-list] Harken Lazy Jack
> > >> Date: Fri, 16 Feb 2007 09:02:30 -0500
> > >>
> > >> Wally,
> > >>
> > >> Why would a smaller sail need to reef sooner?
> > >>
> > >> Bill Effros
> > >>
> > >> TN Rhodey wrote:
> > >>> Joe, There are some performance trade offs with IMF.
> > The sail is
> > >>> smaller and I would think an IMF R22 would need to
> > reef sooner but I
> > >>> am just guessing. That extra weight aloft must have
> > some effect on
> > >>> balance.
> > >>>
> > >>> Wally
> > >>>
> > >>>> From: Joseph Hadzima <josef508 at yahoo.com>
> > >>>> Reply-To: The Rhodes 22 mail list
> > <rhodes22-list at rhodes22.org>
> > >>>> To: The Rhodes 22 mail list
> > <rhodes22-list at rhodes22.org>
> > >>>> Subject: Re: [Rhodes22-list] Harken Lazy Jack
> > >>>> Date: Thu, 15 Feb 2007 16:45:37 -0800 (PST)
> > >>>>
> > >>>> I've seen some other cool sail systems, some with
> > sail covers so
> > >>>> you only need to zip it closed. Several replace the
> > slot in the
> > >>>> main with a track system so even a kid could hoist
> > the main, and it
> >
>=== message truncated ===
>
>
>HADZ (a.k.a. joe)
>
>"That's what a ship is, you know. It's not just a keel and hull and a deck 
>and sails. That's what a ship needs. But what a ship is... is freedom."
>-- Captain Jack Sparrow
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