CLASSIC BOAT AUGUST 2016COTTON SAILS FOR PATNA
46cloth was required and research led to Nat Wilson,
sailmaker in the USA. He for many years had sourced
good cotton sail cloth from Scotland, woven on
ancient shuttle looms set up for the purpose.
Unfortunately, upon seeking to order suitable cloth
for Patna, he found that the looms had been laid up,
they being no longer economical to run and thus
effectively ending centuries-old related skills. Further
research then revealed other canvas suppliers in
Scotland, including J&D Wilkie Ltd, established in- Discussions with the director, Bob Low,
realised the idea that we could have a special cloth
manufactured, by J&D Wilkie, in India, where shuttle
looms are still in use. Sailcloth was woven on shuttle
looms because the shuttle moving from side to side
allowed a continuous weft, creating a true selvedge
with no cut yarns, unlike most canvas produced on
modern looms, which can operate 40 times faster.
What was needed was a cotton based sailcloth that
was as stable as Egyptian, but also rot-resistant and
waterproofed, so that the material would be as practical
as a modern synthetic in use. Bob suggested this would
be feasible by using a core spun poly cotton yarn,
comprising a sheath of cotton fibres surrounding a core
of polyester fibres, resulting in a very stable cloth that
could be waterproofed and treated to prevent rot and
mildew. The polyester core would be hidden, completely
protected from harmful sunlight. Externally the cloth
would be 100 per cent cotton, feeling, looking and
behaving very much like Egyptian cotton – but more
stable: the very thing for an authentic aesthetic in historic
vessels and classic yachts.
Incidentally, widely available ‘plain weave’ poly
cotton is not as suitable for sails as core spun, the
polyester and cotton fibres being mixed together,
resulting in a cloth of semi-synthetic appearance that can
deteriorate in prolonged sunlight and is not as stable.
To make a good sail cloth, the warp and weft are
woven very tightly, with the interlocking yarns
arranged to minimise stretch (the warp being the yarn
that runs down the length of the cloth, and the weft
being woven across its width).
The structure is best when the tension of the
selvedge is equal to the body of the cloth, thus
allowing accurate seaming with no puckering. Early
yachts gained extra stability in their sails by having
narrow cloths, often created by sowing a false seam
down the middle run of the bolt of canvas.
Vertical cut sails, where the seams run parallel to the
leach, have a cloth structured with the warp as the
dominant yarn. Cross cut sails, where the seams run fore
and aft, may have the weft as the dominant yarn, or theFLYPICTURES.COMCB ARCHIVESMARTINEZ STUDIO/PUIGVELACLASSICA.COMAbove: Patna
flies her new
cotton sails.
Above right top
to bottom: Greg
Powlesland; new
cotton jib.
Below: Nat
Wilson, renowned
US sailmaker