Keel Strips

Well it's been pretty slow on the boat lately but just before heading out of town for Christmas I got the two strips on that run down the center of the bottom of the kayak forming the keel. These strips are regular bead and cove strips and they both face cove out. Thus, the bead had to be cut off of both strips (since I had my router set up as jointer I used that to take 1/8" off the bead) then the strips beveled such that they mated together flushly despite the changing angle of the keel. The bevel was cut with a small block plane. The angle is quite flat in the middle of the boat but gets increasingly sharp towards the bow and stern. The strips meet at a near 45 degree angle near the ends. The strips along the sides of the kayak eventually came to a point where they were meeting each other more on the side than on the ends. In other words, the strips being added to the side were more on the bottom than on the side. The strips added to the side are cove-side up and thus the strips along the keel line had to be rounded on a taper at the tips in order to fit into the cove.

With the keel strips in place, I have now started to add strips to fill in the two crescent shaped gaps on either side of the keel. Since I now have a cove facing towards the keel on the outermost strips, and a cove facing away from the keel on those strips adjacent to the keel, the strips being added not only need to be tapered but they also need to be rounded in order to fit into where the coves come together. The meeting of the two coves creates gap between the strips beyond what is seen. Thus the tapered strips must extend into this gap. Add to this the fact that I have to get it just right at both ends and it must be exactly the right length and it seems a bit daunting. Regarding the length, because the taper is on such an angle, removing a small amount from the taper can make a big difference in the length. Thus, I err on the side of having my strip too long and once both ends fit well, I plane or sand small amounts off until the strips snaps into place. The first couple of tapers were a bit tricky to get right but I think I'm getting the hang of it. In fact I went back this evening and re-did the first strip I did, tossing the old one (actually the taper fit perfectly as the next strip so I just had to cut it a bit shorter and put a new taper onto the other end). In the photo at right which shows the tapered strip fit into place you can notice a gap at the left of the photo at the tip of the tapered strip. This was my first attempt at fitting the taper and was the one I went back to fix.

The first two tapered strips filling the bottom go along the sides, one on each side of the keel. The next two strips have been fit to run adjacent to the keel strips. The subsequent strips will alternate fitting along the side or the keel. I now have 4 strips cut and tapered to fit, ready to be glued in. I'll wait with that for another day since I have to warm up the shop and keep it warm for a period so I want to be able to do as much as possible during that time.

The Journey of Wood

One thing I have yet to discuss in any detail is where the cedar wood came from. For quite some time now I have been thinking about building a boat and about a year ago my wife & I had settled on building a kayak. After viewing a number of kayaks built by local folks (thanks Gary, Morris, & Carl) we had decided to build one of the Waters Dancing kayaks, probably the Solace 17 or 16 EX. All we had to do was order the kit and I was just about ready to do so when I happened across a posting on the MEC OutdoorGearswap, a bulletin board for used outdoor gear. An ad was posted stating that the seller had "everything needed to build your own kayak" for an asking price of $450. The kayak in question was the 17' Guillemot, and although it really was not everything to build the kayak (no fiberglass or epoxy which are a substantial cost, nor varnish, closed cell foam, bungees, deck lines, nor any of the other items needed to finish the boat), it was enough to make it worth pursuing. For sale was enough pre-milled strips to build the kayak, and the forms, along with a copy of Nick Schade's book. It seems the seller (Piers) had them sitting in his apartment for some time and he had bought them off of a friend who had had them sitting around in his garage for some time. Where the original guy got the materials from was only identified as "a company" (or something to that effect). The problem was that the materials were in Vancouver while I am in Saskatoon (~1700 km, 1050 miles); however where there's a will, there's a way. A boatbuilder from the Vancouver area, Rod Tait of Orca Boats, hearing of my situation very generously volunteered to go have a look at the materials on my behalf. Here is what he had to say after viewing the strips:

Bryan,
I took a look at the strips and the forms. The forms are computer cut with center already cut out for internal strongback, all lines already on them and it appears that they have not been used. The strip are a nice chocolate brown and uniform in colour. The bead and cove is clean except for a few areas where there was some tear out during milling (perfectly normal). there seems to be enough to build a boat, but long lengths are limited. I am not sure if there is enough full lengths to build the hull and deck, so strips may need to be scarfed or butt joined, but not many if at all. The grain is tight with some knots which you can certainly work around. The wood will certainly look [good] ... with a few accents of a lighter wood such as yellow cedar or eastern white cedar.... I did take my camera, but the wood was in their house, so I politely declined to ask to take a pic. If you are interested, I think it is well worth the price. I think other builders will be envious of the nice wood.
Rod Tait.

After Rod's comments, how could I not buy it? I pursued it further and ended up purchasing the materials and Rod again came to my rescue by picking up the strips, forms and book, and bringing them back to his shop in Port Moody, a service for which he charged me his "consulting fee". From there, the only obstacle was figuring out how to get the pile of materials 1700 km to the East. That's where it's sometimes good to know a truck driver. My cousin Cory Richmond graciously agreed to pick up the strips the next time he was out that way with his truck and had both the room and the time to accommodate my extra load. It took a few weeks but in June when Cory was on his way home after dropping off/picking up a load on Vancouver Island, he stopped in at Orca Boats to load up my future boat. From there, the materials made their to Saskatchewan and into Cory's garage in Warman, about 1/2 hour drive from my house. (I still owe Cory.) I was then able to transport the strips (a bundle of 3/4" x 1/4" strips, some as long as 19') home by tying them to an extended ladder secured to the roof racks of our Honda Accord. From there they found their way onto the shelves of my garage where they could recover from their ordeal for the next few months until I began my project.

As Rod stated, the strips are mostly a dark brown in colour, with a few being a bit lighter. They were not quite long enough for full-length strips in the longest regions of the boat so about 12 strips had to be scarfed (just the 2 at the sheer) or butt jointed. I haven't touched the 19' long strips that Rod added to the pile; they will be incorporated in some fashion into the deck. The bead and cove on most of the strips is OK, but a few strips seem to be cut unevenly & or had the milling of the cove less than perfect (which may be normal). In all of the strips added thus far to the boat, I have seen only one knot (which I have left in place because I like the looks of it, but I hope it won't give me grief when it comes time to scrape/plane/sand the hull).

Well, there you go - now everybody knows where the wood came from, or at least now you know pretty much what I do about the subject.

Up and Over

Well I'm now into the process of rounding the fairly sharp corner at the chine where the strips transition from the kayak side to the bottom. Here is the boat as it looked after adding another two strips to this side this evening. Some of the other photos below are taken prior to this addition. The ~15' long bungee cord is my attempt to minimise gaps between strips in the region between forms. The glue residue that shows up bright white in the photo is not quite as bad as it appears here.

The prominent gap seen in the photo above to allow for the insertion of a cheater strip as described in an earlier post was filled this evening. It was actually fairly easy to get a strip planed down to fit. Now I just have 5 more cheater strips to get into place.

The photo below shows the kayak side after 6 strips per side, bringing the strips in this region right to the point where I have to make the sharp curve to the kayak bottom.
I may have a problem developing at the stern. Where the strips meet it is apparent that the strips on one side of the kayak are ~3/16" higher than on the other, illustrated in the next 2 photos (same spot, different angle). I'm not sure if this is really a problem or not; I fear that it may cause problems down the road when I'm trying to fill in the bottom and have things look even.

Rounding the chine while maintaining a tight joint without gaps is giving me some troubles. Since the bead and cove on these 1/4" thick strips were cut with a 1/4" router bit, the strips really only fit together perfectly if there is little angle in the joint. (For more on bead & cove of strips, go here.) The more angle there is, the more that the inside portion of the cove gets in the way. Some strip manufacturers and commercial builders use a slightly larger radius (5/16") bead & cove which allows the strips to better fit together around a tight curve. Recently 5/16" radius bead & cove bits became available to the home builder and after my experience the last couple of nights, I think that this would be pretty helpful in areas where the curve is tight.

Since my strips are now more horizontal than vertical, my bungee cord is no longer really pulling the strip down tight against the previous strip. This is in a way confounding the problem described above. Thus, some small gaps have formed as seen in the photo below (taken with a light shining behind the strips to better show the gap). Part of the problem might be that the cove on some of these strips was really shallow. I used a round rasp to put a better cove in, but it may not be enough. This won't affect the function of the kayak but it will probably soak up a bit more resin and anyone who chooses to stick their head inside the boat and wear it like a hat will see some sunlight. I'll probably fill the gaps with a mixture of sawdust & epoxy to make them a little less evident, but it'll still add a couple of grams to the boat (an issue if there are lots of gaps).

A Few Good Strips

Things have progressed rather slowly lately. We were out of town 2 weekends in a row, and our kids have been sick for the last week. Last night was the first time working on the boat in about 1 1/2 weeks and I now have 9 strips on the kayak.

Below is a close-up of the bow and another photo of the kayak taken from the bow end. In these photos you can see gaps in the strips at the tip of the bow, each one strip wide. These gaps will be filled by "cheater strips" and allow curve of the subsequent strips to be reduced. I am using two cheater strips at the bow and one at the stern (which has less curve than the bow).

Things look pretty rough in these photos with the smeared glue looking white on the cedar wood. I expect that this residue will easily scrape/sand/plane off when I am smoothing things out later. The glue I am using is the Lee Valley 2002 GF glue, reported to blend well with the darker shades of cedar. I have been using a dry rag to wipe away the squeeze out. Now as I write this I am wondering if I shouldn't maybe be using a damp rag to clean away more of the residue. If you know if this is important or not, please let me know.

To this point I have been using strips that are less than the full length of the boat, joining two shorter strips with a butt joint somewhere towards the middle of the boat. (For more on butt joints and the strip length go here.) Now that I've come far enough up the side of the boat, the strips no longer need be quite so long and I should be able to use full length strips for the rest of the boat with the possible exception of a few deck strips (which will depend on the pattern I choose to strip the deck with). Actually, this was the major reason I eventually changed my mind & decided to use the cheater strips. (I was initially put off by the daunting task of trying to cut & insert the thin wedge-shaped pieces but this was overridden by my desire to decrease the amount of bend and to reach the point where I can start using full-length strips and not do the butt joints.) Without the cheater strips, I would need quite a few more strips longer than those I have.

Those that look closely may notice that there are a few more staples than would be expected after reading what I've written in earlier posts. Two weeks ago I had a visit from Martin Bernardin, canoe builder extraordinaire and proprietor of Kisseynew Canoe Company. He watched me screw around with all of the clamps and clamping jigs while I carefully put in place 1 or two strips. He was not impressed and commented that using staples he'd have "half the boat done by now". This certainly eroded my resolve to try to go without making too many staple holes in the boat. The next strips were done using a few staples and by the time I added the most recent strips I had abandoned the clamps in favour of staples, choosing instead to try to do a decent job with the staples and ensure I had tight joints. To this latter end, I am wrapping the strips with a long bungee cord in order to close the gaps that sometimes occur between the forms. The cove is protected by pieces of 1/4" dowel. The dark wood will liekly help to hide the staple holes on the finished boat and I will not likely try to hide them by filling them with sawdust & epoxy. Things did seem to go a fair bit more quickly than with the clamps but the process is still not fast.

That's it for today.

Tallies

Strips: 6 (3/side)
Staples: 26
Finishing Nails: 2
Hours: Best not to count

Bryan Strips!

Well I got the first 2 strips on over the last couple of nights - one on each side of the boat along the sheer line. The bend at the bow and stern is tight and across the width of the strip so a heat gun was used to encourage the strips to bend. This worked well enough but it didn't exactly turn the strips into a wet noodle. The strips are held in place with a few staples here and there, packing tape, hot glue (at every station), and a few clamps. I am not really going staple-less but am trying to minimize the staple holes that I introduce. I consider the staple to be just another one of the tools I have available and I will use them when needed, along with tape, clamps, bungee cords, super glue, 4" screws, or whatever. Actually, I was not impressed with how easily the staples pulled out of the mdf forms and they did not do as well as I expected at holding the the strip in place on the forms close to the bow & stern where it twists as the strip curves downward, inward and becomes angled. The tips of the strips have been glued and clamped to the internal stem pieces carved earlier.

n.b. If you are scarfing together strips to make full-length pieces for the sheer strips, piece together two medium to short strips rather than tacking a couple of feet onto one that's almost long enough. Although it doesn't appear to have caused a problem, I realised last night that my scarf joints are right in the area that's bending and twisting the most and under the most stress. It would have been much better to have had this joint in the gently curving section towards the middle of the boat. The potential problem is that the jointed area of strip may not be quite as inclined to bend, or may not bend the same as the non-jointed regions on either side. Plus, the scarf would probably be less noticeable somewhere other than the bow & stern where the eye will be drawn.

After putting the first strip on, aligned with the sheer marked on each form, one of the forms appeared to sit slightly lower than the others. This was evident because the strip on that side dipped slightly at that spot. I put the strip onto the other side and that side seemed straight & fair. With the sheer strips attached to the forms, loosening the screws allowed the strips to shift the form into exactly the right spot, and remain there when the screws were re-tightened. Everything appears to be in good alignment now.

I can now start adding strips up the sides of the hull, using my sheer strips as a base.

Staple Tally: 8

Almost ready to start

Well it's taking me a heckuva long time, but I think I'm almost ready to begin building this boat. Over the last week I have ..... ummm, I don't know, but it sure took a long time to do it.

1) I have made up about 30 c-shaped jigs that will be used to hold the strips in place while the glue dries.

2) I have cut a bunch of wedges out of scrap that will be used together with the jigs mentioned above. I still need to make more of these.

3) I found a use for the crappy peg board hooks that I was told would fit my slot wall in the garage but didn't even though I kept trying to use them to hold stuff on the wall and they kept falling off but I would curse and valiantly try to put them back up where they would stay until bumped slightly. [My advice - get slot wall hooks for your slot wall, don't try to "make do". And don't buy the hooks at the hardware store either, go to a place that sells store fixtures and pick up a bunch of used ones for cheap.] Now, what was I talking about? Oh yeah ... I drilled holes into the external strongback that the pegs of these hooks would fit into and voila, instant strip holders. I bent the end of some of the pegboard hooks in order to keep the strips from falling off. As a result, I now have a handy place to keep a small pile of strips on either side of the boat.

4) I put a strip-gluing holder onto the external strongback so that it will hold 3 strips at a time, cove side up, while I add the glue in preparation for their being placed on the forms.

5) I put masking tape on the edge of all of the forms so that the strips will not end up glued permanently to the forms.

6) I knocked the internal stems off of the bow and stern end forms (they were hot glued on) and then taped the end forms & sparingly re-hot glued the stem pieces in place. The way I had originally done it, the glue joint would have been too strong and I would have run into troubles trying to remove the forms from the kayak. As it is now I am hoping that the glue is strong enough to keep the stems in place during stripping, but weak enough to separate easily when the time comes to pull the hull off of the forms.

7.1) I scarfed some 16' pieces of cedar together with short pieces to make 4 strips about 18 feet long. The first strips that go on the boat are aligned with the "sheer" line - the line that defines where the deck and hull meet. On the guillemot kayak the sheer starts at the tip of the bow and curves down along the toward the middle, then back up towards the tip of the stern. According to the book, it is best to use full-length strips for this first strip since it is the one to which all others are aligned. My first attempt at scarfing strips "across the thickness" did not go well despite the able assistance of my uncle-in-law Barry. The trouble was that I am trying to do the cuts (on a steep angle of 1:7 or thereabouts) using a handsaw. The aforementioned book describes a method using a belt sander, which I do not have. My method was to clamp all the pieces together in a stack (8 pieces - two for each strip), and cut them on an angle (no mitre box) all at the same time with a japanese pull saw. Theoretically, this should mean that the strips end up cut with the same angle and should mate together nicely. I was wrong. Without a jig to keep the saw straight, the angle cut was not precise. I glued together the strips but after the glue dried I was unsatisfied with the results and cut them apart and started over. Part of the problem was also that the strips seem to have shifted after being clamped, something that was bound to happen since the strips were clamped on the bench but extended well beyond the bench and may have been bumped by the door when it was opened or by me as I worked in the shop.

7.2) On my second attempt to cut a decent scarf, I chose to cut across the width which proved to be a bit more manageable. I also did not set them up to glue until the very end of my work night in the shop so that I could not inadvertently bump them while I worked. This second attempt was somewhat more successful and produced a satisfactory (not great but it'll be OK) scarf on 2 out of 4 strips. That should give me the material I need to put on those first 2 strips (one each side) along the sheer line. If I'm gonna have to do this again, I really should build some sort of mitre box.

8) I have started to plane the bead off of the 2 strips that will be the first ones to go along the sheer line. Once that's finished (a few minutes?) I'll have to bevel the edge so that it is parallel to the floor when installed. This allows the deck and hull to meet flush without any gaps (theoretically). Once that's done, I'll have to fix that sheer strip in place (hot glue, staples, clamps) and I will at that point have officially begun to strip the kayak. Finally.

Screw-up #2

This is my second screw-up so far for those that are counting (well, the second of note anyway). If you look closely at the picture of the stern end form (click on it for a larger version) you might notice that there is a gap of 1/2" between the end of the strongback and the end of slot into which the strongback fits. "Hmmm ... that doesn't look quite right." Last night I realised that I had placed the last form forward of the end form on the aft side of the reference line when it should have been to the forward side of the line. The form is 1/2" thick and therefore, that shifts the end form back by 1/2". See the ruler sitting there - it is 12" and should not fit between the forms, but should be 1/2" too long to fit between. The forms are positioned such that the strips contact the aft edge of the form and thus, it is the aft edge of this form that should have been at the line rather than the forward edge. Oh well, it's easily fixed. Just moving that one form forward 0.5" would have been the simple answer, but it would have meant moving my very carefully aligned form. Instead I chose a different, yet still simple, approach. I tapered the form so that strips would still make contact with the edge of the form that is in the correct position (now the forward edge) and be able to come together at the stern. I then cut 1/2" off of the front edge of the stern end form so that it fit properly where it was supposed to be. The gap disappeared, order was restored to the world. Phwew, good thing I caught that one - who knows what sort of apocalyptic effects it might have had to produce a boat 12.7 mm too long!

[Screw-up #1 occurred a week or two ago while cutting the taper into the boxbeam that holds the forms. The beam must be tapered so that it fits into the narrow ends of the kayak. I cut the one for the bow which went well enough, then I flipped the beam around and thought to myself "better make sure to cut the taper on the correct side because that would be a pretty stupid mistake if I cut them on opposite sides of the beam." And, of course, that's what I promptly did. I realised it before finishing the cut and since the saw has an 1/8" kerf, I filled the gap by gluing in some 1/8" hardboard I had handy. Then I went to bed. After a good sleep and a with a clearer mind, I re-cut the taper properly. You can just barely see the fixed cut in the photo above, but it extends almost all the way through the strongback beam stopping within about 3/4" of the edge.]

Laser Light Show

I borrowed a friend's laser level (thanks Rod!) and used it to project a straight line onto the side of the strongback giving me a reference line in which I had some confidence. I was correct in my suspicion that the line put onto the side of the internal strongback with a string was less than perfect. The aligning of forms has since gone fairly smoothly and with a minimum of frustration. I took my time to get them right so hopefully it's all good. I then installed the endforms which are installed parallel to the strongback and project into the ends of the kayak. The forms are all now fixed in place and a stringline down the center confirmed that they are aligned well in at least that one direction. With everything fixed in place, I flipped the whole thing over so that the hull side (bottom) is up. The hull is the first to be stripped so it is now in position to start the stripping (i.e. attaching strips of cedar to the forms), after I re-check that the forms are all still aligned on the horizontal plane post-flip.

Some of this work was done late Saturday night while listening to the soundtrack of the "Rocky Horror Picture Show" as played in full on the air by CFCR radio (with commentary). Throughout the whole show I kept picturing the play as performed by Shortstuff Productions, and particularly was disturbed by images of Mike (a friend of mine, second from the left in the picture) in his skivvies!

More on form alignment

This article describes the various ways my forms are out of alignment. One of my problems is that although I marked a centerline on the strongback, the blocks of wood (cleats) used to hold the forms in place obscure the line. This is a problem since I used cleats on both sides of the form (thanks to the recomendation of Patrick C on the KBBB) to pinch the form in place, but didn't mark the centerline on the cleats (not sure how I could have since the cleats are put in place with the forms in position and thus the forms are in the way of effectively marking the line on the cleats - a catch 22). Also, my "elevation line" marking a horizontal straight line down the side of the strongback may not be 100% due to the fact that when I marked it using a string, the supports that hold the strongback were in the way of having the string run directly against the strongback. I used my combination square to press the string in against the strongback to mark the line, but who knows, it could be out by 1/16" of an inch in places.

Last night I was aligning forms and set up a stringline above the strongback and forms by tying some fishing line to the ends of a pair speed clamps clamped to the ends of the strongback, ensuring that the string was in line with the center-line marked on the strongback. The method I eventually settled on is to clamp a straightedge to the forms so that it is in line with the center-line marked on the form and that in essence extends that center line upwards so that it meets with the string line. I clamped a small level to the form such that it was paralell with one of the horizontal alingment lines on the form (waterline or sheerline). I then nudged the forms this way and that until 1) the ruler marking the center line just touched the string line, 2) the level was level, and 3) the mark indicating the center of the form hole was aligned with the "elevation line" (horizontal line marked on the side of the strongback). For some reason this is proving to be very difficult to achieve as when I nudge the form to get it to line up in one dimension, it shifts out of alignment in the other direction. Then, just when I had it perfect in 3 dimensions, I'd realise that somewhere along the way my ruler or level had shifted out of alignment.

Aaargh.

Distractions

Here is the reason things are not going to progress at lightning speed:


Our second daughter was born on September 23, 2005.

Aligning Forms

What a PITA!

2 down, lots to go.

Forms

Here's a panoramic view of the forms temporarily set up on the strongback. It looks like I need to stand a little farther back for that function on our camera to work well. I also just noticed that the software stitched the pics together wrong so that there's an extra form in there.
Maybe I'll just stick with opening up the garage door and standing back a few feet.

My first wound of the project. I planed a good chunk out of the tip of my finger. I was holding the piece of wood that will be the internal stem (scrap door-frame mahogany picked up today at Habitat Re-Store) and with my left hand and holding the plane with my right. What I didn't realise was that my finger-tip wrapped around the piece of wood and was in line with the material I was removing.


My next step is to attach all of those forms in a precisely lined up and secure position. So far I've figured out that it's much trickier than it seems. I am finding it difficult for some reason to get the cleats attached to the strongback so that they are square. I guess I'll have to clamp as I screw them down rather than trying to hold them by hand as I had been doing. I've found a couple of points in Nick Schade's book where things weren't quite as clear as I would have liked. I may have to pull all the forms off again and add an "elevation line" in order to line them up with the straight line that's on the side of the strongback. I'll figure it out tomorrow.

I was having a heckuva time trying to add photos to the entry below so I figured I'd sort out the bugs in a separate post. I see the images now so hopefully it's working. I had a separate photo editor open earlier so maybe that was interfering with the upload?

So what you have in these two photos is the 16' long 2x4 that is actually 1 15/16" x 3 15/16". The slightly reduced size is so that the forms fit easily over the beam. The boxbeam or internal strongback is resting on the external strongback. See the earlier post for details.

See that bundle of dark brown strips of wood in the back - that's 95% of the cedar for this boat, and they tell me there's probably 30% extra as a fudge factor. I also have some contrasting light coloured strips thanks to Rod Tait but they are much longer and on the shelf out of these photos. I'll have to post some better photos of the strips some time later.

Two Strongbacks Better than One?

Canoes are typically built on an external strongback - essentially a rigid beam on which the forms are mounted above the strongback. Kayaks may use an external or internal strongback. An internal strongback is a beam where the forms for the boat are placed around the beam such that the beam pierces the form and the boat is built around the beam and form structure. A few years ago I purchased an external strongback along with the forms for a Kipawa canoe. I have never quite gotten around to building the canoe but since I had the strongback I thought that I might as well put it into service as a very rigid platform to support the internal strongback for my kayak, much as Dale did (in fact it was seeing his web site that gave me the idea and convinced me to ditch the sawhorses). An internal strongback is usually supported on a pair of sawhorses.

I find it interesting that there is such a difference in opinion out there. The canoe-building folks and followers of Ted Moores in particular, seem to believe that the strongback has to be incredibly rigid and even epoxy the strongback to the floor to prevent it from ever shifting, even though a strongback built to the Moore's design is an incredibly solid piece of wood. The kayak-building folks, and followers of Nick Schade in particular, opt instead for using a crooked 2x4 supported on a couple of rickety sawhorses as their backbone for building. I guess I chose to combine the methods. Rather than use a 16' 2x4 (ever see a straight one?), I chose to make a 2"x4" box beam strongback out of 3/4" plywood. The resulting beam is not as rigid as I might have expected, but at least when it's done wobbling it returns to a straight line. Although I had made a pair of sawhorses, I am instead mounting the internal strongback on supports mounted on the Moores'-style external strongback. Since this provides me a nice rigid platform to build on, I have mounted the whole apparatus on 4 casters so that I can move it around in my space-limited shop. Sure, it might flex a couple of thousandths of an inch as I move it around, but it should still be better than the sawhorses.

For an interesting and evolving perspective on a boxbeam-type internal strongback, see Bryan Hansel's comments during the building of a kayak of his own design. He started off hating the internal strongback, but by the end he seemed to like it.

Preparations

I have spent the last week preparing to build our kayak by building an internal box-beam to hold the forms and setting up the strongback to hold the box-beam. The box-beam is a 2"x4" beam constructed of 3/4" plywood with the corners rounded using a router. The idea is to create a dimensional stable (so it won't warp) and straight platform on which to build the kayak. The forms have a 2"x4" hole through the center so that they are fastened along the length of the beam with a spacing of 12". The result when it is set up should be a sort of kayak skeleton upon which the strips of cedar are attached to form the boat.