Subject: [baidarka] The Saran Wrap Kayak
From: Peter A. Chopelas (pac@premier1.net)
Date: Tue Jun 26 2001 - 21:51:51 EDT
Hi everyone,
I just want to share my experience last week-end with doing the Saran Wrap
test on a kayak frame. I thought I would take it one step further however
since I was working with a new design.
I cut seven frames out of 1/2 inch plywood scraps and used sheet rock
screws to attach the stringers to the frames and the bow and stern pieces.
I also lashed a few of the joints for extra strength. I only had to cut
out the center of these frames at the mastic so I can get my legs in and I
cut a "toilet seat" like coaming out of plywood to mock up the cock pit and
give the plastic something to staple to.
I wrapped the frame my hanging it from nails in the tip and tail and having
someone roll the frame while I stretched on the plastic wrap. I wrapped
from stem to stern three times with a significant amount of overlap each
wrap, altogether it had about 6 layers of plastic wrap on it. About two
dollars worth when you buy the bulk pack at the warehouse type stores
(Costco in my case).
I thought I would make it more durable to be able to spend more time in the
water, so I wrapped the bow and stern with 3 inch clear packing tape, also
wrapped the cockpit and foot area, spiral wrapped the whole hull at about
12 inch apart (this was to prevent unraveling if the outer layer ripped),
and extra layers around the plywood coaming.
I used a staple gun around the coaming (though the layers of packing tape)
and cut out the hole. Folded the "skin" under the coaming and placed
another row of staples underneath the lip. I finished the coaming by
stapling around the opening a 4 inch tall sheet foam "skirt" to keep the
water from spilling in if the water splashed over the gunwales since there
was no way to attach a spray skirt. I also stapled in a piece of heavy
sheet plastic for a seat and foot rest so we would be sitting right on the
plastic wrap.
All together including the frame parts cutout, mock-up and assembly was
only about 16 hours from paper to first launch of a new design. I also
have a full sized mock-up now to use as a template to cut out the "real"
parts to check fit etc. A real time saver, and clearly better that then
spending 100 or more hours building a kayak no one wants to use. This
particular one will be for my wife and it was a bit on the small size for a
typical male paddler, so I wanted her to be happy with it (so I did not
have to build another one for her!).
My wife, daughter and I took turns paddling it Sunday afternoon at a near
by lake. It probably spent over two hours in the water, so the extra
wrapping with the packing tape was worth it, I will use even more packing
tape next time I do this. The water sill leaked in eventually through the
layers of wrap, but slow enough we could paddle out on to the lake and take
our time coming back, and emptying it between each trial run.
Not a bad way to test out a new design, the plywood frames were free scrap,
the plastic wrap and tape was only about $3 or $4 worth at most. It was
also fun to actually "see" and try the new hull design so quickly. I
imagine you could take plastic wrap, tape and blocks of wood to try mods
out on the spot. We were all pleased enough with the new design's behavior
I saw no reason to mess with it at the lake. As a result of the test I
will also make a few minor changes to the original design (already mocked
up in fact so I am ready to start cutting good wood into actual parts).
Will have pictures to post soon.
Peter
-
Baidarka Mailing List - All postings copyright the author and not to be
reproduced outside Baidarka or Baidarka archives without author's permission
Submissions: baidarka@lists.intelenet.net
Subscriptions: baidarka-request@lists.intelenet.net
Searchable archive: http://rtpnet.org/robroy/baidarka
This archive was generated by hypermail 2b27 : Sun Jul 01 2001 - 01:30:01 EDT