Tuesday 24 May 2011

(6) Make and Instal mast Step and Partner, Yards and booms

Not there yet but I'm thinking ahead about mast boom and Yard battons etc etc..

I have decided to make the yard and boom from a round/oval type dingy masts (approx 4" (10cm) at the bottom).... I needed to get hold of two masts as both the yard and boom will to be about 14' (4 mr) long so together they would probably be too long to cut from one mast (?)...
Once again E-Bay has come up trumps, I got hold of a complete proctor mast and boom for £45, when I was cutting it up the guy said he had another in the garage ... would you believe it had already been cut and was 4 mr long.... all a bit spooky eh ?!

Back to fitting the hatch!!

(5) Fitting the Sheet Anchorage to a gantry at Stern

Not quite there yet!!!

I planned to do this next,  the idea is use a 50" stainless steel ladder as a gantry to enable the sheets to be run to a point 50" above the stern deck,  so the blocks and sheets will swing above the bimini and awning and the sheet to run in from the stern to the warm, dry and comfy-cozy wheelhouse... the gantry will be fixed to the stainless steel push pit and have 4 stays attached to the deck to give it some lateral strength... so a wee bit of welding is in order to attach a fex stainless plates to fix the stays etc etc !

Now...then, the last time I tried any welding, you could say it was less than perfect .. evry pretty as the rods kept bloody sticking on the damn plates... all very fine if you like hedge-hogs or want an exhibit for the Tate gallery.. but for a boat? Nah!!

So I will need to arrange someone to help me with the welding (I know my limits!!) .. so, this element may be delayed a bit .. if so, when I finish fitting the hatch on the dog roof (etc) if it ain't ready, I will jump ahead to reinforcing the coach roof and making the mast step and partner...

Tuesday 17 May 2011

(4) Fitting the hatch to the dog-house

As I mentioned earlier, I bought a great hatch at the boat jumble, so time to fit it!
Part of the Cunning Master Plan is that yours truly will not, under any circumstances, get cold or wet , when we sail away to the sun, well, probably we'll get as far as Cowes and stop by the pub, as usual ?!
The sheets and lines will all be led back to the doghouse near to where I sit next by the kettle.
There are a couple of options where to lead the sheets, either on the dog house itself or the stern.
There are potential challenges (we don't have no problems here, moosh):
  • On the doghouse: (1) No access: solved: fit a new hatch (yarp yarp, wot a cool idea!) (2) the angle of the sheet to the lower block(s) fitting, as you can see from the drawing, if the sheet is led here the angle is only about 10-15 degrees but looks OK when you close one eye and squint? unfortunately, this could lead to tangles when we tack. We simply will not know until we try. but worryingly when I showed Robin Blain, after delivering the mast,  he did do a fair bit of yer 2nd hand car-dealer type teeth sucking with this idea, so I now have even more doubts!!
  • At the stern. Whist the angles are much better, the problems with leading the sheets to the stern is that I would need to locate the lower blocks above the Bimini, which means some sort of structure about 50" above the deck deck (stress?). Also, when we do tack, the sheets could batter the canvas Bimini to death..I think I have a solution regards locating the blocks, I picked up a stainless steel ladder at the Chandler's barge at Bursledon (£40) which, believe it not, is exactly 50" high and perfect for the job. The idea is to fit this to the deck and to the push pit rail and use a series of mini stays to provide the lateral strength needed.
So, being the decisive type, I will set it up so I can use either! (good decision, Chris) I will initially set it up for the stern fitting but could then change it to the dog-house roof if this doesn't work out or I get bored and want to play...

Irrespective of the sheet issue, having the access panel in the dog house is a real bonus, it will mean that I can easily get to the lasy-jacks and boom to secure the bundle of reefed sails and step them, etc. Also, it will be great for letting out the steam from the kettle and hot pasties and throwing the bits left over to the seagulls when on route?!

So, fitting the hatch. I am coming to the conclusion that whoever built Bobtail confused it with a nuclear bomb shelter... when I started hacking away with my jig-saw it took forever, I kid-you-not it is over 1" thick, 2 layers of GRP (over a 1/4" thick) sandwiching a 1/2" balsa woof inner bit... wow?!. The only doubt I have is the side walls are only one layer of GRP and the windows could be a weakness there with the side way stresses from the sails when running or tacking etc. The last thing I need is the bloody roof to blow off, my ruddy toast could get cold?


Hatch in position, GRP time!
 Answer? Reinforce the structure, nuptie!
Side view - bit weak by the windows?
The solution will be by a combination of  3 or 4 1/4" ply-wood laminates all glued in place with cascamite and mega glops of GRP at the edges, joins. corners.... on the floor, me and Gypsy the dog, no doubt ...

 All together now (to a Reggae beat):


" Yep, i'm yer boatee builder chum, HEY, loadsa GRP, loadsa mess n' loadsa fun, fun, fun (etc etc) yeah, yeah (etc etc), hey dude innit, YEAH "... What jolly old jinks we have, Eurovision Song contest eat yer heart out (better than that Azzer-by-jan jobie or wot!!

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!!

Friday 6 May 2011

(2) Where to plonk the mast - CLR

Stage 1. Practical Junk Rig page 92:  How to work out the Centre of Lateral Resistance (CLR). Make a scale Drawing.
The weather is fantastic.. what more do you need but some helpful assistance (Artie the willing),  a measuring gizzie and the boat sitting on the trailer to take all the necessary dimensions to result in a scale drawing  on A3 size graph paper.. piece of cake!! (yeah)... Luckiliy, Robin Blain (Junk Rig Association) kindly gave me a copy of the original Colvic Watson sales bumf and some photos of  another conversion job, so not only having some dimensions and outline drawings, I have something to compare my results to!!
Unfortunately, my first result looked more like the ruddy Titanic than Bobtail (very worrying?!).. so recheck time, this time with a 3 mr "ruler" made out or a piece of 2x1, Much better as I hadn't measured the gap under the keel properly (idiot).. but result is now as accurate as I can make it!
From the scale drawing, we made a tracing of the under water profile (incl the rudder),  we then folded it into a concertina shape so it didn't flop about and then see-saw'ed it on a knife ... when finally we managed to balance it, the fulcrum point is the CLR... wow, what fun!
It was Blue Peter time again, the only thing missing was the proverbial toilet roll tube ? (if you don't know what I am prattling on about: you are too young!!)...
Anyway, from this we transferred the information to the Scale drawing... cool!
The next step it to work out the Centre of Effort (CE) of the proposed sail and how this relates to the CLR of the hull. Apparently this should be somewhere between 5% -  9% of the length of the water line forward of this CLR, this will then identify where the mast should ideally be... there are a number of things to consider (listed on page 110 and 119) to achieve this. It seems a bit complicated, but involves more bits of paper and card to cut and pins and string and scissors (no crayons though) ... what fun: more Blue Peter stuff!!


The end result of where to actually plonk the mast will still be a bit of a compromise, despite the theory. There will be a lot of windage area on the stern as I aim sail inside the wheelhouse with the full canopy up, this could have some considerable impact on the lee/weather helm effect on the rig, so whatever I do, I must be able to adjust position of the mast or rake it (etc) after I have done some real sailing ..
Later, darling, later, but happy days: we will need a touch of Harbour Acceptance Trials, just like in my old job with the MOD(N),  my motto was:
 "Don't cross bridges sunshine, if you have two birds in the hand and cant get through the eye of the needle because the bush is too big"...
Confused ? you betcha, join the club ha ha!!

Tuesday 3 May 2011

(1) The First post

)
Bobtail
Hi.. Its May 2011 and after a couple of years' hmmming' and 'humming', I have finally decided to fit a mast to our delightful 1980's 22' Colvic Watson, my excuse is that she was designed for motor/cruising but, for whatever reason, was never fitted with a mast or sails,she looks naked and wrong..
But I suppose the real truth is I was getting bored of trundling around Portsmouth harbour and the solent with the gert great donkey drowning out my IPod and felt the urge to get back to the simple delights of pottering around with sails,  pulling strings and the sheer facination and pleasure that sailing has always given me for well over 20 years.

My biggest concern has been how to keep things cheap and simple, to produce something that will enable me to sail single-handed, but now retired and suffering from a variety of rheumatic problems, I cannot leap around tacking and reefing as I used to, even if I wanted to!
My wife Artie and I have often reflected on how nice it would be to sail from the warmth and comfort of the wheel house and not to have to jump around (and spill the tea/beer/wine) every time we have to tack or tug on the ropes, and, on the subject of tacking: what is the attraction of beating to windward and racing around the bouys like a demented idiot ? soaking wet and cold? why do it? are we mad? why did God invent the engine if it was not to turn on when the wind and tides ain't right innit?"
To me it's got to be simple: Set it up, get on a nice quiet run put on the kettle and then relax...Yes/No?

The most essential thing for me is to be able to design and do most (if not all) of the work myself, within a very strict budget and avoid high tech (= expensive) solutions/kit...
So far, every time I looked at it, my dream project was scuppered by the reality checks: stays?, stresses?, cambered/complex sails?, self-furling kit? and so on and so forth simply racked up the complexity of the work needed and prohibative costs, it disheartened me, to say the very least!.....

Then, one eventful day, our chum (Artie's colleage John Potter) happened to mention that he had got hold of a junk rig 23' bilge keel yacht called "Hippo" and raved on regards the simplicity of the beastie in it's unstayed mast, handling and design...after  I expressed my interest, he kindly lent me

THE DREADED BOOK ..."Practical Junk Rig" by HG Haslar and JK McLeod

It was written in 1988 explaining in unbelievable, technical detail, how to design, build and sail a junk rig.. I am not kidding: it has every nook and cranny fully explained, although it takes about 4-5 readings just to start to take in the detail. It is inspired and was, for me, fatal...

"Oh noooo" wails Artie, he's off on another project!...... Yes, the seed of the new project was now well and truly bedded and germinating !!

Step 1; After initial research, I have joined the Junk Rig Association and I have already had some great advice and help from Robin Blain.. so the saga begins!!!

My aim with this blog is to record the progress and the hopefully not too many pitfalls and maybe inspire others to go Junk Rig ...

Heretical as it may be and hopefully wrong,  I have the impression that the high point of  western-Junking (if that is the right expression?) has probably passed and the sailing fraternity have little alternative but simply swallow the bulk-standard Bermudan rigs churned out by the big main manufacturers or maybe the potential benefits of the simple junk-rig approach is not appreciated?....
I suppose the reality is'nt that simple, but I suspect that much of it will probably be about the  'economy of scales' and the modern CAD driven computor based sail design and automated production techniques (reduced costs to build?) that constraints the commercial market or is it simply a lack of demand or too few boat builders?
In my view, if this is the case, it is real a shame because there is a whole field of sailing technology and skills that are now closed to the sailing enthusiast.

So this leads me to my next aim... your comments!!!

I would really appreciate your support, thoughts and guidance... whilst I have no professional boat building or sail-making experience I am very much a hands on type and having restored a number of boats, I am fairly confident (or deluded?) that I can do most of this project myself ... weeeeel we shall see?!

From the initial planning, the boat conversion itself, the sail design/construction, rigging and fitting out seems to be well within my abilities ( well, OK, so far !!) But, tempting as it is, whilst I think will be able to define the unstayed mast requirements, making one in wood might just be a step to far.Well, to be honest, its maybe a very stupid thing for me to even consider doing myself and my instincts tell me that there would be too much top hamper regards the weight of a wooden mast on our beatie (but have faith my son?!!)  I have pondered using tapered flag poles (I am still not convinced and they are expensive) so its probably either a 2nd hand or new alumiumum purpose made jobbi ... but as this is probably the most expensive item on the agenda I would welcome your thoughts and suggestions on this!!!

Cheers , Chris