Products

Asymmetric Spinnakers (Gennakers)

KempSails Aspin

With its clew higher than the tack, it looks like a Cruising Chute, but with much more curvature and area on the Luff and Leech.  Often an Assymetric flies from a bowsprit or pole for the ultimate in reaching performance and to gain space for Gybing through in front of the Forestay.

Full-radial construction ensures panels are lined up with loads.  Generally these sails are better suited to deeper wind angles as their larger area and Full Shoulders make sailing tight reaching angles difficult on anything but the lighter wind days.

Kemp Sails Asymetric Spinnaker

Flying Asymmetrics (Gennakers)

If you've been put off spinnakers by witnessing or experiencing wraps, broaches and assorted mishaps, take heart. By following a few simple rules and not trying anything too ambitious, you'll find it's all pretty simple! And you'll be amazed at how much faster, steadier and more enjoyable your downwind sailing becomes.

When hoisting an Asymmetric/Gennaker), you have a choice of launching it from the bow or the leeward side. As a rule, the second option is safer because you hoist in the lee of the genoa. We supply different types of bag according to your preference - a round one for attaching to the pulpit, a rectangular side launching bag or a Companionway Launch bag (which needs lines to hang on).

As for the rest of the equipment, on most boats you just need a pair of sheets (ideally tied onto the Sail's Clew corner) and one Tack Line - with a substantial Block for turning each line (One on the Bow right forward and two on the aft Quarters).  The Tack Line ideally will have a Snap Shackle to attach to the Tack ring and allows easy release in an emergency, and of course the Halyard itself. Ensure the sheets are led outside everything and that the 'lazy' sheet goes around infront of the Forestay.

Put the boat onto a Broad Reach and with all the lines set up ready hoist the sail.  If you have a genoa set then roll it up afterwards - as the wind shadow will help you fully hoist the sail before it sets.  As soon as the halyard reaches the Top sheet on the Leeward sheet and check that the sail has filled correctly.  Roll away the Genoa (if necessary) and trim the sail essentially like a Genoa, but easing until the Luff just curls and the trimming back on.  

Deeper sailing angles can be achived with racing Asymmetrics - often easing the Tack line by as much as a meter and healing the boat to windward help Downwind progress (VMG).

To drop an Asymmetric or Gennaker sail in a competitive environment, it would be normal not to use a snuffer and to let the Halyard off in a controlled manner, so as to allow the crew to recover the sail onto the deck or below on the Leeward side.

Fully-battened Mainsails

Fully Battened Main SailsOver the past 10 years or so, fullybattened mainsails have become ever more popular. In fact many sailors now automatically assume they're the best choice - but are they?

In-Mast Furling Mainsails

Kemp Sails Furling Mainsails

Ever since Ted Hood’s “Stoway” In-Mast Furling system brought Mainsail Furling to the mainstream, it has made great strides and earned a ‘refined and reliable’ rating throughout the industry. What are the options for sails?

Classic ‘In-Mast Main’ – Easy Simplicity

unbattened

Kemp Sails recognises that rolling up cloth that’s not designed to lay flat can create pinches of sail material that may jam during the furling or unfurling process. To avoid this, we shape our Furling Mainsails a little flatter and build them with a hollow roach. Kemp Sails only make In-Mast Furling Mainsails from stiffer Yarn-Tempered Polyester or a High-Modulus material, that resists stretch and wrinkling.

The Foot and Leech of Furling Mainsails can come under a great deal more stress than ordinary sails, which is why Kemp Sails also reinforce these edges with a specially created Kevlar Tape.

Adding Battens

short leech battens

Adding Short Leech Battens to an In-Mast Furling Mainsail, allows us to support a straighter Leech profile.  This maintains more of the sail area which would otherwise have to be 'hollowed out' without the use of battens, therefore improving Light Airs Performance.  The use of battens also helps control the Leech and reduces the potential for vibration and flutter.

‘Vertimax’ – Ultimate Vertical Battened Reefing

VBM full length battens

The Vertimax In-Mast Mainsail Reefing system accomplishes that simple function which many other battened In-Mast Reefing sails absolutely fail to achieve,
and that is: Long-Lasting Furling Performance.  The reasons for this are simple – and two fold:

Firstly, Kemp Sails recognise that space is at a premium in most Mainsail Furling mast chambers and therefore the batten configuration is critical. Kemp Sails use 4 Full Length Vertical Leech battens to support the increased Roach Area, placed to be as accurately aligned as possible when furled.

Secondly, the life of such sails is largely governed by the quality of the fabric used in the manufacture, so Kemp Sails only offer these sails in one of 3 options: Premium Dacron Sailcloth; Laminated Cruising Sailcloth; or ‘Hybrid Wovens’ (where the fibres are mixed with an exotic material such as Vectran or Dyneema). In our experience, other fabrics with less Tenacity simply don’t offer the long term support required.

Unfotunately, to add Full Length battens is only possible if the mast design itself will accomodate the battens, so the chamber needs adequate size and the sail entry gap must be wide enough to allow the battens and their patches/reinforcing.

Kemp Sails are always happy to talk about Vertimax and other In-Mast Sail systems and recommend the best solution for your In-Mast Furling Mainsail.

 Area Increases

The Operation of In-Mast Furling Mainsails

Selden's Linedrive operated Furling masts have asymmetric tensioned luffspars. This reduces furling friction. The linedriver must be rotated clockwise when furling or reefing, and the sail must be wound on tightly. To achieve this, there must be some residual tension in the outhaul line when reefing or furling.

Note: Many other Furling Masts do not have not tensioned Luff spars and so they require extra care and vigilance in use and to get the best operation from them.

Before any sail area change, slacken the kicker & mainsheet, then adjust the boom vertical angle using the topping lift or gas spring powered kicker. Adjusting the boom slightly allows the loads in the sail to be spread more evenly between foot and leech, promoting a neat furl. The degree ofvertical boom adjustment required depends entirely on the individual sail’s shape. The sail should never be furled or reefed with a slack foot or leech.

For deploying the sail in light conditions, when the full main is required, slacken both sides of the endless reefline and pull the outhaul. The linedriver slips under the slack reefline, and has almost no friction. Adjust the outhaul to give the correct sail camber for the conditions.

If a reef is required immediately, deploy the sail completely as above, then reef to the required size before tensioning the outhaul.

To reef, adjust the boom vertical angle slightly, and ease the outhaul until the sail has a large “S” shaped camber. Take in on the reefline (Stbd side of linedriver), and allow the return side to be pulled forward. Secure both ends tightly. Slacken the outhaul again and repeat. It is best to reef in a series of “bites”, as the sail will be wound more snugly round the luffspar. Finally, secure the reefline tightly and tension the outhaul.

For increasing sail area from a reefed size to less reefed, a different technique is required.

Obviously the sail wants to unfurl by itself, so leave the outhaul in a stopper, have the "Return side"(Port) reefline line in hand, and the "Reef side"(Stbd) line ready to surge round the winch. As the Reef side is surged, ensure that the slack in the Return side is taken in immediately. If this is not done, a bight of reefline can emerge in the 11 o’clock position of the linedriver, and then it may slip out of control. The sail would then unroll completely. Once the handling technique has been learned, linedriver operation is simple and very effective.  

For most applications, the control lever above the linedriver is set to the “Free” position, allowing free rotation in either direction. If on a very long leg with a reefed sail, the left hand “Ratchet” position may be selected, allowing the reefline to be offloaded. The most likely time for selecting “Ratchet” is when the vessel is left unattended. In this case, the ratchet is a good safety feature in that it guards against unintentional deployment.

In light airs on the wind, it pays to ease the outhaul to match the genoa camber and also top up the boom to induce a little twist. The mainsheet must be used carefully, and not pulled directly against the topping lift. At all times when sailing off the wind (not close hauled), increasing mainsail camber is effective.

 

Genoas / Headsails

Genoas and HeadsailsOn many boats, the genoa is the main driving sail to windward. It's also the one which often poses the biggest question: do you choose a roller reefing system, or a suit of separate headsails?

Choosing Sail Fabrics

Kemp Sail's Guide to Choosing Sailcloth Fabric

Choosing the right fabric in the first place is probably the most important decision in getting the best from your sails. Kemp Sails put sail fabric choice right at the forefront of our discussions with potential customers and we are always happy to supply samples of the fabrics we are recommending. It's fair to say that in recent years we would send fabric swatches out as a matter of course with all our quotes - though with the email revolution and rising postage costs we now tend to attach fabric data for speed - but please don't hesitate to ask!
In fact that is the most important sentiment we could make here - simply to 'ask us!' We are concerned that this is an area where we are the 'experts' and our customers should make sure they get 'best advice' and not feel that they should be experts or have a lot of technical understanding themselves - above all Kemp Sail want our customers to feel that they were able to make an informed decision, so please talk to us....

Who makes Sail fabric?

There are four mainstream Sailcloth suppliers around (there are others) but these are Dimension Polyant (German), Contender Sailcloth (Dutch), Bainbridge International (UK/American) and Challenge Sailcloth (American). All of the above have websites with more detailed information on their fabrics and in many cases data sheets on their specific styles. 

Largely speaking we stick to using materials from these suppliers, as they hold stocks and they produce consistent material which is reliable in quality; ie. flatness, dimensional stability, free from structural weaving flaws, and help provide technical backup and R&D development. There are more fabrics becoming available from Asia and the Far East now but these Main companies have specialised in their fabrics and will stand by the products if there ever any problems, so we prefer to stick with them.

So, what are the main types of fabric?

For most modern cruising yachts there are essentially two categories of sail fabrics:

  1. Those suitable for the fore/aft sails or white sails, (Mainsails, Genoas etc.) and,
  2. Those materials for Downwind Sails. (for Spinnakers & Cruising Chutes etc)

Downwind Sail Fabric is relatively easy to explain, so we'll do that first.

Spinnaker Seamstress

Most of us have sailed with a Spinnaker or Cruising Chute at some time and you may remember the sail is flying unsupported from the spars, hence occasionally the sail will fill and collapse. Often this can be be with quite a 'pop' and for this reason as Sailmakers we want the sail to absorb some of that 'shock' and so we choose a slightly forgiving fabric.

So, we usually choose Nylon as it has a little more elasticity as a fibre and it's usually woven in a form these days that we call Ripstop. Which means it has a square weave pattern that is formed by periodically twisting a few fibre together to increase tear strength, or occasionally by added a larger fibre into the weave at even spaces.

So, Nylon Downwind sail fabric is very light, a little stretchy and surprisingly strong... In the UK the fabric weight is usually expressed firstly within a generic weight category - such as '¾ ounce', or '1½ ounce' and then as a style name with a more detailed weight that may well now be in grams.

Most importantly these materials are available in attractive colours so you can personalise your sail and keep the crew entertained!
Either of the weight categories will 'fly' in quite light winds even as smaller sails - but often the heavier wind range sails (or more All Purpose Sails) will be in the 1½ ounce weight range. Because the lightest material comes at the expensive of some durability and tear resistance if the sail handling isn't quite as slick as you had planned for!

So, in cruising sails usually ¾ ounce is good for Light Symmetrical shaped Spinnakers and 1½ ounce is best for Heavy Symmetrical shaped Spinnakers, Asymmetric and Cruising Chutes.

There are also heavier weights of Downwind sail fabrics for bigger yachts and for racing sails there are lighter ones..some are more heavily coated with a stabilising resin to make a harder 'crispier' feel and support that unsupported flying sail shape....but this is meant as a simple laymans guide and so we'll move on to the Mainsail and Genoa fabrics. If you would like some more detailed information then you know what to do! ...just drop us an enquiry note, or call....

Upwind Sail Fabrics are more complex and since there are more variations in weight and factors of construction to consider we'll again try to make a Layman's guide. More detailed or specific questions can be answered individually....

Laminate or Woven Sailcloth?

It's well accepted that Woven Sailcloth lasts longer that Laminated Sailcloth in terms if its 'Terminal Durability' i.e. how long it stays together in one piece...but that's not the whole story - there is a 'Performance Durability' aspect, that is how long the sail performs acceptably as an efficient method of propulsion. After all we don't usually wear our clothes until they fall off us - So, when a sail has stretched beyond an acceptable point that is the end of it's Performance life. To examine what this is for each fabric option we need to understand what each option actually is.

What is Woven Sailcloth?

Weaving looms have made enormous technical leaps in speed and consistency but the basic Sailcloth weaving principle remains the same since the first ever looms. Woven styles are made up from differing weights of finished fabric and the fibre size construction determines the weight and stability (read stretch resistance!) of the finished material.

The more tightly woven the material, the more stable it will be and thus the longer your sails will hold the shape that you sail maker designed them to have. So, to understand what aspects make the difference....

Very basically, what happens is that a huge rack of thread spools are wound onto a big straight pole called a 'Beam'. These form the fibres that run the length of the finished roll and they are called the Warp threads. Thus the Warp Beam is fundamentally at the heart of any woven fabric style and often one Warp beam will be used for creating several styles or weights of material. The quality of the fibre used for this beam is determined by it's tenacity (strength) and it's pre-weaving preparation.

Looms

The Warp beam fibres are tyed-in or drawn into the weaving loom and are pulled through under some tension. There are four principle operations:

  1. Warp Fibres are pulled alternately up and down which is called 'shedding', i.e. creating a 'shed' or tunnel through which:
  2. The Weft/Fill yarn (often on a shuttle) passes across. Inserting the Weft/Fill yarn is called 'Picking'.
  3. 'Beating up' which is packing the Fill yarn in tightly against the Warp Yarns which held (wrapped) around it.
  4. 'Taking up' is the newly woven material process of winding onto the new cloth beam.

Now we have a roll of raw cloth roll that is woven as tightly as the size of the fibres allow and as the loom could pack it all in.....(so you can see how there can be differences already in here...) Small fibres will pack in more densely, but would take longer to weave and as always "time = money". Bigger fibres are also stronger, but they don't weave in so tightly.

The natural cloth at this stage would be very 'soft' and stretchy - particularly on the 'bias'- and to see roughly what it looks like at this stage you may find some in some yacht sails - usually if you have a 'lens foot', which is soft stretchy panel in the very bottom of some sails where it attaches to the boom.

So the 'Bias' is the 45 degree angle that lies between the Warp thread and the Fill/Weft threads. If you pull most non-sailcloth woven fabrics in this way you will see a surprising result and a big crease! If that happens with your sail it's not good!

Since sail loads go all over the place (especially when you part Furl or Reef them) we need this bias to be stabilised and locked up. Hence, the natural cloth will have to undergo at least two more basic processes (and often several more in terms and washing and dying to become usable Woven Sailcloth.

  1. Heat Setting (which is essentially shrinking it, by passing it between two super-heated rollers).
  2. By Coating or Impregnating it with a resin, to 'glue' all the fibres in place.

The fabric will of course be rolled onto smaller more manageable rolls and is inspected and any flaws broken fibres marked or cut out.
What type of fibres are used?

What type of fibres are used?

So, we can see that any woven material that Kemp Sails recommends for you will be judged on it's fibre quality for consistency, strength and shrinkage qualities, and also the way it wears in UV as lesser quality fibres degrade more quickly in the harsh UV light.

Over the years Sailcloth manufacturers have tried all the fibres names that you have ever heard of and the best combination of strength performance (taking into account the basic cost), wear longevity in both UV light and in flex durability, and fibre shrinkage (which helps) and water absorption (which doesn't!) is actually Polyester! It isn't necessarily the best fibre in any one particular aspect - but it's by far the best right across the board.....So usually we recommend a fabric that employs a top quality, High Tenacity Polyester.

Stabilising the Weave.

Then we look at the weave quality and the stability that is achieved in the fabric before it is fluttered (a simulated test of the wear sailcloth gets) and then afterwards. This tells us how well the fabric can rely on it's initial weave quality and also how much it relies on the subsequent resin impregnation to hold it all together.

Remember resin coating isn't necessarily a bad thing, some top quality racing woven fabrics are heavily coated and stiff to feel, so this aspect is often wrongly stated...it's just important that the resin impregnation is not the ONLY thing holding it together!
To judge and compare a fabric feel it yourself in your fingers and crinkle it up in you hand - that'll give you a good indication of how much coating is on there - some fabrics actually 'marble' where the creases are, so you can tell if you are being told a fabric has no coating and then go and decide for yourself!

Some fabrics have a Ripstop weave incorporated into them. This can be a very good thing such as in D/P's Square range, adding tear strength and stability, but it depends how it's woven (the construction differences are explained in the Nylon section). It's not so good if it determines how the fabric ages and if it frays excessively along the fibres - you can have too much of a good thing.

How does the Sail Aspect Ratio affect the choice of fabric?

Finally, the construction of a woven fabric has to lend itself towards the Aspect Ratio of a sail. High aspect ratios sails are tall and thin and the loads run closer together up the Luff and Leach edges. Fabrics for these sails can be stronger in the Weft/Fill and so have more fibres, or bigger fibres, or even High Modulus Fibres included such as Vectron cloth (using Vectran fibre) or Hydra Net (using Dyneema/Spectra fibres) to assist the performance.

Low Aspect Sails (long footed with a shorter hoist) typically warrant a more 'balanced' construction and a more evenly spread construction. However, keep in mind that using fibres of the same size in both Warp & Fill is likely to make a very unstable initial weave set because the Warp won't wrap around or 'pack' so tightly into the weave. For this reason a lot of fabric ranges are design to be the best they can be in all applications - and the Sailmaker is left to orientate the panel's angle in the sail to suit the fabric and gain the best performance.

Radial or Cross-Cut?

Having now mentioned the concept of sail panel orientation, it is possible to align the Fill fibres which we know are the 'straightest' fibres within the weave, with the principle Leech loads, and it means that the loads along the Foot are then catered for by the other main fibre direction (the Warp). If the Fabric has a good bias stability, then this should make a good sail configuration and it's called a Cross-Cut layout. The material is used very efficiently like this and the panel width (typically around 1.4m wide) means there is ample option to build the shape progressively into the sail, as this 'shaping' is introduced at each seam joint.

The other common method (there are others - but this covers most modern sails) of panel layout is Radial cutting and Bi-Radials radiate from the Two, (Head and Clew) corners, hence the name 'Bi-Radial'...the Tri-Radial's are also Radiating out from the Third (Tack) corner.

The idea here being that the Warp (Long) fibres are laid in the direction of the loads in longer and thinner panels that are all fanning out from each corner. Technically, this is correct, however, we also know that the woven fabrics are narrow in weave width (typically 1.4m) because the Fill shuttle can only travel across a short 'shed' distance....hence we must use the Warp fibres to get a panel of sufficient length.

The drawback here is that of the two fibres the Warp is typically smaller, so that it can wrap around the Fill fibre tightly to get that all-important weave stability. So if we load this Warp fibre up heavily it will then naturally want to straighten out and eventually will give us corrugations from the corners rather than than strong smooth sails.

One other problem for Radial sails is that when we come to cut the panels out of the rolled cloth we use a computer and 'nest' them in together (like Tetris!) aligning the fibres with the long edges of the panels.....however, this does mean a lot more fabric wastage and that has a price.

In summary, to make a Radial sail in a woven fabric you MUST use a very good sail fabric with a balanced performance in Warp & Fill (e.g. D/P's Square fabric range, or Contender's Radial Wide).

Better still, if you are set on a Radial layout, use a Strong Warped Radial fabric, such as Hydra Net Radial, or just forget about wovens and use a

Laminate Sailcloth

Laminates were invented as a way to avoid the bias instability of woven cloth sailcloth and also to avoid the Warp 'crimp' (bending) that comes with 'Shedding and Packing' the weave.

With Laminates, instead of coating and impregnating the weave with resin, the early idea was to simply laminate (bond) one or more sheets of Mylar film onto a side and achieve the same result.

Sailcloth Laminating

Quickly it was identified that the strength coming from the weave could be dramatically improved if it wasn't woven and if the fibres giving the fabric it's strength were actually laid straight and so 'scrims' were created, holding the fibres in a grid (you can usually see those easily and they give away the fabric as a laminate construction).

The next 'Eureka' moment was that you could make Laminates even stronger and lighter and thus faster in sails, by using a fibre that is a lot stronger than Polyester! This opens up a whole new subject - so here let us suffice to say that most laminates used for racing are made with High Modulus fibre Scrims, such as Kevlar and Carbon fibre, or Pentex (which is a 'posh' Polyester). And the determinate factor is usually cost.

For Cruising Laminates the issue of durability is again a factor, for inevitably higher mileage sailing is involved, and so we quickly revert to Polyester again or a mix of Polyester and sometimes Spectra /Dyneema (though this is notably hard to glue and bond for enough durability).

Laminates have the simple drawback that they don't stand the flex fatigue that sails suffer as well as woven materials - so going full circle they have a better 'performance life', but a far shorter 'terminal lifespan' and they also suffer from mildew where the layers generate a perfect environment for Mildew spores to grow. Mould grows on things (and inside too if it can get there) so unfortunately even new sails can quickly develop Mildew marks from airborn dirt and polutants and there is precious little that can be done to prevent it.

Kemp Sails recommend if you are thinking about laminates, that you ask yourself if you are a frequent club racing sailor, or if the sailcloth shape performance is that 'critical' for you. If it is? then you get a laminate and look after it carefully and enjoy it whilst it lasts - by all measn talk to us about it because there are things we can do to help it last longer and definitely things that yo can do to help it last longer.

If you are concerned that laminates won't live up to your expectations of longevity, or that you want to cross seas and oceans - Or more likely, your boat budget simply won't stand replacing the laminates when they are in great shape still but now have holes worn all over them....

Hy-Brid woven fabrics

Do not fear - the top spec Hy-Brid wovens are superb and they have come along way in the last few years. Kemp Sails probably recommend more Vektran (from D/P and Contender) and Hydra Net (from D/P) than ever before nowadays, and if they fit in the boat's budget - we rarely hear anything other than positive comments about them subsequently.

This was Kemp Sail's Guide to Choosing Sailcloth Fabric and we haven't covered every aspect or angle - because as you can now appreciate, it's quite a complex subject. But you will hopefully have gained an insight into what to look for and why we may have suggested the material that we have. Ultimately, we need to look at the sail you need, the boat you have and the sailing aspirations you are planning for - then its time to call us, or come and see us for that chat!

Mainsail Stacking Systems

The Kemp Sails - Packaway

It is many years since Kemp Sails first introduced the Packaway mainsail stacking system. Proof of its success can be seen in any marina in the country, with many manufacturers emulating the principle.

KempSails Packaway

 

Furling Downwind Sails

CHECK OUT the RolleX TD Gennaker Furling System

 

This is a furling system for rolling up Cruising Chutes, Gennakers and Assymetric Spinnakers - using a Hi-Modulus Torque rope, with a swivel at the Sail's Tack and a 'continuous line' furling system.  It can be purchased as a complete system including a sail, or retro-fitted to an existing sail. 

Easier to use and handle than a Snuffer, it also makes the sail far smaller to store when not in use.

 

For further information email:    This email address is being protected from spambots. You need JavaScript enabled to view it.
Stating your boats make and model, with your name and a contact number.

 Let's get Rolling!

Originally, Kemp Sails developed our own swivel system for 'Top Down' furling of free-luffed Gennakers and Cruising Chutes, that we called called RolleX TD. 

Until the recent era of Top Down Furling arrived, to roll away a sail meant that the sail needed to be very flat in shape and also must be straight Luffed (Like a Genoa). ( These sails are often called Code Zero's - but Kemp Sails call them Ultra Light Genoa or (ULG's), as a Code Zero is actually a Racing Sail - see Below)

Top Down Furling is achieved by turning the central (Torsion) rope around with a Continuous Line Furler at the Bottom end, and fixing (by means of a lashing) the sail to the Torsion Rope at the Head.  

By allowing the Tack of the sail to swivel freely around the central rope, a very ‘3D’ and deep shaped downwind sail can be furled surprisingly neatly around the Torsion Rope.. 

It was the bottom (Tack) swivel that Kemp Sails developed for the RolleX system, however, several manufacturers have now made furlers available with an integrated Tack swivel, which has some benefits as a single unit.

With Top Down furling, normally no modifications are needed to the sail and so if you have a sail that fits already then you should be able to use it. 

Equipment wise, for Top Down Furling, you will need enough room to mount this furler ahead of the existing Forestay (and/or mount on a bowsprit).  The Chute itself would also need a pair of sheets – using a Tack line isn’t required under the furler, as it must be anchored very securely. To slacken and deepen the Luff when sailing, the Halyard can be eased, much more easily than at the Tack.

Kemp Sails include a full length continuous line in our RolleX Downwind furling syetems, so the furling can be done from the cockpit. Also it’s a good idea to put the lazy side of the continuous sheet around a winch to maintain back pressure and grip on the rope around the furler.

Sails furled this way are not suitable for leaving up long term or using part furled - they are purely furled up for convenience and ease of use.

 

 Kemp Sails - Ultra Light Genoas (U.L.G.'s)

Using a Continous Line Furler (as described above) a Genoa shaped sail can also be furled away easily.  These are often refered to as Code Zero's - but a Code Zero is actually a racing sail, so for Cruising we call such sails ULG's.#

The advent of modern larger Mainsail rigs has meant smaller (more easily handled) headsails.  In fact many normally larger headsailed boats have scaled down there Genoas too.  There comes a time though when a long Fetch in light wind is a tighter angle thanis comfortable with a Cruising Chute or Assymetric and What you really need is a Big Genoa again!  Hence the ULG. 

Made in a lightweight Dacron (not Nylon which stretches) the sail can be used in light winds on closer angles and also as a secondary 'poled out' Headsail - for Twin Headsail downwind sailing.

Main Sails

Astra Swan 55

At Kemp Sails, we take pride in building mainsails which perform exactly as they should. That means ensuring accurate measurements, selecting the most appropriate cloth and panel layout, and taking care over every detail of the design and construction.

We also need to know about your rig, to make sure we incorporate the right amount of luff curve to match the bend in your mast - a particularly important consideration with fractional rigs. Here are some of the design aspects and features to consider:

Cloth

We’ll recommend the cloth which best matches the panel layout. For example, a low aspect-ratio sail has very different stress patterns to one with a relatively longer luff. When the luff/foot ratio exceeds 3:1, we recommend the use of high-tenacity fabrics designed specifically for minimal stretch in sails with high leech loads. Other types of commonly-used cloth cost less, which may explain why some quotations are lower than ours. But for a stable, long-lasting shape, you won’t get away with cutting corners or using inferior fabrics. That’s why we always suggest comparing quotations on a like-for-like basis. And if there’s anything you don’t understand about ours, please ask. We’ll be happy to explain exactly why we’ve made a particular recommendation.

Panel layout

The sail’s size and aspect-ratio, plus your budget and intended use, determine whether we suggest a cross-cut or radial layout. Radial designs are more expensive because they’re more complex to make, and need specialised types of cloth (see separate page on radial sails).

Bolt ropes or luff sliders

Up to the size where a bolt rope creates too much friction, you have a choice - a rope for optimum performance, or sliders for easy handling.

Reefing points

Unless you have cockpit-controlled reefing, we can offer ‘reef spectacles’ on the luff cringles for easier attachment to the tack horn. And at the outer end of the boom, we leave the last few feet of the sail loose-footed, so you can loop the reefing lines between the boom and sail. See opposite for more detail of both these features.

Battens

Two-ply batten pockets ensure no part of the batten is in direct contact with a load-bearing part of the sail. Tapered, glassfibre battens in Velcro-fastened pockets are standard on our Racing, Performance Cruising and Cruisemaster sails.

MAINSAILS

The following features are either standard, or available as an option, with most of our mainsails:

  • Tell-tails Indicate whether the wind is flowing cleanly off the leech.
  • Camber lines Make it easy to see the depth and shape of the sail.
  • Lens foot A lightweight panel of cloth along the foot, which substantially increases the sail’s fullness when the outhaul is slackened.
  • Leech line exits at reef points Let you eliminate any ‘leech flutter’ when the sail is reefed.
  • Luff cunningham Allows you to tension the luff in stronger winds, pulling the draft forward and opening the leech.
  • Leech flattener Lifts the boom and flattens the lower section of the sail in heavier conditions.

Reef spectacles

The most difficult part of reefing can be forcing the luff cringle down over the tack horn - and then finding you’ve hooked it on upside-down. But there’s no struggling with a Kemp sail, thanks to our ‘reef spectacles’ - stainless steel rings on the end of a strong webbing strap which passes through the luff cringle. Hooking on is quick and easy, so you spend minimal time on deck.

Loose foot at the clew

One of the most crucial elements in a neat reef is having the leech lines in the right place on the boom. Some older types of boom have attachment points on the bottom or side - but, if these aren’t accurately positioned in relation to the leech cringles, you’ll end up with an untidy, inefficient reef.

Our solution is to remove the bolt rope from the last few feet ahead of the clew slider, so you can pass the leech lines under the foot and secure them around the boom. This way, they’ll be able to slide to the best position automatically when the load comes on. Another example of simple, sensible solutions from Kemp.

Velcro-fastened batten pockets

To hold the battens firmly in place with minimal weight and clutter at the leech, we use Velcro ‘hookand- loop’ flaps, whose hooks fasten to the loops on the insides of the pockets. The flaps are pushed in with a flat, glass fibre ‘prodder’, which also keeps the hooks and loops apart. Then, when the ‘prodder’ is withdrawn, the flaps attach themselves along their entire length, making it virtually impossible for the batten to escape by accident.

 

 

Cruising Sails

Cruising SailsThe Kemp Sails Range of Specifications

We try to offer a consistent level of quailty - with a varying degrees of features and upgrades thereafter, to suit your sailing aspirations and your budget.  If you want something different then please just ask us...

 

Supercruise

If you want no-nonsense, straightforward cruising sails without all the bells and whistles, our Super Cruise range is the perfect choice.

We incorporate all the features you're ever likely to need for coastal cruising - and, should you take part in the occasional club race, you'll be surprised at the difference a new suit of sails can make.

Power Main

Power MainThe popularity of Fully-Battened mainsails is well known and this subject has been extensively covered by the Yachting Press. However, these glowing reports tend to be biased towards more modern yachts with new mast designs, with no reference being made to the vast majority of sailors who own older style yachts.

Downwind Sails

Spinnaker or Cruising Chute?

Compared with other types of rig, the modern bermudan sail plan is highly efficient to windward. Downwind, though, it's a different story - and that's where spinnakers and cruising chutes come in.

Not so long ago, lightweight downwind sails were regarded by many cruising sailors as the exclusive preserve of the racing fraternity, who employed vast crews to tussle with acres of unruly spinnaker nylon. But the reality is now very different. In the same way that upwind sailing has been made less strenuous by the increasing popularity of selftacking jibs, fully-battened mainsails and cockpit-controlled reefing systems, developments with spinnakers and cruising chutes have resulted in more stable, easily-managed sails which can be comfortably handled by smaller crews.

For optimum efficiency, you need a spinnaker whose tack is projected from the end of a pole to bring it out from behind the mainsail on a broad reach or run.  The drawback is that, since the sail is larger than a cruising chute and only firmly attached at one corner (the head), it needs more care in hoisting, trimming and dowsing.

A cruising chute, on the other hand, is smaller and easier to manage, but less efficient as the wind comes further astern. The solution we often suggest is to have one of each: perhaps a 0.9oz spinnaker for racing, and lightweather running/broad reaching in cruising mode, plus a 1.5oz cruising chute. Not only can the chute be tacked to the stemhead when cruising but, flown from the pole as an asymmetric spinnaker, it will double as a highly effective reaching kite in breezy conditions.

This way, you'll keep the family happy and have a 'secret weapon' on the race course!

 Design your own Spinnaker Colour layout Here Online & RIGHT NOW!

 Just use on our KEMP SPINNAKER WIZARD link below:

(Please note, the layouts are artistic impressions and may differ slightly from the actual finished sail panel layout)

CLICK HERE to use the Kemp Sails Spinnaker Wizard Designer

Alternatively, download our own "Kemp Sails Spinnaker Layout Sheet", from the "Measurement Forms" area on this website, and you can print and colour the sails yourself. If you fax this form back to us please remember to mark the colours on the panels by name / letter as fax's are only Black & White !!!!

 

For Furling Downwind Sails (see the dedicated page)

Snuffers

No matter how experienced you are in handling spinnakers or cruising chutes, the combination of large sails, fresh winds and small crews sometimes calls for some extra help.This is where the snuffer comes in - a nylon sock which pulls down over your spinnaker and turns it in to a long sausage, with the head at the top and the tack and clew at the bottom. When you want to use the spinnaker, you start by hoisting the snuffer to the masthead with the sail bundled up inside.The spinnaker will only start to fill when you pull the snuffer up from the bottom using its own internal halyard - so you can make sure everything's totally under control before any wind gets into the sail.When you've finished spinnakering, you pull the snuffer down again and lower everything back on deck.

Racing Sails

Kemp's radial cut laminate racing sails can be made in a variety of fabrics and fibre types, depending upon your sailing program, your yacht and your budget.

Ben 31.7tn IMG 3939ToftFreedom2Laminates are like a 'sandwich' of Mylar film with the Scrim (that's the internal net or grid) giving the strength and being made of a choice of High Modulus fibres:

1.  CLUB RACE:  Polyester (PET) & Pentex (PEN) - 'Pentex' is a chemical hybrid, developed from PET by Honeywell and it has up to 40% higher modulus strength than regular Polyester PET.  Kemp Sails recommend the PX BLACK (PXB) Line fabric - for that 'Stealthy' appearance.

  DP Logo  PX Black Line 

PX Black Sailcloth in Use:PXB

  2. REGATTA RACE:  Aramid (Kevlar, Twaron & Technora ) - has become the predominant fiber for racing sails. It is stronger, has a higher strength to weight ratio than steel, and has a modulus that is five times greater than PET, and about twice as high as PEN.

Kevlar, along with other aramid fibers, have poor UV resistance (Kevlar loses strength roughly twice as quickly in sunlight as PET) and rapid loss of strength with flexing, folding and flogging. Minimal flogging and careful handling can greatly extend the life of a Kevlar sail.

Twaron has a slightly lower modulus strength than Kevlar 29 but a slightly higher resistance to flex fatigue. The fiber’s lower UV resistance is enhanced by dying the naturally gold fiber black.

 DP Logo  X-Tech Performance Aramid

Hope  Glory

 

 

 

 

 DP Logo  X-Tech Performance BLACK Aramid

 3. GRAND PRIX REGATTA RACE - made in the latest 'State of the Art' Carbon fibre material GPL.  Carbon Fibre is a high modulus synthetic fiber made from carbon atoms.  It is largely unaffected by UV but can be very brittle as it becomes more 'refined'.  Typically the stronger the Carbon fibres are, the more brittle the fibre is.  

 

 KempCarbonSails

 DP Logo  GPL Carbon - Available with internal Tafeta (iT) & Double Taffeta (dT) options

 Taffetas - Taffetas are a lightweight woven layer, that can be inserted into or added onto the outside surface of the laminate.  The addition of a taffeta adds considerable strength to the stitching and seam joins and helps avoid the film of the laminate cracking at the hinge points.   Internal Taffteas don't add the chafe resistance in the same way that external taffetas do, but they soak up less water, so they have other advantages.

 

 

 

Above all, Kemp Sail understand how to maximise a sail inventory with a combination of sails that give you the desired level of performance and with a longevity that is understood and that regularly exceeds expectations.

 

Cruising Chutes

Compared with other types of rig, the modern bermudan sail plan is highly efficient to windward. Downwind, though, it's a different story - and that's where spinnakers and cruising chutes come in. Not so long ago, lightweight downwind sails were regarded by many cruising sailors as the exclusive preserve of the racing fraternity, who employed vast crews to tussle with acres of unruly spinnaker nylon. But the reality is now very different. In the same way that upwind sailing has been made less strenuous by the increasing popularity of selftacking jibs, fully-battened mainsails and cockpit-controlled reefing systems, developments with spinnakers and cruising chutes have resulted in more stable, easily-managed sails which can be comfortably handled by smaller crews. 

KempSails Cruising Chute

Spinnaker or Cruising Chute?

For optimum efficiency, you need a spinnaker whose tack is projected from the end of a pole to bring it out from behind the mainsail on a broad reach or run.The drawback is that, since the sail is larger than a cruising chute and only firmly attached at one corner (the head), it needs more care in hoisting, trimming and dowsing. A cruising chute, on the other hand, is smaller and easier to manage, but less efficient as the wind comes further astern. The solution we often suggest is to have one of each: perhaps a 0.9oz spinnaker for racing, and lightweather running/broad reaching in cruising mode, plus a 1.5oz cruising chute. Not only can the chute be tacked to the stemhead when cruising but, flown from the pole as an asymmetric spinnaker, it will double as a highly effective reaching kite in breezy conditions.This way, you'll keep the family happy and have a 'secret weapon' on the race course!

Image

Cruising Chute (Radial Head)

The most economical design of cruising chute (small boats only). Ideal for enhancing your offwind performance in light to moderate winds at minimal cost.

Cruising Chute (Tri-Radial)

Incorporates radial panels in Tack & Clew for greater shape stability.

Cruising Chute (Full Radial)

The No. 1 Cruising Chute choice for most situations. A Full-radial construction ensures panels are lined up with load patterns.

 

Flying Cruising Chutes

If you've been put off spinnakers by witnessing or experiencing wraps, broaches and assorted mishaps, take heart. By following a few simple rules and not trying anything too ambitious, you'll find it's all pretty simple! And you'll be amazed at how much faster, steadier and more enjoyable your downwind sailing becomes.

When hoisting a Cruising Chute (or Assymetric/Gennaker), you have a choice of launching it from the bow or the leeward side. As a rule, the second option is safer because you hoist in the lee of the genoa. We supply different types of bag according to your preference - a round one for attaching to the pulpit, or a rectangular sidelaunching bag.

As for the rest of the equipment, on most boats you just need a pair of sheets (ideally tied onto the Sail's Clew corner) and one Tack Line - with a substantial Block for turning each line (One on the Bow right forward and two on the aft Quarters).  The Tack Line ideally will have a Snap Shackle to attach to the Tack ring and allows easy release in an emergency, and of course the Halyard itself. Ensure the sheets are led outside everything and that the 'lazy' sheet goes around infront of the Forestay.

Put the boat onto a Broad Reach and with all the lines set up ready hoist the sail.  If you have a genoa set then roll it up afterwards - as the wind shadow will help you fully hoist the sail before it sets.  As soon as the halyard reaches the Top sheet on the Leeward sheet and check that the sail has filled correctly.  Roll away the Genoa (if necessary) and trim the sail essentially like a Genoa, but easing until the Luff just curls and the trimming back on.  

Deeper sailing angles can be achived by dropping the Mainsail or Goose-winging the Chute....If you are going to then don't forget to put a preventer on the Mainsail!

To drop the sail shorthanded and without a sock it is best to trip the Snap Shackle on the Tack and keep the Clew sheeted on.  This way you can ease the haylard down and gather the sail downwards by working up the Leech and dropping it into the companionway.  On most cruising boats over about 22ft then using a Snuffer makes this operation simpler.

Snuffers...

No matter how experienced you are in handling spinnakers or cruising chutes, the combination of large sails, fresh winds and small crews sometimes calls for some extra help. This is where the snuffer comes in - a nylon sock which pulls down over your spinnaker and turns it in to a long sausage, with the head at the top and the tack and clew at the bottom. When you want to use the spinnaker, you start by hoisting the snuffer to the masthead with the sail bundled up inside.The spinnaker will only start to fill when you pull the snuffer up from the bottom using its own internal halyard - so you can make sure everything's totally under control before any wind gets into the sail.When you've finished spinnakering, you pull the snuffer down again and lower everything back on deck.

 Design your own Cruising Chute Colour layout, Here online & RIGHT NOW!

 Just use on our KEMP SPINNAKER WIZARD link below:

(Please note, the layouts are artistic impressions and may differ slightly from the actual finished sail panel layout)

CLICK HERE to use the Kemp Sails Spinnaker Wizard Designer

Alternatively, download our own " default Kemp Sails Spinnaker Layout Sheet (1.18 MB)", from the "Measurement Forms" area on this website, and you can print and colour the sails yourself. If you fax this form back to us please remember to mark the colours on the panels by name / letter as fax's are only Black & White !!!!

Radial Sails

Radial SailsUntil the early ‘80s, sails were usually made to a cross-cut design - that is, with their panels running horizontally from leech to luff. Most are still made this way - and for good reason: it’s a simple, reliable and relatively economical method of construction which is best suited to the majority of readily-available fabrics.