Got the chance of a standart sail in vertually new condition for little money complete with infills and boom, Intended for use on my fed 5. I need to check out if the sail had a particular special mast of would any decent fed five mast fit, length of my masts(I have several rdm and sdm windsurf masts of stiffnes from 21 to 29) can be altered just unsure if the wide luff on the seagull sail would be too much for a normal mast. Has any one used a standart sail on a class five or a mini, not bothered about sticking to class its just for recreational use. If any one has the time and a Standart would be good to get the length of the mast and the general thickness
Fair winds to all force 5bf please

much bigger diameter and stiffness of mast.. very different creature. however if your getting it cheap you could then trade it for a more suitable class 5 sail maybe even a mast and sail. what happened to the rest of the standard?

much bigger diameter and stiffness of mast.. very different creature. however if your getting it cheap you could then trade it for a more suitable class 5 sail maybe even a mast and sail. what happened to the rest of the standard?

He only has the sail and boom,advertised on facebook,I did think it would be a no go ,Ive been up close to a Standart and saw that it had a monster thick mast . Might get R J sails to make me a new sail they have an excellent reputation in the UK. don't see used Land yacht sails, on E Bay very often,
Still unsure,I have a variety of sails from windsurfing. My Fav being a 6.2 non camber induced Severn Blade. I can hold and regularly beat a 5.5 frog sail on a beam and broad reach,but struggle to hold on to him upwind,I need to put in more tacks,and fail on anything nearing straight down wind.or in lighter winds ,the 6.2 needs a reasonable wind to work.The frog just keeps going in any lulls.
Not interested in racing the CL 5 so rules don't apply .Although I do have a FED 5 which I use, very often just to upset my sailing buddy. You should see the look on his face when I roll it out of my van
My self build Mini,was deliberately made so I could extend and retract the front section and rear axles so fits the 5.6 rules but can be extended to just short of the CL5 dimentions best of both world

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kennatt said..
He only has the sail and boom,advertised on facebook,I did think it would be a no go ,Ive been up close to a Standart and saw that it had a monster thick mast . Might get R J sails to make me a new sail they have an excellent reputation in the UK. don't see used Land yacht sails, on E Bay very often,

I wonder if somebody has lost or even "lost" a sail and boom off their roof rack or trailer

possible but don't think he would advertize on the group page on facebook.anyway, decided to go for a 5.6 R &Jj when they are made.only decision is to get it made in Mylar ,or dacron ?100 diference but same profile a Frogg.

possible but don't think he would advertize on the group page on facebook.anyway, decided to go for a 5.6 R &Jj when they are made.only decision is to get it made in Mylar ,or dacron ?100 diference but same profile as Frog.

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kennatt said..
possible but don't think he would advertize on the group page on facebook.anyway, decided to go for a 5.6 R &Jj when they are made.only decision is to get it made in Mylar ,or dacron ?100 diference but same profile as Frog.

Hello Kennatt, as I turn around sail-mast combination, I would be quite interested in learning...

Will you give R&J the luff curve derived from the Frog sail one ? Or will they design the sail completely ?

On which mast are you going to use that sail when made ? Windsurfing sail ?

JMF

they design the sail around your mast,but have the same profile as the 5.5 FROG
,Dick from R J, Depending on the size you want,will give you the straight lengths from the top of the mast to the base and from the top to the boom end and also the boom length. This is without the luff tube or roach on the trailing edge.
You then fit the mast to the yacht without sail. tie the front of the boom to the mast,then get a length of non stretch rope the same length as the mast top to boom end, tie one end to top of mast and the other at the point on the boom as indicated by the boom length given.
Rig up a pully system from seat to end of boom, forwards to front of boom then lay it on its side and down haul the boom , this pulls the boom down causing the mast to bend,
Measure the straight line from the top of mast to base at the boom front fitting point ,alter the downhaul on and off and keep measuring the straight line untill it hits the given length.
Then measure the distance from the straight line to the mast at the centre, at the piont half way from top to centre and the same from the bottom to centre.
Measure circumference of the mast at base and top.
send it off you (hopefully ) get a sail that is cut perfectly to suit the bend characteristic of your mast.
I know several in my area who have used Dick and non have any issues with the result.The only snagg is that they also do several other sails for water use and dingy covers etc, so you sometimes have to wait untill they are doing a run of Land Yacht .
sails

Sounds complicated but if you draw it out on paper its pretty clear how it works.I'm going to use a 490 75% carbon IMCS29 two piece,windsurfmast,don't worry about masts, the only reason Land yachts traditionally use ally masts is that in the early days the masts had to be metal to comply with class rules,thats changed over the years ,much better ,there is a ready supply of used w.s.masts ,but not many ally ones.
They are doing a run of LY sails at the present for delivry later this month

Good luck.

Thanks Kennatt for the explanation on the process. I have to draw it on the paper to fully grasp the downhaul part. But I already did something similar on a A-Cata catamaran mast for similar purpose.

When you say that R&J sails have the same profile as the 5.5 FROG, do you mean the luff curve, or more the "sail mould" (profiles, depth distribution, twist) ? I imagine that it is the "sail mould", but I'm not sure.

For sure you will have a nice sail ! Hope you will post pictures.

For the mast type, SDM Windsurf masts seem to have a lot of advantages: standardized curve, consistancy, weight... And second hand low carbon SDM masts are pretty cheap. When good aluminum seem quite difficult to source. The fact that People like sailworks go in that same direction is a good confirmation for me. I use some of their windsurf sails and they are really good.

Have to measure now ;-)

JMF

I've seen a5.5 RJ copy of the frog It's basically a semi high profile,ie the draught is low to mid hight and the top half is cut narrow so alowing less drag,the owner says it is excellent in morerate to high winds . I have a older 5.5 RJ which is tremendous in light winds very full top to bottom. My class 5 is 57kg,I'm 85kg(Solid muscle of course if any ladies as watching) I can easily get going in 8mph.But it tops out speed wize,in 12mph upwards gets going early but matter not what you do,impossible to get it going faster than others on 4.5s Too much fullness and drag. Hence the new sail. The only difference is that the RJ ,to keep costs down .use less exotic cloths but same basic shape/

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kennatt said..
they design the sail around your mast,but have the same profile as the 5.5 FROG
,Dick from R J, Depending on the size you want,will give you the straight lengths from the top of the mast to the base and from the top to the boom end and also the boom length. This is without the luff tube or roach on the trailing edge.
You then fit the mast to the yacht without sail. tie the front of the boom to the mast,then get a length of non stretch rope the same length as the mast top to boom end, tie one end to top of mast and the other at the point on the boom as indicated by the boom length given.
Rig up a pully system from seat to end of boom, forwards to front of boom then lay it on its side and down haul the boom , this pulls the boom down causing the mast to bend,
Measure the straight line from the top of mast to base at the boom front fitting point ,alter the downhaul on and off and keep measuring the straight line untill it hits the given length.
Then measure the distance from the straight line to the mast at the centre, at the piont half way from top to centre and the same from the bottom to centre.
Measure circumference of the mast at base and top.
send it off you (hopefully ) get a sail that is cut perfectly to suit the bend characteristic of your mast.
I know several in my area who have used Dick and non have any issues with the result.The only snagg is that they also do several other sails for water use and dingy covers etc, so you sometimes have to wait untill they are doing a run of Land Yacht .
sails

Sounds complicated but if you draw it out on paper its pretty clear how it works.I'm going to use a 490 75% carbon IMCS29 two piece,windsurfmast,don't worry about masts, the only reason Land yachts traditionally use ally masts is that in the early days the masts had to be metal to comply with class rules,thats changed over the years ,much better ,there is a ready supply of used w.s.masts ,but not many ally ones.
They are doing a run of LY sails at the present for delivry later this month

Good luck.

Hi Kennatt,

I made the drawing and I have a point I don't understand. See the attached schema. I understand that:
- L1 is top of the mast to the boom end,
- L2 is boom length
-L3 is top of the mast to the base.

On my kart and several LY, the boom is "floating" compared to the mast - no gooseneck. Depending at which level of the mast you attach the boom will influence the downhaul needed to achieve L3 = the given value. Is there a missing value (or value from class rules) giving the straight mast distance from top to boom? Or another constraint?

l3 is the distance from top of mast to the bottom of the sail ieThe point at which the sail would be attached to the front of the boom. this is without the luff /sail tube. Its the optimum length that ensures that when sheeted hard in the mast will be bent to fill the luff tube, and the sail will be forced into a foil shape with the correct forwards draught as per the profile bult into the sail. u need to fix the front of the boom to the mast to simulate that the sail is fitted so that the front of the boom can not be pushed forwards ,which would reduce the required length of L2,but can move down the mast as the downhaul is applied.
The position of the front boom to mast needs to be shorter than L3,so that as the boom slides down and the mast bends L3 is formed,It needs a bit of re adjustment to get the boom into the required starting positioc, think I started off with 20c.
So to answer your question. The boom front needs to have a sliding fix to the straight mast so that when pulled down ends up at the lenght L3. (exactly as if the sail was fitted)
The length of the mast is not taken into account since you are just using the bit of the mast that the sail will eventually fit on,Obviously has to be longer that L3 to fit into /over the mast tube and give enough hieght to see under and downhaul the boom,Not like a W S sail where the sail fits all of the mast down to U J. Thats why uncut w s sails sometimes cause problems because the mast always needs extensions so that you get the extra lenght ,This obviously alters the IMCS rating.
The rear of the boom to top of mast will always be L1 (Non Stretch rope).
Different fixing positions of the front boom will give different bends but Since you have the optimum lenght of the L3 for the sail sizes ,that is what you are aiming for Thats why you need to expirement with the starting position.
What R & J are after is how much shape they need to put into the luff tube,so that the sail fits the bend of the mast . The only thing that can vary is L3 ..only on sheeting out as the boom/sail tack moves up the mast. With a windsurf rig this distance is fixed permanently via the downhaul.
If you are interested here are the measurements for 5.5 >My old 5.5 L1 4040 L2 1660 L34642. Straight line L3 to mast 150 top 175 centre....120 bottom.

The new R J 5.5 L1 4050 L2 1650 L3 4650 Straight line to mast 145 top 175 centre 120 bottom.

If you are going to cut W S sails (Never done it myself) I would think you would need to cut the foot straight Then take the measurement from top to new tack to get L3 Then do above to get the shape and measurments for new luff tube to suit mast bend.Probably not that simple but a satisfactory project when you get it right.
Cheers Ken

Thanks Kennatt for all the explanations, but I still bug to understand a point. See my picture below. I feel that I can "achieve" correct L1-L2 and L3 with very different mast bends. From 0 mast bend to a very big mast bend, sheeting more in and moving the boom lower. And this will give very different sails.

Landenberger for A-Cat sails was giving the target tension on L1. So he vas collecting the mast bend for a given "leech" / main sheet tension. Sort of tension in the rig. That makes sense.

Or maybe here the measurement is not about the absolute mast bend measures, but relative ones (1/4 and 3/4 compared to 1/2) ?

The instructions from R & J are fit both lines to mast and boom,fit pullys on boom fit a pully close to the bast base (Pulls the boom front towards the mast) Downhaul until boom is at the position on mast that it would be in normal use ie Fully sheeted in,but alowing vision forwards.Or not ,if not bothered about class rules on boom hieght.
Pull front of boom forwards till it touches the mast tie off ,Measure bend and mast circm at top and bottm. The bottom third or so of the mast has very little flex so the only thing they need is the bend offset along the luff length of the sail.Most masts need to be a fair bit longer than the luff of the sail,since they need to be fitted into /over the mast base. So this takes into account any tip extensions that have been fitted to W S masts.
They build all the sails in batches ,so all identical,then make up individual luff tubes to suit the mast you are ueing.
If you PM me your e mail add I'll forward you the photo I got from R J.
Cheers ken

instructions from R & J

( OK Ken, I have looked at the measurements on your other email. Sorry but I should have included these instructions , so lets start again :-1. You should secure the line connecting the top of the mast to the 1650mm along the boom ( replicates the leech of the sail ) 2. Rather than using the downhaul, sheet in as if sailing in a fresh breeze3. Fasten a line from the top of the mast to the normal position of the boom ( the straight luff )4. Now measure the luff offsets. As an indication an example of an 28 IMC mast gave :- Top 160mm Middle 225mm Bottom 165mm )

I found that just fixing mast to boom with a cord held it in place while just sheeting in with no pully on the front of the boom just on the back,had the desired effect of bending the mast,then just slid the boom up to be at the end of the line(L3) from top of mast. My measurments fell in line =+/- a couple of mm with the example given by R J.

Cheers Ken

Maybe, what I was missing is " Rather than using the downhaul, sheet in as if sailing in a fresh breeze3.". I PM my email.

Thanks a lot Kennatt