Endplates

  • 14 Jun 2021 09:26
    Reply # 10632667 on 10624893

    Thanks Guys,

    I’ll make them in advance then fit them when next out of the water, though that may not be until the end of the season.

    David, as the rudder is skeg mounted shortening it would not be so simple. Anyway it doesn’t shunt up and down on the mud very often- usually only in a north or north east wind when the stern swings towards the shore.

  • 14 Jun 2021 07:43
    Reply # 10632021 on 10624893

    Paul, I have a similar stern setup to yours, and with twin keels. The rudder was the same one as used on the fin keeled Sonata, too long for twin keels, and I was bouncing it on the bottom when I dried out. The rudder hangings permit it to rise about 150mm, but even so, I thought it a bit risky. So I sawed 150mm off the bottom and added an end plate. This keeps the rudder clear of the bottom most of the time, and the steering is just as good as before. But last year, I took the ground in very soft mud so that the keels sank well in and the rudder was also into the mud. No problem there, but I wouldn't want to bounce the end plate on a hard bottom.

    [Arne, Fenix is a Sadler 26, not a 25 - only a foot longer, but a much larger boat.]

  • 14 Jun 2021 00:23
    Reply # 10630584 on 10624893
    Anonymous member (Administrator)

    Paul.
    As said, it is a low-risk project to fit end-plates. I think it is worth trying, even if raised 15-20cm up from the tip. Just sand off the anti-fouling but leave any epoxy or gelcoat on before gluing on the (now separate) wings.

    Good luck!

    Arne

  • 13 Jun 2021 23:42
    Reply # 10630525 on 10624893

    Thanks Arne,

    Just thought, my mooring dries on spring tides which leaves the bottom 6 inches of my rudder stuck in the mud.

    This may stress endplates during the half hour or so before low water when she’s splurging her rudder up and down on its fittings

    Would mounting them a little higher up the rudder still work (albeit in a reduced way)?

    ps

    When I have the appropriate amount of sail up she’s wonderfully balanced (thanks to Slieve’s calculations)- It’s even possible in some conditions to let go of the tiller altogether for extended periods.


  • 13 Jun 2021 10:00
    Reply # 10627006 on 10624893
    Anonymous member (Administrator)

    Paul,

    your boat appears to be a sister boat of the famous Sadler 25, Fenix. Fenix visited Stavanger in 2007 and was laid up here over the winter, before being launched the summer after. Her rudder looks quite good as it is, but as you think, an endplate could make it even better. Since the lower end is horizontal, I suggest you make a one-piece endplate, just glued to the tip of the rudder. I would let its total wingspan approach the chord of the rudder.
    Good luck, and tell us how it worked out after trying it!

    Cheers,
    Arne

    PS: My Ingeborg's hull is finer-lined and probably more balanced than the Sadler 25, so there may be a stronger build-up of weather helm as you heel the Sadler. Still, that endplate is worth a try, as it is a very quick and low-risk test.

    Last modified: 13 Jun 2021 13:36 | Anonymous member (Administrator)
  • 12 Jun 2021 22:24
    Message # 10624893

    Great write up as always Arne, I’ve replied here to avoid thread drift.

    “However, I have now tried her in ’30°-conditions’, and it seems that the endplates pay back here: As the heel increases from 20 to 30°, there is hardly any need for more tiller input. The “I suggest you reef”-signals from the boat didn’t show up, so I could keep driving the boat harder and faster.”

    Hmm..
    You now have me tempted to try endplates on my rudder. 

    As the  SJR is such a powerful sail, weather helm can become quite vicious quite quickly in a gust.- It would be good to have a little more rudder bite in reserve..

    The subject of endplates on rudders got me thinking- 

    Sailcatchers are an integral part of Split Junk Rig to tame the jiblets when reefed, but are optional on other rigs.

    Is it possible that a Sailcatcher will also act like a rudder endplate and reduce turbulant airflow spilling below the sail, thus aiding performance ?

    Has anyone tried a sail with and without sailcatcher ?

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