Furling headsail question

Discussion in 'Sailboats' started by Jetboy, Mar 19, 2015.

  1. Jetboy
    Joined: Feb 2012
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    Jetboy Senior Member

    I know this might be kinda elementary, but I don't totally understand furling. I've made a home built furler for a jib on a 17' daysailer and that's my only experience. In that case it was a tube around the forestay and the jib sail was attached with very small shackles where the hanks were removed to the tube with a small spool at the bottom. It worked fine, but was very basic.

    So I'm nearing completion of an 18' trimaran and want to buy a furling system or build one that is better.

    I understand that there seem to be two options - the first having a solid extrusion that sleeves outside the head stay; the second is one that rolls the sail around the stay with a swivel at the top.

    Many I see are code 0 or similar with their own internal stay like the ones that roll on the forestay and simply run parallel to the forestay but a bit further toward the bow.

    I also see some where you have the jib on an internal jib stay inside the bare forestay and don't use the forestay for both the jib luff, but use two cables instead.

    Since this will be a trailer sailor I'd very much prefer a flexible furled sail for storage.

    My questions are these:

    Is there a reason I shouldn't use a jib furler that wraps around the forestay? Like the one on a hobie 18? I was thinking something like this: http://www.apsltd.com/c-7526-selden-furlex-20s-furling-system.aspx

    And possibly two of them so I'd have both a jib and a code 0 or something like that ahead of it.

    If that's not a good option, what is more appropriate for a trailer sailed 18' boat?
  2. Richard Woods
    Joined: Jun 2006
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    Richard Woods Woods Designs

    You have to differentiate between furling and reefing. In general the sails that roll round a forestay are just furled, as for a screecher for example.

    If you want to reef the sail you should use a tubed system. two reasons. First if you pull on the sheet when partly furled it will tend to unfurl if you use just the forestay. And th etube increases the leverage so you a) don't have so many turns to roll it up, b) it requires less force to do so

    I used a Plastimo 406 on my Strike 18 for the reefing genoa. My Strider Clubs used a wire jib luff as the forestay and furled, not reefed

    You may be lucky and find a used flexible Harken reefing gear (they stopped making them) otherwise the CDI units are flexible (but also pretty crude and horrible)

    Hope that helps

    Richard Woods of Woods Designs

  3. sharpii2
    Joined: May 2004
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    sharpii2 Senior Member

    The Siren 17 I used to own had a wire luff jib, which was set behind the fore stay. It had a spool on the bottom and a swivel bearing, on the top, which the halyard attached to.

    This sail was obviously designed for this system and set reasonably well, considering the probably insufficient luff tension.

    As Richard just said, it was really a furling system and not a reefing one. Once the jib was partially rolled up, it became quite bag like and probably didn't contribute much driving power. What it did do was to help balance the helm, due probably to its drag.

    Typically, when the wind started rising, I rolled up the jib first.

    Because the Siren had a long Center Board, I was able to crank it up some, and move the Center of Lateral Area (CLA) aft, to suit the mainsail only. Then the boat still sailed quite well.

    The reason I'm bringing this up is to help make your choices clearer.

    With this sort of jib, it is all or nothing at all, or some forward drag to hold the bow off the wind.

    You could almost do just as well with a down haul device for a jib hanked on the fore stay. This too is an all-or-nothing-at-all system, but it brings the jib down to the deck quite reliably, so it can be doused without going onto the foredeck.

    Since you're talking about a trailer sail boat, I assume you plan on rigging and de-rigging quite often. A real roller-reefing system could make this process more difficult, as the bar the sail attaches to is really a spar, and should not be bent when stored.

    It may not be worth the trouble.

    Since most modern trimarans use a 3/4 or less fractional rig, you might be better served with an all-or-nothing-at-all jib furling system, as lack of a jib may not affect your boat's balance that much.
  4. Jetboy
    Joined: Feb 2012
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    Jetboy Senior Member

    Thank you for the advice! The jib is small - like a typical beach cat. So I'm probably OK with going with a roller furling and not reefing. I guess if I decide I need to reef, I'll probably have to accept a non-flexible setup like I had before. It's just a PITA to store on a trailer sailboat.

    Do I need a special type of cable for a small boat or will a regular one work?
  5. Jammer Six

    Jammer Six Previous Member

    This is just my opinion, but one of the main benefits of a furling system in the first place is stowing and deploying the jib, and a trailer boat has to deploy it from a sailbag every time, anyway.

    So with that given, I would suggest relying on a hanked-on jib, and avoid some of the sail shape problems a furler generates.
  6. Jetboy
    Joined: Feb 2012
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    Jetboy Senior Member

    On my last boat I just left the whole thing rolled up on the furler, and sewed up a long sail tube out of sunbrella and slipped the whole works into it. Since it was about a 2/3 sloop, it wasn't all that long. Then I just stored it by hanging it under the mast on the trailer. Seemed to work pretty well that way. I'm guessing my forestay in the new boat won't be more than 20' so it could work the same way if I wanted to do it that way. So long as it's flexible on the new boat I have a full cover, so it could just sit under the cover around the side of the cabin.

    For me the roller furling seems a lot less hassle than hank on raising - especially dousing in a breeze when I'm single handed and not putting it in the water. My biggest issue is my sailing is all on lakes where there are a lot of power boats, so I often end up doing this in a marina with a cross wind and heavy boat traffic.

    This is one of my common sailing ramps: [​IMG]

    Motoring in and out can be a challenge just avoiding all the power boaters, trying to sail reasonably close in a cross wind is a nightmare single handed. So a furling jib is pretty handy just for the sake of being able to drop the main into some lazy jacks and use the little jib to pull up to the dock. I do have little Nissan 3.5 for the new boat, but it's always nice to be able to sail in if you have to.

    I think some type of downhaul line could serve the same purpose. I've never used one though. Maybe that would be better?

  7. sharpii2
    Joined: May 2004
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    sharpii2 Senior Member

    On the one boat I rigged one on, it worked quite well.

    The halyard would be let go and the down haul would be pulled. This would bring the head of the jib down to the deck. The lee sheet line would then be hauled tight. This kept the jib on the deck and out of the water.

    The boat I rigged this on was a very old 15ft day sailor, just purchased by an elderly couple. Sending one of them out to the fore deck every time the jib had to be raised or struck didn't seem like a good idea.

    So, for about $10 worth of hardware, I set this up for them.

    The key piece is a pulley at the base of the fore stay, as close to it as I could get. Luckily, there was a plate that the fore stay attached to there, that had more than one hole. I shackled the pulley to the second one, which was about an inch and a half aft the first.

    From a small cleat at the forward end of the cockpit, I ran a line of sash cord. It went through the pulley and up through each of the jib hanks to the head of the jib.

    We took the boat out on a windy day and tried this new system out. It worked perfectly.

    Turning the boat upwind, we brought the jib down quite quickly, without any of it getting in the water. We then raised it, by un-cleating the down haul line and pulling on the halyard.

    The beauty of this system is that it would work with any jib which had hanks, and was not too hard to set up on a different jib.
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