Richard Oates wrote:It's the balance of the rig that concerns me, will the helm be nice and balanced, it seems almost impossible to predict this. I would love to hear how you get on in the future.

Richard, while the cognoscenti may experiment with a tad more lead here or a an adjustment of relationships there, I think that it's fair to say that if you follow the 'recipe' in PJR, you won't go far wrong, especially with a boat like yours, that doesn't go out of its way to push any boundaries.  Moreover, once you have rigged your boat, you will find that the sail can be moved around the mast in many different ways, simply by adjusting some of the standing lines.  But I do sympathise with your dilemma: my feeling is that the tanks might be easier to replace (bladder? jerricans?) than attractive joinery.  If all else fails, toss a coin.  Remember, in this naughty world you never know if you made the best decision, only if the one you made is satisfactory!

Richard

Re your enquiry as to how partners and mast were fitted in my Sabre 27

The mast is protected from chaffing / excessive movement at the partners by a thin (~ 3 mm) rubber sheet which is wrapped once around the mast in that area. It is secured by an adjustable  circular s/s clip fitted above the partners casting. The mast can move a little in the partners, it is not a tight fit. As shown in the photo of our boat (photo) a rubber collar then fits over the mast partners again secured by adjustable s/s circular clips to provide a watertight seal.

I needed to prepare a suitable base to mount the partners casting because there was insufficient flat area on the foredeck. Additionally, to get the CoE of the Junk sail in the right position, I had to rake the mast 3 degrees aft relative to the waterline. To ensure that the partners made even contact with the mast, the partners casting had to sit on it’s base perpendicular to the mast. Adding a circular base allowed me cover both these requirements. The hull had been set up with the waterline horizontal both along its length and across the beam to facilitate the fitting out process. This made setting up the mast a little easier.

I first made up a simple circular shaped plug then made a mould. I ground down the underneath of my moulding to fit over the raised portion of the foredeck (the king post moulding) and to allow it to sit at the correct angle. This was then bonded to the foredeck using epoxy. Later I cut a circular hole to take the partners casting which has a flange to allow the casting to be through bolted to the foredeck.(photos, image no 9)

 I also prepared the hull for the mast foot, first laminating sever layers of  18 mm marine ply and shaping to fit the hull. This was then bonded to the hull and glassed over. A drainage channel was built in to this base to allow any water that might enter the mast to drain freely.

The mast with the partners in place was then craned into position and the base passed through the hole in the foredeck. The mast foot fitting (Photos image no 12) was then inserted and attached to the mast foot ( pre - drilled holes, large through bolt). I used temporary stays to hold mast in correct position while I glassed in the mast foot. Later I drilled holes for the through bolts to secure  the partners to the foredeck and bedded the partners casting down on Sikaflex which was also used to seal beneath the bolt heads.

As to the ease of removing or re-stepping  the mast, I haven't tried that yet but since mast is not a tight fit through the partners it shouldn’t present too many difficulties. Granted, refitting the mast could be a little more tricky, but I think that  if the rubber protective sheet which wraps around the mast, as described above, is fitted once the mast has been re-stepped, (easy to do just need s talcum powder to allow it to slide down the mast and into the partners), there would be sufficient clearance when passing the mast through the partners casting.

Hope I have covered your enquiry please let me know if you would like more detail on this/ other build topics.

Frank

Thank you very much for your response, (no worries about the delay) this is a great and very useful contribution for me.

I too have a twin keel Sabre.  I particularly like the mast position you have chosen, going through the foredeck seems infinitely preferable to fabricating partners to fit the inclined forward face of the coachroof.  Your machined partner fitting seems very elegant and simple. One question regarding fitting the mast. Is the partner a tight fit on the mast or relatively loose? If the latter are you fitting wedges? If the former, how is the mast lowered into position without the risk of lateral rotational movement of the tabernacle damaging the deck, I assume it would be hard to lower the mast and keep it in a perfectly vertical position while doing so.

I am going to have to swot up on all the aspects of mast position. I would favour the position you have chosen although in a reply near the beginning of this thread David seemed to favour a position much further back, through the hatch in fact.  I wonder if this is because he favours a high aspect ratio rig?  Arne earlier on included a sketch (section 2 with a AR of 2.10 S/a 16.1 and a 1.6 degree mast rake. Considering the arrangement of bulkheads below deck this would seem to be very suitable.

However you mention that Robin found severe lee helm with the first Sabre conversion and corrected it by moving the mast top 18 inches back. With the mast at 10 feet this would equate to about  2.5 degrees compared to Arne’s 1.6. I am imagining the sail now out at 90 degrees on a run, and it seems to me that the critical thing is how the yard is hung from the mast which results in the position the sail now takes up. I guess I need to read ‘The Bible’ on these matters before expecting experts to explain them to me!

Meanwhile I am pursuing my trimaran project for the time being, I think it will be a good test bed for leaning more about the intricacies of the rig without spending a fortune. It also gives me much more time to get to understand the dynamics of the JR before committing myself on the larger project.

I’ll start making the tabernacle tomorrow!

I’ve been away for a while and just seen the new posts, very interested to hear of epoxy moulding techniques and the nearly finished  Sabre 27 junk rig conversion. I would be really interested as to what mast and sail configuration you have chosen and the mast position adapted together with detail of how you arranged the partners and foot. I have nearly decided how to do mine but it’s hard to make the final  choice, there are so many options.

I have decided to spend this year thinking about the Sabre conversion, work out the details and likely cost and perhaps carry out the work over the winter, otherwise I won’t get much sailing in this year. Meanwhile I have an interesting option. A few years ago I completed a Strike 16 folding trimaran but have always been unhappy with the mast position on top of the cuddy, and indeed with the cuddy itself which is cramped and prevents easy access to the foredeck.  Also I hate the bright white sails which give me a headache in bright sunshine. I think it would make a great JR conversion.  It would be really easy to fit a tabernacle in the foredeck and as the sail area is about the same as my friend David’s Westerly Nimrod (see separate post re this JR conversion) I thought I might adopt the same weaverbird configuration.  It would be an economical way for me to learn more about JRs and improve this boat.

The tri has an 8 inch draft with no centreplate and relies on the box section of the centre hull and the V shaped amas for lateral resistance. She will be a great boat for the shallow waters of Morecambe Bay.  Being very light and easily driven she should be pretty fast and I am wondering if this has any implications for the sail design. Any comments on this idea will be gratefully received.  Also being a new member I am not sure if this warrants a new thread?

Interested to read about your planned conversion of Marcon Sabre 27. I am also converting a Sabre 27 to Junk rig. I started some years ago and am now nearing completion of the project, aiming to launch this year. I started with a bare hull which the previous owner had purchased from the moulders in 1982. Happy to share experience gained so far.