Building a new composite coaming

I'm back in the boat shop. After nearly 4 years since her launch, my cedar strip baidarka is languishing on the kayak rack with a leaky front hatch. With repeated exposure to moisture, the hatch, which used to fit with an airtight seal, warped just enough at the edges to allow some water through the rubber gasket. 

In addition to the leaky hatch problem, she has a tendency to leecock which can be dangerous in a strong wind. I don't think this is a problem with the original Shooting Star design, but is probably specific to this particular build.  I think it demonstrates how sensitive to trim the Shooting Star design is. While touring I could fix the trim by packing more gear in the front. Moving the seat forward would fix it permanently. Unfortunately, I built the cockpit "ocean size" so there was very little room to move the seat forward. In addition, the front bulkhead served as my footrest, so moving the seat forward requires moving the front bulkhead forward as well. This meant that I had a lot of modifications to get this kayak seaworthy again: rebuilding the hatch, the cockpit, and the forward bulkhead.

I'll start by describing how I expanded the cockpit opening from a small “ocean” cockpit to a “keyhole” opening. The old coaming was incredibly tough. I used a combination of hand saws, a saber saw, a Dremel tool, and a router to cut it out. In retrospect, the best tool for the job would have been the Dremel tool with the diamond wheel, which I used to cut the new coaming lip to size.

After cutting out the old coaming I drew the shape of the new, larger cockpit opening on the deck, cut it out with a saber saw, then cleaned up the edges with a rasp and sandpaper.

Next I fashioned a mould for the new coaming lip with a 3/4 in layer of minicell foam. I've also seen insulating foam used which is easier to shape. I chose minicell only because I already had plenty of it lying around. I shaped the foam with coarse sandpaper and fixed it temporarily to the deck around the opening with hot glue. Then I covered the foam with duct tape to keep the epoxy from sticking to it, being careful to keep the inside edge of the deck exposed though so that the coaming rim would stick to the deck. I stretched the duct tape over the foam to keep it as smooth as possible. Every wrinkle in the tape is one that will need to be sanded out later, and any unfairness in the mold can only be fixed by adding more layers of glass and carbon fiber.

After protecting the deck surrounding the coaming with masking tape and plastic, I placed several layers of carbon fiber over the mold. I wet it out by laying it flat on a plastic sheet and spreading epoxy over it with a spreader. Then I shaped it around the mould and around the inside of the opening and underneath the deck. The fiber is cut on the bias (i.e, cut so that the fibers run diagonally at a 45 degree angle to the edges). This makes it easier to shape the cloth around curves. Sometimes the cloth fibers would sag and drop off the underside of the deck. As it cured it left a lot of sharp edges that needed to be ground down later. I don’t remember how many layers I put on-- probably 4 to 5.

After the epoxy cured I removed the mold. This part was difficut. I had to dig underneath the foam with a knife to separate it from the hot glue that held it to the deck. I recommend using hot glue sparingly. I dug into the side of the mold and grabbed hold of the duct tape with a pair of pliers. Once I got a good hold of the duct tape, I was able to pull the foam out in large segments. A lot of hot glue residue was left on the deck. Paint thinner seemed to work to remove it.

Now I had a coaming lip with rough, sharp edges. I ran a white crayon about 1 1/4 inch from the inside edge and cut the lip to size along the line with a Dremel tool diamond wheel. It cut like "a hot knife through butter"! To clean up the rough and irregular outside edge of the coaming rim I ran a fillet of epoxy thickened with sanding dust along the outside and covered it up with a layer of fiberglass.

 

After the epoxy cured all I needed to do was sand the whole thing down. Now it is ready for varnish. The underside of the deck is still a little rough despite all the grinding and sanding. I'm planning to pad the underside with minicell foam. I don’t really recommend this method of replacing a coaming because it's difficult to get a good cosmetic result around the outside of the rim and underside of the coaming lip. I did it as a shortcut.

 

The Work of a Master

Joe Greenley of Redfish Kayaks recently posted a picture of his latest cedar strip project, the Ursa 420, a unique rough water expedition kayak designed by and built for Robert Livingston, creator of the Bearboat Pro boat design software.  I remember seeing this project in the stripping stage in Joe's workshop maybe a year and a half ago.  Probably the most striking feature of the design is the really big aft compartment, which I think makes the boat self-righting.  There are four hatches, all secured by rare earth magnets.  As to be expected from Joe Greenley, the craftsmanship is superb!

While looking over Robert Livingston's site it struck me that I saw a kayak very similar to this years ago when I first joined the Washington Kayak Club and started going to their pool sessions in Tacoma.  I was struggling to teach myself how to roll and after an exhausting hour or so thrashing around, I sat on the edge of the pool and watched this guy perform slow and graceful sculling rolls in a short stubby white fiberglass kayak.  It had kind of a bulbous bow and a very large aft compartment just like the Robert Livingston design. A fellow observer told me he thought that boat was "self-righting".  Note the picture of the kid doing a hand roll with the Ursa 350 on the Robert Livingston site. 

Do you think they would let one of these boats into the Greenland National Kayaking Championships?

Two at a Time

I just wanted to share a couple pictures of the kayaks that Ricardo is currently making at the Bates Boatbuilding Program.  As a more or less legitimate tuition-paying "student" over there, he has the luxury of plenty of tools and space to work with and is able to build on two kayaks at a time.  The top is a strip-built Red Fish Return, and the bottom a Greenland skin-on-frame that will serve as a "guest boat", that is, something wide and comfortable for friends who don't necessarily paddle all the time. 

As a builder, Ricardo likes to dive in and work quickly.   He has a talent for finding excellent sources of wood for cheap. His boats are characterised by pragmatism and durability.  He does his research, but plays fast and loose with the instructions.  If he can think of an easier way to do something, he'll try it.  He won't get hung up over little details or whether a technique is "traditional" or not (such as using plenty of epoxy on a skin-on-frame).  It's a refreshing contrast to my personal style.  For instance, I'm too single-minded to be able to work on two kayaks at a time.  Still his efforts result in remarkable boats, such as the replica of the Howard Chapelle skiff Farmer's Daughter (bottom pic), the boat that inspired me to build a sailing skiff of my own.

Cedar Strip Kayak Building: Flush Deck Fittings

It's been difficult bringing Moonlight Dancer back into the shop for repairs and modifications. Not only do I have to admit that I made some mistakes, but I'm losing a lot of quality paddling time working in the garage. So I don't like to post about it. But now that I'll be ready to paddle her again to the Lake Union Wooden Boat Festival I'll describe how I ripped out the leaky soft padeyes and installed some flush deck fittings. The Dremel was indispensable for this project. It just melts away wood/fiberglass/epoxy and was perfect for cutting the 1/8 brass rod.

The steps are:

Mark out the deck fittings on a mahogany board.
Build a jig for the router. Test it and rebuild it again if necessary. Repeat until you get it right.
Rout out the recesses on the deck fittings.
Cut out the deck fittings and sand smooth.
Install the brass rods in the deck fittings.
Seal the deck fittings with epoxy.
Mark out the holes for the deck fittings on the deck.
Drill big holes in the deck (yikes!) and file the edges smooth.
Dry fit the deck fittings.
Apply a bead of epoxy thickened with wood flour on the fittings and install with the kayak upside down.

Now I have the whole kayak sanded down and revarnished. I also attempted to get rid of a number of scratches on the hull where the weave of the glass shows by sanding down to the glass and applying another coat of epoxy. I won't bother again --it doesn't work! I figured out that when the glass is stressed like that the only way to get rid of the scratch is to sand away the glass entirely. Then you are left with a deep gouge and a weak spot. Revarnishing actually makes a big difference cosmetically, but will not eliminate the scratch. I've decided that as long as scratches are below the waterline I will not attempt to get rid of them.  Hmmm, maybe on my next kayak I'll paint graphite powder/epoxy below the waterline.

 

Cedar Strip Kayak Building: Shooting Stars

Shooting Stars from top: Richard Kohlström's, Scott Fitzgerrell's, then me (before installing a backband) and Henry Romer (after installing a backband which moves the paddler foreward) in Moonlight Dancer

 

I've been asking other Shooting Star owners where they put their cockpits, since I was concerned that I trimmed mine stern heavy. From the pictures it looks like I put the cockpit way to far back.  Could it be the angle the pictures were taken?  In the top two pictures the kayaks may be angled away from the camera, which would make the bow look shorter relative to the stern.  That effect may be exaggerated with a zoom lens. 

According to Rob Macks, the cockpit on mine isn't more than 2 inches too far back if anything.  Since cockpit sizes will vary, the plans should really specify where the backrest should be, and not the front and back edges of the coaming.  I know I'm probably making a big deal about nothing, since there is really nothing wrong with the way she paddles, as far as I or anyone else can tell.  I haven't started asking someone to take video of me paddling so I can analyze it... yet.

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Cedar Strip Kayak Building: Hatch Repairs

So three weeks after the official launch on Moonlight Dancer I'm still working on my kayak!  After all, if I were completely done what would I have to blog about, especially on those days when I'm busy at work and get home with just with enough time to check my email and put in five minutes of epoxy work before going to bed?

My repair of the leaky back hatch consists of two things: adjusting the bungees so that they apply more downward pressure on the hatch and putting gaskets on the hatch lip as well as the hatch cover.  The problem with putting gaskets on both the hatch lip and cover is that the hatch will no longer sit flush with the deck.  To get the hatch to sit flush I routed out a groove (about 1/16 in deep, probably less) where the gaskets will fit in both the cover and the lip.  And how did I accomplish this?  Using the Dremel tool I got for Father's Day!  I first heard about the Dremel from Derrick's blog, when he got one to cut out the seat in his Anas Acuta.  My first thought was, "What is the big deal about the Dremel?"  Well, now I know!  It cuts and carves wood and metal like a dream.  I think I'm going to get plenty of use out of this tool.  I can't wait to try it out on the pieces of caribou antler I got at SSTIKS!

 

Cedar Strip Kayak Building: Back in the shop

Clockwise from top left: BlueWater 4mm NITELINE reflective deck rigging; new inflatable seat from Thermarest/SealLine next to Newfound seat; composite tubes curing for new hatch mechanism; carbon fiber/fiberglass ready for wet out

Moonlight Dancer is all dried out and back in the shop for some more work.  I'll be honest about the problems: every one of my soft padeyes leaks, the hatches leak, and the seat is awful. To be fair to Joe Greenley, I did not follow his instructions on making the soft padeyes. And if I only used more silicone sealant they probably would not leak at all. I am thinking about making recessed mahogany flush deck fittings instead, so that it will be unquestionably watertight and easier to sand and revarnish. For the hatches I'm going to put gaskets on both the hatch cover and the hatch lip, and reposition the bungees to apply more downward pressure on the hatch cover. People say they can get their hatches watertight even in surf with an internal bungee mechanism so I'll keep trying! If could do it over I would use a bulkhead hatch for the aft compartment, with some kind of bombproof screw hatch mechanism. The small forward hatch is actually reasonably watertight. Maybe all the water in the forward compartment comes from the padeyes.  I got an inflatable seat from Pygmy as a replacement for the foam seat from Newfound Woodworks. I've found that a simple inflatable Thermarest pad is a very comforatable seat even for all-day touring. 

 

Cedar Strip Kayak Building: Launching Moonlight Dancer

As the last flap on the after-deck is sewn, after the frame is shoved into the completed covering, the now naked owner, accompanied by all the men present, sings his childbirth song to his new kaiak. The owner washes the cover with urine to remove any oil that may adhere to the surface, and rinses it in salt water. He then hauls his craft through the smoke-hole of the house and rests it on the snow, which will absorb dampness from its surface.  Later he puts the kaiak on its rack and drapes over it his talismans, strung on belts, which are later to be kept in the kaiak... [From David W. Zimmerly, Qayaq: Kayaks of Alaska and Siberia]

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After getting home from work early I spend the afternoon on the final touches to the Shooting Star. My fingers are sore from pulling knots on bungee cord, undoing them, then doing them again to get it right.  After dinner we walk to the beach. The sky is drizzling and overcast. The wind is building. I set the kayak down by the water. I hold a bottle of champagne in one hand, and pop the cork. "I hereby name you... Moonlight Dancer!"  A generous splash on the bow and a little sip for myself. I squeeze in and secure my tuilik. The coaming has a very low profile. The fit is pleasantly tight around my thighs, but I have an inch or two extra footroom. She speeds me away. I put her on edge and bow rudder -- so smooth! Then a standard Greenland roll. She rolls easily and is stable on recovery. A few more rolls: reverse sweep, shoulder, butterfly, masikkut aalatsineq -- simply awesome! I've reached the end. She is finished.

See you at SSTIKS!

Cedar Strip Kayak Building: Racing to Finish

Isn't it amazing how you can spend an entire day working on a kayak and time just flies by?  I'm almost done with my Shooting Star. On this beautiful sunny day I had to resist the urge to try it out on the water. I will launch it either tomorrow or the next day. Of course it's typical that builders are never really "done" with their kayaks because they are always tweaking them, adjusting the seat, changing the rigging or hatches, or revarnishing. "Done" for me means that it is equipped with everything I need for an overnight trip. I wish I had another couple months to really finish it the way I want to but then I would never go out paddling. I guess I'll just have to live the imperfections for a while. Some recent developments:

I finished making all the beads and sliders for the deck rigging after all. I made them out of the artificial ivory I had left over from building Necromancer. 

I stopped at 4 coats of varnish. That's all the 1 L can will cover. The last coat was the worst -- dust all over, and a couple sags. I don't think the "Clean Room" really worked, because I had to take it down between coats to sand the kayak. It might have been better to just wet down the floor and walls between coats instead. Unless you look very closely though the finish looks good. I'll probably put on another 4 coats in the winter when I'm not in a hurry and paddling slows down.

The hatch covers are secured with internal bungees. The bungees make a loop through carbon fiber tubes attached to the inside where the deck meets the hull right next to the hatch, then loop around wooden hooks on the underside of the hatch cover. Another cord keeps the hatch cover attached to the deck so it doesn't get lost when the hatch is off or if the bungees fail.

I had a problem with the hatches gaskets. The gasket that came with the kit is a strip of adhesive 3/16 in foam that is supposed to be applied to the inside of the hatch cover. When I did this the hatch wouldn't sit flush with the deck. So I spent half the day worrying about this and trying to figure out when I would get the chance to rebuild the hatch lips. Fortunately while I was at West Marine getting some supplies I found a roll of 1/8 in weatherstripping. It is very compressible and will let the hatch sit reasonably flush. Although I haven't tested it I'm sure it will give a watertight seal, at least for rolling. When touring I plan to use float bags for back up floatation. My experience has been that designing and building watertight flush hatches is one of the most problematic parts of wooden kayak construction.

I installed the Joe Greenley's soft padeyes. Like other builders, I modified his design by adding a small plywood backing to the nylon webbing. I was a little uncomfortable with how small the lip was on the webbing made according to his instructions (even though he says that it will hold 300 lbs). With the plywood epoxied to the webbing there is no question that it will hold and provide a good seal. I installed the padeyes by running a line through holes drilled through the deck, through the webbing loop formed by the padeye, then out again through the hole in the deck. A bead of silicone sealer is applied to the plywood and the padeye is pulled up through the deck with the line. It is possible to remove the padeyes when the time comes to revarnish.

Next post will be the launching ceremony (maybe). I better go out and get some champagne. Three more days until SSTIKS.

 

 

Cedar Strip Kayak Building: Deck Rigging

As I'm finishing up the last few coats of varnish I've started thinking about deck rigging. Some wooden kayak builders omit it completely. Who really wants to spoil the clean lines and distract from the beauty of a wooden deck? The kayaker in the picture told me he's had his Pygmy Coho for 4 or 5 years and he still doesn't have any rigging!  Depending on the conditions in which you paddle in that could be a big mistake.  It's not just about having a few bungees to hold your camera or water bottle. Picture yourself as the rescuer or victim in a deep water rescue, with waves pushing you against the rocks or a steep cliff. It's important to have perimeter lines to grab onto if you're swimming, and strong enough so that a rescuer can grab hold of your flooded kayak that's packed with gear and pull it half out of the water, without the padeyes coming off the deck like buttons popping off a shirt. It helps if the perimeter lines are raised above the deck, so you can grab hold of them easily with a gloved hand that's numb from being in cold water too long. 

When we were practicing rescues in the 4-star training in I kept running into problems stowing my paddle as the rescuer. It would either take me way too long or I ended up with the paddle swinging loose under the lines. It would have helped to either have a proper paddle park or have the cross deck bungees raised so I could slip the paddle under them in a second. Leon Sommé added a little blue ball to the right perimeter line on his NDK Romany so he could quickly stow his paddle. I thought it resembled the bone and ivory beads that raised lines up off the deck on traditional boats (To be accurate, traditional boats don’t have perimeter lines. Of course the Inuit never considered wet exits and T rescues an option). Brian Nystrom illustrates some good ideas for modifying rigging on production kayaks to be more functional on his website.

I think modern kayak manufacturers can learn something from ancient design. Think about how easy or difficult is it to take out or stow away your gear when you are underway. The beads of ivory on traditional boats function to  keep the lines from freezing to the deck but also make it easier to slip a spare paddle, harpoon, norsaq or whatever under them. Since the lines were made out of strips of inelastic leather, sliders were used to adjust the tension on them. I find sliders useful to keep gear in place, so I still plan to use them even though I’ll be using bungee for my cross deck lines (over time bungees can get a little frayed from the sliders though).

Pictured above is one of Mark Wade's kayaks, with antler beads and sliders, and below a baidarka by John Petersen, with caribou antler beads and sliders carved into sea mammal shapes --really works of art by themselves.  So far I've played with making beads out of HDPE (easy to carve but difficult to sand smooth), artificial ivory (easy to sand but difficult to carve), and wood. Another possibility is making them out of bone (bones for dogs sold in pet stores are a good source), but because  HDPE or artificial ivory are less likely to scratch the deck I think are my first choices. I'm going to have to postpone making any beads and sliders until later though because there are only 5 more days until SSTIKS!