Message-Id: <31234197.2E30@mindport.net>
Date: Thu, 15 Feb 1996 09:22:15 -0500
From: Nick Schade <mindport.net!Schade@imagelan.com>
To: baidarka@imagelan.com
Subject: Re: Ikyak Skin
aol.com!Kylevan@imagelan.com wrote:
>
> I have heard of people using Dacron for covering boat frames. In fact, the
> ultralight boats, as I have seen in The Wooden Boat Store catalog are built
> with dacron and sealed with a polyurethane paint. I would think it would
> stay pretty flexible, but this is pure speculation. A second idea would be
> to orient the skin material, whether using nylon, canvas or dacron, on the
> bias which would put the threads that make up the weave of the cloth at a 45
> degree angle to the keel. It seems like this would make for a very flexible
> skin over the length of the kayak. This orientation of cloth would most
> likely make seams across the hull necessary, but didn't all kayaks
> historically have seams below the waterline. Maybe dacron comes in wide
> enough widths to keep the number of seams to a minimum. The use of dacron is
> borrowed from the classic aircraft wing covering technique and would be
> available from Alexander Aeroplane Supply.
The problem as I see it is not flexibility of the fabric stiffening the
boat. It is the ability of the fabric to stretch. Think of the ultalight
boats wrapped with kevlar. Untreated kevlar (as used in these boats) is
completely flexible and is wrapped diagonally (as if it was on the
bias). These boats are very rigid before application of the fabric. This
is because the kevlar does not stretch much. When flexing the kevlar or
fabric on the outside of the bend must get longer. While dacron or nylon
may stretch enough when left untreated almost any coating is going to
restrict it's ability to stretch. I don't think polyurethane paint will
deal nicely with stretching. Another problem is if you coat the fabric
while on the frame some of the coating will wick through and glue the
fabric to the frame. This will further restrict the fabrics ability to
move and stretch
--
Nick Schade Guillemot Kayaks 104 South Second Avenue Taftville, CT 06380 (203) 887-5847
Distinctive Kayak Designs for Strip Building Unique performance kayak plans for home builders
http://www.mindport.net/~schade/Kayak.html
>>>>"Just Build It"<<<<