Saturday 14 May 2011

(3) Time to spend some money!

Busy Week! After completing the calculations and worked out where the mast should go  I was able draw up the first shopping list, which coincided with the Warsash Boat-jumble... with Artie away for the weekend and great weather, I could really graze amongst the stalls and not feel too guilty !!
In the end I bought a brand new hatch (500 x 400) which will go on the dog-house (more later) for £60 (these are over £200 in the chandlers) some lengths of 3mm rope and whipping twine for £2 - £3 from some old moosh... what a great old boy, I spent about 20 minutes with him, he was about 80 and a real old sea dog with all the appropriate dits and tips.. great! I also got some other bits and pieces but the best was I found a couple of Junk-Rig types so another hour yapping!! (who said only women gossip!!)
Anyway lots of bargains and a great day!!

THE MAST:
The size I would need would be approx 28' above the deck and 69" "bury" (the distance between the deck and the keel), with a 4 degree backward rake... why the rake?
  • This will allow the mast to be fitted without blocking access to the forward bunks (etc)
  • From the drawings, I found that when the centre of effort (CE) of the sail was lined up with the point where CLR of the boat is (+ 9% to 12% of the waterline length), that the central sail hoist point was not as near to the mast as it should ideally be. The further away the hoist is from the vertical, the harder it will be to hoist the sail and battons, and
  • In theory, a reverse rake should make sail control easier when on a run (no need to pole it out etc).
So a mast of about 34' is what we are looking for. Having ditched the idea of making one, and as a new one would cost over £1500, a 2nd hand aluminium jobbie is the answer. Unfortunately, although there are loads of 2nd hand masts lurking around ({PS thanks to John Potter for his advice on this), the problem is that an unstayed mast  is very different to the conventional mast and must be much much wider where it passes through the deck (about 6" dia !) found and tapered, which is about as easy to find as rocking horse droppings (or virgins?) in Portsmouth ?!!
So I contacted Robin Blain again, what a star! he just happened to have a 33' one hiding in his Aladdin's cave! (unbelievable). As this was little shorter than planned, I had a quick look at the sail design and with a bit of re-jigging of the design it was...."Houston, we have a go for a burn" ... in this case, my bank balance.... at £750 this may seem a wee bit high when compared to what you can get a 2nd hand conventional mast for but, given the difficulty sourcing this type of mast, it was OK (I did try for £7.50 but Robin thought I was making a joke, nah ?!)  But, to be fair, I knew the mast would be the dearest bit, so hey ho eh?!...
That was on Monday, Tuesday duly delivered to the club and stowed on the club house roof !
A piece of cake, particularly as our club (the Portsmouth Harbour Cruising Club at Tipnor) has every piece of kit you could ever imagine needing and everyone there will drop everything to help you when you need it (unlike some clubs I have been in) ... in this case it was Bernie-the-bosun and the club's trusty forklift truck to the rescue (I said we had everything imaginable!) assisted by my poor brother Dave, who had only popped in for a chat and a cup of tea (he should know better by now ha ha!!)...
As they say in Germany.. "Ende Gut: Alles Gut!" and here it is (big'n wot?!)


The new mast!


THE SAIL.
I have gone for a simple conventional "Blondie" Haslar type design, the final statistics, for the record, are:

  • Foot: 12'6",
  • Luff: 13'4"
  • Panels: 4 bottom panels (40") deep, 3 top panels. Note; 2 at the top should be sufficient, but the theory is that with the extra baton, this should be easier to reef?) From the calculations (Panel height/foot width) the max panel width permitted would be 0.5 or 75", in this case 0.26 so well within tolerance.
  • Rise: the rise at the clew is approx 24" to the horizontal, again well within tolerance, as the minimum is 15" (i.e. 1 % of the foot). This additional rise should allow for the possibility of considerable repositioning of the sail without affecting the ease of reefing and improves clearance of the dog-house (I suppose they call it that cos I sits there innit?)
  • The height to the peak of the sail is 295", so the aspect ratio works out to 1.97, as the ideal is about 2 so, again, conservative. There are all sorts of arguments regards the advantages of high or low ratio so if you are keen, buy the Practical Junk Rig !! but one small point,  the aspect ratio is calculated by peak height/ the width, taken about a third from the foot, but be careful with this as it is the width  taken at 180 degrees to the vertical height line, taking into account the the rise, I could not use the foot length in these calculations.
  • Sail Area: I worked it out to be about somewhere about 260 sq ft.. calculating the areas of triangles at the top are not exactly exact but near enough (?) , anyway, it should be large enough to give a decent sail, but small enough to be easy to hoist and handle too. If it turns out to be too large, I can always chop it down a bit. Also, being reasonably small, it should be very flexible and allow repositioning on the mast...
theory is fine: practice will be the proof..

From this, I could now work out what material I need.  Remarkable as it is, it seems that you could use just about any old material to make the sail, with some fascinating examples of creations using B&Q type PVC tarpaulins or old sacks... as I ain't got enough Pompey whore's knickers for the job, I thought I would stick with traditional Dacron.
Because of the batons, the weight of the Dacron can be much lighter than sails for Bermudan type rigs, normally you would expect something like 6oz, but it would seem 5 or 5.5oz is adequate.
Also it would have to be traditional tan colour... white is just so boring, darlings and the other colours are just too bright and sexy for an old fart like me!
So, allowing for baton pockets, clews etc etc I reckoned that I would need about 35 - 40 linear Mr (3' wide). We are lucky, as we have Kayospruce (who probably the best sail maker's wholesaler in the UK) right on our doorstep... so, I thought, we must get something there at a really good price. Wrong. The cheapest white 5.5oz worked out well over £15 a linear Mr and the tan? nightmare: over £22 !! So, after picking myself off the floor and changing my underpants, I arrived at a mega "bugger that" moment!
But, thank you God for all your creations, one of the best being the holy of holy's:
E-Bay!!.. £3.95 a linear Mr? for 5.5 oz tan Dacron? new? delivery only £9? I almost bit his arm off!!
As I have never made a sail before I also bought a very useful book called: "The sail makers Apprentice" by Emiliano Marino, although he is American, he is forgiven cos it has some really interesting stuff, the best (for me) was why sails are better sewn with zig-zag stitch than with straight stitch (not so stiff, less creases and less likely to split) which has probably saved me a few quid! why you may ask ? (I will tell you, if you have a bit of patience !!)... I have a reasonably good sewing machine that just about deals with upholstery grade material so I thought i would replace it with yer pucker industrial Jobie but but but, most industrials only have straight stitch, so you need to look out for a "semi-industrial" which in reality is a more powerful (usually older) domestic machine with zig-zag etc... well folks, I have been looking on jolly old  E-Bay (again) and these are now going for about £150+ which is incredible, cos about a year or so ago you could pick these up for £30-40 (maybe people are repairing their clothes more in these hard times? who knows?) but yours truly will try the old sewing machine first and see how it goes!!

Well, its beer o'clock time, so you will have to wait for the next exciting instalment: putting in the new hatch... and maybe some photos too...wow!!

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