Bruce Finlay Sails - Home Page
Frequently Asked Questions
Contact Us
Links
Quadrant Marine
 

 
 
Visit our Sail Loft
Sail Materials
Boat Covers
Shades and Awnings
Shade Structures Birdair
 
 
 
Below are some frequently asked questions about the fabrics chosen by Bruce Finlay Sails, and responses which may assist you in your selection process.

Q.

What difference does the sailcloth make to me?

A.
Bruce Finlay Sails will design the best shape into your sail but how well that shape is retained in different wind strengths is down to the cloth.  Obviously good shape retention is important for racing but increasingly cruising sailors are realising the benefits: less heeling, better pointing and easier boat handling.  Quality cloth also lasts longer making a little extra for better laminated or woven fabric a sound investment.
Q.
Laminated or woven?  What's the difference?
A.
Since sailing began woven sailcloth has been made on a loom with warp yarns being rocked up and down around fill yarns although the technology we use today is very leading edge.  Most wovens are made of polyester (also called Dacron) that was introduced by Bainbridge as a replacement for cotton in the 50's.  Wovens are very durable making them ideal for cruising sails.
  Laminates are made by bonding together layers of different materials to form a sandwich.  A simple laminate will consist of an open scrim of fibres with a layer of film bonded to each side.  The film stops air blowing through the laminate while the load is taken by the scrim.  Laminates are far more efficient than wovens as the fibres have no crimp.

Q.

What is Crimp?
A.
Crimp in a yarn after weaving.
When we weave a cloth the yarns have to snake over-and under each other.  This is called crimp.  When the cloth is loaded these yarns straighten resulting in 'initial stretch'.
The scrim in our laminates is 'formed' and not woven.  This process bonds flat ribbons of fibre into a lattice.  No weaving, no crimp, less stretch on the threadline.
Q.
Should my sail be crosscut or radial?
A.
This depends on the cloth.  In the weaving process warp fibres running along the cloth are bent round the fill fibres that run across the cloth.  Fill fibres therefore have less crimp so a woven cloth stretches less across the roll than along the roll.  We take advantage of this by using larger (sometimes 400% larger) fill yarns than warp yarns.
  So woven cloth should be used in crosscut sails where most of the load is across the cloth. Some Sailmakers will offer radial woven sails using cloth with large warp yarns.  This works well for smaller sails but read on to find out about the ultimate radial cruising cloth.
In a laminate the scrim is fed into the laminator under tension so further reducing initial stretch on the warp.  Again we take advantage of this by using more fibre in the warp than the fill.  So laminates should always be used for radial cut sails where the load travels along the length of the cloth.
Q.
Sounds good, but not all the load can exactly follow the yarns!
A.
Bruce Finlay Sails will know how the loads in your sail radiates out from the corners but with so many variables a fair percentage of the stress is 'off threadline'.  To reduce the effects of this we try to minimise bias (diagonal) stretch.  In a woven we do this by locking the warp and fill yams together so bias loads cannot move the weave.  This is achieved by making the weave as tight as possible by compacting and heat shrinking.  Hold your handkerchief up to the window and compare the weave to a 1 100 X magnified piece of our cloth.  To further stabilise the bias we then impregnate our cloth with a resin finish that chemically bonds the warp and fill together.  For dinghies and small keelboats we also coat our fabrics with resin to make a super hard but very stable cloth.  We call this NYT.
Our latest DIAX laminates use a 45-degree diagonal scrim to resist bias loads and, just like a road bridge, form a truss that locks together the warp and fill yarns.  In most other laminates bias load is born by the film which easily becomes over stressed and then deforms.  Using a diagonal fibre helps our laminates to last longer and lock in sail shape.
Q.
So, its cross cut woven for cruising and radial laminates for racing, right?
A.
Wrong!   One of the fastest growing markets for us is cruising laminates.
These are based on our race products so are just as strong, but have a light woven fabric bonded to both sides to give them the durability of a woven.  We have made over 250,000 meters of this cloth and firmly believe it is the best cruising cloth available today.  Unfortunately many people still only associate laminates with high-end race sails with limited durability.  For more information see the Cruising Laminates page.
Q.
What about my spinnaker?
A.
Most spinnakers are made from woven nylon because it has good tear strength.   A few years ago polyester spinnaker fabrics were fashionable but these are only suitable for specialist applications, so we would not recommend them.  Nylons come in different generic families ranging from 2.2oz down to 0.4oz but be careful, these numbers do not directly relate to the cloth weight.  See the Spinnaker Fabrics page for a full explanation.
  Nylons can also be coated or impregnated and warp or fill orientated, but the important thing is the relationship between stretch, tear strength and weight.  Heavier nylons do not always have lower stretch and better tear strength as a high quality light fabric can easily outperform heavy low quality products.  Our new ARX products have just proved this with lighter fabrics having similar properties to other's heavier styles.
 
     
 
Visit our Sail Loft
Sail Materials
Boat Covers
Shades and Awnings
Shade Structures Birdair
 

PO. Box 43,  Airlie Beach,  Queensland 4802,  Australia  Tel: 0419 707 458 ~ Email