Maxi 95 Conversion

  • 12 Feb 2017 19:58
    Reply # 4605658 on 4592562

    Thank you Annie, for the thoughtful reply.  The IW 31 had been, for want of a better description, butchered internally prior to Victor putting the junk rig in and I found myself not even knowing how to begin putting a cruising interior together.  Although I have done a lot of work on the Maxi, it has all been of the order of taking things out, tidying up and then putting them back. Much easier!

    Earlier today, I struggled through a couple of feet of fresh snow to climb aboard and have another look. I really am starting to feel that the fore hatch is going to be the best bet.  The floor of the fore cabin is an inner moulding - about 8 mm think - that is bonded to the hull sides, and I think that a couple of layers of 12mm ply on top of that, with perhaps some further reinforcement to the bonding under the bunks, would give a good base for the mast step.  Building up partners in the hatch aperture would be no more difficult than on the flat deck further forward.

    I had also thought about hollowing the topmast, but was rather overwhelmed by the idea of cutting it in half. Still not sure how I would go about it - I am thinking that the use of a guide and a circular saw on each side would give me 52 mm in from each side to act as a guide for a long hand saw.  Does that sound realistic?

    I will take some more printouts of the various bits at work next week, and put them together with a bit more rake.  If it looks OK, I will scan a copy for the forum to judge!

    Many thanks,

    Mark

  • 08 Feb 2017 20:27
    Reply # 4598703 on 4592562
    Mark Case wrote:

    After taking the rig out of my old IW31 for putting into a Maxi 95, I found myself overwhelmed with enthusiasm for a total renovation of the Maxi, rather than the simple rig replacement I had envisaged.  However, even with part time professional help it has taken a lot of time and, with a house (and boat) move factored in, I found myself wondering at New Year if I would actually get to sail this year.  So I am determined to prioritise the jobs needed to get a basically fitted out boat afloat this year, and so far as the rig is concerned, that means getting the partners in place ASAP, so we are ready to paint the decks and fit or refit hardware as soon as the weather improves.

    Hi Mark - I had no idea what an IW31 was, but having Googled it discovered an image of one with junk rig, Kari II, which I assume is the one that you had.  I'm surprised you didn't sell it with the rig!   

    I had always figured (though only on the basis of 'it looks about right') that the mast would go in the V of the V berth, sitting in a fabricated step that bolted through to the network of the inner moulding with suitable reinforcement. Having spent the last cold of weeks messing about with photocopies of the hull and rig, and looking more carefully at where I am thinking of cutting the holes, I have found:

    As you say, usually, the mast goes through the V of the V-berth, which was the logical place on Fantail, too.

    1. The hole in the deck would be worryingly close (less then ten centimetres) to the hole for the fore hatch, and I am unsure about the strength of that.
    2. The CE of the junk rig would be forward of the CE of the bermudan rig (though only slightly)
    I could move the mast forward a few centimetres, but, apart from requiring a lot of destruction of the inner moulding, the IW31 also had the mast well forward and I needed to winch the THP right in tight to reduce the balance enough to reduce lee helm, rather reducing the advantage of the low-stress rig.  I would rather have a balance level that sits a bit more comfortably, so am loth to move the mast too far forward.

    So I am wondering about moving the mast back like in this rough image. The purple arrow shows my original idea, but in this version the mast would go through the fore hatch, and I am considering a couple of degrees of forward rake with a step tied into the main bulkhead.  With the balance as drawn at about ten percent, it gives a lead of about 11% of waterline.  On paper, it looks like it should work, but the CE is further aft than the original and I am worried about weather helm.  Does anyone have any experience with the bermudan Maxi 95, or any thoughts on the matter in general? I find myself going back and forwards several times a day as to what the best solution may be.

    Did you work out all the centres for the IW31?  It seems odd that she would have had so much lee helm.  On Fantail, I wanted the mast in a different place because of accommodation issues, and by putting it well raked, could keep the CE where I wanted it, without putting the mast through the bunk.  While I think it's obviously best to try to get the CE and the lead correct, junk rig seems pretty forgiving.  Arne found himself unhappy with Ingeborg's new rig and shifted the whole sail forward on the mast, quite transforming her, so you could experiment once the sail is bent on, to get everything just so. If you are worried that the CE is too far aft, would putting more balance on the sail plan help?  It seems that (as is often the case) the fore hatch is just where you don't want it.  But I suppose with an inner lining, you are pretty loth to move that, too.  And as you have the rig, you won't want to consider split junk.  I suggest you try a bit more forward rake and see how that goes, but I'm sure Arne, or David will be able to give a more detailed analysis.

    Additionally, I have cut the pole mast from the IW down to 7.5 metres and notched the end ready to pop into an alloy tube for a hybrid mast.  But I am having second thoughts about that, too.  I guess that from an engineering point of view, it should be plenty strong enough, but I am worried about high weight, and that I am putting a weak joint in the mast in exactly the wrong place.  I have been searching through these forums for all of the options and am starting to make a list of companies to talk to, but before I do that, do any of our Norwegian members have any alternative suggestions in the Norwegian market?

    The matter of weight aloft is overstated.  If you think of the average bermudian rig with its heavy mast cap and the gear aloft for a roller furling headsail, to say nothing of wires, tangs, etc, the weight of a bare pole is not a serious consideration.  Too light a mast, and the boat will have a violent motion.  Why not cut the pole in two, hollow it out and glue it back together, if you're seriously concerned?  If you give the topmast plenty of 'bury', the joint should be perfectly adequate.  Tystie sailed for thousands of miles, in all sorts of weather, with a hybrid mast.  


  • 05 Feb 2017 20:09
    Message # 4592562

    After taking the rig out of my old IW31 for putting into a Maxi 95, I found myself overwhelmed with enthusiasm for a total renovation of the Maxi, rather than the simple rig replacement I had envisaged.  However, even with part time professional help it has taken a lot of time and, with a house (and boat) move factored in, I found myself wondering at New Year if I would actually get to sail this year.  So I am determined to prioritise the jobs needed to get a basically fitted out boat afloat this year, and so far as the rig is concerned, that means getting the partners in place ASAP, so we are ready to paint the decks and fit or refit hardware as soon as the weather improves.

    I had always figured (though only on the basis of 'it looks about right') that the mast would go in the V of the V berth, sitting in a fabricated step that bolted through to the network of the inner moulding with suitable reinforcement. Having spent the last cold of weeks messing about with photocopies of the hull and rig, and looking more carefully at where I am thinking of cutting the holes, I have found:

    1. The hole in the deck would be worryingly close (less then ten centimetres) to the hole for the fore hatch, and I am unsure about the strength of that.
    2. The CE of the junk rig would be forward of the CE of the bermudan rig (though only slightly)
    I could move the mast forward a few centimetres, but, apart from requiring a lot of destruction of the inner moulding, the IW31 also had the mast well forward and I needed to winch the THP right in tight to reduce the balance enough to reduce lee helm, rather reducing the advantage of the low-stress rig.  I would rather have a balance level that sits a bit more comfortably, so am loth to move the mast too far forward.

    So I am wondering about moving the mast back like in this rough image. The purple arrow shows my original idea, but in this version the mast would go through the fore hatch, and I am considering a couple of degrees of forward rake with a step tied into the main bulkhead.  With the balance as drawn at about ten percent, it gives a lead of about 11% of waterline.  On paper, it looks like it should work, but the CE is further aft than the original and I am worried about weather helm.  Does anyone have any experience with the bermudan Maxi 95, or any thoughts on the matter in general? I find myself going back and forwards several times a day as to what the best solution may be.

    Additionally, I have cut the pole mast from the IW down to 7.5 metres and notched the end ready to pop into an alloy tube for a hybrid mast.  But I am having second thoughts about that, too.  I guess that from an engineering point of view, it should be plenty strong enough, but I am worried about high weight, and that I am putting a weak joint in the mast in exactly the wrong place.  I have been searching through these forums for all of the options and am starting to make a list of companies to talk to, but before I do that, do any of our Norwegian members have any alternative suggestions in the Norwegian market?

    Many thanks,

    Mark


       " ...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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