These design notes describe the Fender-Max - its features and function. To inform with proven data and not mislead with disingenuous fact.

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1 Welcome These design notes describe the Fender-Max - its features and function. To inform with proven data and not mislead with disingenuous fact. The nautical fender must be tough, durable and quick to deploy. It's purpose is to provide maximum protection to a yacht when coming alongside the harbour wall or pontoon. It must resist abrasion, it must absorb shock, it must be kind to the hull. The choice of material and method of construction are paramount to success. Originating from the 13 th century, the fender started life as a hemp rope that was back spliced into a multi-layered crown knot until it was thick enough to absorb the chafing the vessel encountered. Often dipped in tar to extend it's life, the odd mark was tolerated providing deep scars were avoided. The same principle applies today, except boats are often of composite or aluminium construction and cuts and gouges are damaging whilst marks are unsightly and difficult to clean off. The 20 th century solution to fendering has varied from old car tyres, to planks of wood with blocks of foam. Most have fallen into disuse, though one, the injection moulded PVC fender, is still employed. This is not without its drawbacks, which can be significant when examined in detail. Though cheap, the PVC injection moulded fender, when correctly sized, becomes too bulky to stow once a vessel is prepared for sea. To resolve this problem the inflatable fender was born. It can be deflated up to 1/30 th of its original size. To excel an inflatable fender must have a tough surface, a strong textile weave and a welded seam. Modern inflatable fenders can be made in three materials PVC, Hypalon and Polyurethane. Choosing the best is important. PVC (Polyvinyl Chloride) PVC is normally a rigid plastic. To be pliable, so that it can be made into a moulded or inflatable fender, a plasticiser is added. Damagingly, and overtime, this plasticiser leaches

2 out of the PVC forming a gum upon its surface. This gum collects dirt and grit and fender becomes abrasive, scouring all it touches. To counter this problem the fender sock was devised, an unwanted extra that does not tackle the problem at source. Abrasion resistance of PVC fabric is poor - though some try to claim otherwise. This claim is based on PVC being wet, with water lubricating its surface. An unlikely scenario in service - unless you stand there with a hose. Hypalon (CSM) Hypalon, a trade name, was invented by Dupont Chemicals in the early fifties. Due to production costs, environmental concerns and falling demand Dupont stopped manufacturing it in It should now be called CSM or Chlorosulfonated Polyethylene (CSPE). There is a lot misinformation about CSM and it can be difficult for the layman to sort fact from fiction. Most CSM fabrics start as a chloroprene coating to both sides of a textile weave. Chloroprene, also known as neoprene, is a comparatively soft synthetic rubber. This is followed by a fine 200/300 micron coating of chlorosulfonated polyethylene - to just the outer surface. CSM is vulnerable to abrasion and this extremely thin layer is easily penetrated exposing the unguarded chloroprene beneath. It is illogical to make a fender from Hypalon/CSM when there are much tougher alternatives. Polyurethane (PU) Polyurethane has a different chemistry to PVC and Hypalon. It is much tougher as proved by its use in industrial conveyor belting, hard wearing walking boots and roller wheels. Production is cleaner and more environmentally friendly. No chlorine and sulphur are used. Test after test shows Polyurethane to be over 10 x times tougher than Hypalon, 10 x times tougher than PVC, and over 20 x times tougher than chloroprene. These are proven facts.

3 Polyurethane is more expensive than PVC and Hypalon but, pro rata, provides superior performance and protection. Welding Welding is always recommended for the construction of fenders. It is much stronger than gluing and infinitely more durable. It is stable, will not age harden, and is able to withstand higher forces when in service. A welded joint can be as strong as the material being joined eg. the steel hull of a supertanker or the roll cage of a rally car. In contrast the glued joint can only be as strong as 'itself' or the material it is joining. It is not possible to weld Hypalon fabric - it can only be glued. This glue, a solvent based chloroprene, is slow to cure, prone to age and weak in structural strength. Hypalon/CSM is never actually glued during construction as, conversely, it has to be abraded off to achieve a bond. It is the tenuous chloroprene base layer that is glued. A procedure hidden and not mentioned by the manufacturers. Polyurethane is exceptionally tough which is why the welded seam is so strong. Try stretching and breaking a piece in your hand if you want to experience this strength - you won't. The welded seam of a polyurethane fender is at least 4 x times stronger than the glued seam of a Hypalon fender.

4 Fender Socks/Covers The fender sock originated as a cover for the moulded PVC fender when boat owners discovered their hulls were being damaged by the fenders they had bought. The first socks were polyester garments reshaped to fit the fender. These evolved into purpose built knitted socks, of acrylic and polyester, though the function remained the same. Examining the traditional fender sock reveals a host of limitations 1) They need to be fitted to the fender before deployment. 2) They need to be maintained and washed regularly. 3) They clog with dirt and fine particles. 4) They snag and catch on sharp objects. 5) They give no protection to puncture. 6) They add no structural support 7) They have to be purchased for PVC and Hypalon and are an additional and unnecessary cost. The use of a traditional polyester/acrylic sock underlines the failings of the PVC and Hypalon fender by covering up its deficiencies. We have devised a simple test to replicate fender wear and abuse. A Polyurethane fender, supporting 100 kilos load, is dragged along a gravel track and then onto a concrete road. After 300m the fender is examined. The result a few minor scratches and a slight dulling of its exterior surface. A fender that is serviceable and ready to fight another day. Visualise the same test on a PVC or Hypalon fender. All punctured and shredded beyond repair. About Us Fender-Max is made in Portugal by DivexPro. The company, run by ex professional divers and mariners, understands the rigours of the marine environment and the havoc poor design engenders. Nestled close to the shores of the Atlantic Ocean, the factory is a short distance from the water's edge where some of the Worlds biggest surf waves roll up the golden beach. Steeped in Maritime History, the Portuguese have a reputation for being open, friendly and conscientious in thought and deed. This is reflected in the care and attention paid to detail and the testing done to ensure perfection. With over 35 years experience of working with polyurethane our expertise is second to none. Our dedication to perfection - absolute. Fender-Max The Fender-Max is made from a heavy duty Polyurethane fabric. An 1880 decitex polyamide weave coated both sides with a thick film of tough PU polymer. At a total weight of 1700 grms/m2 or (50 ozs/yds2) nothing exceeds this specification. It is the toughest polymer fabric you can buy. Easy to maintain and simple to wash you will love its many attributes and the confidence it bestows. A fully welded jointing system with reinforced end caps and stainless steel securing rings complete the picture Triple-Max Cover

5 The Triple Max cover is a flexible armoured shield that slides over your fender to increase its wear capabilities. You do not need a Triple-Max Pro cover to moor in safety as the basic Fender-Max is strong enough. However if you want the ultimate in protection and an even longer life then the Triple-Max cover is worth considering. The Triple Max Pro reinforces the fenders structural integrity by doubling the 1880 decitex fabric construction. The cover is reversible so if you damage one side you remove it, turn it inside out, and use the inner face. You have three wear layer - the fenders original and covers two. The Triple-Max cover allows you to operate with a choice of colours switching from black to blue to grey depending on location and mood. The Triple-Max cover is replaceable Choosing and Sizing the Fender The bigger the boat, the bigger the fender, however there are other factors to bear in mind when selecting the size, shape, and number. Always have more than you need. A backup should one fail or you need to reposition fast. Consider the vessel displacement, the tidal flow, the crew numbers and experience, the local weather and the moorings condition. Then prepare for the unexpected... Cylinder fenders can dissipate more energy than the ball fender and can be made structurally stronger. Conversely ball fenders can be inflated more quickly, can be positioned more accurately and are lighter to move about. Ball fenders can rotate on all axis so are less likely to drag across the boat when manoeuvring. Ball fenders are required when springing off a harbour wall and work better under the bow. Cylinder fenders can be more compact if the mooring space is restricted A combination of fenders is better - rather than all of one type. Sizes from 30cm to 175cm in diameter. Lengths from 100cm to 400cm. Specials both larger and smaller can be made. For further information and availability protection@fender-max.com