Centerboard

The centerboard was probably one of the more interesting challenges in building the boat so far. Getting the basic shape was just a matter of taking the measurements off the plans and marking it out on a piece of plywood. Again, I used my router trammel setup to cut the big curve at the one end and the jigsaw for the smaller curves. 

The plans did not have any information on how to shape the centerboard though so it was off to the Internet for another lesson and to solicit advice. A big thanks to everyone who is willing to share and help, it is invaluable to first timers like us. We learned that a good rule of thumb is to shape the centerboard with the trailing edge being half the width of the leading edge. And that the bottom 6-8” of the centerboard should be shaped to a thin edge (we went with ~1/4”). Shaping was done by hand with a plane and basically the shape was determined by “eye balling” it. Plywood really is easy to work with in this way as you can see exactly how many “plys” you have cut through all the way along. The leading edge was rounded over using a router and lightly sanded smooth.

Roughed out centerboard

Taper on bottom edge

With the final shape determined it was on to addressing the two lead weights that keep the centerboard in the water during sailing. We made the holes with a small trammel jig that I have for my router—a vintage original Black & Decker jig from the 60’s? that has only seen service a handful of times. Screws were then drilled on the inside of the holes and the heads left protruding by approximately 5/8”. The molten lead will form around these and keep the lead from falling out as it cools and contracts.

All set to pour the molten lead

A view of the whole centerboard

We had read on the Internet that some people have used old tire weights as a source of free lead. Being frugally minded this seemed like the best way to go, so off to my local Costco to ask them if they would help me out. The guy I spoke with was more than eager to help but a little apologetic that they didn’t have much old lead around that day. Still he filled a little bag for me and off I went as happy as can be. Once home we ran a few calculations to determine exactly how much lead we really needed. It was just a matter of a little geometry and specific weight calculations to determine that we needed almost twice as much as my little bag contained. No troubles though, I just stopped by Costco again the following week and got a little larger bag this time.

Now on to the fun stuff, melting and pouring the lead. Everyone knows that lead isn’t good for you so some precautions are necessary to minimize your exposure to harmful lead fumes. Even though I did grow up in the era of leaded gasoline and the fact that this would be a one time job I decided to take no chances. The lead would be melted outside in a can on a propane burner and a large fan was positioned to blow the fumes downwind and away from me.



Fan and melting pot setup



With everything set up properly I lit the burner and started the melting process. Not much happened at first but then some of the lead started to melt so I added more. Still some of the lead was clearly not melting. A little probing and I realized that some of the non-melted material was the steel section of the lead weights that is used to attach the weights to the tire rim. I started carefully removing these with a pair of pliers. Looking at the rest of the lead mass, some molten and some still in its original state I realized that there are two distinct types of lead weights, ones that are obviously lead and others that seem to be made of another type of material that will not easily melt (these weights are much harder and do not bend easily).



Cauldron of melting lead



This revelation meant that I would not have enough molten lead to pour the two weights in one pour…..so I decided to pack the holes with larger pieces of the non-lead weights and then pour my molten lead around these rather than going through the whole process of securing more lead weights and another pour. Thankfully it worked out perfectly, I used all of the molten lead and both of the holes were full. The actual pour was both rush and terrifying at the same time…I would do it again in a heart beat.

The pour



The finished result


Once the lead was cold I filed the tops until they were smooth to the surface of the centerboard and then used a little bondo to fill in any imperfections on the whole centerboard. To add strength to the centerboard we decided to cover it with 4 oz fiberglass. However, before we could start the fiberglassing I drilled a hole for the centerboard pin and inserted a short section of ½” copper pipe and epoxied it in place. The pipe will serve as a sleeve for the pin and allow the centerboard to rotate freely if we can find the correct sized rod for the pin (I understand that a 9/16” bolt is a perfect match). But, that is a problem for later.

Centerboard with copper pipe epoxied in place

First, we cut the fiberglass cloth to size by wrapping it around the centerboard and marking directly on cloth where to cut. With the cloth cut, we now had to decide how to proceed. Do we try to apply the fiberglass cloth to the entire centerboard in a single application, or do we tackle one side at a time? I could not see how it would be possible support the wet board to do the whole job in a single application so I decided to do one side at a time. With the glass in place, I wet out one side of the glass completely working from the middle to the edges. At the edges I just left them floating beyond the edge of the plywood. When the epoxy dried, I just trimmed off the overhanging hardened cloth with a sharp knife—very slick. The only difficulty I encountered glassing the second side was dealing with the leading edge. What I discovered was that you have to be really careful to keep the glass tight and not to apply too much epoxy or it will run onto the already hardened side. The final step will be to apply another one or two plies of glass cloth to the bottom edge (and maybe the leading edge too) to reinforce this area (note: after the initial glassing there is no fiberglass on the bottom edge). I haven’t finished this step yet but will get around to it in the near future. We also plan to paint the centerboard.

First side glassed



Second side glassed



Centerboard Case

No doubt you have noticed that during the finishing process time was flying by and little was getting done on the boat, to combat that I started work concurrently on the centerboard and the case. The plans called for a solid mahogany case and centerboard but, I didn’t have that much mahogany kicking around and I didn’t feel like buying another mahogany plank—too cheap I guess. So we elected to build everything out of plywood, cheap exterior grade plywood.



Stern spacer and the two sides of the case

For the case I glued a sheet of 1/8” mahogany plywood to the 5/8” ply so that the exterior of the case will match the mahogany on the inside of the boat. Cutting out the case was just a matter of following the plans.  The stern end of our case is curved (following the shape of the centerboard) and was built up from two pieces of 5/8" ply epoxied together and cut using a router on a trammel.  It was a little tricky to match the bottom curvature of the boat but with a trial and error approach the shape came together.

Trial fitting the two sides

Atkins has an interesting way of dealing with the centerboard pin though. In most boats that I have seen a hole is drilled through the centerboard case and then that hole is sealed off on each side of the case by some elaborate means. Atkins instead has you cut a channel in each side of the case that secures the centerboard pin on each side. The centerboard can move up and down vertically along this channel but is constrained from moving the other two dimensions; fore and aft and starboard and port (seemed like a good time to start using some nautical terms). I have elected to run a piece of UHMW (ultra-high molecular weight) plastic that I purchased from Lee Valley Tools in the channel and to drill a hole in that to position the centerboard pin. I believe that if I run a piece of UHMW the full length of the channel then the vertical movement will also to stopped. We plan to find a way to make the top of the centerboard case removable so that we can access the centerboard easily if needed.

To make the case watertight we applied a few coats of epoxy to the interior surfaces prior to screwing the two halves together. A thin coat of Sika was applied to the joints and the whole case was screwed together with 2 ½ stainless steel screws.

Assembling the case note the Sika and the channel

The scary bit: cutting the slot in the bottom planking for the centerboard to pass through.  I must admit that this was a little intimidating.  A lot of hard work had gone into installing the bottom planking and some how it just didn’t seem right to start cutting a huge hole right down the middle of it.  I also have to admit that it still doesn’t make sense to me that you can cut a board in half that is only supported on each end and not have it sag significantly in the middle—but it didn’t.  So after carefully measuring (twice at least) and marking its position it was time to take the plunge.  First I drilled a hole at each end and then marked a line to each side of the hole.  Then with jigsaw in hand I carefully cut at least a 1/8” to the inside of the marked line (what a chicken I am) all along thinking that I will finish cut it from the bottom with a router using a pilot bearing bit.  Like most of our fears they are all between our ears and are never realized—everything went really smoothly.



All marked and in the midst of cutting



There's a hole in my boat

 Prior to installing the centerboard case we laid down a generous bead of Sikaflex and then carefully lowered the case into position (we pre-marked its location to facilitate this process). With the case in position a long clamp was dropped down through the case so that it made contact on both the exterior of the bottom planking and the top of the case. It was then lightly tightened before a second clamp was positioned at the opposite end and tightened. At this point we double checked to ensure that the case was square and then proceeded to apply a little more pressure to each of the clamps—not too much though as we did not want to squeeze out all of the Sika. We left the Sika to cure for a couple of days before screwing the case in from the bottom side through the planking. The case is approximately 48” long and on average our planks are 3”, so I expect that we will put over 32, 3” stainless steel screws into the case from the bottom—that ought to hold it!

All done

A picture that shows the centerpin channel from the top

Interior Finish

Flipping the boat over resulted in several revelations. The first was that all of a sudden the boat seems really big, surprisingly big, much bigger than we had imagined it when it was upside down. The second was that our planking looked pretty good, both the bottom and side planking had turned up well. The third was that we had been quite generous with our use of Sika to seal the planks. While it is tremendous to know that the boat is well-sealed and shouldn’t leak we didn’t quite know what to expect the interior would look like once we cleaned up the excess Sika. If you decide to follow our approach be forewarned that cleaning up the squeeze-out can be quite time consuming. We went at it with a variety of tools, chisels, cabinet scraper, exacto knife, and paint scraper. Each has its application and we found that no one tool was successful in all situations. But slowly but surely we eventually removed the entire squeeze-out. Whoo-hoo!




Transom prepped for staining

 And finally the fourth revelation was that we had over cut the width of the gains in some instances and while on the outside of the boat the planks were flush there was a small gap on the inside. To tidy this up we carefully selected gain and color matched mahogany planking cut-offs and cut and glued slivers of matching wood into the over cut gains. Another pain staking process that you just want to get over so that you can get on with the real work.

Bow prepped for staining

The real work was to set our hands to the construction of the centerboard and its case. But the more we thought about it the more set we became in our belief that now was also the time to finish the interior planking of the boat before it became cluttered up with side knees, and bench supports, and benches. Now was the last opportunity we would have to have complete and easy access to the side planks.

Of course the question was how to finish the interior? From our investigations there are as many ways to finish a boat as there are ships in the water it seemed. At first we had decided to go with an oil based solution. Lee Valley Tools sells a couple of products that seemed like good candidates, Deftoil (Marine or Exterior Finish) or Tung oil. A couple of years ago we had used Tung oil on our outdoor cedar planters and had been reasonably happy with the results. The nice thing about this product is that it has a smooth finish and you can really still feel the wood. We also liked the Deftoil because it has some dye in it that we thought would be good for evening out the differences in the natural coloring (some light and some dark) of our mahogany planking. But further reading about oil type finishes revealed that they have a tendency to turn black over time. And I can see this taking place on the planters now that they are two years old. I just couldn’t imagine sanding down the whole interior every 2 years and refinishing!

After considerable time spent investigating our other options we decided that we would first stain and then varnish the interior. Choosing the stain was pretty straightforward, a trip to the local big box lumber store provided us with all the ammo we needed to narrow the choice to a couple of stain colors. We bought both of them and stained both a light and dark plank to see how they would look. In the end we choose Minwax “Red Chestnut” for the stain. The process of staining the wood was really simple and quick—a quick application with a rag, wait, and then a light buff to pick any excess.

The choice of varnish was another long drawn out process as we had read a lot about Behr Spar Varnish and how wonderful it is—apparently an original formulation that has been made for years and years, inexpensive, and easy to apply. It is available at Home Depot in Canada but no longer available in the US, I do not know why. Our local store had 1 litre cans of gloss (we wanted to use gloss vs. satin because it has more UV protection and had decided to follow that with satin if we found the gloss too reflective) but no 4 litre cans, the pricing was $15/ 1 litre can and $35/ 4 litre can so naturally I wanted to get my hands on the 4 litre can. So I had them do an inventory check of all the surrounding stores. What followed was totally comical, the sales clerk would first check availability on the in-store computer and then phone a store that according to the computer had inventory only to discover that the product wasn’t actually in the store. He repeated this process for at least three of their stores until eventually he came back and basically said that it wasn’t available. On a whim a couple of days later I decided to hit a couple of the stores that the sales clerk couldn’t get a phone verification from because the stores were just too busy. The first store was a bust but at the next store I hit the mother load, they had 10 cans of the stuff—hoarding it no doubt!

By now I was all pumped up to start varnishing but needed to wait for the right weather, humidity below 60% and temperature above 60F as varnish can blush if the humidity is too high. And I needed a few consecutive days as the plan was to apply 8 coats and I needed at least 12 hours between coats but no more than 24 hours. In a perfect world 4 days would be sufficient. What followed was the coldest and wettest fall in ages. Every time it looked promising the forecast would change and the rain would come again—this went on for weeks. As it turned out I applied a couple of coats using a foam brush and then it rained. So I waited, then sanded. Sanding turned out to be a really time consuming process, each re-sand would take ~2.5 hours. All those copper roves look nice but really slow down sanding and the narrow planks make it difficult to use a powered sander so most of the work was done by hand. Here is how the work progressed, first I applied 2 coats then sanded, then another 2 coats and sanded, then another 2 coats and sanded, then I applied coat 7 and sanded and then finally coat 8. In the end I was happy with the way the finish looked and evened out the color differences in our boards—the scarf joints have all but disappeared. But in all honesty I can tell you the finish is not furniture smooth and silky but it should be functional—it is a boat after all! We still have bluff the transom with some really fine grit to smooth it out further but, that will have to wait for another day.


Finishing done, starting work on side knees



Note marks for location of molds and centerboard on green tape

Lessons learned:

1. Finish sand your planks before installing them as sanding around the roves is slow and painstaking work.

2. Mark location of molds on floor, chine, and top of planks (both sides or you will be wondering which is which).

3. If you have access to a sprayer, use it, the varnish will go on smoother—although for the cost the foam brush did a great job.

4. Get sand paper that will not load up quickly—I used 220 grit especially designed for sanding varnish.

5. The roves like to hold vanish and will eventually start a small run—I wish I had some sage advise on how to address this problem but, I do not, good luck!


The next post will cover the centerboard and its case, this work proceeded in conjunction with the finishing work.

Bottoms Up!

It was with some anticipation that we launched into planking the bottom as we would now be able to use those amazing clear fir boards that we had bought on Kijiji back in April. This was quite possibly the buy of the century. The ad read, “Clear Douglas Fir 3/4"x3'"x5' 0.10/linear foot Lumber” (~$0.50 per board foot). The material was off-cuts from a siding job and although the actual widths of the boards varied between 2-3.5” it was absolutely clear, straight grained, old growth fir. What a coup!

At first the prospect of planking seemed quite straight forward, joint the two edges of each board dead flat, apply a thin bead of Sikaflex, clamp the over hanging ends of each board securely to the previous plank until the fit is tight, counter bore a screw hole through the plank and into the chine, and then drive home a 1 ¼” stainless steel screw. Repeat until you reach the front of the boat, then cut off the overhanging pieces flush to the garboard plank.

Of course we agonized over planning a slight angle on each plank so that we would get a slight “v” between each set of planks. We understand that on many traditional boats this is standard practice and that these “v” joints would subsequently be chinked with cotton. But in the end we decided that a modern sealant like Sikaflex should provide similar performance characteristics to the old world methods, plus it would be a lot easier to implement.

We started at the transom and worked our way forward. The first plank was really easy, just line it up parallel to the transom and screw it down all the way around. The work progressed quite quickly for the first couple of feet until we encountered our first challenge—clamping the boards together. As we approached the 2 foot mark we realized that our 2 foot quick grip clamps would soon on longer be long enough to clamp the board together. You are probably thinking, “just get longer clamps”, and while that would an acceptable solution for a while it would not be a fix all as our longest clamp is 6’. Instead, we started to stagger the amount of overlap from side to side so that we would always have a point of purchase on each side. Although there were a few occasions where we ended up drilling a hole in the overhanging plank so we could get a clamp in place.

On the first day we decided to plank approximately 5 feet and then to put a couple of clamps on the whole set up to draw it up nice and tight as there were a few small gaps starting to form in the middle of the planks. To address any up/down crown or sagging in the planks we initially put light pressure on the clamps and then carefully knocked individual planks up/down until the whole area was generally quite flat. We left the clamps in place for several days to allow the Sika to set before proceeding with any further.

The next 5 feet were straight forward as we had established a good routine that quickly allowed us to put the bottom planks on. In fact we spent more time prepping the boards and selecting which boards would go where than actually installing them. We did come up with a good trick for clamping the next 5 feet set up together to close any small gaps that may have formed. We clamped a couple of 2x4’s to our molds that had a groove cut in it the exact size of the end of our quick clamps. Then by reversing our clamps to make them into spreaders we fit the other end into another small groove that we cut into our caul. The picture is worth a thousand words….

As you can see from the photos we trimmed the overlap excess in between the 2nd and 3rd sections of planking and started the process of hand planning the bottom to a smooth finish while the Sika set. The sides were first roughly cut off with a circular saw (being very careful!) and then fine tuned with a block plane. This was slow and arduous work slicing through end grain—again a sharp plane is invaluable for this type of work. The last plank was interesting, it was cut to fit snuggly against the stem and was generously slathered with Sika to prevent water penetration before it was forced in with a mallet. This effectively closed up any possible gaps that may have existed between the middles of the last section of planking.

We were extremely pleased with the final appearance of the bottom and were paid the highest of compliments when someone asked if the bottom was a single piece of wood.

With the bottom all done it was time to build the skeg—the sternward extension of the keel. The plans called for a piece of 7/8” softwood but now that we have it made I am considering building another out of hardwood as I am concerned about the durability of the softwood version. It was a little tricky to get the same curve on the bottom of the skeg as the bottom of the boat but after a little trial and error we managed a good fit. We elected to wait to install the skeg and the two bottom rub rails until after the bottom is painted. Hopefully, this will result a better layer of water protection than a bare wood to wood joint.

You can really see the curve in the bottom of the boat

After a couple of days of letting the Sika dry on the last set of planks we were eager to turn the boat over so one night just after we returned from being out we gathered the family together—the four of us. The two boys took the stem and I lifted the stern. Straight up at first to clear the molds and then we slowly started to rotate the boat until it was right side up. About half way through my bad shoulder went crazy and it felt like I had dislocated it. As it turned out I was okay after about half an hour but, did it ever hurt at the time! Now we really had a sense that we are building a boat. We also incredibly taken by how big the boat seemed.

Joe Lapstrake

The Procession of The Strakes

After completing all of the preparatory work, we finally had the opportunity to begin the process of planking the craft. Although, on most craft, the garboard is inherently difficult to shape and attach because of the tight curves that it must accept, Willy’s first planks were a simple matter. This can be largely attributed to the flat-bottomed construction of the hull, not our boatbuilding prowess. However, after completing these strakes, we were faced with a new challenge. Unlike the bottom boards, which are affixed to the chine using screws, the remainder of the planks (8 in total) are fastened to the previous strake with copper rivets. Being a non-ferrous metal, copper is fairly inert in moist environments, which makes it an ideal candidate for this application. Spaced at 3½-inch intervals along each lap, we had a total of almost 400 rivets to install over the entire craft. Needless to say, we were somewhat daunted by this prospect. Fortunately, although this process does require the builder to develop a certain rhythm, it is, in reality, quite simple. The most important resources in this procedure are a willing assistant and a surplus of time, as it can be rather lengthy. Below, the system is condensed into five steps. Please recognize that, while this is a brief overview of the process, more detailed information concerning this method is outlined in many boatbuilding books.


1. Bore a slightly undersized hole in the hull at the intended location of the rivet. After the nail is inserted, this will create compressive forces on the wood that effectively seal the joint from water penetration.

2. Counterbore the hole on the outer face of the board to the dimensions of the nail head. Although this step is not necessary, it helps to seat the nails flush to the hull without scarring nearby wood through overzealous use of the hammer. In addition, we also found that some of our mahogany planks so hard that it would have been very difficult to sink the nail heads without counterboring them. If you are have softwood planking this step may not be necessary.

3. Drive the nail ¾ of its length into the pre-drilled hole. At this point, the assistant places the rove (in the rivet punch) on the opposite side of the plank. Proceed to drive the nail until level with the exterior surface of the hull. By this point, the rove should be snug to the plank’s interior. However, if this is not the case, a few taps on the punch with a hammer will remedy the situation.

4. Cut the protruding nail off, leaving it about 1/8” proud of the apex of the conical rove. While the exterior individual braces the nail head, peen the excess metal into an even, symmetrical dome, preventing the nail from retracting the future.

5. Repeat 399 times.

Although riveting is somewhat time-consuming, mundane work, if both workers are able to develop a sense of cadence, it is possible to affix a strake in little over an hour.

Close up of exterior hull rivets

Seeing as the process used for each subsequent plank is identical to the system outlined above, it would seem overly repetitive to give a detailed account of each strake. Instead, we have consolidated this task into a series of photographs, allowing the reader to witness the accomplishment of hours of our labour in a convenient photographic form.

One strake per side



Two strakes per side

Three strakes per side

Three pictures of four strakes

Done - Five strakes


Now that all of the constituent elements of the hull sides are completed, the next item on our agenda is that of bottom planking. Seeing that Willy is of flat-bottomed, cross-planked construction, we anticipate that this will be a fairly straightforward task. Tune in for the next installment soon!

Joe Lap

Preparing The Strakes

After obtaining the strake shape, it is important to scribe the hood (forward) ends of the strakes to mimic the curve present in the stem rabbet. Ideally, the planks should converge neatly with the stem, without any gaps or differences in level. Although this is a simple concept, the builder must be careful to attain an accurate profile on the strake, as any discrepancies between the two components will become obvious later on. To shape these ends, we used the circular saw to make initial cuts and finalized the shape with a block plane, much like the process used on the strake edges. As is often the case, blade sharpness is essential here. Although a keen plane blade will make short work of the task, this step can be very frustrating if one is forced to contend with a dull blade. Because our strakes are mahogany, it was necessary to redress the blade several times during the process of forming all ten strakes. When this is complete, each plank must have “gains” cut into the ends. Usually about 14 inches in length and identical in width to the lap, these long, tapering rabbets effectively remove 50% of the board’s thickness at the stem and stern.

When two gains mate at a lap, the result is a smooth transition from lapstrake to carvel-type planking at both ends of the hull. This allows the builder to form a watertight seal at the transom without going to the effort of coping the stern to accept the laps. Traditionally, this task would be completed with a rabbet plane. However, in the interest of efficiency and accuracy, we opted to design a gain jig for the router. Although it was a highly effective device, we found that it was still necessary to use the hand plane to fine-tune the gains, as, in reality, they must be cut on a slight curve, something that the jig could not provide. For this step, test fitting of the gains on the craft is essential to forming tight joints between the strakes. However, if the task is completed with care to detail, the effect formed by the laps swooping upwards as they taper away at each end of the craft is striking.

Simple inclined plane rabbet jig

Jig in action with router

Once satisfied with all aspects of the first two planks, we finally had the opportunity to begin attaching the strakes to the frame. At this stage, we were eager to begin the true “construction” of the craft, but still had some misgivings about the process. However, although this seemed to be a rather daunting task, it was, in reality, surprisingly simple. At both stem and stern, we secured the planks with 1¼” 316 stainless steel screws, which are purported to have superb corrosion resistance. The same screws were used to secure the garboard to the oak chine. It is truly at this stage that all of the effort exerted during the spiling becomes worthwhile. Because we were able to determine the proper strake shape earlier, we found that each plank readily conformed to the contours of the hull. If a builder neglects the task of spiling, however, he will find that a great amount of force is needed to coax the boards into their proper locations. Stern view of rabbets

Although, by this point in time, we were eager to begin placing the strakes on the strongback, we had to address one final concern—how to seal our craft. In an ideal world, all joints would be perfectly seated against each other, eliminating the need for any sort of bedding compound. However, unless a builder is incredibly skilled and highly accurate, it is inevitable that a boat will have some voids in the joints. This issue can be addressed through two primary means. In traditional lapstrake construction, joints are caulked with textile fibres, such as jute, hemp, or cotton. This system acted upon a simple principle: all of these fibre types swell dramatically when in contact with water. In this way, a craft will “self-seal” due to the expansion of the caulking in its joints. Some builders also believe that this method helps to create pressure within the laps, which subsequently adds some rigidity to the hull. However, there is one major drawback to this approach: the boat will not seal immediately. As a general rule, the craft must be immersed in water for several hours before it will become watertight. In the context of our Willy Winship, a dry-storage daysailer, this means that we would be forced to pre-wet our boat before each sailing session in order to ensure a dry hull. Not only would this be inconvienient, but the retention of water in the caulk during storage would promote the growth of mold and fungi. Fortunately for us, the advent of 21st century technology brought myriad new marine sealants to the marketplace. Builders can now choose from a wide range of polyurethanes, polysulfides, and other petrochemical products that can be handled much like ordinary silicon caulk (note: never mention silicon caulk in the context of a boat, as most builders are vehemently opposed to this material. It is worthwhile to invest the extra $ in a marine sealant, if only to avoid the disapproving looks from other builders). Although some of these products, like 3m 5200, act as both an adhesive and a sealant, the general consensus among the masses is that bedding compounds should have very low adhesive properties and high elasticities in order to allow the wood to move on its own accord. After processing the overwhelming number of opinions that surround this topic (a task unto itself), we finally concluded that we would use Sikaflex 291 on all wood-to-wood joints around the craft. Being an all-purpose, low-strength marine sealant, Sikaflex has the durability and watertight characteristics of a synthetic caulk and the ability to allow wood to undergo seasonal changes unimpeded.

The only drawback to this compound is that it may draw disapproving glances from the devout traditionalists. Fortunately, seeing as the Sika is concealed by the joints, the boat, when finished, will be nearly indistinguishable from a cottoned craft—except, of course, for the fact that Willy, unlike the ships of old, will be reliably watertight.

Joe Lap

COMING SOON: THE PROCESSION OF THE STRAKES

The Formation of a Hull

It is a pleasure to be able to blog again! As has been the case many other times, recent building activity has conflicted with our ability to keep our readers updated. However, although our blog was silent, the boatshed was abuzz with activity. I am pleased to report that we have made significant headway since the previous post. As shown below, we have completed the side planking and have begun the process of laying the flat bottom. After our most recent efforts, our project is truly starting to take on the likeness of a ship. After such a significant lapse in reporting, it is probably most appropriate to recount the month of June in chronological order. Because the last post detailed the installation of the transom onto the strongback, the last step before planking, it seems appropriate to begin with the garboard.



When constructing a lapstrake craft, the boards (strakes) overlap each other, much like the shingles of a house. Besides aesthetic appeal, the advantages of this system are twofold. Firstly, the overlapping areas are doubly thick, meaning that they act much like stabilizing stringers running from stem to stern. Because of this, it is possible to create a clinker craft using relatively light material. In addition to adding strength, lapstrake construction also aids in maintaining a dry interior, as the ridges on the outside of the hull serve to direct spray downwards. When sailing in adverse or cool conditions, this is incredibly valuable! Because of the craft’s design, The bottom board, or garboard, is the first plank to be laid, as it is the base on which all of the other strakes will rest. In all boatbuilding books, authors seem to regard the garboard as a formidable challenge. This is primarily because, on round-bilged boats, the first strake must accommodate for the compound curve present at the lower extent of the hull. However, because Willy Winship is a flat-bottomed craft, we were able to avoid many of the issues that generally plague the garboard. Still, we were faced with the difficulty of deriving the correct plank profile in order to minimize stresses exerted on the strake during assembly and use. Although it may appear that a correctly-spiled craft has planks that are slightly curved, or scimitar-shaped, in reality, strakes can be incredibly odd. For example, the sheer on this boat had to be distinctly “s” shaped in order to take the contours of the hull. Thus, it is important to devise a process through which the proper plank form can be determined. When faced with this challenge, the amateur boatbuilder may be tempted to panic, as some experts tout methods that entail the use of several spiling battens, dividers, and transfer marks. Fortunately, there is a simple method of establishing strake shape, sometimes called the “truss method”, consisting of three straightforward steps:

1. After obtaining two flexible, true battens the width of the laps in question (Plywood seems to be the ideal material for this application, as it is not subject to the natural stresses found in natural woods), clamp one to the previous lap, or, in the case of the garboard, to the chine or keel.

2. The second batten should be affixed to the molds at the positions predetermined through spiling the hull. It is important to remember to place the batten with the top edge aligned with the mark, as the width of the batten represents an area that will be covered by the following strake

3. Using a few dozen short scraps of batten material, attach cross braces in a triangular fashion akin to that employed in truss bridges. This will result in the formation of a rigid replica of the plank that can be used to transfer the correct shape to the waiting board.

Okay, enough theory....here is what really happened:
 
1. We took one of our scrap planks that we made while we were practising scarfing and bent it around the molds and marked the chine and battens on the inside with pencil lines. We cut the plank to the lines and put it back on the molds. A total failure--it needed about 6" of edge setting to get it to lie properly on the molds.

2. Having already been burned once we were too chicken to just jump straight into cutting a valuable plank so we decided to cut up a piece of plywood first to see if we could put the theory into practise. Here is our first truss.

3. Laying out the truss on the plywood.

4 . Plywood plank being fitted to the boat. Success!

5. Transferring to the mahogany plank.

By using this process, we found that it was possible to obtain board form quickly. After reviewing the lines on the completed craft, we concluded that they closely followed the initial spiling batten locations that we had deemed to be fair earlier—the objective of any spiling technique. No aspect of this method is difficult to master, and, as such, it is ideal for any first-time builder. Despite its simplicity, however, the accuracy of the above system rivals any of the other spiling methods presented by experts.

6. Lines on the plank, ready to be cut to shape.

7. Planning to the line after rough cutting with the circular saw.

After transferring the proper dimensions of the plank to the scarfed boards using the assembled truss, it was relatively easy to shape the strakes. In most books, authors recommend using a circular saw for this step, as most planks have too much curve to be cut using a tablesaw. Initially, we were somewhat apprehensive about this prospect, as, for us, the circular saw has been a tool usually reserved for basic cuts requiring little accuracy, or for jobsite construction. It seemed to have no application in the fine craft of boatbuilding. However, having now cut ten boards with this tool, we can attest to the fact that it is effective in this use. By using the saw for rough cuts and reaching our final shape using the hand plane, we were able to combine accuracy and efficiency. Although the saw was useful for this task, we were reminded of the sheer versatility of the hand plane. Although it appears a simple tool, we have reached for the plane countless times for tasks no other tool could do in the construction of Willy. From leveling the chines to squaring the planks at the transom, our two planes have been indispensable in this undertaking. In addition, they are a sheer joy to use! There is something about the rhythmic motion and the whisper of the blade in use that has an entirely unique sensation. Unlike with power tools, where all senses are obscured by the incessant vibration and din of the motor, the user is able to wield a plane purely through feel. Although one could write extensively upon this topic (and that shall probably come), it will suffice to say that any shop that lacks planes is inadequately equipped. 

8. Hood end cut to shape (trial and error to fit) and the gain cut.

9. First plank in place and the spiling battens positioned and ready for the truss webs to be added.