Shaping the Coaming Lip

Once all the glue had dried it was time to shape the coaming lip. First I cut off the excess strips above the coaming using a flush cut saw. I used this saw from Carbatec. Because it is a flush cut saw, I could run the saw along the coaming lip as a guide without damaging the lip.

Caption: The coaming lip after sawing off the tops of the vertical strips.

Once this was done, the rest of the shaping was done with sandpaper. I started with 40 grit and worked up to 120.

Caption: Shaping the coaming.

To sand the top of the coaming I used 40 grit paper wrapped round a section of 2 by 4. You can see this in the photo above. This allowed me to keep the top of the coaming even all the way around.

Caption: Sanding complete.

I also had to cut the bottom of the vertical strips. Once the top was done, I marked out the height using a scrap piece of wood as the template and then made the rough cut with the flush cut saw. Final shaping was again done with sandpaper.

Caption: Sanding complete.

Once the rough shaping was completed by hand, I used a mouse sander with 120 grit paper to finish the job. This was then coated with a seal coat of epoxy. Next step is to fiberglass the coaming.

Installing the Coaming Lip

I decided to build a laminated coaming lip as I have always liked the look of them. This entails building up the lip layer by layer until the required thickness is achieved. I am building the lip out of Western Red Cedar and will glass over the top of it.

To begin, I put about eight long cedar strips through the thickness planer, thinning the strips down to about 2mm. I then tried to bend a test strip around the tightest corner of the coaming (the front) but it cracked. Soaking the strips for a few minutes in hot water was enough to get them to bend around the corner. Excessive boiling or steaming not required.

Next I used a pencil and a block of scrap wood to mark the correct height all along the coaming. I then put a long taper on one end of the first strip. Once this was completed, I began gluing and clamping the strip around the coaming, starting from the beveled end. One strip made it about 2/3rds of the way round. This end was then butt joined to the next strip and the coaming continued. When I reached the beveled end of the first strip I just continued on, overlapping the first strip.

Caption: Never enough clamps.

This was a bit fiddly as I had to remove the earlier clamps to place the second layer of strip on and then reclamp them in place. I was lucky as I had my clamps plus a load of other clamps I was able to beg, borrow and steal. This process continued until I had about 5 layers of cedar built up. The end of the final strip was also cut and beveled to finish in the same place as the first bevel giving a uniform thickness all the way around.

Caption: Re-gluing a few problems spots.

The next day, I removed all the clamps and found I had to reglue a couple of spots. I think there was too much water in the cedar and not enough glue in these areas. I applied more glue and clamped these spots for one more day.

Tip of the Day: If you need to soak your strips to get them to take the curves, then make sure your glue is capable of sticking to wet wood. Otherwise, clamp the strips to the form overnight and let them dry out. Then do your gluing with the pre-bent dry strips.

Fiberglassing the Coaming

The order of the steps in which to build the coaming varies a bit depending on who you listen to. I chose to glass the outside of the coaming as the next step.

Before fiberglassing, I created a fillet between the deck and the coaming. This adds a bit of strength but also creates a rounded edge for the glass to go around. (Fiberglass does not like hard edges.) The fillet was made of epoxy thickened with dust from my earlier sanding. I wanted something that would blend in with both the cedar and the paulownia so I used a mix of dust from both woods. I also added a bit of flour (baking not wood). I read somewhere that plain old kitchen flour acts in the same way as silica, thickening the mix so that it does not run and lightening the colour slightly. It seemed to work well enough, but I can’t find the original reference so proceed at your own risk.

Caption: Front of the cockpit with external glass.

The fillet was applied using a ziploc bag like an icing bag and then rounded with a popsicle stick. I then covered the outside of the coaming, the fillet and a few inches of the deck with a piece of 6 oz (200 gram) fiberglass cloth wet out with epoxy.

Caption: Stern of the cockpit.

I let it set for a few hours and then put on a second fill coat. Next step, the coaming lip.

Tip of the day: When you are sanding the hull. save the dust in ziploc bags or tupperware containers. You can use it later to make putty or fillet material. If you run out, you can easily make more using a belt sander with a collection bag and a scrap of wood.

Installing the Coaming

Once I belt sanded the strips, I found they were flexible enough to fit the curves I had. However, this is a big, open cockpit and your mileage may vary. I used a few dots of hot glue to hold the strips in place temporarily and more wood glue to hold them there permanently. Roughly one dot of hot glue every 3 inches of wood glue.

Caption: Look closely and you can see the hot glue dots between the deck and the coaming. (Click to enlarge.)

One thing I didn’t take into account when making up my bulk strips of cedar was that the height of the strips needs to change over the length of the cockpit. No problem though, I just broke the big strips into manageable pieces and glued them in at the right height for the section I was working on.

Caption: The final coaming strips go in. Note the different heights of each section.

I also had to brace the strips in place overnight until the glue dried, there is probably more bracing than normal required using this approach as you are forcing the pre-glued straight pieces into a curved shape.

Caption: The end result.

One of the other advantages of this approach is that the sanding is cut to a minimum thanks to the pre-fitting sanding being done with the belt sander.

Tip of the Day: Make sure your strips are straight and level when you are bracing them to avoid complications later. Be sure to look from several different angles as the curve of the hull can be deceptive.

Building the Coaming

The coaming is the raised portion of the hull around the cockpit. It reinforces the shape, protects the exposed edges and also keeps a bit of water out of the hull. On smaller, one-man kayaks it also provides a lip to hold onto the spray skirt.

Most of the instructions out there suggest that you hot glue individual pieces to the hull and at the same time use wood glue to glue them to each other. I tried this and quickly gave up in frustration. Here’s what I did instead.

I cut a bucket full of 2 inch long cedar strips. (I used the leftover bead and cove strips that I had already). I then glued these to each other using the same waterproof glue I have been using on the hull strips. I then carefully squeezed them together and clamped them on a coated piece of wood to dry.

Once they were dry, I removed the clamps, knocked them free of the board and used a belt sander to roughly clean them all up. End result, lots of large chunks of wood to glue together for the coaming rather than hundreds of fiddly little pieces.

Caption: Cedar pieces ready for gluing.

I used a melamine (formica) coated board as there was a scrap piece lying around. However, you can use any wood for a template, just cover it with packing tape first so the strips don’t stick.

Caption: One completed strip already clamped and wiped down with a wet rag. Second strip underway.

I used a straight board as the curves on my cockpit are not too extreme, however if you are trying to do this for a one man kayak cockpit you should probably put some bend into your forms so the strips are roughly the right shape. However, I found that after belt sanding the strips were still flexible enough to fit the cockpit shape.

Caption: Strip of cedar pieces drying.

The different colours in the strip above were caused by using a piece of cedar that had weathered a bit. Not to worry though, a few minutes with the belt sander once it was dry and all the strips were the same colour again.

Fiberglassing the Deck

I won’t bore you with the extended fairing, sanding, filling, fairing steps between the last post and now. Suffice it to say that it went much quicker and easier as I did not uncover any hidden surprises caused by insufficient clamping pressure and bead and cove edges.

I also didn’t bother to use the Cabot’s woodtone putty to fill the few gaps I did have. I simply mixed up my own using a mix of sanding dust and woodglue. This ended up with a much better colour match than the commercial putty. It will also be a lot stronger. In his book, Nick recommends making a putty out of sanding dust and epoxy.

Caption: The deck fiberglassed with one coat of epoxy.

Once the hull was ready I wet it down with a damp rag to raise the grain and gave it a last light sanding. A final dusting with a clean rag and it was time to start fiberglassing again.

Caption: The (almost) final fiberglassing job with the extra glass trimmed away. One more coat to go here.

Again, I won’t bore you with the fiberglassing steps, if you are interested you can read more about how I glassed the hull.

Tip of the Day: Don’t bother purchasing expensive wood putties, make your own with epoxy and sanding dust or even just wood glue and sanding dust. It will be cheaper, stronger and match the colour better as well.

Bow Stem

The treatment on the bow stem is the same as has been shown earlier here and here. Cut some thin strips of cedar, soak them in boiling hot water, prebend them on a cheap form made with nails and scrap plywood and glue to the hull.

Caption: Soaked cedar strips left on the form overnight to dry. (The blue tape prevents the steel nails from staining the wet cedar.)

Clamping these is a royal pain as there is nowhere useful to clamp to. I made it a bit easier this time by gluing it up in several sessions. That way I am only wrestling a couple of strips of cedar at a time instead of an entire stack of slippery, glue covered strips.

Caption: The final build up (6 layers) of cedar strips.

Next, more longboarding and fairing.

Tip of the day: Steel nails will stain wet cedar, even overnight. Ask me how I know this.

Disaster and Disaster Recovery

Doh! It turns out that when I was taping all the form edges I neglected to tape the tops of the temporary internal stems at the bow and the stern. As a result the strips (especially the centre cedar strip) glued themselves to the stem forms. This required lots of prying, chipping, levering and praying to get off.

In the process I ended up breaking the deck in two across the stern. Lots of rude words were uttered let me assure you. However, I won’t repeat them here. Suffice it to say I was… annoyed… at my oversight.

Caption: The break across the stern deck.

The break was not this large to begin with but it quickly expanded to the length of the deck between the stern and the cockpit as I moved it around.

Caption: Another view of the break.

Fixing this was a matter of lining the two pieces back up, applying copious amounts of glue to the new join line and taping and clamping the join tightly together overnight.

Caption: Tape and clamps hold the repair together.

I used a LOT of packing tape to get the join as tightly back together as possible as I don’t want this repair to be visible. The blue tape is nothing special, just another roll of slightly stretchy packing tape.

Caption: Repair clamped, just have to wait now.

I am pleased to report that the break was fairly easy to repair and there is now almost no sign that it ever occurred. There is a glue line where the repair was done, but it is very hard to see unless you are looking for it. More obvious is a couple of small chips where some wood was lost at the join. Hopefully I can fill these in before fiberglassing.

Caption: The finished repair.

Tip of the day: Make sure that every surface of your strongback that is not intended to be permanently attached to the boat is covered in a layer or two of packing tape.

I also had to do a similar repair on the bow, but the repair process was identical. Luckily I had not attached the external stem yet, so the repair will be mostly hidden by the stem at the bow.

Cutting Out the Cockpit

With the stripping done, it’s time to cut out the cockpit opening. First I used the paper pattern to make sure what I had marked out as the cockpit was even on both sides, centered on the deck and over the correct forms.

Once I was happy I had the correct opening marked on the deck, I cut it out using a jigsaw. I was careful to cut just inside the line so that I could work back to the final marks later using the Ryoba saw and sandpaper.

Caption: Cockpit opening done!

Once the rough cut was made, I carefully worked back to the marks with the Ryoba saw. Final fairing was done with 60 grit sandpaper glued to a very flexible board. This setup is similar to the longboard I used on the hull but it is much thinner to allow the sandpaper to curve to fit the cockpit edge. The fairing board I used was only about 4mm thick (.15 inch).

Caption: Cockpit opening done.

I was quite worried about this step leading up to it as there is a large emotional barrier to taking a jigsaw to the deck after all the time I spent building it. However, in the end this was pretty painless and went fairly quickly. All in all not nearly as hard as I feared.

The Hull

Here are a couple of shots of the hull off the strongback. In the immortal words of Louis Winthorpe III: Looking good, Billy Ray!

Caption: Fiberglassed hull on the shop floor

The lighting in the shop is a horrible mix of flourescent, incandescent and natural. I had to take the hull outside to see what colour it really is. It turns out to be much less yellow than seen in most of the photos to date.

Caption: The hull in full natural light.

I have also realised that the camera in my phone is far inferior to my real camera. It gets points for portability and handiness, and can even take a decent photo in full light. But in the dodgy light of the shop it’s not the best. So no more crappy phone photos from now on.

P.S. You can click on any of my photos for a larger view.