Sail cuts and cloth materials, explained by Dick Beaumont.
The cruising yachtsman should take as much care selecting his sail wardrobe as his racing colleagues.
The sails of any yacht are its ‘engine,’ a fact often overlooked by the cruising fraternity. This issue came to a head recently when a Kraken client asked us to quote for a hybrid drive system. It was expensive and yet still relied, albeit less so, on main engine power.
Having analysed the request, I concluded that if you want to sail around the world leaving the smallest possible carbon footprint, do just that, sail. To do so efficiently one needs to have a rig and a wardrobe of sails that can best utilise whatever wind there is for your intended voyages, wherever they may be. These, combined with good planning, will have you sailing carbon free passages (See Part 1 of Sailing the World in this edition).
We covered light wind cruising chutes and code sails in the April edition. If you missed it, all the Kraken News/ Ocean Sailor back articles are now cataloged on our website.
Choosing the right sail and cloth cut, and material for your type of cruising, will bring many benefits. I went to talk to my friend Kaan Is of Quantum Sails, Kraken Yachts’s partner for sails, at his Turkish sail loft.
Cut or build of the sails
Sails can be made from woven cloth in panels which are stitched together, or membrane fibre material, which are one piece or several large pieces that are glued or welded.
For blue water cruising a woven cloth made in panels stitched together is the best choice, because any sail loft in the world can work on a panel sail to replace a damaged panel, or repair stitching. Generally, woven sails are either: Cross-Cut or Radial-Cut.
Cross-Cut sails are relatively low cost, this is the only real adavantage over Radial-Cut’.
The material used is woven polyester, popularly known as Dacron which is actually a Dupont brand name for the thread that the sails may be made from.
The disadvantages of Cross-Cut sails are threefold.
- The load that is applied to the sail is not in line with the direction of effort, so the sail will lose shape more quickly.
- The sailmaker must use the same weight of cloth across the whole sail, so the sail is heavier and not so responsive in lighter wind.
- The stitching does not run in the direction of load and therefore will require more maintenance.
Radial-Cut panel sails are made from polyester cloths, or other materials and are much more labour intensive, therefore the main disadvantage is cost.
The benefits of a Radial-Cut sail are:
- The sail panels are built with the weave and fill (weft) in the direction of load
so that the sail will hold its shape for longer.
- The panels which take less load than other parts of the sail, can be made of lighter cloth which improves the drive of the sail.
- The stitching of the panels lay in the direction of load and therefore is under less tension and lasts longer.
Sail cloths and materials
There are four types of cloths or materials to choose from for mainsails and foresails, in the order of cost they are:
- Plain polyester cloths
- Enhanced Polyester/Dyneema Hybrid cloths\
- Hydra Net Ultra PE cloths
- Laminate cloths
- (not recommended now)
1. Plain woven polyester cloths
These break down into those suitable for Cross-Cut sails or Radial-Cut sails. Woven polyester does stretch over time so the sail will lose its shape. They are suitable for low cost cruising sails.
Plain woven polyester cloths suitable for Cross-Cut sails
Examples of these cloths are:
- Fibercon by Contender Sailcloth, AP Low Aspect and C Breeze by Dimension Polyant.
- CzBreeze is more expensive but has high tenacity and it will stretch less and last longer. It is standard with all Kraken yachts.
Plain woven polyester cloths suitable for Radial-Cut sails
Examples of these cloths are:
- Fibercon Pro Radial, which we recommend as the first upgrade from standard Cross-Cut.
- Dimension Pro Radial
2. Enhanced Polyester/Dyneema Hybrid cloths
These are polyester cloths strengthened with Dyneena fibres.
The tenacity of the hybrid cloth is much higher and has two advantages over
- Because it is stronger a lighter cloth can be used with all the benefits of handling which come with that, as well as better performance and tighter more compact furling. Weight aloft is also reduced assisting righting moment.
- The Dyneema fibres hold the sail in shape much longer.
This cloth is made by Contender Sailcloth and is called Fibercon Hybrid.
3. Hydra Net Ultra
This is a relatively new, high cost material developed by Dimension Polyant and is seen as a replacement to cruising laminates.
Advantages over Hybrid cloths:
- It is stronger and can therefore be lighter.
- It will stretch less.
- It will last longer.
- It is mildew resistant
Advantages over laminate:
- Whilst holding its shape equally
- it lasts much longer
- It is lighter
- It is thinner
Considering the advances of Hybrid and Hydra Net materials, laminates are no longer an appropriate choice for blue water or world cruising yachts, in my opinion, because both these materials hold their shape very well and have much longer life than laminates.
Flying Sail cloths and materials
For flying sails ( cruising chutes, gennakers or code sails ) for a blue water cruiser there are two types of materials to choose from:
- Rip stop polyester PP300
Nylon is available in weights 1.5-2.1 oz but even at the heavier end still has a low wind threshold, 2-15 kts apparent wind is its working range . It’s excellent for cruising chutes but the crew have to keep a careful eye on the apparent wind strength as otherwise the sail soon becomes unmanageable and may blow out.
Nylon is also very susceptible to UV and will deteriorate quite quickly if left exposed to sunlight.
2. Ripstop Polyester PP300
Ripstop Polyester PP300 is a little heavier than nylon and is therefore not as effective in very light winds but has a much wider wind threshold 5-20kts and a greater wind angle threshold, 180 round to 90 deg, depending on the sail cut, and because it can be easily used on a continuous furler and can be UV proofed, the sail is used easily and more often.
Dacron based polyester is a tried and tested quality cloth that will be sufficient for offshore cruising. A radial cut sail based on polyester will undoubtedly improve performance and will last longer than a Cross-Cut sail if the comparisons are uniform. The cost of upgrading from polyester Cross-Cut to polyester Radial-Cut is approx 6,000 euros on a Kraken 50 for mainsail, jib and genoa, for an example.
If the sailor is expecting to voyage across oceans and clock up above average nautical miles, the move up to hybrid cloths will be well justified as the sails are likely to last a lot longer in good shape and require a great deal less maintenance, a bonus in areas where competent sail lofts are a rarity.
The cost of upgrading to Hybrid Radial-Cut sails from standard Cross-Cut polyester is approx 9,000 euros for the
same yacht and sails.
If budget is not a concern Hydra Net is the ultimate solution. The cost of upgrading to Hydra Net from standard Cross-Cut polyester is approx 15,000 euros like for like.
As our sail maker Kaan Is said ‘Once you’ve sold a customer Hydra Net sails you can wave him goodbye, he won’t need a sail loft for a very long time’.