The purpose of these articles is to inform cruisers of potential sail problems associated with bluewater cruising. Sail repair services in remote locations can be non-existent so sail reliability is key to a safe and stress free journey.
Luff Hardware - Standard Sliders
Plastic slider or shackle failure is a common problem we see. In a heavy squall or while dropping the sail in heavy air, one slider failing can cause the rest to "pop" resulting in a flogging, out of control sail!
It is advisable to use the strongest plastic sliders available for each mast track. We use fiber reinforced plastic sliders or plastic coated metal sliders where possible. Un-coated metal sliders will almost never fail, but can cause wear on the mast track over thousands of miles. Sometimes there is no other option due to the type of mast track and size of sail.
Attaching the sliders to the sail with plastic shackles can reduce some friction but isn't recommended as the shackles are prone to breaking with age, sun damage or excessive load. Attaching the sliders with webbing on to the luff is preferred.
The trend with racing sails has been to machine sew the slider to the sail with webbing straps. Some sailmakers have carried this over to cruising sails. While this simplifies the manufacturing process, if a slider does fail it is not possible to replace the slider without a sewing machine, which of course involves removing the sail.
The preferred method for blue water sails is to attach the slider to the sail with webbing though an eyelet on the sail or slot in the batten box. This is the strongest connection and if a slider does break it is possible to replace it yourself at sea with the hand sewing needle and thread found in the sail repair kit, or with a simple 2mm rope lashing.
Low Friction hardware
Low friction hardware can be broken down into two categories, using the existing mast track or installing an extra external track attached to the existing track.
1. Existing track hardware
Rutgerson wheeled low friction sliders - Used either only on the full battens or also on intermediate sliders. For certain mast types the wheeled sliders do a good job of reducing friction.
Ronstan Ballslide system
The Ballslide system does a good job of reducing friction via bearings running on the back surface of the mast. Once again, this system is only compatible with certain mast models. It is more expensive than the Rutgerson Sliders.
For both systems we need highly accurate measurements to determine compatibility. Also of note is sometimes the presence of a close trysail track prevents these sliders being used.
2. External track hardware
Tides Marine Strong track
A very popular cost effective solution for blue water cruisers. A low friction strong plastic track is slid up the existing sail track. This system is compatible with almost any existing mast track. The sliders are all S/S. The plastic track will last 10-15 years at which time it can be replaced while the sliders can be reused. We have used this system on up to 60ft mono-hulls and 45ft Catamarans.
Ronstan and Harken external bearing systems
Ronstan and Harken both make external track systems that attach to the mast's existing sail track. They use cars with low friction torlon bearings and when sized correctly are very strong and low friction. Cost is quite high but for boats over a certain size this is the only solution. The systems work very well but do wear out eventually.
Other types of external track.
A few other types and brands of car systems do exist, for example the Antal, Facslide, etc. Each have advantages and disadvantages with a varied price. Normally a local rigger will advise his preferred system.
Sailcloth Part 2 - Dacron and woven HMWPE
With so many different dacrons available it is hard enough for the sailmaker, let alone the customer, to figure out the good and the bad. Of course, if you read the marketing material every dacron is made to sound good. But the reality is quite different and only independent testing can shed some light on the true durability, UV resistance and quality of the fabric. Even between batches the quality can vary so most quality sail producers test a sample from each roll to check it is up to standard; if not, it is returned to the cloth supplier. We have ongoing testing projects to find both the best dacron and the best value for money dacron.
Stretch testing involves measuring the material stretch in three directions, the warp, the weft and the bias; in other words, up, down and diagonally. Diagonally the material is the most stretchy due to dacron only having fibers running in two directions. The diagonal stretch is controlled by the resin finish of the sail cloth. The harder the resin, the less diagonal stretch is present. Tightness of the weave also has an effect of diagonal stretch. However the disadvantage of the tight weave is that the yarns are smaller and so the cloth tears more easily. The smaller yarns are also more susceptible to UV damage than bigger yarns so the cloth will end up with a low tear strength a lot quicker than a material woven with bigger yarns.
The firmness of the resin finish is a balancing act for cruising sails between performance and sail handling, especially for traditional slab reefing mainsails and hank on headsails. The harder the resin the harder the sail is to handle for the sailor. For this reason most cruising sails are made with dacron that has a medium finish - which still feels hard to most cruisers.
Different resins break down at different rates so one of the ways we test dacron is to flutter the sample on a fluttering machine to see how quickly the resin deteriorates for each dacron sample.
UV testing involves leaving samples in the sun and weather for months at a time and then comparing the dacron to identical samples kept inside out of direct sunlight. The same machine used for stretch testing is also able to measure tear strength of sun damaged and undamaged samples.
Sailcloth - Woven HMWPE
Our most popular high performance woven material is Hydra-Net Radial by Dimension Polyant. This fabric is a woven blend of polyester and super strong hmwpe (dyneema/spectra) fibers.
The reason for its popularity is it offers a more performance orientated sail, but without the molding or lamination issues of a laminated material in high humidity climates. It also outlasts performance laminated materials by at least two times. The price is high and the material is more popular on bigger or more performance orientated cruising yachts.
The purpose of this article to make cruisers aware of potential sail problems associated with bluewater cruising. In remote locations sail repairs can be non-existent so sail reliability is very important. We spent three years of full time cruising and as a sailmaker and designer I helped fellow cruisers deal with various sail issues. I've attained a very good understanding of the sail problems faced by cruisers over the years evaluating and repairing damaged sails.
In this first article we’ll talk about UV damage as it is a prime cause of sail problems for cruisers.
The most common cruising sail cloth is still woven polyester (dacron) so we'll focus our attention here in this article.
Dacron (polyester) sailcloth degrades at a steady rate in UV light and obviously should always be kept covered when not in use. Some tell tale signs that dacron is sun damaged are a yellow discoloration and a slightly furry look to the fabric surface. The fabric will also tear easily and small 2 or 3mm holes may appear. Before embarking on a long passage it is worth having a close inspection of your sails to identify any cloth problems. The more UV hours the dacron is subjected to, the more the strength loss.
While dacron sailcloth may all appear to look the same to the untrained eye, there are at least 5 different manufacturers, each having 2-4 different grades of dacron in their range. Even with a lot of research it is still tough for the customer to know which cloth is high quality and which is low. We weather and stretch tested as many dacrons as we could with some surprising results. We found a massive variation in strength loss due to UV damage – up to 90% strength loss in 6 months for some fabrics, while others are low as 30%. We put this down to the different types of polyester yarns used in the construction and the different resins/coatings used in the manufacturing process.
We use Dacron with a fairly balanced weave opposed to high aspect dacron. This avoids vertical tearing (as seen in above photo), high aspect dacron has most of its strength in only one direction. We only use dacron from trusted suppliers that has performed well in our UV testing.
UV Cover stitching
One of the most common problems is the Sunbrella or Acrylic UV cover on genoas and furling mainsails separating from the sail due to stitching failure from UV damage. While some UV polyester threads will last well we typically see the stitching on the UV cover failing after 3-5 years in tropical sun. This can lead to the UV cover partly detaching and flogging apart. The dacron material of the sail is then subjected to 24 hour UV damage until the sail can be repaired.
The solution is PTFE (Teflon) thread which is not affected by UV light and will outlast any fabric including Sunbrella. Sold under many brand names the most common being Gore - Tenara this thread has been around for many years, but is rarely used by sail manufacturers.
We sew all our sail UV covers with this product and the extra cost of the thread is overall a big saving of money and headache later on.
Another not as common but more serious problem on furling sails is the stitching and webbing holding the corner rings or loops to the sail degrading to the point that the corner fails. In the photos above the stitching has degraded to a point where if the sail corner was subjected to a strong load, the ring or pulley would separate from the sail.
While we cover all out corner webbing with Sunbrella or UV material and sew it with PTFE Tenara thread, many sailmakers do not. Polyester thread can lose 50% of its strength after 1 year in the sun. Exposing the thread and webbing holding the corner ring (which is regularly taking hundreds of kgs of load) to constant UV is a really bad idea in a tropical climate. We've seen many of these webbings hand stitched or even riveted back on to the sail. The corner webbing is also susceptible to UV damage and we also cover all webbing with polyester tube webbing or sunbrella.
Mainsails and hanked on genoas are also susceptible to corner failure due to UV damage. So it is important to make sure the sail bags and covers are over the sail corners. We too often see the corners poking out the ends of the covers.
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