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Vintage Champs 25/6 June

Started by paul turner, 12 May 2016, 08:16

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NTOACertification

Hi Robbo

Looking at the history of this boat. In its early days 1976 the mast band indicated a measurement of 5500 between the top and bottom bands.
and In those days the boom would have been level with the lower band.
In 1997 the rig was re-measured and the luff band was changed to 5418 at this time the gooseneck may not have been moved but the sail would have
attached to the mast about 80mm above the boom. Another consideration is that the luff rope in mainsails shrink over time and sometimes to such an extent that the sail cannot be stretched to its correct length! This can usually be remedied by a sailmaker or by releasing the stitching at the bottom of the rope and releasing the rope yourself.

Kevan Bloor certification and sometime sail maker

robbo

hi kevan,
I hope you are well. This Robbo is Alan Robinson ( he sometime sailmaker as in Performance) yep we all got older !! I can see why you might sneak 100mm at the gooseneck by way of measured area . i.e. put the boom on the 380mm and then have the tack and the lower band a bit above it thereby giving you a smaller measured area than is actually really the case. But not 350mm- actually if I measure the luff as from the gooseneck to the upper band (and the gooseneck at a quick look would be about the 380mm and then work the main area on the mast and boom bands  - 5.6 x 2.2 divided by 2  and then add it to the 2.24 sq M of the jib it's bang on 8.4 sqM . - What led me ask the question was given that both the mainsails I have came off a boat sail number 3220 did/have boats gone to a shorter mast length . I had no plans to make any sails -just thought I'd get a nice old boat and clean it up and teach my grandson ( he's 5 and a half now) in a proper boat down on the river but I can see myself getting sucked into this all over again . Cheers and thanks for your help. Robbo  p.s. what I've done for now is slashed the oldest main (they're both mylar) accross just below the bottom batten and let in a 300mm piece of of Dacron -yea I know the batten pockets are then well out of position but interestingly apart from being 35mm too wide at the half height it measures - which leads me to think that boat 3220 must have had a massive jib !! -it's like running in the fog -loadsa fun but no idea where you are !!

NTOACertification

Hi Alan
Didn't make the connection!
I would check the mast - The rig height hasn't changed 6.100 mtrs from the sheerline( to  the top band ). And I would expect the boom to be at 5400-5490 from the top band.
On looking at the Pics on the boat Database , taken at Henley SC, the boom does look exceedingly low and the sail is way above it. N 3220 had a 3490 mm
Luff length according to my certificate info.
Kevan

Dave Croft

Hi Robo,


Your new 12 is the sister-shop to my boat - 2935. both were built by Dave Proctor in Whitstable, if fact he made three Cheshire Cats. I haven't sailed my boat much since the 90's but last year I decided that as she was 40 years old in 2016 she deserved dragging out of the shed and putting back in commision. In fact in a moment of craziness I have entered for Burton Week. Unfortunately there isn''t very much activity for 12's now in the London area so we haven't been out yet this year.


In answer to your question re sails it sounds like someone has picked up some used-sails for your boat. If they were made for a carbon rig you may need to change the luff-curve so it would be an opportunity to get the luff-rope matched up to the mast at the same time. So a trip to a friendly sail maker looks the best bet.


Cheers,

Dave


robbo

hi Dave - nice bit of historical information Cheers. They are beautifully made boats are they not. I'm just on re-gluing the deck around the mast gate having stripped the deck back to the bare wood ( I've only had it six days!) . The point I was keen to get to understand was that the sails which were clearly got second hand for it are VERY short on the luff and can only have come from a boat with a much shorter mast, The mast on my boat fits and measures well and clearly has been with it for many years. the top band to gooseneck is 5600 and the sail is 5300.( that's 5300 stretched banged out on the table and it has elastic luff rope - it;'ll be 50mm longer now than when it was new!!) As a newcomer to 12's  it a surprise to discover that that the lower band and the gooseneck can be in two very different places. if I tie the tack of the main in a 'sensible' place it's a foot short at the top and even with the tack say 80mm above the gooseneck the ridiculous foot skirt is half a yard below the boom. It'll do for now - I've let a bit in across it and once I get sorted and have a few sails in it I'll make a proper rig for it- the holt allen delta with it is a nice mast but it weighs in at 10.5 kilos!!. I would've liked to have gone down for a look about at the Burton but it's the very same dates as the Ok Nationals but Hopefully we'll meet sometime at an event. Cheers Roibbo

paul turner

Come on guys, let's stick to the subject! >:( Numbers still a bit on the quiet side! JLS has collected China Doll from the farm to "bimble" this week and Gerald is briefed to pick up Mr Jones on Saturday morning. Starfish and Smuggler are sitting on their trailers looking lonely...  Px  :-\

angus

Come on Gerald you have got to prove I am not as hopeless as I appear, nothing less than a consistent last place will do. At Heathrow on the way to Canada. Funny how everybody can spot the guy who has never flown before and never been abroad. Never mind everybody is most patient and helpful.  By the way I have flown before....on a turboprop, but not a biplane as my son is telling everyone. We
All smoke and Mirrors. N2153, 2969, 3411