[Rhodes22-list] Jammed IMF:(

[Stan Spitzer]

OK, I suppose I have to run aground more often to have the time to 
respond to some of your occasional S.O.S. signals.

The IMF never jams at boat shows, where it gets more use in less than a 
week than most of you give it in a lifetime.  It does not jam on 
demonstrations or rentals or even when//*I* go sailing which admittedly 
has not been for several months now.  And there are owners out there who 
have never figured out how to jam their IMFs.

Why is that.

It is absolutely a fool proof piece of equipment because it has no 
springs or gears and merely floats freely in a chamber.  (Well, maybe 
"fool" proof is a poor choice of words since I know that most of you who 
jammed your IMF are normally brilliant,)

There are only three reasons for an IMF system to refuse your bidding:  
Mechanical.  Human.  And all others.

Mechanical failure:  The sail may have ripped.  Or the sail may have 
come loose from its connection at the top of its furling tube and 
partially slid down its tube.  Or a bearing like the one atop the tube 
may have come off.  That sort of rare stuff.

Human failure:  You may have caused a mechanical failure like putting a 
curve in the mast by incorrect rigging or trailing with the mast up and 
everyone understands how hard it would be to roll up a carpet on a "C" 
shaped core. Or you may have forgotten to undue a cleat.  (This idiot 
almost always forgets the vertical locking cam cleat on the aft 
underside of the boom.)  Or you may be standing on the line on the 
cockpit floor.  Or you may have turned emotional; a hammer or lots of 
extra force only makes your Rhodes fight back.  Be kind and thoughtful.

What makes an IMF sail go inside its mast in a bunched up fashion:  
Either your putting it away with the boom so high above horizontal that 
more material than normal tries to wrap around the furling tube at the 
same location;  visualize that carpet on the floor where you fold over 
part of one side before staring to roll it up.  Or putting your IMF sail 
away with the boat not pointed into the wind. Now you can put your IMF 
main away in light airs with the boat in any direction relative to the 
wind but in heavy winds, with the sail taking just the right beating as 
it is being wrapped around the tube, it could be in a folded position at 
that instant.   So, whenever you can, follow the prescribed way to put 
away an IMF sail:  Boat pointed into the wind with the topping lift 
supported horizontal boom having naturally moved itself slightly to 
starboard of the boat's center line.  Sounds complicated but actually it 
all can be automatic.  If you are not one who likes continual fussing 
with sail shape, always sail with the topping lift supporting the boom 
horizontally.  Then, when you want to put your sail away, do it as you 
come about, just at that moment when the boom has moved itself to 
starboard of the cockpit center line.  With all these stars in alignment 
automatically, a pull on the furling line puts the main sail away in an 
effortless instant.  Try it.  You will like it once you get your body 
coordinated.

Reason for having the boom setting itself to be slightly to starboard:  
The furling tube die (a proprietary GB extrusion for all you out there 
who scoff at the Certificate of Support program) is designed for the 
sail to wrap around it in a prescribed direction that both makes the 
sail come out and go in easier because its wrapping direction is already 
started by the tube's design and because that angle with the wind that 
is established with the boom having moved to slightly starboard of 
center, takes sail cloth pressure off the mast slot while it is emerging 
from the mast, and conversely, when the cloth is going into the mast. 
With the boat not into the wind, when in heavy winds, the cloth pressure 
against the edge of the 26 foot long mast slot can get so huge as to 
make it unreasonable to expect the sail to want to go back inside the 
mast without complaining - or, for that matter, come out to sail ..

The Others:

Those weak on spacial relations might not consider that trying to pull 
out a sail of cloth made not to stretch, cannot work if the boom is held 
fast _below_ horizontal by the main sheet cleat. The explanation is so 
simple that I can explain it.  The length of the back side of the sail 
triangle cannot change. Lowering the aft end of the boom and holding it 
there so it cannot rise means the sail length would have to increase to 
fill this increasing space and that is impossible so the sail simply 
stops coming out of the mast.  A good practice is for the boom to be 
free and not locked down by the main sheet when taking out the IMF main.

If by chance a guest not attuned to all of the above common sense does 
cause a sail jam it is easily corrected.  Not having had this problem I 
learned its solution by seeing what the big boys with big In mast 
furling did at boat shows.  They approached the mast, put two hands on 
the sail cloth as close to the mast slot as reasonable and pulled the 
sail material not out but /*straight down - */ The one place where force 
is apparently not a no, no.

In conclusion a huckster remark:  If along the way of various owners, 
someone has re-mounted the IMF main too high or too low on its IMF 
furling tube, it will not work properly.  I will not go into explaining 
this here but think of two fat ladies (or governors) trying to get 
through a doorway at the same time.  If mounted too low the sail bottom 
will be rubbing on the top of the boom slider and causing bunching - if 
mounted too high the designed pulling out angle gets beyond its working 
boundary causing the problem of the two fatties trying to go thru a 
doorway.   As the sail comes out of the mast it should stay fairly 
parallel to the boom with about an inch of continuous clearance. The cut 
of the sail and its mounting on its furling tube are important to the 
easy operation the IMF can provide under all conditions.

While early outhaul car systems will let you sail, the newer outhaul car 
design (price C of S dependent) not only allows for better sail shape 
through superior draft control, but keeps the sail bottom continuously 
parallel to the boom and the boom much better in alignment with sail 
direction, all of this allowing a broader range of orientation to put 
the IMF sail in or out with greater grace.

there is probably something I forgot but have to get to my physical therapy.

ss