Photographic Evidence of Progress

Here's the Dart 16' kayak bottom panels, joined by hog and cable ties and trussed up with various ropes and ratchet straps to force the roundness into her bottom. It looks brutal, and it is.

Overnight, one of the screws holding the panels to the hog burst out, leaving a nasty kink in the panel. I managed to get some 60 grit paper in through the gap and cleared away as much semi-cured epoxy as possible. I then drilled a 6mm hole through the centre of the affected area and re-packed the gap with fresh resin. Finally a 6mm bolt with a big washer on the back and a spreader of 9mm ply on the top forced the panel back into shape.

I've just finished planing the fair curves to the chine edges of the bottom panels. Next I need to drill all the holes to stitch in the side panels. I've also cut out the bulkheads so the next week should see some big changes. I'm close to finishing the footrest for the 14' Dart kayak, a little work is required for the rail it will be mounted on and then I'll be ready to reveal the design.

New Tool

Between boats I took time out to read the Gougeon Brothers on Boat Construction: Wood and West Systems Materials. The Gougeon Brothers are the guys who invented, market and continue to refine West System epoxy resin.

In the book they suggest splitting up a foam roller sleeve and attaching pieces to sticks with a slot cut in the end and using them as resin applicators. Well I tried, but obviously I had the wrong kind of foam roller, so I tried again with pieces of closed-cell foam from the end of a camping mat, and two pieces of 4mm play bound together with tape, and individually bound with plastic parcel tape at the foam end to allow re-use.
It works really well. I'm able to get a far more even spread of resin than when using a chip brush, and the cost is considerably less as well, not to mention the waste. I'm hoping that using better application methods, I'll make a much tidier job and therefore a faster, better build than with my first kayak.

More Projects

I've not got much further with the proa plans, the basics are laid out in a CAD drawing but I need to refine my ideas before I can publish anything there.

Meanwhile, I read a book on DIY projects for the owners of cruising boats and saw a nice little 1-sheet dory style dinghy. I like the idea of trying something like this with my son, since he is light enough to float in it. I wasn't too keen on the shape of the boat in the book, but I liked the concept. I've worked on it some more and my second attempt came out nearly right. A little more refining and I'll have the plans available for the plywood part. It's not a true one-sheet boat because it will also require some wood for the seats and gunwales. And in fact to avoid exposing my lad to epoxy, I'll probably try making it with gluing batons planed to the right angles, polyeurathane glue and stainless screws.

Finally, I've also sent off to Selway-Fisher for plans to build the Rhum 11'6" dinghy in which I hope to learn to sail.

Cockpit Coaming

So after the deck went on the last real job of building was to cut out the cockpit hole and line it with a coaming strip.  I wasn't looking forward to this part too much because while it is woodwork, its not the orthogonal, easy-to-measure joinery that I'm more accustomed to.

I made a template for the hole by turning one of the plan sheets over and on the plain back marking the centre line, deck beam positions and the run of the cockpit stringers.  I joined the tapering lines of the stringers with the curve of the dustbin lid at the aft end, and to an upturned bucket at the forward end.  I transferred the curves to the kayak by punching through the paper with an awl.  A little adjustment by eye was required to get a more pleasing line on the forward end before the line was followed by the jigsaw.

On the same day I prepared some pieces of ply, 120mm wide and 700mm long, cut across the outer grains of the ply (the way it bends easiest).  I laid these pieces on the driveway with an old towel over the top and soaked them with boiling water.  A few minutes later I filled the bucket that had acted as a template with sand and the wrapped the pieces (all stacked together) round the bucket and held them in place with a ratchet strap.

Two days later the ply was mostly dry and so I started to lay the curved pieces up on the kayak.  I was originally going to make the coaming out of two thicknesses of the 4mm ply on end, wrapped aroung the inside edge of the cockpit cutout.  This looked a little clunky though, so after mulling it over for a couple of days, I abandoned the inner layer.

So tonight I trimmed up the pieces with a jigsaw.  I marked line parallel to the deck with an offset block then partially flattened out the curved end pieces to trim them.  The straight side pieces were then trimmed to fit between the ends from ply with the outer grain running length ways.  For the bottom edge, I marked the back of the coaming where it was level with the bottm edge of the cockpit stringers down the sides, and with the bottom of the deck beams on the fore and aft centre line.  I faired a curve between the straight sides and the mid point and then cut it out hoping it would look OK when curved back on the boat.  This shape has meant the a very deep section to the coaming at the aft edge, which was the intention since there is no real provision for a separate back rest in this kayak.

After a dry fit test I mixed up the epoxy, pre-wet each joint surface and primed out any parts that would be no longer accessible.  I then added plenty of microfibres and used this to bong in the coaming.  I held everything in place with temporary screws, and on the end joints between the side and end pieces I used broad packers (covered in plastic parcel tape) under the screw to cover the edge and keep the faces flush.  The leftover epoxy and any squeeze out was then stuffed back into the gap between the deck and coaming to form a small fillet and improve the bond.  Its definitely warming up here now and for the first time I noticed the pot of epoxy getting really hot in my hand as the curing reaction started to happen.

To finish the coaming of I will trim the edges into a fair curve and fit a lip the the upper, outer edge to take a spray skirt.  I was going to use some steamed pine for this, but I think the curves are too severe to even bother trying.  Instead I'll soak some 10mm rope in epoxy and pin it in place, then fair it in with filler while fairing the rest of the outer hull.  And that's really all that is left to do.  Tape the deck seam, fair it in along with the other external tapes and then sand and sand and sand, and then paint.

Oh, and there's also the small matter of making a paddle...

Catchup

I seem to be falling behind with the blog entries. I think the main reason is that I want photos to help describe a process or an idea, but either don't take them (because I forget or the process is too messy to involve an expensive digital camera) or because I get a bit fed up with the whole download - crop - resize - rename - upload process involved in posting them.

So here's a text only catchup...

On Wednesday I managed to screw the remaining forward portion of deck in place and I removed the still-damp towel to let the wood dry whilst in its new curve.

On Thursday and Friday I was too tired and did nothing - sometimes you just need a break.

On Saturday I only had a couple of hours, so I marked out the position just ahead of the forward bulkhead where I wanted to mount an inspection hatch and then I unscrewed the deck. This took a while. I then trimmed the deck up to within half a carpenter's pencil width of the hull with a new neat cutting jigsaw blade. I then swapped to the thin curve-cut blade and cut out the inspection hatch hole. I also prepared a piece to become an eye for the bow toggle - more of this later.

On Sunday I epoxied in the toggle eye and primed out the underside of the deck with plain epoxy. This was a hassle because it was very windy and all sorts of dust and leaves blew into the garage entrance and stuck the the tacky deck. Also, the wet of the resin caused the deck to try and curve back in the opposite direction of what was required. I quickly mixed up some epoxy and microfibre blend which I applied to the inwales, cockpit stringers , forward deck beam and forward bulkhead. Then it was on with the deck and in with all those screws again. Earlier my son Samuel had helped me take all the screws out of the scrap pads, put shiny brown parcel tape on one side of the pads and then put all the screws back in again so screwing down the deck could be achieved whilst the epoxy was still workable.

Torture Chamber

The main method of construction on the kayak up to this point has been stitch and tape. Pieces of plywood have been cut to shape and stitched together along there edges with cable ties before a permanent fixing of glass fibre tape and epoxy resin was applied. Another related method is called tortured ply, where compound curves are forced into the plywood. Its relatively easy to get a sheet of ply to bend in one direction at a time, so boats designed for this method of construction have panels shaped as sections of cones or cylinders. But the deck on the kayak is convex across the beam but has a concave sheer, the profile of the top edge of the side panels.

Last night I started putting on the deck on the forward end of the kayak. I screwed an oversize sheet in place at the halfway length of the cockpit. this allowed be to strap the middle section of the sheet roughly and draw an outline to trim the sheet to - still oversize but now by 30-50mm all round.

More screws were placed along the inwales working from the midships forward, and the stresses on the screws got greater as the curve was formed. I used scrap ply packers under each screw to prevent the deck springing back and popping all the screws through. As I approached the forward bulkhead the gap between the inwale and the deck was getting bigger and something needed to be done. I persevered for a while with a couple of ratchet straps holding things down, but it wasn't going to work.

At this point I took of the ratchet straps and then rearranged 3 straps over the top of an old towel that was soaked in hot water. The idea is that the warm and wet environment softens the fibres of the ply and makes it more agreeable to the compound curves being forced upon it. Wooden packers over the inwales concentrated the ratchet straps' force in the right direction while rags protected the deck and hull from the heavy metal hooks and ratchets. While tightening all this lot up, holding the ply with one hand and most of my body and tensioning a strap with the other hand, there was a pinging noise and a sharp pain in my shoulder. The torture victim had fought back.

I don't know what the outcome of all this was, I dared not look in the garage this morning so I'll conduct the post mortem tonight.

Pictures of progress

Here's the 6 paddle blade blanks waiting to have their edges rounded and be joined onto the looms.

This is the forward bulkhead, as viewed from the cockpit. A fair bit of sanding still to do.

This is a closeup of the seat, showing how I recessed a washer into the ply using a 16mm spade bit. This gets the head of the screw close to being flush while reinforcing the hole, necessary since the screw head doesn't have much of a shoulder.


A bit shaky since it was taken on a pretty dull day, but even so I think you can see the sleek lines of the kayak in this shot.

Paddles

I made a start on the paddle blades last night. I made a template out of a rough piece and got it as symmetrical as possible before using it to mark out the others. To check the symmetry,I measured a centre line and marked it in both sides of the template, drew a corresponding line on a board, then drew round the template with the centres aligned. Then I flipped it over and re-aligned the centres and checked the curves had a similar profile as those drawn on the board.

I cut the paddle blanks oversize from 4mm ply off-cuts. I then planed them close to the line before putting 4 pieces (2 paddles worth) together and finishing the planing and profiling as a stack to get them all alike. The other two blanks were marked to match the slightly narrower loom and the profiles adjusted accordingly. I then trimmed about 15mm from the ends to just make them that bit smaller and more manageable for Sam.

Th next challenge is to make a jug to get the correct profile in the ends of the looms, and to get the profile faces at exactly 90 degrees to each other on either end of the loom. I'm still thinking about that one. Meanwhile I'll get a bit of sanding done tonight, and take some photos too.

I'm favouring making a really neat job of the paddles. Partly because I want to prove I can, and partly because I think it might be less work to finish them bright (i.e. wood grain showing through layers of sealer and varnish).

Things I've Learnt So Far...

The whole point of building the kayaks was to learn a little about the boat building process before tackling something bigger and more expensive. I've read extensively on other blogs, on boat designers web sites and in books borrowed from the library and from friends. Some of the snags I've encountered I've read about previously, because they seem to catch everybody out. I guess that means the first lesson is "There is no replacement for experience. Read all you like, but you don't know until you've done it."

So what are these common problems. The biggest surprise was handling the epoxy resin. It was also the area I had the most apprehension about. A common mistake, apparently is not mixing it thick enough when filleting or bonding. Now I've done that too. The epoxy by itself is about as viscous as maple syrup. It will run pretty much anywhere where its laid deep enough to not get soaked up by the wood grain. To make fillers it is mixed with small, low density spheres that bulk it up, thicken it and make it easier to sand. The spheres actually flow better than the resin, so it takes an awful lot of them to come up with a mix that defies gravity and stays where it is put. For bonding, the spheres are replaces by fibres that are so fine and short they look like dust. These thicken the mix more readily, but again I didn't use enough of them in the early stages. Its quite disheartening to watch that beautiful fillet that you've spent all the allotted 'wet' time shaping start slumping down the bilges into the bottom of the boat, just as the epoxy starts going off into its gel stage where it's no longer workable.

Tools I think I've got just about right. My two planes and my jigsaw get lot and lots of use. My cheap screwdrivers also seem to be getting a fair bit of use, usually while bonding up parts with epoxy, which now covers their handles, so its a good job they were cheap. I'm getting closer and closer to the dreaded sanding stage ready to paint the first boat. This may see some further tool expenditure in the form of an orbital sander. I have a very basic 1/3 sheet sander but it's so poor I usually find it quicker to put a 1/4 sheet round a cork block and use some elbow grease. Watch this space on the verdict of whether a power sander is worth its cost.

On timber, I think I got it right with the plywood, or if anything I maybe bought better than was required or the kayaks. That's by-the-by because anything bigger and of greater value would get the full-on BS1088 Marine Ply spec treatment, its silly to scrimp on the small difference in price per sheet between good ply and the best ply.

Where I got it wrong was with the finger-jointed softwood moulding I bought. Its OK for the inwales, they're really only there to provide a glue surface for the deck. The problem lies when I try to shape the stuff. Its very hard to plane a length of wood when the grain direction changes every 300-450mm. Because the grain changes direction and density, you can't use it to form a fair curve. It would be no good, for example, in forming a batten that was used to hag a plank off to derive the plank's shape. Again, I should have known this because I've read about other builders having trouble with finger-jointed softwood not curving well. Also, its not very strong. The same builders who can't get it to form a fair curve have also had it fail when bending over a tighter radius. I think I'll get some continuous lengths of 18mm square pine for the cockpit stringers before I put the deck on. After all, I've read the warnings from others and I know these parts are under stress when climbing in and out of the boat. It'll be one mistake I'm happy to learn from others making.

Another slow week

I've only managed to get dribs and drabs of time on the boat again this week. Mostly its been tidying up after the weekend. I had about 4 dozen screws to remove from the inwales, and various drips and runs to try and clean up.

On Thursday I got out of work a little earlier than usual, but decided to go and get more supplies on the way home. I went to the Glue Guru on Wairau Rd, Glenfield for some cheap brushes and some West Systems 410 low density filler to add to the epoxy. So far I've used 411 blended filler that is slightly more dense and therefore harder to sand. Since the main use for it now is as a fairing compound to smooth everything out, I think ease of sanding is very important.

I got home and planed a bit of the boat. To get more room I took it out of the garage and up to the deck. It was he first time in a while I've seen the outside lines, and it does look very sleek. I've noticed a slight curve to the centreline in the last foot or so, as the chine angle increases to make the stern almost fin like. I suspect this will impart a fair amount of natural curve to the boats travel, so I need to do something about it. The problem was a less than perfect alignment of the ply panels before they were joined. A combination of planing down one side and filling on the other might remedy the situation to a degree.

I think, on balance, I prefer the time I've spend shaping the wooden pieces to the time I've spent in a one piece Tyvek suit, gloves and goggles, smearing gloop over the pieces of wood in an attempt to stick them together. I've got a few ideas that will make building the sister boat, a two man version of the Dart, easier, less frustrating, and hopefully more refined. Some of the woodworking tools have become firm favourites, especially the block plane that is a delight to use. I'm thinking a ply lapstrake boat like the Rogue will require plenty of shaping so the wood to gloop, joy to misery ratio should be higher than with the kayak.

I had to stop early on the Thursday to have a kick about of the rugby ball with Sam. Besides, the clouds were gathering so I couldn't have stayed outside much longer anyway. While he was waiting for me to pack up and play with him, I got Sam to take this picture. Bridgit obviously feels left out and sought to remedy the situation by getting in on the act, but she may regret it when she realises that her pushed-up nose on the window is on the web for all to see.

Rear Bulkhead Version 3.0

Sunday morning was taken up with a trip to the library and Kings Plant Barn. I returned my copies of John Welsford's Backyard Boatbuilder and John Gardner's Dory Book and got some books on sea kayaking to make sure I 'll be prepared by the time launch date arrives. Since my partner, Bridgit, has suddenly decided to go all Earth Mother on us, we were at the garden centre to buy some olive trees and tomato plants, and Sam got some strawberry plants which no doubt he'll fail to look after.

When I finally got around to looking at the kayak, I decided it was time to address the rear bulkhead, the second version of which I failed to make fit while i was tweaking the lines of the hull on Saturday. It seems that as drawn, the transition between the steep vee of the transom and the relatively slack vee of the bulkhead less than 3 feet further forward is just too much for the 4mm plywood to take. In attempting to make the piece fit I was forcing the seams of the boat apart.

The solution, I decided after much pondering, was to make my own bulkhead according to the shape of my hull. I used the top profile of the existing part and carefully measured the width across the inwales, the width at the chines and the depth from a line between the chines and the centreline of the boat. These details were transferred onto a piece of cardboard, and when that fitted snugly, the shape was transferred onto 9mm ply and cut and planed to shape.

To finish for the day I took of the inwales and laid them out on a plastic covered board to scarf joint them with epoxy. I nailed the epoxy joint tight while it cured, and then used up the rest of the mix putting little dabs on all the hull panel joins, so that when I come to fillet and tape the seams I can take out all the cable ties first. The first mix was a bit too thin and worked OK on the centreline but it tended to run down from the chine joints. A second batch was made much thicker with extra microfibres and it all looked good when I closed the garage door on it for the night.

Stringers

On Saturday I lost a significant chunk of the morning while waiting in line for a haircut with my son at the Birkenhead Corner Barbers. Once shorn, we took the Land Rover down to the Birkdale Timber World to pick up the softwood for the stringers and running strips. I didn't want to waste more of the day going further afield, and my friend Simon works there, a fellow Land Rover nut.

After talking Land Rovers for about 15 minutes, I selected some fairly cheap 18mm square finger jointed softwood. Its not great stuff, but since the designer had e-mailed me back with some details about its purpose in the boat, I decided that it was more than up to the job. Basically, as in any true stitch and tape boat design, the plywood monocoque provided the boat with all its strength, and the stringers are there primarily to provide a gluing surface where a more usual epoxy fillet and glass tape join can't be made, i.e. in fitting the deck to the kayak, where no internal access is possible.

The rest of the day was spent tweaking the kayak hull and fitting the stringers along the top edge with screws, ready to be epoxied on later. I also spent a while planing the bottom inner corner of the stringers. This will remove a little bit of weight, since the timber I'm using is slightly over sized from the original specification.

While sanding one of these pieces, I had a bit of a mishap. My ring finger got caught in one of the accessory holes in the top of my portable workbench. It's ripped a lump of finger-tip away, I managed to stick it back down with a plaster and stem the blood, but it was very sore. I was using sharp tools all day, planes, saws, chisels and the jigsaw, and I managed to wound myself on a blunt work bench!

Friday - a day off from the build

No boat building today, but I was working at a customer site in Albany, close to the PlyMan. I took the opportunity to call in and buy the West System Epoxy components required. I got 4 litres of resin, 800ml of slow hardener, some low density filling additives and some microfibres, and the mini pump system that makes measuring and mixing simple and mess free.

I then tried to find Fibreglass Supplies to buy some tape, but got a bit lost in an industrial estate (I hadn't checked them on a map before leaving and was winging it). Just then the customer called me back on the cell phone, so I pulled over to take the call. As I was talking them through their support issue, I realised I was staring straight at the sign for Fibreglass supplies.

Although PlyMan could have sold me 100mm tape, it would have cost over twice as much as the 75mm tape I really wanted as sold by Fibreglass Supplies, and I was going to get the epoxy from the Glue Guru, but noticed it in the PlyMan when I bought the ply last weekend, and it was a good few dollars cheaper. It just goes to show how a bit of shopping around can save a few bucks if you have the time and patience.

Day 1 of the Kayak Build

So today (well yesterday by now) it was pleasantly sunny when I woke up, so time to get on with the build.

I prepared the deck outside the living room with the main tools for the day's activities, marking out and cutting the lower hull panels.

I also took over the dining room with the plans, and took a copy of the offsets so I could have them outside without fear of the master plans blowing away or getting damaged.

The first job was to mark station lines at 305mm intervals along the plywood sheets before measuring the widths for each panel edge as per the offset table. I soon realised that the pine moulding I was intending to rule these lines with was far from straight.

Plan B was to take an old flat pack wardrobe door and cut a set square, roughly 400mm by 1300mm, thus saving a good few dollars at the big shed DIY store. It save a bit of time as well, I want to plan my buying with the tasks ahead in mind and not spend half the build time going back and forth to Mitre10 or some other supplier of hardware.

So, back to the main task. I got 1 version of the four main parts measured out and then I faired the edges to get smooth, curved lines. For this I used a 3m length of PVC electrical trunking cover, pierced with a bradawl and then pinned to the ply. I also pinned both boards to the deck, aligned down one edge with a taught string, and faired over the panels.

Cutting out the parts was going to be a problem. I only have one workbench and the 4mm ply is very floppy. I decided to nip out and buy 4 fence posts, 100mm square and 2.4m long. They'll be used in a later landscaping project so its not money wasted, and they're the ideal height to keep the jigsaw blade off the deck.

Each piece (bottom panel fore and aft sections and side panel fore and aft sections) was used as a template to draw and cut a duplicate. The matching pair of parts were then clamped together and put in the workbench. I used a block plane to trim the edges and get the two pieces as similar to each other as possible. The planing process also fairs out any kinks in the edges introduced by less than skillful handling of the jigsaw.

That was enough for day one of the build. I'll do nothing tomorrow because of the Land Rover Owners Club Auckland meeting, but on Tuesday I hope to 'get out' (proper boat-building term that) the transom, bulkheads and deck beams.

Dart14

The plans I decided upon were the Dart14 single seat and Dart16 two seat kayaks from Selway Fisher.

These are relatively simple designs, although the 14' version looks somewhat more basic in its construction than the 16' variant, so it is the singlekayak that I shall make first.

I ordered the plans online and the arrived a week later. I read over them a few times and then got on with a few jobs around the house to clear the way for the kayak project. I also rang around for a few quotes. I'll post links to the suppliers as I actually purchase materials.

First off is the plywood, which I bought yesterday. I went to the PlyMan in Albany. It seemed an obvious choice because the stock is good, they comes recommended by John Welsford, the designer of the Rogue, my ultimate boat building goal, and they advertise on the radio, so I'd already heard of them.

I bought 6 sheets of 1220x2440x4mm Meranti Marine Bond B/BB ply, and 1 shhet of 1220x2440x9mm. Its beautiful looking stuff and a shame I will have to paint it, but I don't think my first-timer skills will be up to producing a bright finished work of art. Besides, I've already decided that orange will look best to compliment the Land Rover's shade of green and also look suitably safe and nautical.

Talking of the Land Rover, here it is, complete with roof bars after picking up the ply. I had to unload in a hurry because it was starting to rain.



















There's enough space to store the ply in the garage, but I think most of the build will have to take place outside. Roll on spring.