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Under deck furler / sport boat

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I have a Rocket 22 (#15 - last one made).  It is a fantastic boat and extremely solidly built - hull, mast & boom, & keel, and a joy to sail. (Interestingly this one has carbon layers in the outer hull skin which I didn't see in the original descriptions of the boat.) However a lot of the hardware and fittings that came with the boat originally were, IMHO undersized or not up to the job. Most have been replaced with more robust fittings, modified, or otherwise made more bullet proof, one at a time.  For anyone not familiar, the R22 has a tall double spreader mast with 3/16" shrouds and no backstay.  With a powerful sail plan (for a 22 foot boat), an 800 lbs lifting keel 6 feet down, a 9 foot beam, and a downstairs mast-ram jacking up an over engineered carbon mast, a lot of tension can occur on the rig.  

So, the last item that remains untouched, and the subject of this inquiry, is the Harken underdeck furler. Like the other sometimes marginal fittings that came on an otherwise bullet-proof hull / mast / boom / keel,  I suspect that this too was taken from a parts bin for more lightly loaded rigs. 

Out on the water: It is very hard to furl if there is any real tension on the system. If there is a lot of load the thing just does not want to turn easily. Furling in high winds with tension on the rig can be dicey... Just when you need it to cooperate! Over 15 knots and I sail by the lee a bit to  to blanket the jib and crew works it in a bit at a time. And unrolling the thing... (again if under tension) getting the last wrap or two off is dicey. Sometimes you have to do it by hand!  Light air, no problem. But light air is not when you really need it to work!  BTW I have tried all different sizes of line and number of wraps; it has been removed, inspected and cleaned, etc. 

I am open to and would appreciate any suggestions... Please fire away!

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Make sure the angle of the line as it feeds into the furler is 90 degrees to the forestay.   We have a final block that is attached by a line about 10 inches long, to the end of the front bunk.  Having the correct alignment made a bigger difference then anything else.  ( we have boat #10)

We also replaced the balls in the furler and in the piece at the top.   Simple to do

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I actually did the same making sure the line in and out of the drum was at 90 degrees with a block about a foot from the drum. 

I have been thinking that the problem is in the bottom unit as it is carrying the entire force of the headstay while the top unit is only carrying the force of the jib halyard. In any case I haven't had a try at taking either the top or bottom unit apart as yet.  Do you know what kind / size balls they use?  Also I think the top unit is Facnor while the bottom is Harken.

I also had the fear, which may or may not be grounded, that a furler unit that is probably meant for smaller boats with less load, like the J70 for example, might at some point be at risk of coming apart.   I do imagine the problem is more just an issue of not operating well when under too much load, but still, it makes you wonder that about where the total failure point is... It is one thing to hassle with a reluctant furler; another to have the bottom unit implode and lose the mast.

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It sounds like something is out of alignment or you're working over the SWL. I agree with the above comments about checking furling line entry is at the correct angle - this seems most likely cause and should be a fairly straightforward fix - maybe using a low friction ring on a strop go guide the line onto the furler similar to how it's done on above deck units but depends what you have down blow to anchor the strop to...

If you're confident the furling line is correctly aligned and you're still getting issues then my next step would be disassembly - this could diagnose other alignment issues or overloading (assymetrical wear on furler surfaces vs compressed bearings). Ideally you'd pull the furler off and insert a load sensor into the stay to load up the rig and determine whether you're within the SWL of the furler but this might require contracting a rigger...

Is there an evidence of wear around the hull penetration? This could diagnose any alignment issues

Also, and I might be getting myself confused here, but if you're struggling to unfurl the jib in strong winds with the kite up then this could suggest sag in the forestay when the kite is powered up and taking the load off the stay. If here isn't enough tension in the stay it's much harder to unfurl - the sag moves the stay off centreline and means you need way more energy to transfer the torsion up the stay. You mention sailing by the lee during the unfurl which should transfer the load back to the forestay but maybe worth checking out as a potential culprit.....

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