Date: Mon, 19 Feb 1996 21:54:46 -0500
From: aol.com!Kylevan@imagelan.com
Subject: Re: Ikyak Skin
To: baidarka@imagelan.com
Message-Id: <960219215444_226277293@mail04.mail.aol.com>
In a message dated 96-02-18 04:40:49 EST, you write:
>
>Why did you use butyrate dope as a sealer on the canvas? I have an
>old klepper (canvas) and am considering what to use as a replacement
>cover. Cj
When I built my Baidarka I followed some of the construction techniques as
detailed in the two part article in Sea Kayaker Winter '92 and Spring '93.
This article, by Chris Cunningham, illustrates buiding a Greenland style
Kayak but I adapted it to a Baidarka hull. Butyrate dope has several
advantages as a sealer. If the raw canvas skin is somewhat loose after it is
stitched around the frame, the dope, if you get "taughtening type", will
make it tighter. It shrinks as it dries and tightens the skin. Butyrate
dope is not very fussy to apply. The recommended procedure is to spray it,
but brushing worked fine. Just sand lightly between coats. A filler coat of
dope mixed with aluminum paste fills in the weave of the cloth. and then more
coats of dope are applied over. Repairs and recoats are very easy and
effective because the over coat actually disolves the existing coat and welds
itself on the the existing coats. I felt this was important for repairs but
I have not had to make any. I was easily able to weld a one inch wide nylon
rub strip down the length of the keel by soaking it and applying several
coats on top.
There are disadvantage in using Butyrate Dope. The greatest
being the smell and, without a doubt, potentially toxic effects of it, It
smells like the old plastic model glue. When you have multiple square yards
of the stuff drying, it requires working outside and with a good respirator
and cartridge filters. Do the coating away from sources of spark or flame
because of fire danger. The cost is also a slight disadvantage. While it is
still a small cost in comparison to the over all cost of the project it is
rather pricey as compared to paint which can be used.
It has been a durable, low maintenance coating having seen lots of
paddling over the last three seasons. I ordered it from Alexander Aeroplane
Supply, I don't have the address any more, but look in an ariplane mag. I do
recomment that you read at least the second part of Chris Cunningham's
article. The techniques worked excellently for me.