S2 6.7 Junk Rig Conversion

  • 12 Jul 2021 20:57
    Reply # 10746815 on 6872873

    I was happy to spend about 8 hours sailing on Saturday. A rare east wind, with no rain, made sailing north on beam reach easy and comfortable. I made it to the next port and then headed home on the reciprocal tack. All wind and no waves. Good times.

    Having a tiller brake is definitely better than hand steering all the time but I think I need something more for a longer trip. There was too much variation in the wind speed for me to leave the tiller for more a minute.

    I would like to build a wind vane based on David Tyler's design.

    The boat is small and has a kick-up rudder. Does anyone have some advice for the easiest type of steering to build? A full servo-pendulum seems more complex on paper, but I can imagine fitting a trim tab that works with a kick-up rudder might actually be more difficult.

    Any advice would be appreciated.

  • 07 Jul 2021 16:12
    Reply # 10734939 on 6872873

    I finally got the weather I was hoping for several weeks ago back when I had time to sail.

    I took two videos, one on each tack.

    https://youtu.be/EGLLaMZDk1k

    https://youtu.be/nOMcg62qUzw

    This also shows my imitation of Arne's tiller brake design.

    With this wind I was able to trim the boat such that I was making a steady 4.5 knots, with the boat doing all the steering, on a heading for that anchorage about 80 miles away over the horizon. Days like this make it hard to turn the boat around and go back home.

    If anyone sees something wrong with how I have the sail rigged, please let me know.

    Arne, I have all the stuff to fit telltales onboat the boat. I plan to do that sometime soon!

  • 30 Jun 2021 21:24
    Reply # 10715193 on 10711566
    Arne wrote:

    Chapter 7, about rigging the sail

    I realise now that a few makers of these sails have run into trouble during rigging it. This was much due to the fact that I was late to write the ‘rigging Chapter’  -  no.7.
    Now I have put a PS at the end of Chapter 5, suggesting reading Chapter 7 before starting on the rigging.

    I read the 'rigging Chapter' again and noticed, or finally understood, what you wrote about the halyard attachments. I have an annoying issue with halyard twist at the moment. I rigged the halyard with a swivel block at the mast head. For some reason this seemed like the right thing to do. It was not. I have some persistent problems with halyard twist.

    I am not going up the mast and I don't really want to un-rig everything to take the mast down right now. But, in the offseason, I will be reworking the mast head to use two blocks at the mast head, in the locations you described.

    For now I am getting pretty good at pulling the halyard out of the deck hardware, untwisting it, and reeving it back through the rope clutch on the deck.

    I got the boom fendering on, eventually. There are a whole bunch of lines right around that part of the boom. I kept lacing different things into the fender accidentally. I think it turned out OK, but I did not take a photo.

    Last modified: 30 Jun 2021 21:25 | Anonymous member
  • 29 Jun 2021 21:50
    Reply # 10712001 on 6872873
    Anonymous member (Administrator)

    You’d better look out David, or your family members will have to start locking their things away from you!

    This yoga mat stuff seems to have very useful properties, if it is the same stuff I am thinking of. It appears to be a sheet of polyurethane rubber which, in liquid form (with solvents?) makes an incredibly strong, flexible and resilient glue. I don’t know anything about the chemistry of it, but it appears to be the same stuff which is used industrially to mount big engines on, between the engine and the concrete floor. I’ve not heard of it being used for marine engines, but I did once mount a little single cylinder Volvo Penta on some lumps of the industrial stuff, and as far as I could see it worked OK.

    I once did a Hiab job on a yacht, whose owner told me he had bought (from The Warehouse) a cheap camping ground mat – same stuff as your wife’s yoga mat I think - and used it as a dry bedding for going between his chainplates and the ferrocement hull – bolted down extremely tight and the excess cut off – a quick, easy and cheap job which, on inspection a few years later, proved to have allowed no moisture to penetrate (often a problem with fc in this sort of detail). Its not cheap to buy in its industrial form, but if it’s the same stuff as used domestically it is relatively cheap and its amazing “memory” makes it potentially a material worth considering for a lot of applications besides fendering spars.

    Maybe someone who knows more about these things can enlighten us with a bit more information.

    PS

    Leather, as you used on your boom jaws, is tougher of course. Good old-fashion leather- I read somewhere that the famous Fangio once ran a big-end bearing during a long-distance rally in Argentina - drained the oil and pulled off the sump on the side of the road and replaced the bearing shells with some pieces cut from his leather belt - and completed the race. I guess that toughness, and its ability to carry stiches, makes leather so good for fendering between oars and rowlocks as has been done probably for centuries.

    Last modified: 29 Jun 2021 22:12 | Anonymous member (Administrator)
  • 29 Jun 2021 20:28
    Reply # 10711807 on 6872873
    Deleted user

    On the subject of fendering of the yard, boom, and battens; On the new sail on 'Footprints' we cut up my wife's yoga mat into strips and sewed that into the batten pockets, and yard and boom pockets. This seemed to work well, and yes, I did eventually replace the yoga mat.

    But I also came against this issue in a small way on the gaff jaws of my little catamaran. I tried a couple of different types of rubber glued onto the inside of the jaws to provide some cushioning and prevent damage to the paint work on the mast. I was not having much success because whatever I used I seemed to get a lot of friction when raising or lowering the sail. Then I came on some scraps of sheep skin which my daughter had been using in some craftwork. I cut up a strip of that, trimmed back the wooly bits and then glued it on top of the thin bit of rubber already in the jaw. It works really well, no friction, and no damage to the mast. So maybe worth a try for cushioning on a junk rig.

  • 29 Jun 2021 19:06
    Reply # 10711566 on 6872873
    Anonymous member (Administrator)

    Chapter 7, about rigging the sail

    I realise now that a few makers of these sails have run into trouble during rigging it. This was much due to the fact that I was late to write the ‘rigging Chapter’  -  no.7.
    Now I have put a PS at the end of Chapter 5, suggesting reading Chapter 7 before starting on the rigging.

    Arne


    Last modified: 30 Jun 2021 08:40 | Anonymous member (Administrator)
  • 29 Jun 2021 18:18
    Reply # 10711419 on 6872873

    After my short overnight coastal trip I noticed something had been scraping up the mast pretty good. It is inside the red box drawn on the attached photo.

    I think this was caused by the YHP block, which has a stainless steel body, hitting the mast when the sail is squared out on a port tack.

    After reading Arne's instructions again I figured out how to rig the YHP higher up the yard than the sling point. I hope this will prevent more metal-on-metal damage.

    I also added some more appropriate fendering to the yard. I used marine vinyl that was left over from the batten pockets and laced it to the yard.

    Both of these updates are shown in the attached photo.

    I still need to get fendering on the boom. I have the material cut and the holes punched, but the wind was blowing around 12 knots or so when I installed the yard fendering. Now I am waiting for calm weather to coincide with my free time. When that happens I will lace on the the boom fendering.


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    Last modified: 29 Jun 2021 18:18 | Anonymous member
  • 29 Jun 2021 16:48
    Reply # 10711124 on 10647269
    Arne wrote:

    Scott,

    [...]

    • If the batten parrels are slack, the sail will ride at a bit distance from the mast on sb. tack. Then the sail will act as if it has been sheeted harder in, sort of.
    [...]


    Arne,

    Thank you for the suggestions. At the moment the sail acts as if it is sheeted in harder when sailing on a port tack. If the slack parrels can cause the opposite effect then it seems like I have the sheet attached way too far to the port side. I may make some sort of adjustable anchor point this winter so I can fuss with it out on the water next year. For now it is not so bad to mess with the sheet after tacking. It is certainly a lot less trouble than handling a large head sail on a Bermudian rig.

  • 16 Jun 2021 10:46
    Reply # 10647269 on 6872873
    Anonymous member (Administrator)

    Scott,

    I notice the same asymmetry on my Ingeborg. When doing very short tacking up a channel, I leave it as it is, but on longer legs, I may do small corrections from tack to tack.

    Anyway, it is common practice among racing folks to ease the mainsheet a bit as they come about, to speed up acceleration, and then they haul in the sheet, as the speed has been won.

    There are two more noise-factors with respect to symmetric tacking in a JR:

    • ·         If the batten parrels are slack, the sail will ride at a bit distance from the mast on sb. tack. Then the sail will act as if it has been sheeted harder in, sort of.
    • ·         In my waters, at least, the direction of wind and waves is often not the same: On one tack, it feels like heading almost right into the chop, while on the other, the waves are more on the side. I frequently adjust the pointing angle with this in mind.

    I therefore am not too concerned about getting the sheetpoint perfectly “symmetric”.

    Arne


  • 15 Jun 2021 14:16
    Reply # 10641578 on 10602152
    David wrote:

    [...]

    Just a thought about your difference in tack.

    I notice the sheeting point on the transom is more to one side.

    Is it a bit too far to one side, I wonder.

    If you don't adjust your sheet slightly after you tack from starboard to port, I think the sail will be hauled in tighter on port, resulting in more weather helm on port.

    [...]

    Hi David,

    After correcting the more significant problem by adding HK parrels it is clear that the double block for the sheet should be closer to the center of the boat. When starting on a new tack I have to adjust the sheet to make up for this difference.

    I think I will re-work the entire sheeting setup. In addition to getting it positioned properly, I would like to have the sheet block up on a rail and add some sort of hoop to prevent the sheets from grabbing me and/or the tiller!

       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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