Strip Planking by Nick Schade [video series]

Strip Planking 01: Cutting Forms for Strip-Built Kayaks:

Nick Schade writes: The first step to assuring your boat comes out right is to assure you have accurate forms. You could buy a kit with pre-cut forms made on a CNC machine, but if you want to do it all yourself, cutting the forms from the paper patterns provided in the plans is not hard.

The patterns in the kayak plans from Guillemot Kayaks are all full-size and drawn out in full. This means you can just glue the plans to your forms material and cut out around the lines. Cut out each individual pattern leaving about 1/2" around the outside. I typically use Medium Density Fiberboard (MDF) for the forms because it is dimensionally stable, doesn't have any interior voids and holds a staple pretty well. It is a little heavy, which for a large boat can make the set-up strongback with all the forms may be heavy, but if this is a concern, you can cut holes in the forms to make them lighter.

In this case I bought 2 foot by 4 foot pieces of MDF from the local big-box homecenter. This size is easier to handle than a full 4x8 sheet. It is lighter and fits in the back of most cars. It costs a couple dollars more than the equivalent amount of material in a full sheet, but the convenience may be worth it.

I lay out all the patterns on the MDF seeking an efficient arrangement that uses as little material as possible. I start with the patterns up-side-down so I can spray them immediately after I find my arrangement. I use a spray adheasive such as 3M Super 77, spraying a mist over the back of the patterns, then lifting the patterns and spraying the MDF. Align the patterns back in place, then start by sticking down one edge, holding up the other while you wipe your hand from the stuck-down end to the lifted-end. This way you won't get wrinkles in the pattern.

Next, roughly cut out each form as shown in the video. This makes the pieces easier to handle when you go to make the accurate cut. Just hack the pieces out, don't worry too much about the outline, just cut into the actual form.

With a bandsaw, cut around the outline. I cut in a clockwise manner, with the form to the right of the blade and the scrap going to the left. Cut right up to the line, leaving the line to pass just to the right of the blade. I generally try to make this my finished cut. If you are having trouble keeping close to the line, you can sand down to the line later with a table mounted belt or disk sander.

On tight rounded corners, you may find the blade wandering away from the line. Back up the forms slightly and cut back on the line.

On sharp corners such as hard chines, cut straight past the corner, then come back and cut on the new direction.

With an internal strongback for a kayak, you need a hole cut through each form. It is important that this hole is accurate. I accomplish this in a couple steps. First I drill holes at each corner, just inside the line. Then I saw out the bulk of the material, leaving about 1/16" to 1/8" from the line. Then using an accurately cut template, I use a template-following router bit and a router table to make the final accurate hole.

 

Strip Planking 02: Cutting & Milling Cedar Strips

This is my setup for milling strips. I use a Delta Unisaw, with a Freud "Diablo" blade, the fence is the Delta "Unifence". I've got a couple saw horses on the in feed side and a table on the out feed side. I use a Delta power stock feeder to drive the wood and a magnetic feather board to hold the wood against the fence. I don't yet have a good dust collection system so in this case I am using 2 shop vacuums, one drawing from the top and another from the bottom.

In this case I am milling 1/8" thick mahogany strips from a 2" thick plank. Normally I would prefer a thinner (3/4" - 1") plank, but to get enough wood for this particular project I needed the thicker stock. I will later take the 2" wide strips and rip them into narrow strips. I have not yet decided exactly how wide.

The boat I am building will have "book matched" strips so I have a rack set up on saw horses to hold all the strips in order as they come off the board.

 

Strip Planking 03: Ripping and Sorting Cedar Strips

The 2" strips were too wide for the kayak I am building so I ripped them in thirds. I will be "book matching" the strips on the boat, so I am keeping the strips in the order they came off the plank. As I rip the strips into thirds I sort each third into groups of corresponding thirds from all the other strips.

To help maintain the order of all the strips I number them individually. Since each strip may be cut into several pieces I repeat the numbers in several locations along the length. Some of the strips will be flipped over to make the mirror-image pattern on the kayak so I repeat the numbering on the other side of the strips.

A reference line is drawn across the strips to facilitate easier alignment of the grain when installing the strips on the boat. I put single reference lines on one side and double lines on the other to help mark which side is which.

The groups of strips are then bundled together ready to be used on the kayak.

This whole process took all day for enough strips for one boat. This is a bit of a tedious task, but the effort can produce quite a striking effect and all the prep-work saves time in the long run and helps prevent mistakes.

 

Strip Planking 04: Shaping Internal Stems for Strip-Built Kayaks

I pre-shape the internal stems before installing them on the forms. I start with an over-sized piece of wood so I have material to hold on to while shaping. The wood can be any light-weight species. In this case I used pine that I ran through the thickness planer to bring it down to 1/2" thickness. Cedar would work as well. You could use a hardwood for strength, but this area is actually pretty strong even without an internal stem. Mainly the stem serves as a solid point to attach the strips while build.

Use the bevel-line on the end forms as your stem pattern. Cut out the end forms to the outer line, then cut off the stem pattern by cutting at the bevel line. The stems often come to a sharp, tapered point at the bottom and/or top. There is no reason to make the internal stem this pointy. Instead I mark of a little radius where the pattern starts to get narrow and sharp and then just cut it off short.

Trace the pattern on to your stock. Try to align the longest axis of the pattern with the grain of the wood you are using. Extend the ends of the pattern off the edge of the board in a smooth curve. Mark the inside edge of the form but don't cut it yet. Cut out the stem, following the outer line.

Back at your workbench, flip the stem over and trace the inner line on to the back side. This way you have the amount of bevel indicated on both sides. Mark a centerline down the middle of the edge of the form.

Use a block plane to create the bevel. Plane a flat bevel, adjusting the angle so it touches the centerline and bevel line approximately simultaneously. Work incrementally. Make a straight bevel then work it into a curve following the bevel line. Shape both sides

When you have finished shaping, use the stem pattern to restore the bevel line on one side. Cut off the stem on the band saw, following the bevel line. Clean up the sawed edge with a little sanding.

 

Strip Planking 05: Setting Up Forms for Strip-Built Kayaks 

Here I show using an aluminum strongback and spacers to quickly and accurately set up forms. This same technique would work with a plywood box beam. The aluminum is more rigid, but the plywood will work as well.

My newer book "Building Strip Planked Boats" includes a description of the spacer method of setting up forms on an internal strongback.

 

Strip Planking 06: Installing the First Strips

The first strip on the boat is the most critical because it defines the flow of all the rest of the strips. If the first strip is not fair and smooth, all the other strips will also be out of fair. With these boats (a microBootlegger and a new solo version of the same) I want the side strips to run parallel to the waterline instead of following the sheerline, so I am keeping the strips flat on a horizontal plane. This is a little easier than some designs where the sheer has a lot of curvature and there is a sharp angle between the deck and the hull. With the strips I am installing here, the part-line between the deck and hull is fairly flat and smooth so I don't need to create a rolling bevel on the first strip.

Since I am book matching the strips on these boats, I have reference lines I marked across all the strips to help line up the grain. I use these line to be sure the grain ends up in the same place on both sides of the boat as well as on adjacent strips.

 

Strip Planking 07: Stripping a Wooden Kayak

In this video I am continuing with the stripping on the side of the kayak. Because of the fairly plumb bow and stern of the microBootlegger design, these strips run straight of the ends. This makes the stripping fairly straight-forward as there is no shaping involved beyond the rolling bevel.

I show a quick shot of how I estimate the bevel angle as I proceed down the length of the boat. The numbers at each form are just a quick reference so I can keep track of where I am in the beveling process.

Finally I installed an accent strip. This strip is curly maple and the board was shorter than the boat so I have to join it together end-to-end. I do this by cutting a quick butt-joint and then gluing the joint with Cyanoacrylate (CA) glue. A quick spritz of the accelerate sets the glue up and it is ready to install.

 

Strip Planking 08: Stripping The Bottom Part 1

In this video I am stripping up the bottom. I am doing a "straight" stripping pattern where I strip up one side completely without stripping the other side. I then come back and trim the strips to follow the centerline.

This work is a lot of the same, over and over. I dry fit the strip, check the tightness of the seam between the strips, bevel if necessary, check the tightness again if needed, apply glue to the previous strip, set the new strip (aligning reference marks to keep the grain aligned), clamp the strip to the forms, tape the strip tightly to the previous strip, and then let the glue set up a bit (in this case by installing a strip on the other boat I'm building), then strip off the clamps and the tape (If I am moving fast, I'll leave the tape on until after the dry-fit/bevel step) and then repeat the whole process.

You may notice that late in the video, I start using some colorful spring clamps between the forms. I am experimenting with these to see if they will help keep the alignment between strips. I have not decided if they are worth the effort yet. You may further notice that I am not using a lot of hot-melt glue. I'm finding that the strips are staying down on the forms nicely and not moving much. If I can get away without using glue, it will make it easier to get the boat off the forms later.

 

Strip Planking 09: Trimming the Keel Line

In the previous step I stripped up one side, letting the ends of the strips overhang the center or keel line. In this video I am trimming off those ends so the keel line is straight and true.

First I transfer the center line to the outside of the strip using a little marking gauge made from some scrap plywood. The gauge extends the center line marked on the forms out to the top. I make a little pencil mark on the strips. I then connect these dots using a scrap strip clamped along the marks. After making sure the spline-strip is straight and true, I mark the line with a pencil.

I'm using a small Japanese Pull Saw. I cut proud of the line so I have room to adjust things if I make a mistake. Then I use a rabbet block plane to ease in on the line.

 

Strip Planking 10: Stripping The Bottom Part 2

In part one of stripping the bottom I did not need to worry about the length of the strip much, I just left them over long then trimmed them back when they were in place.

Now I need to fit into the space remaining. Therefore I need to taper the ends. Since I am book-matching the strips, I also need to worry about grain alignment.

Since this boat is using book-matched strips where the strips on one side are aligned with the grain on the other side of the boat and each adjacent strip line up with each other, it is important that this pattern be maintained. To do so I must cut the taper at each end quite precisely. I start by marking the alignment of the strip with some hash-marks that across adjacent strips. I then back of the strip so I marking the taper with the strip a little longer than its intended length. I mark the taper, rough it out with a jack knife and fine tune it with a plane. I then try the fit, checking that the taper is correct and the angle of the bevel forms a tight joint.

Once I get the taper correct, I work on the length, planing away at the taper until the hash marks line up. If I am careful to maintain the taper and bevel as I go I end up with a tight joint with the grain in the right place.

The next obstacle on the bottom is that each strip has two ends. I must go through the same process on both ends. So, after the first end is fitted, I clamp the strip in place and make hash marks on the other end so I can repeat the process.

Once fit, the strips are glued, clamped and taped in place just like the first half.

 

Strip Planking 11: Fixing a Popped Seam

It will happen that as you are building a strip-planked boat, one of your seams will pop open. If you are using staples, you may be able to add glue, squeeze it closed and shoot another staple into it, but if you are trying to avoid staples, you might need to seek other solutions.

In this case I had two strips separate near the stern of the microBootlegger I am building. This can be a difficult place to clamp. My solution was to hot-melt glue on some clamping blocks then use a small spring clamp to pull the seam together. Before placing the clamp I injected CA Glue into the gap, then after clamping, I sprayed the area with the CA glue accelerate.

 

Strip Planking 12: Repairing a Damaged Strip

With book matched strips you can not throw out a damaged strip because doing so would disrupt the pattern of the grain. Instead you will need to repair the damage. If the strip is just broken you can glue it back together. In this case the edge of the strip was torn up and ragged.

I decided to make a "dutchman" for the damaged area. I started by planing away the damaged area with a block plane. I bent the strip slightly so the straight cutting action of the plane would create a shallow hollow in the edge of the strip.

I then found a piece of scrap that was a pretty good match to the area of the repair. I cut this to the approximate size and planed it down so it would bend into the damaged area easily.

I then applied a little CA glue to the newly planed surface and sprayed the repair piece with accelerate. Then, being careful not to touch the glue with my fingers, I pressed the two pieces together and held them for a few seconds.

This was enough to secure the repair in place. Now I just planed off the excess wood to leave a continuous, smooth strip. When installed in the boat this repair will be hard to find.

 

Strip Planking 13: Closing the Bottom

The last strip to close the bottom always takes time. The narrow remaining gap must be matched quite precisely for a tight fit.

Part of the difficulty is the narrow strip is quite flexible. When you try to plane the strip, it just flexes away without being cut by the plane. The first solution to this problem is to be sure your plane is very sharp. A sharp plane requires less pressure to get the same cut. The next solution is to back of the strip somehow so you can apply pressure. In this video I do this in several ways. First by planing on the bench, or on the boat itself. I also show a way to make a quick and dirty tool to hold the strip as you plane.

This jig is just a scrap strip with a couple scraps glued on either side to hold the strip you are working on. Without the side pieces, the strip won't stay aligned. This is not necessary if you are using cove and bead strips, but it helps with square edge strips.

I mark the approximate shape of the strip by reaching inside and using a pencil to mark the shape of the gap. The finished strip will be bent. To mark it, I flip it over and hold the curved edge against the straight keel line. When I install it I flip it over and bend it into place.

You could whittle the strip down to size with a jack knife, but with this length it is quicker to just saw off the excess, leaving a good amount of wood before the marked line. Start planing just smoothing out the saw marks.

Mark where you want the grain to line up, or just start at one end. Work to get one end fitted tightly. If the fit gets loose, you can push the taper farther in to wedge it tight again. When on end is fitted, mark the strip alignment near the other end for easy reference. Work on fitting the other end until you get a tight fit and then plane away at it to adjust the over all length.

 

Strip Planking 14: Sanding the Hull

If you are careful gluing up your strips, the sanding can go quite quickly. My process here was:

• Scrape the Glue
• Rough Sand with 60 grit using a random orbital
• Roughly fair with a long board
• Scrape down high spots
• Do a more complete fairing with the long board
• Sand again with 60 grit to get a uniform surface
• Move up to 80 grit
• Random orbital
• Hand sand
• Move up to 100 grit
• Long Board
• Random Orbital
• Hand sand
• Wet-down the wood
• Move up to 120 grit
• Random Orbital
• Hand Sand

I vary this process depending on the boat and what I feel like.

 

Strip Planking 15: Fiberglassing the Hull

This video shows the fiberglassing of the hull of the microBootlegger. I'm applying one layer of 4 ounce E-glass with a coat of epoxy resin. After the wet-out coat of epoxy starts to set up I apply a thin fill coat.

Before I started I turned the heat in the shop up to 80° F (27° C). After rolling the glass on to the boat I let it all warm up for several hours. I also put a work light behind the jugs of epoxy to warm them up.

By the time I actually started applying resin, both the boat and the epoxy were quite warm. This lowered the viscosity of the epoxy and allowed it to soak quickly into the cloth. Because the shop was so warm I had to work quickly as not only does the heat effect the viscosity of the resin, it also reduces its working time.

I mixed small batches of resin so it would not set up too much before I had a chance to get it on the boat.

After I finished wetting out the cloth, I inspect the boat to look for starved spots, then squeegeed off the excess resin. I slit cut into the edge of a paper cup makes a good tool or "grunge cup" for removing the epoxy from the squeegee.

After another inspection, I left the boat for a few hours until the resin had set up enough that it would not float up on the fill coat.

 

Strip Planking 16: Removing White Glue Lines

Sometimes when you are using carpenters glue between strips, you will end up with white glue lines. These lines are typically due to the glue being too cold as it dried.

One way to make the lines disappear is to heat them up with a hot iron. This heats up the glue enough to melt it slightly. When it cools off it becomes clear.

You could probably use a heat gun as well, but it will heat up a larger area and you may soften the glue to the point that the seams pop. That would not be good.

 

Strip Planking 17: The Cotton Swab Test

When is the best time to apply the next coat of resin? It all depends. But if your schedule allows, you will get the strongest bond when the prior coat is not yet cured. But if you do it too early, when the prior coat is still wet, you may float up the fiberglass, or you may not create the build you want. If you wait too long, you will need to sand.

MAS Epoxies suggests a "cotton ball" test. When the epoxy is still wet the cotton ball will not stick. When the resin is too dry, the cotton won't stick. In between this two extremes is a period when the epoxy has stiffened up somewhat but is still tacky. During this period, the resin will grab the cotton fibers and pull on the ball or swab. This is the best time to apply another coat.

While the epoxy is tacky, new coats will not mix in with the prior coat, or get under the fiberglass. If you wait longer it is not a big deal, but you will need to check for blush, and clean it off, and then you will need to sand. As long as you can push your thumb nail (the "rule of thumb") into the dry resin, you do not need a heavy sanding, but a light sanding will promote a better bond.

 

Strip Planking 18: Trimming off the Excess Glass

After you have wet out the fiberglass and the epoxy has set, you can trim off the excess 'glass. This is easiest done as soon as the epoxy has set up to the "green" stage, i.e. when it is dry to the touch, but still a little rubbery. You can wait longer, but as the epoxy gets harder everything is more difficult to cut.

Here I am using a jack knife, but a utility knife with a sharp new blade also works very well. Slice into the cloth tight up against the edge of the wood strip. Hold the edge of the blade against to the wood so you get as clean a trim on the first go as possible. Cut by smoothly and evenly pulling the blade along the edge. If your blade is sharp the glass will cut easily.

Avoid the inclination to "saw" at the edge. This will not make it any easier and your cut will be more ragged and it will take longer. If you are having trouble cutting cleanly, try pulling a little tension into the cloth.

After the initial trim, I flipped the boat over and cleaned up the edge a bit. I probably would have gotten a cleaner initial cut if I had flipped the boat first. Instead I used my knife to remove the biggest ragged edges. I then took a couple passes with a rabbet plane to remove the remaining edge of glass, making it flush with the wood.

 

Strip Planking 19: Releasing Forms in Staple Free Construction

I used hot-melt glue to install the strips, this let me avoid putting staples in the strips. But now the boat is glued to the forms. Before installing the deck strips, I want to release the hull from the forms as it will be more difficult once the deck is also glued down.

I need to break the glue that holds the hull in place. To this I will pound on the forms with a hammer. But, if I were to do that now, with the forms securely attached to the strongback, they would not move much when I pounded on them and as a result might not force the glue to break. So, I release the forms by removing the spacer wedges installed earlier. This frees up the forms to move.

With the forms freed, I can now tap on the forms to break the glue. I hit the forms so they will move towards the wider part of the boat. In other words I hit the front forms backward and the aft forms forward. This lets them get looser as they mover instead of driving them into a tighter region.

I had not needed to use a lot of glue to keep the strips on the form, so I did not need to hit the forms very hard to break the bond. Each form was probably only glued in 3 to 5 locations.

Once the I have broken the glue, I attempt to lift the forms out of the hull to make sure it can come free. Some additional hammering of forms may be required. Also since the stern "re-curves" forward, it can not be lifted straight up. I ended up hitting the end form forward to break a little glue in the stem.

Once the forms are free, I dropped them back into the hull and then re-installed the spacers and wedges to get the forms back where they need to be to work on the deck.

 

Strip Planking 20: Installing a Center Accent Line on the Deck

I want a light colored accent strip running down the center line of the foredeck. Depending on how the strips line up at the bow, his strip may be fitted in to existing strips or the strips will need to fit in against this strip. I ended up with one of each type on the boats I am building.

After installing the centerline, the side strips are fitted up against the accent strip.

 

Strip Planking 21: Stripping the Back Deck 

The back deck of the microBootlegger has two "chines" or hard knuckles on each side and a relatively flat area in between. Like stripping the bottom earlier I stripped up past the chine line then trimmed it back to the line, cleaned up with a plane and the added strip in between. Not shown in detail here is the steps where I added an accent line along each edge.

The very stern of the microBootlegger deck has a bit of twist. I could probably have forced this twist in as I installed the strips, but I chose to pre-twist the strips just to make it a little easier. Using a heat gun I heated up the strip, then twisted it by hand and let it cool. Seemed to do the trick pretty well.

 

Strip Planking 22: Straightening a Crooked Seam

After carefully stripping the back deck, I notice the feature line had a funny bump in it. I used 2" wide strips on the back deck and as I fitted them in place I let the angle of the taper I planed on the strips push the side of the boat out a bit. Then when I installed the next strip I had to create a tighter angle to match the remaining space. This resulted in a bump along the edge. I should have been more careful in matching the strip to the space instead of letting the strip define the space.

Because I used yellow carpenters glue (AKA PolyVinyl Acetate (AKA "PVA")) which is a thermoplastic that can be softened with heat, I chose to take apart the seam between the deck and the side with a heat gun, re-trim the side of the deck and then reinstall it back in place.

I used a high-output heat gun and a putty knife to take apart the seam. First heating up the area and then pushing the knife into the seam to peel it apart. This was harder to think about than it was to actual accomplish. Within about 20 minutes the whole project was done and I could continue on with other tasks.

 

Strip Planking 23: Cutting the Cockpit Recess

I like to put what I call a "recess" around the cockpit. On some boats, like these microBootleggers, the recess is not all that recessed, i.e. the coaming is not actually set down below the deck much. But, this recess does make the coaming a little lower than it would otherwise be. What it really does is reduce the amount of curvature in the coaming. If the coaming were mounted directly on the existing deck it must follow a curve that twists and turns in all directions as it proceeds around the cockpit. Looking from the top there is the outline of the cockpit. From the side it sweeps down from the front and back up at the back. From the front it follows the arc of the deck bending down from the front towards the side and then back up again at the back.

By installing the recess which are strips running horizontally across the boat, I have slightly reduced one of the above degrees of curvature. From the front of the boat the coaming does not now need to conform to the sectional curvature of the deck. This little reduction in curvature makes it easier to install the coaming lip later on by making the transition around the ends a little straighter.

Plus, I like the look. All the above rationalization may just be an excuse for doing more work earlier on, when in fact the real reason is I just like the way this recess looks. It breaks up the line of the deck, give a feature line that serves to highlight the deck shape. By including an accent strip around the edge of the recess I add a little detail that further highlights the shape.

I used a pattern I generated using my CAD system. I taped it in place and used a jigsaw to cut out the hole. I had not determined the location on both boats so I had to cut right through the forms.

After cutting out the hole I cleaned up the edge with sandpaper and planes, then cut a thin strip of maple to serve as an accent stripe and glued this in place using green tape as clamps. The green tape is a high adhesive tape "high adhesive tape for hard-to-stick surfaces". Blue tape is generally an easy-release product that can release at unfortunate times. I used a razor blade to cut the ends of the stripes into a pseudo-scarf.

After the stripe was installed I glued up some flat panels for each end and fitted them in place. I first rough-cut the shape then tweaked the shape with a block plane and sanding block. I fit in some long strips along the side to finish up the full perimeter.

 

Strip Planking 24: Fairing and Glassing the Deck

This largely time-lapse video starts out with scraping and proceeds through sanding to glassing and finishing with a fill coat. I've found a good source of high quality scrapers that do a very nice job in the initial glue removal and smoothing. I then switch over to a long board with 40 grit sheets. From there I move up to 60 grit to remove pencil marks, then go to 60 grit with the random orbital then 60 grit hand sanding, then 80 grit with the longboard then 80 grit with the random orbital and a soft contour backer pad and 80 grit hand sanding, followed by 100 grit with the random orbital and contour pad and 100 grit hand sanding. After this sanding I wet down the whole boat with fresh water. Not shown is a final hand sanding with 120 grit.

It was now time to lay on one layer of 4 ounce fiberglass. The temperature in the shop is set up to 80 degrees F and the resin has been pre-heated. I wet out the cloth then squeegee off the access. When done I turned down the heat to 70 degrees F. After a few hours of curing I rolled on a light fill coat. The shop temperature is returned to 60 deg F.

This was accomplished over a period of 3 days.

 

Strip Planking 25: Fixing a Broken Seam 

While rolling out the fiberglass before glassing the deck, I ended up cracking a section on the back. The break was along a glue line.

To fix it I just glued it back together. First I put tape on either side of the break to keep from messing up all my sanding. I then injected some glue into the crack. I used green tape to pull the joint tight and reached in underneath to press the seam smooth and flush.

I was in a little bit of a rush so I heated the broken area with a heat gun to accelerate the drying. When it was set up fairly solid, I pealed the tape and sanded off the little bit of glue with 120 grit sand paper.

 

Strip Planking 26: Installing the Coaming Riser

The coaming "riser" is what I call the vertical part of the combing around the cockpit. This is made of the same wood I made the rest of the boat from. For efficiency reason I want to use the 2" wide strips I have, but these don't conform to the sharp curves at the front and back of the coaming. To keep the pattern consistent I chose to rip some of the strips in 1/2 or 1/3rds so each individual piece is narrow enough and then glue them in place in order.

I use hot-melt glue to hold the strips to the edge of the cockpit hole and then use carpenters glue between the strips. The hot-melt sets up fast so I can work quickly but the carpenters is stronger so the final result will be strong. This will all eventually get covered with fiberglass so strength will not be an issue

I strip from the front back and then from the back forward, meeting int the middle with the closing strip shaped to fit.

 

Strip Planking 27: Fiberglassing the Exterior of the Coaming

After installing the riser, I glassed the outside, reinforcing the coaming and securely attaching it to the deck. The riser was initially installed using hot-melt glue which is not particularly strong. It is used because it is quick. The strength comes from the layers of fiberglass installed here.

I start by masking off the deck about 1" from the riser. This masking tape will be used later to clean up the edge of the glass. I then cut several strips of bias-cut glass. This bias tape is useful because it distorts easily which allows it to conform to the curves and form to the angle between the deck and hull. I cut enough 4" wide strips to go all the way around the cockpit once and then set of 2" wide to do the same.

The 4" wide strips go down first extending from the top of the riser strips down onto the deck and overlapping the masking tape. Before applying the tape, I brush on some resin. This resin will help hold the glass in tape as I lay it around the coaming.

I am careful not to pull on the tape as this will stretch it and make it narrower.

The cloth is seated in place with gentle dabs of the brush. Stroking the bias tape will stretch and bunch it up.

I wet out the pieces one at a time and then overlap the ends about 1/2" until I've gone all the way around. This I applied the narrower strip. This one extends from the top down on to the deck about 1/2". I want two full layers at the sharp angle but want to be able to feather it out smooth on the deck.

After the resin has set up to the point that it is a stiffened but not yet rubbery, I use a utility knife to trim off the glass just inside the masking tape. I apply just enough pressure to cut through the fresh cloth. This does not take much pressure, just a light touch. Peeling up the tape removes the cut-off fiberglass.

 

Strip Planking 28: Smoothing the Deck Interior

Unlike the outside where sanding is easy, the inside can be harder to to smooth. I find scrapers are the easiest way to deal with the concave surfaces. A set of scraperswith a variety of different blade profiles can make relatively quick work of the task. I have a selection of different scrapers that I have modified with different shapes to fit the various contours of the boat.

After scraping I wrapped a chunk of foam with 40 grit sandpaper to further level the surface. A few more touch-ups with scraping and more sanding with 60 grit prepared the surface for carbon fiber.

Since I am using carbon fiber fabric which is opaque, I do not need to achieve a cosmetic finish, coarse sandpaper is enough. The rougher surface makes a better bond with the resin.

 

Strip Planking 29: Laying Carbon Fiber Cloth on the Deck Interior

Laying carbon fiber is not that different from fiberglass accept that it is black, and stays black. Where fiberglass starts white and becomes transparent when saturated with epoxy, carbon fiber stays opaque, so it can be tricky to tell if it is fully saturated. Where bubbles under glass are clearly visible you may not find bubble under carbon fiber until after the epoxy has set up. You may actually never find a bubble.

I am using 6 ounce carbon fiber here. Because it is a heavier cloth than the 4 ounce glass I am using it will need more resin. And since carbon is less dense than glass, the same weight cloth is thicker than fiberglass cloth would be, this means it needs even more resin. If you have calibrated yourself to understand how much resin is needed to fill an area, you will need to apply a lot more resin than you are used to.

I am rolling on the resin with a paint roller so I don't have to move the resin around through the cloth as much as if I dumped and spread.

I have the shop temperature turned up high (80° F, 27) to keep the viscosity of the resin low and aid penetration into the cloth. A consequense of this is the resin sets up fast. Therefore I am working on small areas at a time, wetting out the fabric spreading out the resin and then scraping off the excess.

The only way to tell if the fabric is fully saturated is to inspect it carefully. Low, glancing light will help highlight bubbles which usually indicate under saturated cloth. A blacker, less shiny spot is also an indication of insufficient resin in the cloth. If the cloth lifts easily off the surface while rolling on resin, that is a good sign that it has not yet wetted all the way through to the wood.

 

Strip Planking 30: Glassing the Interior of the Coaming

To this point I have only glassed the outside of the coaming. Now that I have applied carbon fiber to the interior of the hull I can proceed to glassing the other side of the coaming.

The first step is to clean up the edges of the carbon fiber. I start by trimming off the fabric with a sharp utility (box-cutter) knife. I try to trim as close to the wood as I can, but inevitably I leave a little edge sticking up. This edge can be quite sharp, especially as the epoxy gets harder. I generally trim this off with a block plane, but a bit of coarse sandpaper on a block will work as well. I trimmed both the sheer edge and the cockpit edge.

Next the rough surface of the coaming needs to be sanded smooth and fair. Wrap the coarsest sandpaper you have around a cylinder of foam or other soft material. Sand aggressively. When the surface is smooth start moving up to finer grits of sandpaper. While you are at it, round over the corner between the coaming and the deck. Also sand about 1/2" onto the inside deck surface to help promote a good epoxy bond.

I'll want a clean edge to my fiberglass, so I will do the masking tape trick. First I ran tape around the perimeter of the coaming about 1/2" (1 cm) from the edge.

Before laying fiberglass on the surface apply a heavy coat of epoxy. This helps hold the cloth in place as you lay it down. I used 4" (10 cm) wide "bias-cut" cloth. Since the bias cut cloth distorts easily, handle it with care. Lay it onto the sticky surface while avoiding pulling on it.

With the fabric in place dab at it gently with a resin-wet brush to form it to the surface. At this point stroking the fabric will cause it to bunch up and wrinkle. Continue to brush down the cloth until it is fully saturated.

All this brush work may leave a fair amount of air trapped in the cloth. This is not a significant structural problem but will effect the clarity of the layup. A quick warming with a heat gun will lower the viscosity of the resin and cause the air bubbles to expand and rise to the surface and then pop. Over heating will force air out of the wood and cause more bubbles, so use this technique with care.

After the resin has set up for a few hours I trim off the glass that overlaps the masking tape. I use a very light touch to avoid cutting into the carbon fiber.

 

Strip Planking 31: Smoothing the Hull Interior

The concave shape of the interior is more difficult to smooth than the exterior. The easiest tool to use is a scraper. These scrapers are not card scrapers but more like paint scrapers. I have a selection of different shaped tools so I can work the various contours of the boat.

A sharp scraper will produce fine shavings similar to a plane, but it can also chatter and jump. If this happens it can create a serious of divots and rip chunks of wood out of your boat. I like to hold the blade in one hand while pulling with the other. The hand on the blade is there primarily to control the pressure on the wood and damp out any tendency to chatter. If the blade is sharp it should cut pretty easily without a lot of pressure. Diving grain may cause the blade to catch and jump, if so you may want to reverse directions. If you get chatter you can try reversing direction or changing the angle you hold the handle.

A mill file will do a good job of sharpening a scraper. Hold the scraper on a vice and put a fresh face on the bevel.

 

Strip Planking 32: Joining the Deck and Hull and Taping the Inside Seam

One of the more frequent questions I get is; "How do you put the deck back on the hull? How do you get the fiberglass all the way up into the end?" My standard answer is "I have a small child I send up in there." but the real answer is "Brush-on-a-stick." But, obviously there is a bit more to it than that.

The first thing I do is make sure the sheer/gunwale edges are cleaned up so the deck will fit tightly to the hull. Beveling the edges slightly so the outer edge is higher than the inner edge will help assure a tight seam.

I then place the deck on top of the hull and align the ends. As I do this, it is not unusual for the the deck to fall off the edges of the hull a little near the middle, but as long as I get the ends secured down I don't worry about the middle yet. The ends do not need to be tight yet, but I put a little bit of fiber-reinforced "filament" strapping tape around the ends to keep them in place. The 3M 893 tape works well, with good adhesive and clean removal.

I then move to the middle and use the strapping tape to start to pull the deck and hull together. It is not unusual for the deck and hull to be different widths at this point. It is fairly inevitable that they spread or curl up slightly while they are off the forms and it is too much to expect that they do this equally. However, the parts should still be flexible and it should be pretty easy to bend the hull and deck to meet each other. Especially in the middle where the boat is at its widest.

I use a metal tape dispenser that helps me pull the tape tight. It is important to pull the tape as tight as you can because this creates the friction between the deck and hull that will hold the seam in alignment. The tape dispenser has a integrated brake in the handle, the metal external flap and internal ring can be squeezed together to slow down how fast the tape comes off the roll. By squeezing this roll tightly I can pull heavily on the tape, putting a lot of tension across the seam.

First fold over the top end of the tape. This will help you later when it comes time to remove the strapping tape. Next stick the tape down on to the deck. I find at least 6" of tape on the deck is needed to keep it from ripping off when I pull on it. Press the tape down on to the deck to assure it is well adhered. Then squat down next to the boat so your arms are below the seam. Squeezing the dispenser brake, pull down hard. With your other hand, get the seam aligned. Then pull the tape down across the seam and press it down onto the surface of the hull. Do not slack up on the tension until you have adhered the tape to the hull. Then the tip of the tape dispenser has a knife that allows the tape to be cut off with a quick twist of the wrist.

At the cockpit you can now reach inside if you need to tweak the alignment of the edges a bit. I strive for a perfectly smooth transition across the outside seam. Due to slight variations in smoothing and fiberglassing, the interior seam may not be quite as smooth.

After strapping down one spot on one side, I walk around to the other and repeat the same process on the middle of the other side. From there I will split the difference between this middle taping and the end of the boat, working on one end and then the other and both sides. Reach inside the boat to help align the seams where you can. Continue to split the difference between taped spot until you have straps of tape every 6 inches or so.

Near the ends you may find that the differences between the widths of the deck and hull become harder to overcome because you can not reach inside as easily to align the seam. I will use a thin, flexible putty knife as a lever to pry the seam into alignment. Insert the putty knife into the seam a little ways away from the spot you are working, and lever it up of down to force the deck and hull edges into alignment. Sometimes this will feel like you need 5 hands to control the putty knife, the tape, and the seam all at once. If you have a friend, now may be a good time to invite someone over to lend a hand. I will add some spring clamps to the knife handle to add weight or push on it with my head as needed.

Do your best to avoid wrinkles in the tape as it crosses the seam. Any irregularity will probably get filled up with resin later on and that will be epoxy you must sand off. Burnish down the strapping tape to be very sure it won't pop off.

After the seam was all aligned and held firmly in place with strapping tape, I chose to add some suspenders to the belts I had in the form of spot-welds of CA Glue in case the tape should give way for some reason. A small dot followed by a quick spritz of accelerant does the trick. A seam that comes out of alignment while you aren't looking is a real hassle.

I then run a strip of masking tape along the seam to prevent resin from dripping through the joint and on to the floor. Again, no wrinkles and rub the tape down to be sure it is properly adhered.

Taping the Inside Seam

When the seam is secure, turn the boat on edge and tie or tape it in place it so it will not fall over.

On some boats I have "cheek-plates" in the cockpit that I can hide the ends of the seam tape behind, but not on this one, so I chose to run one continuous piece from bow to stern. I'm also using a narrow ( 1 inch ) Kevlar™ tape instead of fiberglass so the results are more visible.

I measure out the length of the seam tape by rolling it along the outside seam. I marked a point inside the boat on a length of masking tape and transferred a similar mark to the outside. I then included this mark on the seam tape. This will serve as a center mark, but also mark which end goes towards the bow. In this way I will be able to get the tape to fit inside the boat at the right location without one end being too long and the other too short. I kept the tape slightly shorter than the seam on the outside to account for the stems.

After measuring, marking and cutting the tape I transferred it to work bench covered with waxed paper and brushed the tape down with epoxy resin. The goal is to fully saturate the tape before putting it in the boat. While this resin is soaking into the tape I brush more resin along the inside seam to help hold the seam tape when I roll it in place.

Starting at one end of the seam tape I rolled it up into a tight, smooth, even coil working towards the middle until I approach the center mark I had established earlier, then I roll the other end down to the center mark.

I now transferred the tape to the inside seam. Placing the center mark in alignment with the mark inside the boat and centering the width of the tape on the seam.

At first all you must do is simply unroll the tape along the seam by hand. As the seam proceeds under the deck, reach as far as you can up along the seam to continue unrolling. Eventually you will need longer arms, a small child or a brush-on-a-stick.

The stick just needs to be long enough to reach into the end from the cockpit, with the tip cut at a 45° angle and the brush is a chip-brush screwed on to that end. Cut off any excess handle from your brush and you are good to go.

Use this brush to gently unroll the seam tape coil along the seam. Use the brush to steer the coil as it wanders off center. The seam shown in this video is about as easy as it gets because it is straight and the deck-hull joint is flat across the seam. Other seams that curve and have a sharp angle across the seam are more difficult, but the same process works.

If you mess up, and the seam tape wanders off center you may be able to brush it back into place, but if it does not go easily, your best bet is to pull the tape back, re-roll it and give it another go.

When the tape is rolled all the way out to the end, smooth it out with gentle brush strokes and then brush on some more resin.

Let the first side cure before flipping the boat and doing the other side. Let the second side cure well before peeling off the tape. If you are having trouble lifting the ends of the strapping tape it is probably because you didn't fold over the ends like I told you.

 

Strip Planking 33: Installing a Solid Outer Stem

There are a couple ways to add an external stem to a kayak. While I typically use thin laminations stacked and bent and glued in place, on these boats I want a solid piece of curly maple. Since it is hard to bend a solid chunk of wood to fit a given shape I instead needed to make the mating surfaces match.

To accomplish this I first make a pattern for the stems based on a base thickness of 1/2". Using my CAD system I create a shape that I then print out and transfer to my stem stock. I cut this out with a band saw and then used a table-mounted belt sander to close in on the defined line.

I put some masking tape on the end where the stem will be mounted but did not press it down much. I then used a caliper set at a 1/2" opening to mark where the stem is that wide. Because the tape was not pressed down hard, this pressed down the tape where the caliper touched the boat leaving a slight mark.

I used this mark as a guide for aligning the solid stem that I had cut out. Since it is based on a 1/2" width as well they agree fairly well in shape. I then traced the shape of the cut stem on to the tape.

Using the lines as a guide I used a coping saw to cut off most of the excess outside the line. Then I carefully sanded down towards the line with a belt sander, being careful to hold the face of the sander square to the end of the boat. I got as close as I dared to the line without going past.

The trick to make a tight fit is to make both surface match. My goal is to make the end of the boat match the shape of the pre-cut stem. I have a roll of self-adhesive 80-grit sandpaper that I stick to the cut surface of the pre-cut stem. By rubbing this sandpaper on the end of the boat.

This sanding removes material from the end of the boat. To make this process go faster, I use a gouge to remove wood from the middle (inner stem) of the cut end. In this way I only need to sand away at the edges where the tightness of the joint will be visible.

I continue sanding until the whole edge has uniform, even sanding marks. I then switch to finer grit sandpapers because they are thinner and will help make a tighter joint.

Once the stem fits perfectly I glue it in place. I start by coating both surfaces with regular epoxy resin, then I add thickeners to the epoxy and add another coat. The low-viscosity first coat soaks into the wood and the second coat stays in place and does not drain out of the hollow that was gouged out earlier.

The stem is clamped in place with filament tape until the epoxy sets up. Then using planes, power planes, belt sanders, disk sanders, random orbital sanders and hand sanding, everything that does not look like a stem is removed. A fine finish is put on the maple with fine sandpaper and the sharp leading edge is rounded over so the glass will wrap around it successfully.

The stem is glassed in place with bias cut cloth strips. A little bit of warmth from a heat gun clears up trapped air in the cloth.

 

Strip Planking 34: Applying a Fill Coat

A "Fill-Coat" is what I call the coat of epoxy applied after fiberglassing which is intended to fill in the weave texture of the fiberglass so that it can be sanded smooth. Previously, I had applied a light coat using a roller to start filling the weave. This coat is heavier to really get a thick base on the boat. It is possible to do this by applying several thin coats, but I like to just get it done.

The problem with a heavy coat of resin is it is likely to sag, drip and run. To avoid this the film of wet resin needs to be uniform thickness. It is a localized blob of epoxy that is going to start to flow, collect into a run or drip and create a bump. With an even coat the epoxy may flow, but it will do so evenly and remain smooth.

My technique for applying an even layer is to make sure the resin is spread out well. I do this by first applying the resin to the boat, then spreading it around and finally evening it out. I work on small sections at a time (about 12") and apply with horizontal strokes, spread with vertical strokes and then even it off with horizontal strokes again. This cross-hatch pattern helps enforce a discipline that allows for a careful application of resin.

The inexpensive "chip" brushes I use to apply the resin tend to loose bristles. This is not so much a problem of seeing bristles in the finished product, because they tend to disappear, but the stray bristle will effect the flow of the resin as gravity pulls it down the side, the result will be a bump that needs to be sanded off.

By pulling on the bristles with the tape wrapped sticky-side-out on my hand I can remove most of those that would eventually come out on their own. The CA glue helps secure the rest, and a final pull on the bristles just to double check.

A heat gun can do a nice job of popping bubbles in the finish and eliminating pin-holes. You can over do it, causing the epoxy to boil up, but with care you can have good results.

 

Strip Planking 35: Laminating the Coaming Lip

I make the lip of my coaming (the part that holds on the spray skirt) by laminating a stack of thin laminations around the coaming riser (the vertical part of the coaming). In this way I do not need to make a separate form for the lip, the riser acts as the form.

I cut a bunch of skinny strips to act as laminations. In this case I used four 1/16 inch strips plus a ~1/32" accent strip to make a lip about 1/2" (1 cm) wide. I cut the strips as thick as I can, while still allowing them to bend around the riser with out breaking. Thicker strips means fewer required, thinner strips means more flexible. The number of strips is decided by how wide I want the lip.

I used my power-feed to run 1/4" thick strips through the table saw with a zero-tolerance insert to cut the thin strips. The saw likes to eat these strips. I made a low, short fence out of another strip so the newly cut strip would (hopefully) fall free of the blade when the cut was complete.

I wrap some stretch wrap around the coaming riser to keep the lip from getting glued in place. I then butter up the laminations with glue and wrap them around the riser. I pre-mark the back center so I can get the alignment right. A bunch of spring clamps holds everything tightly in place.

After the glue cures, I strip off the clamps and re-mark the centerline. This mark at the bow is used to cut the length. I use a scraper, plane and sandpaper to clean up both sides of the lip. This clean up is why I did not just glue the lip in place initially, but you could do it that way to save some steps.

The lip is then glued permanently on to the riser. I use the end of a strip as a height gauge so the lip is at a consistent elevation all the way around the coaming. More clamps and a clean up of the squeeze out and I'm ready to let the glue cure.

After the glue cures and the clamps are stripped off, it is time to clean up the front where the two ends of the lip meet. If you are really careful with your fitting you could make this step unnecessary, but this is easier. I cut of the ends of the lip with a straight cut and then glue on another piece of wood to act as the front.

Then it is time to cut off the excess riser above the lip. I use a coping saw. I used a belt sander, plane and hand sanding to level off the ends of the riser, then sanded a nice radius on everything.

This radius allows the fiberglass to conform more easily and makes everything feel good. I have sometimes used a round-over bit in a router to do this, but hand-sanding works also.

I mask off everywhere I don't want fiberglass and protect the inside of the boat with some paper so drips don't mess up the interior finish. I will fiberglass up the inside of the riser, over across the top of the lip, down under the lip, and down the riser.

This will require "bias-cut" cloth or strips of fiberglass fabric cut at 45 degrees to the weave.

These strips are epoxied in to place. Generally I use a chip brush to wet-out the fabric, but a bent-over acid brush helps reach up under the lip.

When the epoxy starts to set up I trim off the excess glass with razor knife.