What makes a great sail? - Part 3 - Materials

The most recent article in our ‘Simplifying the Sail Buying Process’ series covered the way in which sails have been constructed historically. The focus was on panelled sails, cross-cut and tri-radial, which can be built using either woven polyester style cloth and also laminate materials. 

In this instalment we are going to take a closer look at the type of Laminate and Membrane materials which are available with a view to trying to de-bunk some of the jargon used by Sail-makers.

Woven Materials vs Laminate Materials

The basic process of weaving sailcloth has not changed very much through the centuries. ‘Warp’ yarns are rocked up and down around ‘Fill Ribbons’. Many years have passed since the time of cotton sails and the material now used for woven sails is generally a type of Polyester (or Dacron) but the manner in which the fabric is constructed is basically the same.

Laminate and membrane sails are made by bonding together layers of different materials to form a sandwich. A simple laminate will consist of an open scrim (lay-up) of fibres (which can be different weights and strengths) with a layer of film bonded to each side. The film stops the air blowing through the sail whilst the load on the sail is carried by the scrim.

Laminate sails are generally deemed to be more efficient than woven sails because the fibres have no ‘crimp’. That is to say the fibres in a laminate sail do not have to stretch around each other as they do in a woven sail because the fibres of the scrim are laid and bonded into a flat lattice. Fibre can also be laid along the bias (diagonal) of the scrim in a laminate sail to bear loads working on the sail in this direction.

So to put things simply: No weaving = No crimp = Less stretch.

Laminate vs Membrane

A Laminate sail is made from a pre-produced roll of cloth which is purchased off the shelf. This will then be cut into sections which will be glued, bonded or sewn together to make the sail and build shape according to your sailmaker’s design.

In a Membrane sail all of the raw materials, film, scrim fibres, taffeta etc. are put together at the same time and the fibres will be laid out precisely as specified by your sailmaker in his design. Here the traditional 'cloth supplier middleman' is replaced by a manufacturer who makes a sail from raw materials and which is truly bespoke in every aspect. Good sail design will produce superb sails using either a Laminate or Membrane build, but as you would expect, there is a price and performance differential between the two .

When designing and building a Membrane sail for your boat your sailmaker will use different fibre densities according to the varying load areas on the sail and will align the paths of the fibres to precisely correlate with the path of the loads across the sail. This adds strength and durability.

The finish of your sail will vary according to your personal requirements and the design which your sailmaker produces for you. Some membrane sails might be finished with taffeta on one or both sides of the sail to increase their lifespan. You might be able choose the type of the fibres used and even the finish of the film or taffeta! Almost every facet of the design and build is open to interpretation by you and your sail designer.

If you look at the many sailmaker websites you will see that each champions a different build process for their Membrane sails. However, it is important to remember that the single most significant factor affecting the way your sail performs, its shape, longevity and durability as well as the price you will pay for the sail is the quality of the design from your sailmaker and not the build or production process itself.

Over the last twenty years there has been an inordinate amount of technical development in the design and build process of membrane sails. Ultimate Sails’ Technical Director Kevin Sproul has worked ‘at the coalface’ of membrane production throughout this whole period. He has consulted on production techniques, membrane sail design software and on the set-up of sail manufacturing plants across the industry and has advised on the purchase of the capital equipment used to build Membrane sails.

Few operators in the business have better membrane design and build credentials than Ultimate Sails.

Trust Your Sailmaker and Know What You Are Buying

As with so many other manufacturing industries the number of sails which are sold in the UK which have also been physically built in the UK are few and far between. There are still small lofts servicing certain sectors of the UK market but by far the majority of sails which are sold in the UK are built elsewhere, perhaps China, Malaysia, Sri Lanka or the USA.

Some operators in the industry still own their own manufacturing plants but most outsource the manufacture of their membranes to specialist operations. The standards of production, quality control and delivery lead-times do vary across the industry irrespective of whether it is an ‘in house; facility or an outsource plant. It is important that you should seek reassurances from your sailmaker as to the controls he has in place to ensure that the design he has produced for the sails for your boat will be interpreted faithfully by the manufacturer.

No matter how good the concept of a Membrane material, the machinery and control processes of the manufacturer determine the quality of the sails. In-house finishing and operational systems all make a difference to the end product. At Ultimate Sails we have used our vast experience to carefully choose our Membrane partners and help them develop new products of the very best quality.

Most importantly, Ultimate Sails is not constrained by a commitment to a particular 'style' of Membrane; a frequent downside for businesses which own their own manufacturing facilities because they do not have the flexibility to change their recommendations based on developments in the market or (most importantly) to what a particular client might need. This approach tends to push the sail buying client towards more 'generic' styles and offers less freedom to customise the product to their needs and often results in 'developments' based solely on cost savings.

At Ultimate Sails we will take the time to listen to your requirements to ensure that the sail you buy for your boat is exactly right for your boat and for your budget. We will happily answer any questions you may have and we will take the utmost care to answer any questions that you may have in relation to our business and your purchase.