Deck Beam and Carlins

This next step covers some structural components of kayak, the deck beam and the carlins. The deck beam is an arc at the front of the cockpit, attaching to the sheer clamps on each side. This beam will be hidden under the deck but will at as an important reinforcement for the deck and carlins. The carlins are wooden beams (1/2” by ¾”) sticks that will provide the inner support edge that the deck rests on around the cockpit.

There were several parts to this step. The first part was gluing two identical, arced pieces of wood together to form the deck beam. This was rasped and sanded. Following that, the deck beam was cut and glued into its spot at the front of the cockpit. This was glued down with the epoxy bonding mix I’ve discussed earlier. Once this was in place, attaching the carlins was next.

Attaching the carlins was one of the most frustrating steps I’ve encountered so far. The carlins need to be attached to the deck beam with two wooden tabs on the outside edge for reinforcements. These create more surface area for a bond also. The tabs are glued into place and a screw is run through each one. This was the easy part. The carlins must be attached at the front to the tabs and deck beam, and then fit into each of the hanging knees and finally a slot in the top of the rear bulkhead. The carlin itself is bent along this path, which pretty much matches the flow of the kayak’s shape. This is a spot where you need four good, long clamps to hold the carlins into the hanging knees and rear bulkhead. Also, more clamps are really handy for holding together the carlins as they attach to the deck beam and tabs. When the kit is shipped, all the wood is packaged up in a big cardboard folder that’s about 4 by 8 feet square. The company goes through great effort to ensure that all wood is kept in order and protected during shipping. My carlins were straight as an arrow out of the box. When I reached this step, I realized that was not working in my favor. I knew that I needed to have everything set before I started mixing any epoxy, so that means being able to “dry fit” the carlins in place, using the clamps, to ensure I have a good fit at all the touch points. In my first attempt, I could feel the carlins were at their breaking point as I tried to flex them into place. Sure enough, I broke the first one I tried to fit in. I tried to repeat this step with the second and managed to break that also. Now I was out of carlins. One thing I did realize before I started this was that the carlins were simply long, thin pieces of pine that I could easily replace with a drop to Home Depot if needed. The trim isle has these same pieces of wood. I also felt this was another place were the instructions could have been improved. They should have you bend the carlins into a curved shape before you attempt this step. It was too late for that. As I drove to Hope Depot, I already had my plan. I was to buy the most bent piece of ½” by ¾” piece of pine trim that I could find. As typical of big box store lumber, they had no shortage of that. I bought my new sections and was back home in a jiffy. These new “pre-bent” pieces were easy to fit into the needed shape. The one final thing they needed was a slight twist, from about the front to the middle. That was pretty easy to get that done. At the front, I used the wood block “nose block” to get the wood twisted. This piece is used later in that same spot with the cockpit combing. I used a clamp to force the twist and get the carlins flush with the edges of the tabs for a good bond. The clamps on the hanging knees would keep the twist from there back. After I thoroughly checked everything with my dry fit, I was ready to get out the epoxy and do the glue. With the nose block, I used some plastic between it and the wood, as I wanted to ensure that I didn’t actually glue in on.

Interior Epoxy Fillets and Fiberglass

Now that the hull is set in place, we can start working on solidifying it and assembling the remainder of the deck. To accomplish that, we will fill in the joints and seal the inside of the hull with epoxy. The filling of the joints is called “Fillet”. Along with this work, we will completely seal the inside of the hull with clear, two-part epoxy. The Fillet mix is made of the two-part epoxy mix and saw dust. The sawdust is added to allow the epoxy to thicken and “fill in” the joints. A side effect of this technique is that it makes the fillet mix cloudy, not clear. Since I’m going for a bright finish (that’s the clear coat where you can see the wood grain) I want to keep the fillets as small and neat as possible. I want them to be just in and over the joints. This also keeps the kayak lighter. In order to do this and keep a nice, clean look, I used painter’s tape. The tape will keep the fillet in place over the joints and wires. After apply the fillet, I’ll immediately remove the painter’s tape and lay the fiberglass tape over the fillet. This will further strengthen the fill and bond that we need at these joints.

As soon as the tape is in place, I will apply a layer of clear epoxy over the tape and the remainder of the inside of the hull. This will fill in the weave in the tape and waterproof and further strengthen the kayak. Two coats of the clear epoxy will be applied to inside.

The inside of the kayak is divided up into three parts, the front compartment, the middle area where passengers sit, and the back compartment. The best place to start is in either the front or rear compartment. These areas won’t be very visible on the finished product so it’s a great place for me to refine my fillet technique. I’ll complete these compartments first, and then finish on the passenger compartment. When working on these areas, it’s important to realize that the fillet will harden up pretty quick. There’s not much extra time, so you want to get the fiberglass tape on the fillet as soon as you’ve applied in an area. The fiberglass tape must be absorbed into the fillet to create a good bond, which can only happen when it’s still wet. This should remain soft until the first layer of clear epoxy is applied over the top. This combination will form a solid bond. The fillet and epoxy will harden pretty fast, so plan ahead and work in sections. I used small batches, usually about 3-4 pumps on the epoxy jugs and about ¼ cup of sawdust as a fix. I’d check the thickness and add in a little more sawdust as necessary. I’d need 2-3 of these batches to fill an end compartment. I used about 5-6 batches for the larger, middle compartment.

The mix for the fillet is about the consistency peanut butter. When I say this, I mean the thinner, all natural kind. My first fillet mix was a bit too thick, and I quickly realized that I needed to thin it down a bit to get it to spread properly. Think frosting a cake. It needs to be thick enough to stay in place, especially on the upper seam, yet not too thick that it can spread properly over the entire joint surface between the painter’s tape.

It’s important to keep on the temporary beam stick in during this process. The kayak will not be frozen into shape until this step is completely finished and all epoxy is dried.

Make sure to allow enough time to complete each of the compartments. This is one of those steps where we need a good block of time. I used one evening each for the front and back compartments. The middle compartment I reserved for a Saturday afternoon. If something hardens without having everything in place, you would no doubt need to sand a bunch and start over. One final point, the second coat of clear epoxy needs to be applied in a certain amount of time. For slow hardening, which is what used, you have 72 hours to get on the second coat. It’s less for the medium and fast stuff. One last trick, use one of your lights to keep your epoxy nice and warm. It will pump easier and spread easier.

Unwinding my kayak

This step was probably the step that has made me the most nervous so far; outside of the first time I used the epoxy. This step can best be described as "...making sure the boat is straight". Checking for twists, and then trying to remove them is where the term “winding” comes from. This needs to be done before we lock in the hull wiring and then use the epoxy to fill in the joints and seal the inside the boat. If I don’t do this right, it will be forever crooked as there is no way to straighten it once that step is completed.

The technique for doing this is to use your eyes sight it in. Roughly four feet from the bow and the stern, place these temporary boards across the shear clamps. This will allow you to check for twists across the kayak. Before starting this step, the sawhorses and table the kayak is resting on should be level. Next, stand in front of the kayak and look down the center. Move your head down until the back end board disappears behind the front one. Does the edge all along the line disappear behind the front one at exactly the same time? If not, we need to untwist the hull to remove it. For my kayak, I needed to do some untwisting, but not too much. My wife was able to help me in this step. We also used some clamps at the ends to help hold it during the “untwist” we did.

To vertical seam of the bow and stern should be 90 degrees to the cross pieces also. I checked this by using a plumb bob that I hung in front of the kayak. This step went well also. I did a little clamping and twisting here also and it came out pretty straight.

The final step is the “lock in”. This is where we do a final check of the panel joints to make sure we have a nice “V” shape, and the panels look good. When we are all set, we lock in the panels. Pushing all the wires down with a straight edge screwdriver keeps them in place and locks in the kayak's shape.

Fitting the bulkheads and knees

I’ve gotten behind in my posting, and am trying to catch up now. I’ve still been making good progress on the kayak, just not getting this updated. I’ll try and correct that now. I’ve also hit some warmer weather, which is nice. That also seems to motivate me in that I’d love to have this all wrapped in May. The warm weather reminds me that it’s a lot closer than I realize.

The next step in the process following the wiring of the hull is adding in the bulkheads and hanging knees. The kayak has two bulkheads, one at the front and one at the rear. These “walls” form the front and rear storage compartments. They also function as ballast and keep the boat afloat in case of roll over. I purchased the optional hatch kit, which will be added later. The hatches have a watertight seal so I don’t lose the ballast feature. The bulkheads and knees are wired into place like the panels. I’m able to just slide these into place. I did not have to scribe or trim them at all. This is one of those steps where you need to use your eye to check that you don’t bow out the side of the boat. The knees just get wired in place “as is”. Not much to adjust here. Their main purpose is to hold up the carlins, which is essentially the inside edge of the portion of the deck that surrounds the cockpit. More on that will be coming up. Note that I now have in place a temporary beam stick across the middle of the kayak. This keeps the hull in it's proper form. This will remain in place until the inside of the kayak is reinforced. At the end of this step, I also tighten all the wires and check the joints of the panels. These should look even, with the inside edges creating a "V" shaped groove visible on the exterior along each seam.

Also to note, I've got a board sitting across the boat towards one end. In proper terms, I have a board sitting on the shear clamps sitting perpendicular to the kayak. This will be used in the next step.

Wiring the Hull

The next step in the process is wiring the hull together. The kit ships with three spools of copper wire. The wire is cut into 4” lengths for the wiring or stitching of the panels together. When wiring the panels, a 1/16^th inch hole is drilled in each side the edges, creating a pair of holes to wire together. The holes are 3/8^th of an inch in from the edge of the panel. Also, the paired holes are about 4” apart along the seams.

The process starts with wiring the bottom panel onto the bilge panels. The front or bow of the kayak is wired to the bilge, starting at the very tip of the bottom panel. It’s important start the wiring at exactly the right point, where the bottom panel ends and the bilge panels curve up. This point is made clear from the plans. Holes are measured, drilled and wired, about 4 to 5 holes at a time. Starting on either side is fine, and then you alternate over to the other side of the kayak after every 4-5 holes to avoid any ripples in the panels and keep things even. Rope can be used to keep the panels more upright as you work down the sides. The ends are loosely wired to keep the panels upright. When you reach the end or stern, loosely wire it together like you did at the bow. In a later step, you will do any necessary trimming to even things up.

The sheer panels are wired onto the top of the bilge panels. This completely forms the sides of the kayak. Previously, I attached the sheer clamps (3/4” by ¾” solid wood strips) onto the top of the sheer panels. The bottoms of the sheer panels are wired to the top of the bilge panels. Wiring again starts at the bow. The same hole size and distance is the same as was used for the bottom to bilge panel work. Starting the wiring of these panels is a bit tricky. I used some rope to hold up the other end of the panels when I started. This helped keep the proper height so I could align things properly.

The process of wiring the panels together is pretty time consuming. It took me about 3 hours just to do the bilge panels. This also happened to coincide with the coldest weather of the year. This was not so bad as doing any epoxy work during this time would be difficult.

Gluing the sheer clamps

The next step in the process is to join sheer clamps to the top of the sheer panels. The sheer clamps are ¾” by ¾” strips of wood that will be glued to the top edge of the sheer panel for the length of the kayak. This is again the epoxy mix with the cab-o-sil for strengthening. The end result creates strong edge to attach the deck to the rest of the kayak. I will use plane on these ¾” by ¾” strips, along with the plywood they attach to, to create the proper angle to rest the deck on.

Attaching the sheer clamps means gluing over 16 feet of wood to another piece of wood. We do this twice, once for each side. When the instructions suggest that you get a ton of clamps, they mean it. You need to position clamps about every 6-8” along the edge to ensure good bonding between the surfaces. I purchased some clamps at the hardware store, and also followed some instructions from CLC to make clamps from PVC pipe. I must say that it worked reasonably well. These clamps don’t get a great amount of pressure, but enough to keep things together. I did learn one thing; don’t get them too close to your heat source. In my case, that was my lights. I ended up melting one of them. I also had another mishap that I didn’t report in one of the previous steps. I melted my thermometer from a light. That made a bit of a mess also, but nothing on the wood.

Before the gluing starts, you need to check the sides of the panels to determine what side should be the inside vs. the outside. If you are going for a clear or bright finish like I am, get the best looking side on the outside.

Both sides should be glued at the same time, with the wood strips/sheep clamps to the outside. Make sure to use the packing tape between the panels to prevent glue from getting on that surface or gluing the panels together.

Getting the glue on the strips and panels for over 16 ft of wood, on two sides at the same time is a bit of a trick. You need to get the pieces semi-positioned but still be able to sneak between them to get the epoxy in the joint. I clamped down the whole thing at one end and slowly moved from one end to the other, prying things apart to get the epoxy in.

When that process was completed, I made sure everything was lined up properly with the edges. It’s also with noting that the sheer clamps are much longer than the panels, so you don’t need to worry about how much is handing off on each side. These get trimmed later in the next step, wiring the hull together.

This is a really long joint that needs to be string, so I kept the lights on for drying for about three days. I didn’t start the next step until almost a week after I completed this one. I’ve also had some very cold weather to deal with. We’ve had lows below 0 Fahrenheit. I was able to get the temperature around 60 degrees by placing plastic over the whole thing. This is also within the overall plastic sheet tent that I built. Things seem to be working OK with this, even at these temperatures. I think I’m going to run into some trouble when I need to do epoxy work with the whole boat, such as the surface or joint work. That’s coming up very soon (see next post).

Scarfing the sheer clamps

The next step in the process is to join the scarf joints on the sheer clamps. The sheer clamps are ¾” by ¾” strips of wood that are attached to the top insides of the side panels. These are used to support the top or deck of the kayak. There are two sheer clamps to assemble, one for each side of the kayak. The sheer clamps are delivered in three pieces each. You join the pieces together with the scarf joints. Since these are long, thin pieces, they can be tricky to hold together during the gluing process. You also want to make sure the two match again as this will help keep the kayak true when we assemble the panels together in later steps. The total length of the sheer clamps is 18 ft when assembled. They will need to be trimmed later when the panels come together. The best approach is to clamp the strips 2-3 ft behind the joint on each side after ‘dry fitting’. You can then glue and clamp the joints much easier without the worry of the joints slipping a part. This is a good time to use some 2” clamps to keep the joints together. I used two on each joint. The joints are across the surface of the table so clamping down on the table is not useful here. It was a pretty cold day when I did this work. I kept two lights on each joint with some plastic over each.