Building a West Mersea Duck Punt Variation of a Sawfish Kayak
Wanted to build a boat ever since I was about 10 years old. My Grandfather had an old boat building book on his bookshelf and I can remember a wooden pram style duck boat leaning up against the garage. When I approached my Grandfather, who was quite a wizard with wood, about building a boat, he said, "Ask your parents." who, of course thought I was much too young.
In my 20s I was able to sail an O'Day Swift wet sailor, by trail and error, after only reading about tacking. I was hooked for life on sailing.
In my 30s, living in New England, fortune smiled on me when I was able to take a few day trips with a friend that had a Contessa.
Now I'm retired, pushing 69, and finally got my wife's permission to build a boat! I live in Minnesota, Land of 10,000 Lakes, where it is almost a crime NOT to have a boat.
Designs have been researched and sketched for years, but at my age I wanted something I could car-top easily, and it had to sail and double as a fishing platform; it would be a bonus if I could paddle kayak style as well.
Duck punts are small sailing boats, from the marshy areas of England, most often it seems, West Mersea.
A small boat with a single sail, most commonly from an Optimist sailboat.
They have no center board or dagger board, and no rudder, instead they rely on the square edge of the hull heeled over to form a keel, and a paddle for steering. They are usually sailed lying or sitting in the bottom of the boat.
A utility boat from centuries of history, Duck Punts are considered the equivalent of a floating wheelbarrow, a way to get to market, haul your catch or produce to market, sneak up on ducks and geese for hunting, or to just get between islands in the marsh; only recently have they become a club and racing type of boat.
They are considered to be able to sail on very thin water, and are relatively fast for such a small sail. While sailing is what they are more known for, Duck Punts also are paddled or rowed as required.
Having previously researched teardrop trailers (stay with me here) , I found the website Teardrops & Tiny Travel Trailers and information on lightweight foam construction. Within that site was a member posting as Rowerwet who mentioned that he was going to build a boat with the foam technique. He created an Instructable about building his design for a foam kayak named Sawfish.
The wonderfully versatile Sawfish design allowed me to create, with a few modifications, a foam version of the West Mersea Duck Punt. This build journal will show my progress on the boat and the points that are different from the Sawfish Kayak.
I am an artist, I thought you might enjoy seeing some work featuring boats. They are scattererd within the build journal photos. Prints are available at various online art galleries, such as FulcrumGallery.com and Art.com, but this is not a sales site, so there is no pressure here to purchase anything.
Designing a Foam Duck Punt
Dylan Winter's web site has downloadable plans for the traditional wood West Mersea Duck Punt; using the dimensions from these plans and after reviewing Rowerwet's Sawfish building technique, I used my graphics program to lay out a foam duck punt design. I spent months trying different approaches and more months tweaking the design. This was all just design daydreaming because I had no idea if my wife would allow a "major" project since we live in a townhouse with a small double garage.
The drawings to the right and below show the concept and the construction and cutting drawings, which I will endeavor to make available to those who may want to follow in my wake!
The photos below show the stages of construction. I will not attempt to duplicate Rowerwet's fine Instructable, because that will provide you with step by step construction techniques. I will make comments when I have modified items that may be different from Sawfish.
Building a Foam Duck Punt
In laying out the points for the hull curves, I first marked my centerline on the two 4' x 8' sheets of 2" thick xps foam. Because I have a drywall square, I was able to mark the sheets with a Sharpie pen before joining them with Rowerwet's Butterfly Scarf Joint, avoiding a chalk line that might disappear at the wrong time! I then marked my stations per the measurements I found for the duck punt and used to create my design (after converting from metric to inches).
I also marked bulkheads and the point at which the rocker of the boat would be at its lowest.
Rowerwet's instructions show marking the curve with bricks to hold a piece of pvc pipe. I used kabob skewers on either side of an 8' piece of 1/4" pvc lattice trim, which gave me a square edge to trace against. I simply moved the lattice between the skewers to get the full length. Note: since the lattice is 1/4" thick, decide ahead of time which side you intend to trace.
BEACH BONFIRE GATHERING
Dustless cutting can be accomplished with a knife edge jigsaw blade made for cutting foam. I found Bosch and some other brands of blades on Amazon. I bought 4" blades thinking that would be adequate for 2" material. I believe 6" blades would have worked better because the stroke of my jigsaw actually pulled the tip of the blade up into the foam, which I think caused it to wander and not cut square. I am not positive if a 6" blade would cure the problem, but if I built another boat I would buy 6" (they were almost the same price as 4").
Rough stack after cutting. It even looks like a boat at this point!
All foam to foam gluing was with Gorilla Glue. Gluing layers in progress. I had to buy "gravity clamps" (bricks) for about 40¢ a piece. I estimated I would need 56. Worked in the garage in humid weather because Gorilla Glue, Great Stuff and PL Premium 3X (PLP3X) adhesives all like humidity!
CLASSIC CAR & BOAT SHOW
The rocker for the bottom of the hull was set using a piece of lumber 1-1/2" high for the stern and two pieces at a total of 3" high for the bow. The Duck Punt plans are a little vague on this so I went by measurements off the drawings as close as I could get using standard 2x lumber. As the layers get glued the curve locks into place.
Seven layers makes the foam punt 14" high. The English Duck Punt is closer to 12" but with a 2" floor I wanted the inside of the boat to have the same depth as the original. Note that the aft deck extends out beyond the curve of the lower hull; the area under the deck sides will have a sculpted flare. If you do not want the flared sides or the transom, the boat can be constructed as a "double ender" similar to a canoe; the build would be much simpler this way, but I like the lines of the original duck punt.
The flare parts snug up to the aft deck and the transom. Because I wanted this boat to double as a small fishing craft, I made provisions for a board to mount a sturdy transom; if you are not interested in powering the boat (besides wind!), the top two or three layers can be angled out like Rowerwet does with the aft of Sawfish.
Had to try this at the stage of foam only. If my bathroom scale is to be believed the foam hull weighs 23 lbs.! Still to be added are wood parts for transom, thole pin mounts, and mast step and partner; plus canvas, glue and paint. Also intended to add some sort of wood reinforcement to the gunwale area per Rowerwet's recommendations.
Gluing the flares. Gravity clamps won't work, so lots of kabob skewers at various angles to lock foam in position.
Rough cutting the flares with a jab saw.
Motor board being checked for position and marking for cut. Make sure it runs on the center line and is vertically straight.
When trimmed, motor board is glued to the hull, behind it are wedges of foam glued in to support and reinforce mounting (these will be inside the aft hatch). Not shown are similar wedges in the bow to support a wood block for mounting a cleat. There will be a cleat attached to the motor board as well.
Bow is angled 3" back at bottom.
Cut with a jab saw, finish by sanding a nice blunt radius. Foam does not work well with sharp edges.
Bow after first sanding, On the entire boat I first knocked down the rough variations of the layers with a small belt sander with 50 grit paper and a light touch. Followed up with 50 grit wrapped around a piece of 2 x 4 for a sanding block. 50 grit does a nice job of shaping foam.
The hardest thing to do is cut two big holes in the sides of your hull! These areas are where wood structures for thole pins will be constructed.
The theory is that the structures will be attached to a 1/2" ACX plywood panel that in turn is attached to the wide foam bulkhead under the aft deck; distributing the force of the oar/paddle over a broad area.
The original Duck Punt design has structures for thole pins further forward also, this is so there can be multiple positions for rowing; since I do not intend to row, but paddle, I eliminated the forward structures.
Thole Pin structures roughly in place.
Cut from 2 x 6 lumber.
Lots of weird angle cuts for the internal supports.
The 1/2" oak pieces on top are just layed into position at this point. The function of these pieces is to prevent wear on the gunwale when using the oar/paddle.
Drilled 1-1/8" holes for the thole pins. The lower board drilled only half way through.
Clamped together to smooth curves with a belt sander (after rotating the clamps out of the way).
Lots of trial fitting to the hull at this point.
I measured multiple times, but still came up with an odd shaped gap at the rear of this structure. So I cut the odd part off and added some shims.
TRIANGLE POINT LIGHTHOUSE
Gluing the aft plywood bulkhead. Because PLP 3X expands as it cures, many "gravity clamps" are used to hold it in position. Plan to keep the clamps on for 24 hours to assure good cure. Before stacking the bricks I layed down common kitchen waxed paper to prevent the PLP 3X from adhering to the bricks.
Like the thole pin structures, the mast step & partner have a 1/2" ACX plywood backer that will attach to the thick stacked foam bulkhead.
The step & partner are made of 5/4 lumber. I liked the quality of the wood and the fact that is has squarer edges compared to 2X lumber.
Both the step & partner and the thole pin structures were screwed together to check fit and will be disassembled, glued then reassembled and sealed with "the mix" wood preservative (75% paint thinner and 25% oil base polyurethane varnish applied in at least 4 coats).
After seeing many recommendations in various boat building reports, I used stainless screws along with PL Premium 3X (PLP3X) to glue the wood and then used the same adhesive and Rowerwet's "glue bolts" in multiple locations to attach the plywood to the foam.
Gluing the mast step and partner assembly. Again, many "gravity clamps" are used to hold it in position.
Outer surface of the thole pin structures is covered with 5mm water resistant underlayment plywood that I happened to have lying around, 1/4" exterior plywood works as well. Line up the plywood flush with the outer foam surface.
Painted the plywood with Glidden Gripper to promote adhesion to the canvas covering.
Completed structures adhered to the hull with PLP 3X. Not shown are the "gravity clamps" stacked inside, outside and on top.
With the wood structures complete I could still lift the boat!
The mast in rough position.
I am using a stair rail approximately 1-5/8" diameter by 8 feet. It took a lot of searching through the lumber yard stack to find a nice straight piece.
On recommendation from Rowerwet, I applied vinyl edging to the bottom edges of the hull in order to prevent car top tie downs from denting the hull.
The edging is the type that is used to edge sheetrock archways in home construction.
The vinyl is adhered to the foam with Glidden Gripper. regular masking tape holds it in position.
A couple of areas I had to re-apply Gripper and more tape to assure a tight fit.
Once Gripper was dry, the outer surface of the vinyl was coated with Gripper as well, to promote adhesion of the Titebond II glue (TBII) and canvas covering ("Poor Man's Fiberglass" ).
Later I discovered that when the boat sat upside down on the sawhorses the outside gunwale got dented. I used the hot steam iron over an old towel trick to get the dents to pop out. I then applied vinyl edging on the top edge over the canvas, applied Gripper and glued another strip of canvas over the edging. Moral of the story: apply edging to both top and bottom before applying canvas.
The flared sides were faired in with "folded Great Stuff", shaped with a Sureform tool and smoothed with lightweight vinyl spackle. This photo is before sanding and before the angled stern piece that continues the line of the inner transom is faired in.
Per Rowerwet's recommendations, added some wood reinforcement to the gunwale area on the inside of the cockpit. I used 5mm water resistant underlayment plywood, 1/4" exterior plywood would work as well.
The width of the piece is 1-1/2" to match the width of the thole pin structure upper piece.
The lower edge is cut at a 45° angle to make the canvas transition smoother over the wood.
The reinforcement is glued and nailed to the thole pin structure and glued with PLP3X "glue bolts" to the foam.
Note that the end of the reinforcement has been glued into the foam mast bulkhead.
Next step, filling and shaping. Rowerwet recommends lightweight vinyl spackle for filling holes and depressions and repair, I decided to try it to smooth the compound shape of the stern. I found in the end that the spackle is very soft even when cured. If I were to attempt another boat, I would get a small can of automotive bondo to fill in this area, because I think it would give a stronger base for the canvas. However, I have not done any tests to see if TBII would stick to bondo. Because Gripper seems to stick to anything, it may promote adhesion between bondo and TBII.
Sanded spackle with 120 grit, sanded foam with 50 grit.
Filled all voids with folded Great Stuff.
"Folding" is spraying the adhesive on a waste piece of ply or a plastic cutting board and using a plastic bondo spreader, or similar, working the air out of the Great Stuff to keep it from expanding so much.
Notice that even after knocking down the Great Stuff it still expands considerably.
After it cures the Great Stuff can be sanded with rough paper or a Sureform tool. I first trimmed big chunks with a hacksaw blade in a holder.
Final sanding and shaping complete.
Then a wallpaper removal tool is run over the entire hull to make perforations for the TBII to adhere. Rowerwet calls these "glue nails".
I tried to make my own perforator out of a piece of oak and many screws. It was a failure and purchasing the tool made the task much easier and less time consuming than my solution would have been.
150 or more years ago canoes were often covered in canvas and painted. Combining modern foam with a glued traditional covering makes this construction technique work; Rowerwet calls it "Poor Man's Fiberglass" Moved indoors to an unfinished basement so humidity could be controlled for gluing canvas and finish painting.
I wanted a sturdier covering than the bedsheets that Rowerwet uses on the Sawfish kayak.
I bought 10 oz canvas in a 72" wide roll to keep seams to a minimum; canvas tarp could be used but there would be more seams because the boat is over 14 feet long. I was very pleased with the quality of material from Big Duck Canvas. I bought 13 yards, to allow for mistakes.
First wrap of 10 oz. canvas on bow and stern.
On review, I would not have attached the extra pieces shown on the top and bottom of the bow; they added too many wrinkles to the finished product. Bringing both the top and bottom canvas over the sides and covering with the side canvas piece would have given enough strength. I would still apply the final bow piece shown later to wrap over the leading edges of the sides.
Throughout the process, I used small paneling nails, which have small rings on them, to hold the canvas in position, every few inches, while I glued.
Important Note: When cutting the canvas, one item I forgot to take into consideration is shrinkage of the canvas while the glue cures. Add at least 2" to every edge to allow for shrinkage. I have updated my cutting pattern to reflect the added material.
After centering the canvas on the bottom, I pulled the material over to mark the overlap for the sides. I used 6" for the bottom (ended up as 5" with shrinkage).
Glue the bottom canvas first, let it cure and then glue the side overlaps. The canvas will stretch and you may have to cut darts in the canvas to allow the material to lay flat. Work from the center toward the bow and then toward the stern.
Note that everywhere you have a seam or an overlap, you will be able to see it even after final painting, so careful cutting and aligning is critical. I thought my one piece sides would cover all seams, but they are definitely visible.
After wrapping the bottom, the next step is the cockpit areas; first the floor, then the sides and then the bulkheads.After wrapping the bottom, the next step is the cockpit areas; first the floor, then the sides and then the bulkheads. All canvas pieces were overlapped 3” to 4” to assure a sturdy structure.
I overlapped the canvas onto the wood of the mast step/partner... I would not do this again, the edges were difficult to finish.
Wrapping the top is similar to the bottom. Glue the top surface and let cure before gluing the side overlap. do not cut out the cockpit areas until glue is cured.
Mark the cockpit areas from corner to corner and cut with a utility knife. I trimmed the flaps to 4" to get a good strong overlap. I overlapped the wood of the thole pin mounts and wrapped the canvas into the inside; again, because of finishing problems, I feel putting canvas on the inside was unnecessary and would not do it again.
Lay the boat on its side to glue side canvas; it is easier to work and gravity helps the canvas stay in position, along with the paneling nails. Where there was underlying wood structure, I tacked the canvas with a staple gun using light pressure so the staples were easy to remove.
I used the paneling nails to hold the fabric into the compound curves. This is where I wished I would have used bondo for smoothing instead of spackle because the underlying surface was quite soft. In retrospect, instead of gluing the entire area, I would glue the deepest part of the curve, let it cure and then gradually glue outward in stages, always letting each stage cure before moving on. I think this would allow gluing without the nails, which would give a smoother finished surface.
Applied a final bow piece of canvas to wrap over the leading edges of the sides.
Before painting, I "sized" the entire canvas surface with a 25% TBII and 75% water solution; this makes sure all the canvas fibers are soaked with glue.
Gamma Seal lids are used for water tight hatches, see Rowerwet's Instructible. Glued the hatches with PLP3X and used 4 bricks each to hold them in place during glue cure.
Boat is now ready for paint. I primed it with two coats of Glidden Gripper.
Per Rowerwet's recommendation on paint, I used Glidden Exterior 100% acrylic latex. I prefer satin to gloss for a more workboat type finish. Note: the dark green I used took more than a week before it did not feel tacky; called Glidden and tech said dark colors take longer to cure.
Following paint, the craft is ready for the oak transom board and thole pin boards. Because of my experience with hull dents I decided to add a bow sprit so I would have a place to attach a small anchor for fishing. The bowsprit was constructed from a scrap piece of 1/2" oak, it was not sturdy enough so I will try 3/4".
To aid in car-topping and tying up the boat, installed 6" nylon cleats from Duckworks fore and aft. The size screws recommended were hard to find so I used 4” stainless deck screws.
All other hardware was attached with stainless steel screws.
I have read that the reason paint fails on new boats is that the builder is too anxious to get the boat in the water, and that a week is a good cure time.
I had planned to work on my mast and spars while the paint cured.
The English Duck Punt uses an Optimist class sail. The one I chose is a "sleeved club sail" from Intensity Sails, that is quickly set up because it uses no ties. The mast slips into the sleeve and there are loops to attach the boom. This sail is also constructed of heavier material than racing sails.
The 8' mast from a pine stair railing has one flat side which will face the bow so the boom jaw can rotate around the curved side. The flat side will also make a handy mount point for the clam cleat for the snotter supporting the sprit. The top of the mast was rounded to reduce wear on the sail sleeve.
The boom and the sprit are both 1-1/4" pine closet poles.
I used pine rather than oak for the mast and spars because pine moldings were a single piece of wood; the oak moldings were glued up from multiple small pieces and did not look like they would have enough flex.
All pieces were treated with “the mix” and finished with polyurethane spar varnish.
The peak of the Optimist sail has a sewn in rope loop for the top of the sprit. A stainless 3/8" bolt had its hex head rounded off and glued into the end of the sprit with PLP3X.
Because the Optimist sail is a "sleeved club sail" that has loops to attach the boom, there is not a lot of space for a wood boom jaw. I am experimenting by using a brass oarlock from Duckworks as a boom jaw. The oarlock is glued into the boom with PLP3X.
To rig the sail I used clam cleats with fairleads from Duckworks, one for the snotter, one for the downhaul and one for the outhaul.
The end of the boom has a "dumb sheeve" carved into the end for the outhaul.
Lines are in multiple colors based on an article I read that makes it easier for inexperienced crew to "grab the red one".
For sailing I got a wood canoe paddle, which acts as a rudder on a Duck Punt. I also wanted an emergency kayak paddle I could store in the boat, out of the way; found this paddle at Amazon, it comes in a nice drawstring bag and is less than 24" long when disassembled. Also purchased another kayak paddle of a different design to use when paddling with two people.
Although I'll not be sailing at night, there are times when the fish are biting and the sun is making its departure that makes navigation lights a necessity. Duckworks has some nice clamp on LED units that look like they will fill the need nicely.
Using the craft as a fishing vessel was part of the plan from the beginning. I wanted the quiet and efficiency of an electric trolling motor but not the weight of a conventional deep cycle battery. I also did not want to transport a gas motor inside my vehicle, as I had planned that the boat would be car-topped, not trailered.
Although MUCH more expensive, I decided to use Lithium Iron Phosphate batteries. These are popular replacements for mobility scooters and other small electric vehicles. They do not pose the fire risks of other types of lithium batteries. Four of these batteries at 10 AH each (total 40 AH) were parallel wired into a battery box with a circuit breaker for safety. The entire battery pack weighs about 11 lbs. The battery box was constructed from scrap materials.
I chose a MinnKota trolling motor with their digital maximizer technology, which extends battery life. Comparing specifications, a 45 lb thrust motor seemed to give the best compromise between power and battery use.
Since I got a three pack "deal" on Gamma Seal lids on Amazon, I used the third lid to wire a quick connect so that the battery pack would be inside the waterproof hatch.
Part of the process where I live is registering the boat. If it was strictly a sailer or paddler the fees would have been less, but because it is powered for fishing it moves to a different class.
I painted the registration numbers using a homemade stencil.
Launch Day! "Breezy" was christened and launched. It was a sunny, but cool day, high of about 60 degrees and wind about 7 mph.
A rough measurement from putting my hand over the side, the boat seems to draw about 3-1/2" to 4" of water. I took it for a solo paddle first, sitting on the mast step seat paddling stern first as recommended by Dylan Winter, because the fore-aft balance is better.
Then went out with my wife, she sitting on the mast step seat facing forward and me sitting on the aft deck. In both cases the boat seemed to track fairly well, neither one of us has much experience, so there was a little zig zagging, but I didn't feel that the boat couldn't be controlled with a little practice.
Next was the trolling motor. Leaning over the stern to raise and lower the motor and adjust the angle to the water is a little dicey because there is not a lot of stability in that part of the hull. Again, the boat performed nicely, and tracked well. Took my 3 year old grandson out for a little motor ride; he has been watching the progress from the beginning when Grandpa was building a "pink boat"!
Finally rigged up the sail, which was fairly easy with the sleeved club sail. Again, I haven't sailed in decades so there were short episodes of sail power followed by furious paddling! I should have paddled out a little further because the wind kept pushing me towards shore.
The lake is small and only 5' to 10' deep and was chosen specifically in case I got into trouble. I got the mast tangled in a dead tree because I didn't see it above me, as my life vest kept pushing my wide brimmed hat down over my eyes; last time for that hat!
Just when I thought I was getting the Duck Punt style sailing started by getting healed over, I healed WAY over and dumped the boat! There were shouts of warning from shore but I thought I was getting the hang of this Duck Punt thing.
I was only in chest high water, so I was able to stand on the mucky bottom. First went around to the bottom of the boat and grabbed the gunwale and easily pulled her upright. Here's where my over 50 year old Boy Scout canoeing merit badge training kicked in. Tried to get in over the stern like scout training but the motor board was an obstacle, I made multiple attempts to pull myself up onto the rear deck, then by moving the thole pins to their rearmost position, I was able to use them as hand holds to assist in a successful re-boarding. Many cheers from the shore party!
There was maybe a 1/4" of water in the cockpit. I need to modify a milk bottle into a bailing scoop.
Got the boat turned around and actually had a nice sail past the group on shore, which brought more cheers!
Every internet article I've read about Duck Punt builders said that they had a lot of problems sailing early on, so I have high hopes for the future.
The biggest issue is loading and unloading on the car top. I got a swiveling T bar canoe loader for my hitch at Amazon. The problem is that my hoped for completion weight of 50 to 60 lbs. was way off; my Duck Punt ended up at 83 lbs., which is not bad for a 14' 9" boat but it is a struggle to car-top. As you can see by the photo, I can do it, but it is a long, difficult process at my age and body strength. One build article I read on a stitch and glue version weighed 87 lbs.; of course I don't have to add any floatation!
Also, car-topping really scratches up the gunwales, so some paint retouching is required already.
After serious consideration I purchased a small trailer. A utility trailer will work with a flat bottom boat and the bow is narrow enough to run up the trailer tongue a bit. I would be storing the boat in half of my garage all boating season anyway, and a trailer won't take up that much more space. Winter storage is easy, my son has a big shed.
Where I live, in Minnesota, we actually do have more than 10,000 lakes and most of them have public access boat ramps, so trailering will really decrease my prep and put away time when I want to hit the water.
Not to discourage those who want to car-top... I think I probably overbuilt the craft and some judicious experimenting could reduce the weight. For those who have no desire for motor power, about 8 to 10 lbs. could probably be eliminated just for that item.
I ran out of boating season, the roughly three weeks (depending on weather) I thought I had left, got used up locating a suitably low priced trailer and I wasn't able to get wiring in the car to make it legal to tow. The T-bar for loading was returned because it did not function the way I'd hoped. I knew this year would be tight when I got a late start building, I started on July 20 and launched September 17. Next year I'll hopefully figure out this Duck Punt sailing business!
Really enjoyed the whole building process, I loved the Sawfish construction technique and would do it again.
My cost in 2017 for the completed Duck Punt, ready to sail, was approximately $750. This includes all construction materials, paint, mast & spars, boat hardware and marine rope, pre-made Optimist sail and paddle.
The sail, rope and boat hardware came to around $300 and there are less expensive ways of handling those items. Painting the boat one color would have saved about $30.
Cost does not include trolling motor, batteries, registration, extra kayak paddles, lighting, life vests, and car-topping hardware or a trailer. Even after purchase of a trailer, I still have less than $2000 invested in total for a boat I can use in a multitude of situations.
Thanks to Josh Withe (Rowerwet) for his detailed plans and his email guidance, Dylan Winter for the inspiration of this project, and Duckworks for all the great quality parts.
© 2017 Mark Frost