Ken's Kayak Pages

Hull Construction

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This sequence of photos show the actual construction phase of the Georgian Bay Kayak.

This construction sequence demonstrates the elimination of two mainstays of current kayak construction:

(1) The elimination of staples or brads of any kind in the construction process.  The strips are glued only to themselves.  Virtually no attachment to the forms (which are removed after stripping the kayak) are employed.  I began using hot glue as a temporary attachment to the forms, necessary to get the first couple of sheer strips in place.  At this point the hull wraps around the forms because of its shape, and no attachment to the forms exist, except at the sheer lines, to provide a reference point.   Any strips needing severe twists are steamed with an iron and heated with an industrial hot air gun to conform to the required shape before installing.   These techiques yield a hull without the thousands of visible holes seen in stapled construction, where the strips are stapled to the forms to help shape them and hold them in place.

(2) Cove and Bead strips are not being used.  All strips are bevel cut, and the number of bevels that had to be cut is so small as to be negligible.  I have perhaps 70-75% of the keel strips in place, and one small bevel on two strips had to be cut - - Which was very simple.  The sheer strips contain a few more bevels per side, but it takes 10x more time to taper and steam twist a strip than it does to bevel it.  I believe Cove and Bead is simply not necessary except for the most curvaceous of designs.


build01.jpg (28978 bytes) To get an idea what colors the freshly ripped wood strips would actually finish to, I built a test panel from scraps.  I then finished the panel with 4 coats of gloss polyeurathane.  Wow! Some pretty nice contrasts here.  From top down, it is cedar, black walnut, and spruce, repeated twice.  I have 216 feet of spruce, and 107 feet of walnut, and lots of cedar - - Plenty enough to get creative.
build02.jpg (73911 bytes) Here, finally, are the first 2 REAL strips attached to the stations. I am using hot glue for temporary attachment to the stations (forms) that I have now covered with duct tape.  This is done to make the stations easy to remove after the boat is completely stripped.  A few whacks with a mallet should pop the stations free of the hull.
build03.jpg (71961 bytes) The hull will be stripped primarily with red cedar. I am including one pinstripe, a half-width strip of spruce.  The 2 strips attached are the sheer strip, which is red cedar, and the pinstripe just below the sheer, in spruce.  To see the contrast difference, look at strips 3 & 4 (counting from the top) in the first picture on this page.  The deck is where I will attempt to get creative after I learn a bit more . . .
build04.jpg (60821 bytes) A close-up of the station/strip clamping means I decided to use.  I cut some small clamping jigs from 1/2" plywood, and spray painted them with gloss enamel so they wouldn't become permanently attached to the kayak.   these are held with spring clamps and keep the strips tight against the stations and adjacent strip while the glue sets.
build05.jpg (71918 bytes) A little further along in the construction, with a few more strips added.  The operations include cutting a rolling bevel on the edge of the new strip that will allow it to conform to the station profiles.  I think I like a small "pull" surform tool the best, and I also tried a block pland, file, sandpaper on a stick, etc. 
build06.jpg (65236 bytes) Even though we're laying the strips along curved surfaces, there are no gaps between the strips (well, most of the strips), because of the bevel I cut.
build07.jpg (76483 bytes) My favorite clamp has turned out to be duct tape, it is wonderful because of the strength, adhesion, and easy workability.   Thanks for the hint, Dale Frolander.  I use my clamp fixtures only at stations where the strips tend to warp away from the station (form).
build08.jpg (73277 bytes) Working with 17-20 foot strips is a big pain.   I decided early on (after scarfing the sheer strips before their installation) to use my 10-12' strips individually and butt join them.  Less length means that I have lots of time to get the 1/2 strip positioned before the glue starts to set up.  It is much less hectic and frenetic, and the seam can be more easily controlled.  This pic shows the first 1/2 of the strip going in, ready to butt against the next 1/2.   Strength is not a concern, as glass and epoxy will sandwich this layer to produce a classic composite layup.
build09.jpg (79975 bytes) More strips and duct tape - - I buy it in 180 yard bundles as I move along . . .
build10.jpg (57403 bytes) More strips added, it's starting to curve and take on a pleasant shape . . .  The glue must be scraped from the sides before it can be planed or sanded.
build11.jpg (79203 bytes) And yet more of that duct tape,  it is invaluable as a clampimg aid for these cedar strips.
build12.jpg (46545 bytes) A closeup of a typical bevel near the chine.   I use two half strips instead of a full strip for stripping in the hull, and this is the aft view ot the half-strip starting at the bow.  I eyeball the required bevel at each station, and mark the strip as to whether it's a small, medium, or large bevel at that station.  It's sort of like "connect the dots."  I simply "roll" the bevel between the stations.  The end grain of the strip is not red, that is a fluke of the flash/CCD.
build13.jpg (68125 bytes) Here is as far up the side from the sheer as I will go.  It measures 6" total layup.  From this point forward, the keel strips will be laid in place (could be nasties), and stripping will continue from the keel to these existing strips, while remaining parallel to the keel.
build14.jpg (52977 bytes) A view down the keel with the first keel strip laid in place.  It had to be removed and eventualy given to my grandson as "hobby strip" because I needed to start on the other side first, and I cut a bevel on the wrong side of this strip as a consequence . . .  You don't have to be smart to build one of these kayaks, only consistent . . .  It helps not to be stupid at times.  This does show the accuracy of the forms placement, as the strip shown was aligned on the forms to the centerline, and it looks like a straight line to me . . .
build15.jpg (68008 bytes) The two keel strips are now in place, and bow-to-stern filler strips are now being added.  This photo shows the method of "stapleless" attachment I have employed, as well as the severe twist in the new strip that must follow the fair lines of the keel strip.  I use steam to assist in bending while clamps hold the required twist and bend.  Then I use an industrial heat gun to dry the strips and "lock them in place."  When they are dry I apply the wood glue to the adjoining strips.
build16.jpg (65713 bytes) Another view of the clamped, steamed, and air dried assembly. The twists and bends must become fair lines of the kayak.  Any bumps, lumps, or unfair sections will be quite obvious in the finished product . . .  This view is from the bow to the aft section.
build17.jpg (56239 bytes) Here the keel strips have doubled in   number, and you can readily see the twist that is taking place as I approach either stem.  The steam iron with a damp cloth, and the heat gun have become my best friends (next to duct tape).  I lay the strip in, steam it and then dry it, and it assumes the shape it was originally clamped in.  That makes glueing a whole lot easier with a pre-shaped strip.
build18.jpg (55572 bytes) A view from the other side.  You can tell when you are forcing wood to do what it did not originally intend to do by counting the number of clamps it takes to force the wood into position . . .
build19.jpg (72682 bytes) The same sort of conditions exist at the bow, but the twists are more gradual.  That is good and bad, in that it is easier to twist the strips, but very difficult (for me) to tell where the bow begins and ends!  You have to build one to understand this.
build20.jpg (51383 bytes) A view of the stern with a few more strips added, just trying to emphasize the radical 90 degree twist the strips must make when transistioning from the hull to the stem.
build21.jpg (55145 bytes) The stern as viewed from the side.  The Georgian Bay has a long waterline length, and part of this is because the stern does not have much rocker, and has a fairly steep vertical angle at the stem.  That also makes it easier to strip in this area.  Not a "cake-walk," but I have not lost any hair over it either . . .
build22.jpg (60839 bytes) A view toward the bow, the nice lines suggested by these strips make me want to get it done as perfectly as possible.  Let's see, 1800 lineal feet of wood joints, 99% accuracy assumed, HEY!  That's only 18 feet of bum joints!   At this time I have one 12 - 18 inch section on one strip I wish I could do over (impossible), but a hint of filler might save the day.  That joint will NEVER appear in a photograph until it is properly filled . . .
build23.jpg (56352 bytes) Here is the profile of the bow stem.  It is longer than anticipated, because of an 1/8"  warp that developed in the plywood stem itself.  I have been compensating by building a small gap onto the opposite (starboard) side, keeping the stem aligned with the rest of the kayak.  An 1/8" in width corresponds to many inches in length at these sever angles, so I now have a longer than normal Georgian Bay.  It looks cool!
build24.jpg (68512 bytes) View from the bow with keel strips newly joined to sheer strips at the stern.
build25.jpg (70588 bytes) Same as above, but photographed from the stern.
build26.jpg (66705 bytes) The stern strips now meet on both sides of the boat.  The next strip on either side will likewise attach the keel and sheer strips at the bow.  The hard fit-ups are over for the time being.
build27.jpg (63598 bytes) The most used tools for the past week.
build28.jpg (27221 bytes) The only unused tool in the shop . . .
build29.jpg (50544 bytes) Another strip added - - The bow is now joined, as is the stern.  I guess there is no turning back at this point . . .  This is what it is going to look like!  8-)
build30.jpg (60975 bytes) The aft end is sealing up quickly, not too much longer before the hull construction is simply a memory . . . Darn!
build31.jpg (48231 bytes) The long tapers are slowing me down dramatically.  I had a couple each at the bow and stern.  It turns out that the keel strips near the bow (or stern), coming down to meet the sheer strips, have a slight curve to them because of the bends they make.  That requires that the taper on the new strip is a concave surface - - It took me a little planing and measuring to to figure this out.  Here's a pic of the new strip being fitted to the transition area.
build32.jpg (57624 bytes) This is how it looks when done properly (I won't say how long this took).   You'll notice a NEW tapered seam was created at the left of the photo, so the process will repeat ad finitum for each new strip - - Although the angle of the taper gets more manageable with each strip . . .
build33.jpg (41739 bytes) A close-up of the joint, before planing and sanding, or filling.  The upside is that it should look pretty good when I am done. This craft is starting to remind me of a tubular bowling alley . . .
build34.jpg (28144 bytes) Here's the reason for the many tapers that have to be done.  There are many ways to strip the hull of a boat, but this particular technique has some points going in its favor.  About 6" of the hull starting at the sheer line (Where the hull and deck meet) are wrapped around the forms, producing graceful lines that accentuate the shape of the kayak. Above that (if the boat were right-side-up it would be 'below that'), the rest of the hull starting at the keel is stripped parallel to the keel line. Everywhere the straight keel line strips meet the curvy sheer strips, a tapered fit occurs.  One alternative is to continue the sheer lines clear up the hull, producing the familiar "football" shaped area as seen on many canoe hulls.  That affords an opportunity for lots of cutting and shaping as well . . . In the end, it all amounts to simply filling the area with strips, be it the hull or deck, as the glass cloth and epoxy, together with the wood in a sandwich, provide all the structural strength.
build35.jpg (74634 bytes) Here I got very brave and trimmed the bow of all the overlapping strips that were taper joined at the stem.  A new saw, patterned after a Japanese pull-saw was used and it worked great!  I then used my new 12-1/2 degree Record block plane to smooth the surface.
build36.jpg (57634 bytes) This stem will be planed such that the width increases to about 3/8", and a laminated white ash external stem will be added and planed to follow the hull contours.   This will ad to the abrasion resistance afforded by the fiberglass layup soon to be added during the "epoxy the hull" stage . . .
build37.jpg (51813 bytes) I developed the attitude years ago that "I ain't no dummy." Instead of beveling each and every keel strip, I simply butt-joined each one, and when the flat flexible surface developed, I laid wet rags across them and steamed them with my plywood clamps in place. A finish with the hot-air gun locked them in position.
build39.jpg (51112 bytes) Here's a pic of the almost completed hull after the steaming operation . . . Amazing how the hull strips grip the forms even though there is no beveling between the strips . . . <g>
build41.jpg (51901 bytes) Here is the compulsory picture of the last strip on one side (in this case the port side) waiting to be installed.  The sliver of wood laying on the tape to be used for securing said strip, is awaiting installation.  The Queen is dead - Long live the Queen.
build42.jpg (52857 bytes) At last, the port side is stripped. This shows the clamping employed to hold the little fellow in place.  He has been tapered, beveled, steamed and twisted into a loyal subject.
build43.jpg (49730 bytes) This is simply a close-up of the port side of the hull after final closure and a rough planing to shape. Several sanding stages still need to be done, following some scraping to remove all vestiges of glue.
build44.jpg (71434 bytes) The bow and stern stems have been planed to a consistent width of 1/2", awaiting the application of an external stem, consisting of laminations of 1/8" white ash for abrasion resistance under the glass. These were cut today, but no pictures exist.  We will pick up when the hardwood strips are being formed to the stems.
build45.jpg (67720 bytes) Two laminations of 1/8" white ash are being glued to the bow stem, they were pre-bent using steam and a hot air gun.  Pre-bending these parts took all the stress from the tape clamping employed, and the glue joint is a vanishingly thin line.  This detail provides for a very pleasing appearance, as well as some additional abrasion resistance in this vulnerable keel area.
build46.jpg (50628 bytes) Here is a photo after the glue has dried, there is some planing necessary to make the new external stem conform to the hull contours.
build47.jpg (54484 bytes) The aft stem laminations are temporarily in place after a quick steaming and air gun application. 
build48.jpg (25630 bytes) This composite photo (poorly done, but, hey, it's free!) shows non-kayak people the scope of this project in a panoramic sort of way.   The bow and stern shots look nice, but it's hard to visualize just what we are creating without stepping back a bit . . .
build49.jpg (68103 bytes) Using an ROS (Random Orbital Sander) the finishing of the hull has become very, very easy. I used to use the pneumatic DA sanders on my car projects, same thing now in electric - Maybe better . . . Wow, does my new $39 Ryobi ROS sand that there wood!  Here's the bow after a rough (60 grit) sanding.
build50.jpg (41185 bytes) Same application to the stern.  Concave, convex, the ROS really doesn't care . . .  There is a workable position for every need . . .
build51.jpg (42772 bytes) Here's the middle, where I sit.  Geez, the ROS just gobbles up wood that doesn't belong . . .
build52.jpg (31764 bytes) A detail of the white ash laminations on the bow stem.  They look so darned good, it's really a shame they are sacrificial as the "abrasion strips" both fore and aft.  They will be covered with 3 layers of glass, so perhaps they will survive my ownership . . .

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