Sadler 25 conversion..

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  • 20 Jul 2020 08:41
    Reply # 9113340 on 8800878

    When anchored or moored, with the sail furled, it's common practice to tie the fall of the halyard back away from the mast to prevent slapping. I hitch it around the block on the yard.

  • 19 Jul 2020 21:55
    Reply # 9112515 on 8800878

    Thanks David

  • 19 Jul 2020 20:01
    Reply # 9112303 on 8800878

    The max distance is  strongly influenced by the need for the halyard never to get the wrong side of the luff. This happens mostly when taking a reef on a dead run on starboard gybe (assuming sail on port side). What I do to prevent this is to pass the halyard through Barton ring, and tie that ring with a short cord to the lift, at a length such that the halyard can't blow around the luff when slack. With a split rig, of course, the chance of this happening is vanishingly small. I don't think there's a min.  The halyard will slap when deep-reefed, but not usually under full sail.

  • 19 Jul 2020 11:48
    Reply # 9111640 on 8800878

    Hi Folks, a question about halyard/rigging eyebolts at base of the mast..

    is there a recommended min/max position regarding distance from the mast, to avoid halyard slap?
    I’ve been making steady progress and have uploaded some pics to my album..

  • 02 Jul 2020 23:37
    Reply # 9075001 on 8800878

    Thanks guys- slap bang in the middle of the hatch it is then. 
    Incidentally I definitely want the sail on the port side as this puts you on starboard tack when raising sail saving the indignity of having to give way to anyone around in a busy anchorage just as I’m gathering way..

  • 02 Jul 2020 22:33
    Reply # 9074874 on 8800878

    Having worked on a number of fiberglass boats I can say that they are rarely symmetrical, the worst I have come across was a Peterson 33 on which the back-stay was 90 mm off center. It never seems to make a lot of difference so don't worry about it and no one has ever noticed until things were measured to the last millimetre.

  • 02 Jul 2020 20:25
    Reply # 9074653 on 9073515
    Anonymous wrote:

    In using a plum line from the mast position on the  centre line of my fore hatch, I was puzzled to find that it didn’t fall to the centre line of the V berth.

    After loads of measuring I’ve found that the coach roof is offset 20mm or so to port (ie port side deck is narrower than starboard).


    While I suspect the strength is enough and would point out that in other discussions about offsetting the mast the "looks" has generally been deciding factor.... my glib response would be: So, put the sail on the Starboard side of the mast and the sail will be close(r) to centre.

    If the hull and cabin have been designed with the mast slightly off centre, strength should have also been taken into consideration and centring the mast may actually weaken things. You may find the Port side of any bulkheads there are slightly thicker than the Starboard side, for example.

    If you take as an example an extruded square as the hull and cabin, There is the possibility of racking. However, adding an X brace at the point where the racking force occurs will keep the top plane in position with the bottom plane. If the top plane is stiff enough, it doesn't really matter where that force is applied. So having the mast offset will not make it more prone to bending the boat to the side.

    The real issues are that most boats are not flat on the bottom and so moving away from center or the keel means less available bury for the mast and may also mean the foot of the mast does not have the strength of the keel. So long as the bury is still 10% of the mast height that is not a problem. A properly made mast step should not have a problem transferring the load from keel over by 20mm as most are much wider than that and so will still be tied into the keel anyway.

    The one other obvious thing is the the centre of moment will be shifted to one side. How much this affects the motion of the boat depends on beam at the WL, hull shape around WL, mast weight, machinery weight and placement, etc. If these things have already been designed for an offset mast, that might already be reason for leaving "well enough alone".

  • 02 Jul 2020 10:16
    Reply # 9073515 on 8800878

    In using a plum line from the mast position on the  centre line of my fore hatch, I was puzzled to find that it didn’t fall to the centre line of the V berth.

    After loads of measuring I’ve found that the coach roof is offset 20mm or so to port (ie port side deck is narrower than starboard).

    This means that the edge of the mast socket hole is only 20mm at it’s narrowest, from the V berth bulkhead on the port side, and 60mm on the Starboard.

    Is this asking for trouble structurally, ie -will a socket wall thickness of 20mm at it’s narrowest bonded to 10mm bulkhead be too weak?

    If so I could offset the mast to starboard by 20mm to give 40mm at the narrowest point both sides as in this photo (and put up with the no doubt endless observations from strangers that my mast doesn’t look centred).

    The V bulkhead is 10mm fibreglass. I will be filling in the locker holes with 9mm ply.

    The mast socket is 54mm of plywood on top of 54mm of mast step, as per Arne’s method.

  • 18 Jun 2020 15:53
    Reply # 9045174 on 8800878

    Hey thanks Arne..


  • 18 Jun 2020 10:12
    Reply # 9044679 on 8800878
    Anonymous member (Administrator)

    Paul

    Over the years I have rigged three junks with softwood wedges and metal partners. I think the best version is the one I use now, on my 26’ Ingeborg’s mast. Here I made many narrow wedges with a very fine wedge angle and with the shown nose on top to ensure that they will never fall through. The main part of the partners is a cylinder, not angled in any way, so the wedge is resting against the upper part of it. This dents the wedges a tiny bit, but I think that is just good. The fine angle of the wedges has ensured that none of them has tried to creep upwards. Just as important as the wedges, is the making of a watertight mast coat. It both protects the wedges and keeps the v-berth down below dry.

    Good luck!

    Arne

    (PS: See page 9 on wedges, and this one about the mast coat)

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