The care and feeding of canvas

	The Care and Maintenance of Canvas Products Maggie Ross provides a stitch in time

	Check slides, slugs, bolt-rope and head foil tape or hanks to see that all parts of the hardware are functioning, not showing excessive wear or have hair-line cracks. Battens and pockets are the most abused and ignored parts of any sail. Full- length battens chafe on the shrouds when set for down-wind sailing. Standard battens tend to stress the material in the pocket and the sail when the elastic at the luff (bow) end is cut or stretched from age or had too long a batten forced into the pocket because the original batten popped out when the sail flogged. Tears and broken stitches at either end of the batten pocket are usually a strong indication that the elastic is no longer functioning due to age, fatigue, or has been cut by a batten which does not have an end cap. The raw fiberglass, no matter how smoothly it is sanded, cuts the elastic and the fabric. The function of the elastic is to maintain the tension of the batten on the leech and hold the sail shape. When the elastic expired the batten slides forward as the sail fills, this leaves the leech unsupported, the sail curls and hooks allowing the material to chafe on the ends of the battens and at the same time exerts pressure on the stitching causing the thread to bread. At this stage most people repair the tear, the stitching and put in a longer batten. All of this only adds to the problem. The correct procedure is to start by replacing the elastic, replace the damaged material and then fix the broken stitching. Three stitches or three inches of broken stitching cost the same to fix so open a few more stitches and have a good look. DON'T REPLACE BATTENS BEFORE DETERMINING THE CAUSE OF THE PROBLEM AND NEVER SEW THE POCKET CLOSED TO STOP THE BATTEN FROM FLYING WHEN THE SAIL LUFFS. The root of the problem is, more than likely, the elastic and it may be cheaper to buy a new batten at the time but, like in our undergarments, the elastic has a point after which it no longer functions. Repairing the damage caused by neglecting to correct the cause may be far more expensive, not to mention annoying, in the long run. The headboard should have a bronze or stainless steel slide or metal shanked slug, seized directly to it to reduce the chances of the head tearing loose if the other slides/slugs should break. It also holds the head upright when it is not in use. Twisting and bending damages the bolt-rope directly below the headboard and leads to fraying and cutting of the sailcloth and the boltrope, causing major repairs as the headboard has to be removed before any repair can be made. A clew-slug is also advised as this takes the strain away from the boltrope along the foot at the clew. Slugs should have metal shanks as nylon becomes brittle with age and exposure to the elements. If one of these nylon shanks should break while under sail, it is likely to trigger a chain reaction and the remaining nylon slugs are apt to snap, resulting in the luff separating from the mast as if it had been attached with a zip. The shank of nylon slides are considerably thicker and resist the pressures and stresses. Because they are designed to withstand horizontal loads, they frequently develop hairline fractures and will usually break in a very short time, therefore ALL SLIDES AND SLUGS MUST BE CHECKED CAREFULLY even if only one of them has broken.

	Frayed webbing, stitching and nonfunctional or binding parts should be replaced. The tops of boltropes and headfoil tapes which are frayed and difficult to feed into the extrusion may be trimmed, heat-sealed and hand sewn with fine thread. If the headfoil tape is torn anywhere, this may be repaired by sewing a very lightweight Dacron tape over the forward rope. Care must be taken so as not to enlarge the diameter or the thickness of the tapes as this will cause the luff to bind when the sail is being raised or lowered. If the tear is more than four to six inches long then the entire headfoil tape should be replaced as this dramatically reduces the integrity of the strength of the luff when it is loaded. Binding of the slides or slugs may not be the fault of the hardware but may be caused by dirt in the track of the mast. This may be cleaned by wrapping a slide or slug in a piece of fine material, sprayed with a lubricant which is NOT petroleum based, and then carried up the track to remove the dirt and lubricate the track. DO NOT USE PETROLEUM JELLY OR A LIKE PRODUCT as this dissolves the dirt, mixes well with the aluminum oxide and transfers itself very nicely to your sails, and yourself, the next time you have to remove the sail or work on the mast. These methods may also be applied to the headfoil extrusion by using a small piece of line of similar diameter to the headfoil tape with the cloth wrapped around it. To further reduce friction try cleaning the track/extrusion with "303 Protectant" or spraying lightly with DRY Teflon after cleaning. Additional friction may also be the result of the method by which the slides/slugs are attached to the sail. We recommend that webbing be used to seize the slide/slug to the sail to reduce movement and twisting which a metal or nylon shackle allows when raising and lowering the sail. Shape distortion in a mainsail resulting in creases along the luff and radiating from the clew, a luff that cannot be made to reach maximum hoist and a boom which insists on dragging its butt about the cockpit, probably means that the rope in the luff has shrunk with age and exposure to the elements. This is usually inexpensive to repair by adding a new length of rope at the tack or head and stretching the luff back to its original length, unless the rope itself has been sewn to the fabric for the whole length of the luff. If the rope is exterior (not covered in Dacron) or is completely sewn, the entire luff must be removed and replaced, thereby costing much more in both time and materials. Shrinkage of six inches has been seen in a mainsail, which was only three years old, and thirty-two inches in a genoa of fifteen years. To check nylon sails (spinnaker etc.) for damage, tie the head to a post, stretch the sail, turn on the light if you are indoors, then get under the sail and examine it by flapping a section at a time (the trapped air will suspend the sail) while looking at it against the light. All pinholes and stress marks will show up instantly. Grab the damaged area and tie a loose knot in it to make the area easier to find when you go to get it repaired. To test the integrity of the fabric if no damage is obvious, stretch an area of fabric across your mouth and try to inhale through it. There should be no passage of air through the material. The areas to test are just inside the reinforced areas at the Head, Tack, Clew and the panels on the three sides of the sail, as these areas are more subject to stress than the middle of the sail. How many times have we heard, "The sail is great, there are no holes in it even though we fly it in 20+ knots when we race"? For a .75oz. sail, which is designed for winds of 10 to 12 knots, it is not the visible damage but rather the invisible damage which should be of concern, because when you next use the spinnaker in the winds for which it was designed, you will spill wind through the sail and not get the drive it was intended to give. This may cost you the race too! Observe and obey the apparent wind limitations recommended by your sailmaker for each sail in your inventory. Undue stress on sails, even Dacron, can cause instant and irreparable damage. Never over-tension sails as this will shorten the length of the life of the sail and may instantly destroy your Mylar, Kevlar or other high-tech sail.

	Flake sails, preferably on a different fold and in a different direction, avoiding any folds in vinyl windows, each time they are put away. This is especially important with Mylar and anything other than Dacron. If storage space permits, the best way to store "high-tech" sails is to roll them and store them on a flat surface in a bag that is slightly longer than the foot of the sail. If you must put away a sail while it is wet, open it up as soon as possible and let dry completely. Nylon sails, spinnakers etc., will not only develop mildew but their colours may also bleed and your entire inventory is apt to become multi-coloured. Vinyl windows will absorb moisture and become clouded; given enough time the windows will usually dry and clear up. CHECKPOINTS FOR CANVAS. Ultra-violet light and chafing are usually the culprits that cause the most damage to Boomcovers, Biminis etc. Be sure that the materials from which the cover etc. is to be made has been treated against damage form the sun and is water repellent. (Unless the fabric has a vinyl backing, it is virtually impossible to guarantee that any fabric is "waterproof", however this prevents the fabric from breathing.) This should include the thread and in many cased it does not. As an example, a material such as "Sunbrella" is guaranteed by the manufacturer to be U.V. resistant for five years, and water repellant for two years. (These guarantees apply only to the fabric and do not cover the labour.) "Sunbrella" also allows your sail etc. to breathe while maintaining its protection. Mould and mildew are usually caused when condensation develops due to insufficient ventilation through the enclosure. Since there isn't enough movement of air to dry the moisture, mildew and mould will develop virtually ver- night. Since it is almost impossible to "bug-proof" your boat, don't seal it, but make sure that air can pass through and keep it dry when you are not there during the week, leave small openings. Moisture builds due to temperature changes, so give it a chance to escape. For those of you who wish to make your own canvas products: REMEMBER THAT YOU USUALLY GET WHAT YOU PAY FOR. Canvas of less than 10oz. per sq. yard and is not U.V. treated will stand up to the use, abuse and exposure and will have to be replaced in the short term. We frequently see products made of "Sunbrella" which are still serviceable after ten and fifteen years. These types of materials are not inexpensive in the short term but they certainly pay off in the long run. Some of these materials also come in a matching material for interior use and have the same treatments but are manufactured of a lighter weight and do not take the rougher use that exterior material is intended to handle. Many manufacturers still do not use thread which have been treated to protect them against the effects of the sun, therefore you may find that the item may have to be re-sewn in a year or two because it is falling apart at the seams. Enclosures, which have vinyl windows, need special attention. The vinyl should have been manufactured with U.V. protection and must be cleaned with a product which does not have a petroleum or ammonia base as this will eventually eat away the surface of the window, causing it to turn cloudy and impossible to see through. The cleaning agent should also replace some of the Ultra-Violet protection which was built into the vinyl and it should seal the surface to reduce the absorption of moisture which nurtures the growth of algae inside the vinyl, thus causing the window to turn brown and again block your vision. Furniture polish is designed for interior use and was never intended to be used outdoors, therefore it only adds a coat of wax which is of no benefit to the vinyl. Many other products used on cars are petroleum based. Petroleum and ammonia based products slowly eat away the surface of vinyl and rubber causing more problems than they solve. DO NOT COVER your Bimini, Dodger etc with anything in direct contact with it. The material in the Bimini, Dodger etc. will be chafed and worn away on the exterior at all points and corners at each and every point of contact. Every spring, sailors are almost brought to tears when they remove their winter covers and realize that the great idea they had in the fall, really wasn't that great after all, and now it is going to cost many dollars to repair or replace what was once a beautiful and expensive part of his boating pleasure. By all means use additional supports and straps to hold the frame in position and put the winter cover over it, BUT REMOVE THE CANVAS FIRST. Keep in mind that many tubular frames were never designed to hold the weight of freezing rain and heavy wet snow - so act accordingly. Bear in mind that if your cover rests on deck and gathers pools of water, chances are you will develop osmosis on your deck in these areas. The canvas should be checked for chafe and probable mildew. The second most important piece of advise we can give you is to have the canvas, of any used boat you are considering purchasing, examined by a sailmaker or a repair specialist before you sign on the dotted line. Insurance surveyors are more concerned with the integrity of the hull and less so with the canvas or engine. Canvas will help to make your boat a "thing of beauty and a joy forever", but, only if it is in good repair. The most important advice beyond keeping a close check on the points we have made above, is that when you lift your boat at the end of the sailing season, are servicing your engine, cleaning the hull and otherwise preparing for next season, you should also be having the canvas checked and repaired during the slow period (October to December) rather than waiting until the week or so before launch. When you feel the first warm breezes of spring, you may be faced with a waiting period of six weeks or more. If spring comes early, you'll be ready and able to go out on your boat, but the big plus is that the person checking the canvas, has more time to spend with you, to find out what problems you may have had - while they are still fresh in you mind. Copyright: Maggie Ross, November, 1997 E-MAIL:

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