Nose Wheel

A major modification that I needed to add to the duck punt design was a drop-down nose-wheel to help with the number of times that I will have to get it out of the water to get around obstructions.

With August being taken up with a two week holiday in Madeira, and lots of social events, I've only just got back to the build...

Lots of thinking and refining has gone into this over the summer, but I've finally built and fitted the nose wheel. That, in turn, means that I can start work on decking the bow of the duck punt (post to follow).

The first part, which I did in late July, was to cut a large slot in the front of the bow to take a hardwood beam to support the nose wheel.

A Japanese pull saw was used
to cut a slot in the bow to take
the hardwood beam that would support
the drop-down nose-wheel.
(Bottom edge was cut with a sharp chisel).

The beam was then rebated to fit over the front bulkhead and the front of it was shaped to form a raised and extended pivot point for the nose wheel (the design of which was still 'up in the air') .

Wheel-supporting beam in place, though still far from sure
of the design of the drop-down nose wheel...

While I had the punt out in the open, I took the opportunity to clean it up a bit with the orbital sander, and to plane off (one of ) the top edges. Made quite a difference...

The design of the drop-down nose wheel was gradually being simplified and refined in my head over the summer break.

I decided to make the structure from solvent-welded 1.5 inch (38mm) PVC pipe, with a 10 inch (250mm) 'Sandhopper' wheel. The wheel has a 1 inch (25mm) hub and axle, so the pipes had to be a bit bigger to allow the axle to fit inside them.

The drop-down wheel hanging
from the supporting beam

Side view of drop-down wheel

Drop-down wheel in position - engaged angle does away with
the need for fixings to keep it in place

The punt sits on a cross-bar above the wheel
(will have foam tube fitted to protect the hull).
Also minimises loads on the the supporting beam.

Progress on Wharf Rebuild

I'm happy to report that the rebuilding of Shefford's Wharf is going really well.

I was a bit concerned that it would be rebuilt with the bright red bricks that I saw, but these have been been used only for the inner skins (three layers of brick, infilled with concrete) of the wall.

The facing bricks are much closer to the original than I had dared to hope for, and the quality of the bricklaying (a long curve, leaning back, so a seriously compound bit of curvature) is spot-on.

Also, zoom in on the brickwork, and you'll see that they've laid them in alternate face-on and end-on courses (I presume the end-on courses are used to tie the face to the layer behind - as per the original Wharf's wall).

I doubt they're reading this blog, but thanks to the guys who are doing this vitally important work - a unique part of Shefford's history is being repaired to 'heritage standard'. Lots of concrete behind the scenes to make it withstand the pressure and erosion of the river, but faced with some really beautifully laid brickwork, totally in keeping with the original structure.

Couldn't ask for more, thanks!

Feast your eyes on some seriously skilled brickwork:

The long, gentle curve of our Wharf nearing completion,
in just one week!

Another little thing I've noticed is the small piece of the original wall left in place at the far right - 'originality checkpoint'?

They've managed to save a small section (far right)
to show what the original wall looked like

Wonderful curves combine with a purposeful
lean-back to show that true craftsmanship
is being used to restore our precious Wharf.

The Ivel Navigation (true of many canals) was dogged with a lack of proper maintenance. Riverside masonry like our wharf needs constant attention, and it needs to be good enough to do it's job properly. Restoration of this quality and originality is a real and refreshing blessing to our community now, and well into the future.

And I guess the people living in the beautiful apartments whose foundations are supported by this wall are breathing a big sigh of relief right now as well...

About The West Mersea Duck Punt

Some links to the (successfully built) duck punt community to help the uninitiated to understand why this is such cool boat:

1. Dylan Winter - taking his one-week-to-build duck punt from Wells to Blakeney on the north Norfolk coast. Took the darned thing into open sea!! The duck punt has around 1ft/300mm of freeboard, and Dylan's version has no flotation tanks. The cajones of this guy defies belief!!! As always with Dylan, exquisite photography and insightful commentary. Can't stop watching this one... 
2. I Love My Punt - cool video of the West Mersea gang's punts being enjoyed, backed by a rather fine Ed Shearan sound track

Beyond that, just go to You Tube and search for 'Duck Punt' - you'll quickly get the picture. Promise.

Rebuilding Shefford Wharf

Shefford's Wharf, the last visible remains of the Ivel Navigation in Shefford is being rebuilt.

130 years after the canal was abandoned, the Wharf has finally deteriorated to the point that it needs some major work doing to it. The first photo below is one that I took back in February, and clearly shows serious deterioration of the Wharf wall, with sawn-off tree stumps sticking out of it, and large areas of missing grout. (Click on the image to see what a bad state the wall was in).

Let's hope that the rebuilding will be done sympathetically - the civil engineering firm doing the work appear to have retained the distinctive dark grey curved edge capping bricks at least.

Shefford Wharf @ February 2016

Wharf under reconstruction, July 2016

Wet Lay-up Pictorial (Mast Thwart)

I've previously mentioned this technique in some detail, but if you're like me, a few pictures get the message across much better than words, so here goes a run-through of the most recent job - fitting the mast thwart.

Mast thwart frames dry fitted

The screw holes in the edges of the frames need to be centred to avoid splitting the ply, and VERY IMPORTANT THIS: countersink them - makes it a doddle to get the screws in the right place when you're doing the final lay-up/assembly wearing gloves, everything covered in thick sticky epoxy, and fighting the resin's 'curing window'. 

The wonky thwart frame on the left, and the voids in the plywood edges indicate the very poor quality of the 12mm plywood I'm using for the frames (should be 15mm, but my supplier didn't have any). Needless to say, the price I paid did not reflect the poor quality...

OK, enough of the moaning; it's gotta get built, right?

Strips of glass tape cut ready

 So, one strip of glass tape goes behind each thwart frame edge (against the sides), then one goes each side of each thwart frame edge, over the epoxy fillets. 12 strips in total. At this point I'm well into my second 50 metre roll of glass tape!

Thwart frames and seat (with alignment cleats glued on)
ready for epoxy priming

 Because of the crazy twists in the 12mm ply, I decided to orientate them so that they bent towards each other. By fitting some thin cleats 12mm in from each edge of the seat, the seat would be held firmly in place, and straighten up the thwart frames at the same time. It would have worked perfectly if the bends in the plywood only went in one direction...

Thwart frames and seat primed on all edges and faces
(that's why you need gloves!)

Glass tape applied to side panels

Next a strip of glass tape was epoxied in place on the side panels behind each of the four thwart frame mounting points - I've done the same with all frames attached to the sides and bottom of the punt as reinforcement/load spreading.

Then thickened epoxy was spread on the (primed) ends of the thwart frames, and each one was positioned and screwed in place (by hand - power driving is too brutal, and I don't want epoxy all over my nice cordless drill handle/trigger).

Thwart frames in place over glass tape

Thickened epoxy fillets were then spread along front and back edges of each joint - easy without the seat in place.

Glass tape epoxied over fillets

Glass tape was then epoxied over each fillet (both sides), and spare resin used, as always, to seal any bare plywood nearby.

Mast thwart seat epoxied in place (thickened epoxy)

Nearly there - I spread thickened epoxy along the underside edges of the seat and popped it in place. Finally, a fillet of thickened epoxy was run along the ends of the seat where it joins the sides.

Time to fire up the barbecue and crack open a beer or several methinks...

Frames

Next job was to mark out and cut the frames.

Then fit them of course!

I first dry fitted them, held in place with screws through the sides and bottom, then using a simple jig (an offcut of plywood with a hole drilled in it for the sharpie to poke through) marked the lines for the reinforcing tape.

I used a wet lay-up again:

1. Prime the plywood sides and bottom, plus the mating surfaces of the frames with unthickened epoxy
2. Lay glass tape reinforcement strips on the sides and bottom
3. Apply thickened epoxy to mating surfaces of frames
4. Insert frames and hold in place with screws
5. Apply thickened epoxy fillets using rounded wooden sticks (from choc-ices) to get a reasonably neat curve
6. Lay glass tapes over the fillets on both sides of each frame

It took me 5 hours to fit 3 frames, so the main frames took a whole weekend to fit.

The state of build as at mid July 2016

This was followed by fitting the (optional) outer top planks, scavenged from the aborted side panel scarfing exercise I mentioned earlier - the resin had by now hardened enough. I fitted these to restore a fair edge to the topsides which had developed a distinct scalloping effect after the main frames were bonded in, despite my gaffer-tape trick.. I struggled to get measurements for the curve on the bottom edge of these panels until I spotted (on John Milgate's plans) that the curve runs parallel with the bottom of the punt, so I clamped the ludicrously long and bendy panels to the topsides and scribed the line with another simple offcut jig.

The half frames and bulkheads came next (another weekend), followed by the rear seat rails, transom and transom cap, bow and stern blocks (yep, another weekend), and most recently the mast thwart (and yet another weekend).

Mast thwart and step dry fitted

Mast thwart fitted and first sealing coat of resin applied

Together At Last!

Confession time: my first attempt at scarfing the side panels had to be aborted (didn't read the instructions for the resin and hardener dispenser pumps and ended up with non-setting toffee instead of thickened epoxy).

Another sheet of 6mm plywood was ordered, lofted, cut, and scarf jointed.

The two long and impossibly bendy panels were then taped together and lightly trimmed with a hand plane along the edges to fair them up and ensure that they were symmetrical. 

The bottom panel went better (scarfing) and was cut and edge planed very carefully so as not to mess up it's symmetry.

All mating edges were lightly bevelled, and after making  temporary bow and stern blocks, plus a temporary transom, it was time for the first trial fit!

The sides were screwed to the bow and stern blocks, then stood onto the bottom panel and gently opened up to check that they fitted. A couple of whiskers needed shaving off with the plane, but apart from that, they fitted really well.

The design I'm using is 'stitch and tape', but I wanted to be able to run an uninterrupted bead of epoxy fillet topped with two overlapping layers of 75mm glass tape along the whole length of the punt to get a really strong joint.

So instead of stitching the panels with wires which would have got in the way, I used strips of (3M) parcel tape on the outside edges. To my amazement it worked really well. The tape is easily strong enough to hold everything together and pulled the panel edges together for a really nice tight fit. Seriously chuffed!

Anyway, the punt was finally looking like a boat, though far too curvy without the inner frames. I can see why boats are referred to as 'She' with curves like that!

View from stern - parcel tape and a few screws holding it all together

View from the bow - not quite so sexy from this angle

Before applying the epoxy and tape, I stretched gaffer tape across the top edges at the frame positions, making each one the same width as the corresponding frame's top width measurements. I didn't want to 'set' those exaggerated curves into the hull, only to have to pull them in when fitting the frames - the leverage could possibly damage the seam joints, or even crack the very fragile ply.

Curing time when building with epoxy resin really adds to the build time, so where possible, I am laying-up 'wet' - starting with a layer of unthickened resin (to prime the plywood), then thickened epoxy fillet and glass tape/resin (main seems get two overlapping layers) all in one session.

Certainly saves time, but I've also read that the bonding between the layers is stronger this way. Doing the inside seams this way took me several hours (my first time), so although quicker than waiting for individual layers to cure, you do need a good clear time slot in your day.

Standards

The 6mm exterior plywood that I ordered turned out to be barely 5mm thick and only 3 ply. It was CE marked at least, but take a careful look at that mark:

A Chinese CE Mark

Notice anything different about it? If you look at the tips of the letters, they taper in slightly. I don't know how true it is, but I have heard that this is the Chinese Export mark.

So I checked out the EN number:

EN 636 2G

EN 636 2G is defined as:

"Humid Use - Most construction uses fall into this category as they are covered or rarely exposed to weather, but still at risk of wetting"

The G indicates that it's a general purpose board (an S would indicate that it's for structural use).

So, as I need the punt to be structurally sound and it will be getting a little more than humid when in the water all components will be liberally sealed with epoxy resin and the outside of the hull will be sheathed in two layers of woven glass mat (plus double thickness tape along the edges). Then painted of course.

Scarfing

OK, so the punt is 16ft (4.8m) long, but the plywood is only half that. The next step is to join the two halves of each panel together.

In this design, it's done using scarf joints (matching pairs of 1:8 chamfers on the ends of each panel). Thickened epoxy is then used to bond them together.

The cut panels were stacked on the workbench and held in place
with 'holdfasts'

Then the planing began. I started by planing 'down' the slope,
but later found it was better to plane across

A bit wavy, but thickened epoxy is a good filler!

The Build Begins - Lofting and Cutting

The West Mersea Duck Punt is often referred to as a "little" boat. Trust me, at 16ft (4.8m) long it is anything but!

The first construction challenge was to find somewhere to build the darned thing. My own garage couldn't cope, but amazingly, a good neighbour, Frank Bond agreed to let me use his (much longer) garage to build the Punt in. Put simply, without Frank's generosity this project would have remained a pipe-dream. How do you say 'thanks' to people like Frank? I'll find a way... So, the plywood, epoxy resin, glass tape and cloth etc were ordered, and the build began.

I started by 'lofting' the measurements for the side panels from the A4 plans onto the 1200 x 2400 plywood sheets.

6mm ply is very difficult to handle - bends and sags all over the place. I later saw sense and got some lengths of timber to lay lengthwise under the plywood. Much better!

6mm ply was laid across a couple of saw horses.
A tape measure was gaffer-taped along the edge.
Then a large T-square was used to measure and mark
the points of the panel curves.

Panel pins were driven into the marked points, then a length
of plastic conduit was pegged to them, giving a smooth curve.
A sharpie was drawn along the edge of the conduit
to mark the cutting lines

The Flo-Mo plans suggest using a Japanese pull saw
to cut the panels. I broke mine on the third stroke...

Which Boat?

Clearly no ordinary boat is going to be capable of a journey like this.

It needs to have a really shallow draft, be strong enough to deal with submerged obstacles, light enough to haul out and around the larger obstructions (whole trees, the sluice, weirs, and goodness knows what else), yet big enough to live eat and sleep on board for the four days I reckon the journey will take. Ideally it should be easy to paddle, and be able to sail where conditions permit.

Oh, and cheap and easy enough for me to build. I've never built a boat before, and it's more than fourty years since I've sailed anything - my last experience being capsising a Mirror dinghy whilst attempting a jibe at Denver Sluice.

Only one choice really - a West Mersea Duck Punt. The lightweight 'stitch-and-tape' variant of John Milgate's original design, kindly made available by Flo-Mo.

I have to thank an amazing chap called Dylan Winter who has championed the West Mersea Duck Punt and obtained permission to publish the plans for the John Milgate original and the Flo-Mo variant free of charge via his website. Dylan managed to build one of these in a single week, and even offered to lend it to me for this challenge! He is currently sailing anti-clockwise around Great Britain (though NOT in a duck punt), making some truly exquisite videos as he goes. If you haven't done so already, take a look at his utterly superb 'Keep Turning Left' website, and help him in any way that you can. He's worth it...

The Challenge...

So, I've set myself the challenge of navigating from Shefford, where I currently live, to King's Lynn where I lived for 10 years back in the 70s.

In February 2016 I took a walk along the river to see what I'd let myself in for - I've posted some photos of the first mile or so of the Hiz and the Ivel to give you an idea of what this challenge involves. The water level is relatively high in the photos - summer levels are much lower, so only a few inches of water most of the year.

This will be the launch point - a gently sloping grass bank just beyond the weir...

...then under the North Bridge...

...passing the Wharf (now rebuilt)...

...to the first of many fallen branches...

...until it meets the Hit (coming from the right)...

...and turns sharp left, becoming the Ivel...

...then promptly disappears off to the left towards a sluice which I didn't even know existed...

...Shefford Sluice - around a 2 metre drop...

...but preceeded by a nice shallow bank to haul the boat out...

...level ground to haul it round..

...and another shallow bank to pop it back in again...

...more obstructions...

...and more (many more)...

...until the low bridge near Millennium Green...

...with part-submerged lumps of concrete just after it (possible channel on the left?)

...then sharp right over the broken-up remains of a concrete weir.
Before it was broken up, the kids in Shefford
used to call this "The Beach"...

...whereas straight ahead, this appears to be the buried remains
of one of the Ivel Navigation's locks...

...more sunken hazards...

...fallen trees...

...and another...

...and a rusty bit of angle iron...

...then meandering off to Clifton.
The line of wispy willows to the left appears to mark the
path of the old canal (long since filled in)