Dinghy covers and sails

DINGHY COVERS, YACHT COVERS, BOAT COVERS

Breathable polycotton covers let the boat dry out WITH THE COVER ON !

Dinghy covers manufactured in heavy duty PVC Polyester and BREATHABLE Polycotton.

PVC dinghy covers now with further UV coating and attractive canvas finish.

We cover all classes, all sizes, all specifications catered for. Advice freely given.

No strings or eyelets to be seen, snap-together fastenings throughout.

Reinforced shroud and mast openings with soft webbing ties to protect the stem.

Webbing draw-around sides can be tightened at the bow and stern.

On mast-up dinghy covers, Velcro from mast to bow with extra securing buckles.

Years of experience in boat and dinghy cover manufacture.

Sail Register Boat Covers

4 Yarborough Court

Ulceby

North Lincolnshire

DN39 6RZ

Telephone: 01469 589444

Email: info@sailregister.co.uk

Tuning dinghy sails helps you set your boat up close to its ideal settings. These settings should be regarded as a starting point for fine tuning as individual boats and crews may need to alter them slightly for best performance.

When you have your boat set up, remember to mark everything so that the settings can be reproduced quickly.

Spreader Settings

The two measurements for spreader settings are length and deflection. Spreader length controls the sideways stiffness of the mast and is taken by measuring the side wall of

the mast to the shroud. We recommend sailing with 470mm spreaders although very heavy crews may wish to increase this to 480mm to keep the rig powered up in breezier conditions. Spreader Deflection is measured by putting a straight edge from

shroud to shroud and then measuring from the mast to this edge. This measurement is not critical as it is only a guide to getting the correct pre-bend which we check again later.

Rig Tension

Rig tension is measured on the shroud and varies with wind strength. Start off with 400lbs in all light winds and increase up to 470lbs in heavier winds to prevent excessive luff sag.

Mast Rake

Mast rake is measured from the top of the mast to the top of the transom. To do this hoist the jib with 400lbs and no chocks. Attach a long measuring tape to the main halyard and hoist to measure 16’1” to the top of the black band at the gooseneck.

Cleat the halyard and swing the tape around to measure the distance to the top of the transom. This is the mast rake. In 15 knots and under we recommend sailing with a

rake of 19’101/2” – 19’113/4”. Above 15 knots we recommend raking back to about 19’81/2” - 19’9” but measured with 470lbs.

Chocks

The masts neutral position is where the mast sits with full rig tension on but no forces acting upon the sails.

0-5 knots: 0 Chocks when crew siting to leeward. This allows the bottom of the mast to bend, flattening the bottom of the mainsail and reducing the tension in the leech.

5-10 knots: 1 Chock to fill the gap when mast is in neutral position. Crew sitting to windward or high wiring.

10-18 knots: When the crew is flat out trapezing, putting in a second chock will help to maintain the desired pre-bend.

18+ knots: 1 Chock. When you are really overpowered, removing the 2nd chock again allows the mast to bend, opening the leech and de-powering the sail.

Centreboard

In sub-trapezing the board should be angled forward. As you get to flat wiring (almost planing upwind) the leading edge of the board should be vertical. As it gets windier the board can be raked further back. In flat water you may raise it up to 3” on the handle. In rough seas it can be lifted up to 6” to help you steer around the waves.

Mainsails

Top Batten: Push in gently in light air. As the wind builds you should push it in more to remove the vertical creases from the batten pocket (it should be in quite firmly).

Outhaul: This should be pulled out tight almost all the time upwind and should only be eased up to 1” in moderate breezes when it is very choppy. Downwind the outhaul can be eased 11/2 – 2”.

Kickers: Until you are overpowered and have to ease the main upwind, the kicker should only have the slack taken up as mainsheet tension will control the leech profile. Above this wind strength you should ensure there is enough tension to keep

the top tell-tale flying approximately 80% of the time.

Jibs

Sheet Tension: The jib sheet is used to control the jib leech and slot shape. Generally the slot should be kept parallel all the way up which is achieved with a combination of jib sheet tension and barber hauler. If it is light and choppy you may need to ease itmore to give more twist to keep you going through the waves.

Jib Cunninghams: This should be tightened sufficiently to remove the creases from the luff of the sail. More tension is required as it gets windier.

Barberhaulers

Windspeed Ammount of Barberhauler

0-6 knots None

6-18knots Pull in 2-3” when jib sheet is tight

18+ knots Ease it off as you get more overpowered

Spinnakers

The head of the spinnaker is flown 2-3” from the mast. This is done by tying a stopper knot on the spinnaker halyard.

Setting the pole height is very important as it controls the shape of the sail. It should be set to keep both of the clews level. The only exception is on occasions when the wind drops very light and the pole should be lowered to encourage the spinnaker to set.

Sails, even for the smallest sailing dinghy, can be expensive so it's common sense to try and look after them. Here are some hints to help you get the best out of your sails and prolong their life.

General Sail Care

Looking after your sails is often a matter of common sense. All sails wear with use but you can minimize this. For example why use your new set of racing sails for cruising around with the kids ? Many sailors continue to use an old set of sails for 'pottering about' whilst retaining a new set for racing. Also when you get your dinghy ashore don't let the sails flap about in the wind, get them down as soon as possible and try to avoid creasing or folding them.

UV light can deteriorate sails. You can minimize this by packing them away at the earliest opportunity.

Cleaning

If you sail in salt water then make sure you wash the sails in fresh water after use. Salt actually holds moisture so the sails never completely dry. If you need to wash sails then avoid using strong detergents as these can degrade the coatings and glue used on some sails. There are some specialised sail cleansers on the market so try to use one of them. Some sails such as those made of kevlar are often glued together and detergents can often weaken this glue eventually causing it to fail.

The best thing to do is try and ensure your sails don't get dirty in the first place! Try to avoid laying them on the ground if at all possible. Obviously there are times when this has to be done when packing the sails up ready for storage but try and do it on clean dry ground.

Storage

Firstly never store sails wet. Allow them to dry thoroughly. You should roll, not fold, sails. One of the best ways to store sails is to roll the jib up with the main sails to create a nice stiff tube meaning they are stronger and less likely to get crushed. The sails should be rolled from the head which ensures that you never need to crease the sail.

Rolling also ensures that any plastic windows are protected too.

Sail Material

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 Sail performance is directly related to the sail fabrics from which sails are made. So whether you are seeking new or used sails, the following information should help you to decide. The characteristics of fibres (Modulus, Tenacity, Flex Life, UV-resistance, Elongation, Flutter Stability) and how those fibres are incorporated in a laminate or a woven material, influence how the finished sail cloth will perform. With many types of sail fibre and sail fabric to choose from and with new products being introduced annually, purchasing the right sail can be a confusing process.

There are basically two processes used by sail cloth manufacturers. Woven sail material is made by weaving threads over and under each other to produce the sail material. The tighter a sailcloth is woven, the better it will perform.

Laminate sail material is composed of layers of film, scrim or taffeta that are glued together under incredibly high pressures to form a composite sail fabric or sailcloth.

Composite sailcloths or sail fabric Composite sail material are made from sail fabric that is made from two or more constituent components.

- A scrim is a grid of relatively large, unwoven, straight yarns. Scrims have little stretch parallel to the yarns and are usually sandwiched between other layers of scrim in a composite fabric.

- A film is an extruded sheet of isotropic plastic such as DuPont's Mylar® polyester film. Film's good properties are low stretch in every direction, contributing to bias stability, zero porosity, and a surface that adheres well to other elements in the laminating process. Film's weaknesses are low tear resistance and a tendency to shrink.

- Tafetta is a woven substrate that makes up the outside of some laminates. Taffeta sail fabric is usually made from polyester and adds to the durability and chafe resistance of the laminate.

Properties of sailcloth, sail fabric and sail material taken into account by sail makers include -

* Modulus is the ability of a sail fabric to resist stretch. Laminates generally have higher modulus than wovens of the same material because the threads are pre-tensioned and lie straight inside the laminated film. Since sail fabric properties, especially stretch, are not isotropic, (that is, they vary with direction), fabric orientations are significant.

* Fill is the orientation across the width of a sail fabric.

* Warp is the orientation along the length of a sail fabric.

* These terms come from the weavers' names for the two directions of thread in the loom.

* Orientations at a significant angle to the warp and fill, especially 45°, are all called the bias.

* Tenacity is the tensile stress at rupture of a being expressed in grams force per denier. Tenacity relates to the breaking strength of fibres, and should not be confused with modulus, which relates more directly with a fibre's ability to resist stretch.

* Denier is the weight in grams of 9000 meters of a given yarn. A higher denier signifies a heavier fibre.

* Flex Strength is the ability of a fibre to retain its strength after being folded back and forth. Flex strength is commonly expressed as loss in breaking strength after flutter testing.

* Initial Modulus describes a material's inherent ability to resist stretch. Initial modulus is usually expressed as grams of load per unit of stretch for a certain amount of fibre weight. The higher the initial modulus, the less the fibre will stretch.

* UV Resistance measures the effect of sunlight on cloth. UV resistance is usually expressed as the time it would take for a material exposed to sunlight to loose half of its breaking strength. All very different from the requirement for cloth and textiles for clothes and clothing purposes.

Sailcloth Fabric used by sail makers

Dacron®: The DuPont® trade name for man made Polyester fibre. This fibre is the foundation of traditional woven sailcloth. Dacron fibre is also used in cruising laminates and Polyester laminated sailcloth where the use of expensive, low stretch, man made aramid fibre is not necessary.

Polyester: The most common fibre used for both woven sailcloth and laminates. Its properties include good UV and flex resistance, as well as being inexpensive. A proven fibre for durability, polyester has been replaced by higher modulus fibres for most racing applications. Woven Dacron, Polyester laminates and Polyester spinnaker cloth are all products made from this versatile fibre. In the sailmaking industry, "Poly" usually refers to spinnakers and specifically polyester spinnaker material. Polyester laminate such as PX or PP-Diax are usually referred to by their trade names.

Nylon: traditionally used for spinnakers, to make woven spinnaker fabric, this material is very light weight, but not very stretch resistant. Nylon is manufactured in weights of 0.5 oz, 30/20, .75oz., 1.5 oz., and 2oz.

Kevlar®: A gold coloured aramid made by DuPont, Kevlar's modulus is five times greater than polyester so it stretches less and sails made from it can be lighter. Of all the high modulus fibres, Kevlar has the most proven track record. It is available in both standard K-29, and high modulus K-49 fibres, with the latter being used more and more for high-end racing applications. Although much stronger than polyester, Kevlar is not as durable in terms of fatigue and UV resistance. It is also more expensive. The original high tech fibre, Kevlar is UV sensitive and its gold colour turns brown as it is effected by sunlight.

Spectra®: A high molecular weight polyethylene, Spectra is a product of the Allied-Signal Corporation. Spectra has the highest modulus of any fibre, except carbon, used in sailcloth but has seen limited application in racing sails because of its creep property, meaning that the fibre will permanently stretch when placed under high constant load. This stretch makes it difficult for sail designers to lock in the shapes they want. As a result, Spectra is viewed more as a performance cruising fibre where its excellent flex, UV and abrasion properties along with its traditional white colour are perfect for large cruising boats where cloth strength and durability as well as weight aloft are considerations. Spectra is more expensive than Kevlar.

Technora®: Made by the Japanese company Teijin, Technora is an aramid developed as a reinforcement for drive belt applications. In sailcloth, it is dyed black to help its UV resistance. Technora has a modulus similar to Kevlar, slightly better abrasion resistance and is more expensive than Kevlar. Used alone or in composite laminate constructions, Technora is currently recommended as a durable alternative to sun sensitive Kevlar. Often used as a bias support in composite high modulus laminates.

Certran®: A high modulus polyethylene fibre, similar to Spectra, manufactured by Hoechst Celanese. This fibre shares the same resistance to flex fatigue and UV as Spectra so its applications in sailcloth are limited to secondary fibres and areas that can take advantage of its flex, chafe and UV resistance.

Twaron®: High Modulus Twaron or HMT is a fibre very similar to Kevlar but is made by Akzo Nobel. This is a PPTA fibre with similar stretch resistance to Kevlar -49, but higher breaking strength, a better UV resistance than Kevlar, and bright gold in colour.

Vectran®: A polyester based liquid crystal fibre manufactured by Hoechst Celanese. Vectran has a modulus comparable to Kevlar but due to its molecular composition has better flex and abrasion resistance, although its UV properties are worse. Vectran also does not creep. These characteristics make Vectran an interesting candidate as a performance fibre, although it is more expensive than either Kevlar or Spectra.

Dyneema®: Produced by the Dutch company DSM, Dyneema, like Spectra is a highly processed polyethylene that offers good UV resistance, high theoretical initial modulus and super breaking strength. It also shares Spectra's creep characteristics.

Pentex®: polyethylene napthalate polyester fibre. Two times the stretch resistance of regular Dacron polyester, Pentex offers high modulus alternative for woven Dacrons. Best when used in a laminate form. Has similar tenacity to polyester and slightly better UV resistance. This fibre is developing an impressive track record as a laminate.

Carbon: Carbon fibres have extremely high modulus but are not very durable. This problem was addressed with varying degrees of success with the some America's Cup boats. Crews had to be very careful to avoid hard creases in folding. The future will probably see more development, but high cost and inherent fragility may limit this fibre to only the very best funded racing efforts.

PBO Zylon®: Poly (p-phenylene-2,6-benzobisoxazole) (PBO) is a rigid-rod isotropic crystal polymer. PBO fibre is a new high performance fibre developed by TOYOBO Co., Ltd. (Japan). PBO fibre has superior tensile strength and modulus to Aramid fibres, such as Kevlar, Technora and Twaron. It also has outstanding high flame resistance and thermal stability among organic fibres. PBO fibre shows excellent performance, in such properties as creep, chemical resistance, cut/abrasion resistance, and high temperature abrasion resistance, which far exceed Aramid fibres. PBO fibre's moisture regain is low (0.6%) and it is dimensionally stable against humidity. PBO fibre is quite flexible and has very soft hand in spite of its extremely high m echanical properties. It can be processed by sailcloth manufacturers into various product types, such as continuous filament, staple fibre, spun yarn, woven and knitted fabrics, chopped fibre and pulp. PBO fibre's excellent mechanical properties will enable the design of high strength and light weight fibre reinforced composites. PBO is used in high performance grand prix racing laminates. A very expensive material, PBO offers high performance and light weight at a premium price.

For those with a limited budget, or perhaps who are not seeking the ultimate in the latest sail technology, used sails offer a less expensive alternative.