Carbon Fiber Layup On Coaming

The cockpit rims on these boats are being finished with a carbon fiber layup. The fabric is 5.5oz twill weave from U.S. Composites. I cut an oversized piece and laid it over the coaming and cockpit opening, gently smoothing the wrinkles and puckers by hand.

After I was satisfied with the way the fabric was laying I poured a generous amount of unthickened epoxy around the rim. I worked the epoxy into the carbon fiber using a plastic squeegee and a disposable chip brush. The squeegee was used to hold the fabric from sliding while I pushed and dabbed with the brush to work the epoxy into the fabric.

Once the fabric was thoroughly saturated I laid pieces of fiberglass cloth over top of the carbon fiber and wet out the fiberglass with more epoxy. I read so many posts on the forum warning that carbon fiber should be covered in fiberglass to help contain sharp splinters and shards in case it shattered, that I became convinced it was just a ticking timebomb ready to explode at any moment and shower any unsuspecting bystanders with "Carbon Fiber Shrapnel".

Decking

Tie-down straps secure deck in place for nailing

Full sheets of plywood are laid on the hull and traced to the shape. Each piece is rough cut to size and secured down with straps. A marking jig is used to draw a line on the top of the deck for nail placement. Care is taken to place nails in the center of the sheer clamps.

The underside of the deck is coated with unthickened epoxy to seal it. The sheer clamps are coated with thickened epoxy, and the deck is positioned, stern section first.

The front section of deck is two pieces epoxied together with a scarf joint

The deck was nailed in position with bronze ring nails approximately four inches on center. The nails are redundant once the thickened epoxy cures. I debated not using the nails, but I could see the whole process going sideways without them.

Once the deck was securely attached, I used a jigsaw to trim close to the sheer, and finished with the block plane.

The glued and nailed deck is trimmed to the sheer

The Gluing

Carbon Fiber sleeves hold bungee that holds I-pod

Fillets provide strength to the joins between hull panels. The fillet is made by using an epoxy & wood flour mixture and spreading it in the seam between two panels. Much is written about fillets, the manual stresses the importance of good fillets, the forum discusses various techniques & tools used to get perfect fillets, and many builder blogs highlight the process.

Arriving at the point where I needed to start filleting my seams I had read everything I could find on the subject. It really boiled down to a few simple concepts.

Work Efficiently - I needed to plan the process, there are some great videos on YouTube that show the steps of filleting the seams in various boats. I watched the videos and mentally applied the techniques to my boat. Every process has bottlenecks, and I looked for the steps that had the potential to slow down the operation. I arranged my tools as I would need them, made sure I had plenty of mixing cups on hand, and cut my fiberglass tape to size.

Work Neatly - Simple steps like running a strip of tape along both sides of the seam with the desired width of your fillet in between kept my cockpit from becoming one very large fillet.

Work Quickly - The good news is that the Chesapeake kayaks can be done in sections, with the bow, cockpit, and stern sections separated by the bulkheads, I didn't need to attempt the whole boat in one go. However, once I started filleting a section I had to move quickly to get my epoxy mixture out of the cup and into the boat before it stated to firm up and became unworkable. Each fillet was then covered with fiberglass tape, while still wet, and the tape was wet out.

The manual presents two different approaches to addressing the copper wires when doing your fillets. The first approach is to leave the wire in place and run your fillets over the wires and encase them in epoxy. The twisted section of the wire on the outside of the hull is snipped off and filed down once the epoxy fillet has cured. The second approach is to tack the seams together with small dabs of epoxy/wood flour mixture. These dabs are placed between the stitches, and once cured will allow you to remove all the wire stitches before filleting.

I tried both techniques, on the 17LT I left the wires in, and on the 16LT I removed the wires. On any subsequent builds I will certainly remove the wires. The manual says when you leave the wire in, just cut it as close to the outside surface of the hull as you can and file down the nub. The manual does not say what a pain in the butt this is.

Help Is A Mouse-Click Away

So, you're building a boat in your basement? There's a "Support Group" for that. I've done my share of internet forum surfing, forums are great sources of information. The CLC  Builder's Forum is an exceptional resource for boatbuilding. I've spent many hours going through the forum topics, reading several thousand posts on all topics.
The "experts" are knowledgeable, encouraging, courteous, and extremely helpful. This forum is a treasure trove of terrific information freely shared in a friendly environment.

Most common piece of advice on the CLC forum - You can't have too many clamps.

One good thing about building two boats at the same time, is being able to try different approaches to the same task to get better results. When I glued the sheer clamps to the hull side panels on the Chesapeake 16lt I wasn't as careful with the excess glue as I should have been, the panels ended up being a little stuck together and were difficult to separate. When gluing the 17lt I was much more careful and the panels came apart easily.

The sheer clamps are long strips of 3/4" stock glued to the tops of the side panels, the deck will attach to these.