another post of a carbon flavour…

I feel as if I should apologise to my cycling readership for the recently rather kayak-heavy flavour of my posts… It’s not that I am not riding, I am.. it’s just that nothing exciting is going on in that department right now.. Just cruising around on my Storck and DeSalvo fixed and not really missing the racing scene and attendant training schedules at all :-) I may have some adventure cycling flavour of news to share soon however but in the meantime however it is back to kayaking and things of a carbon flavour… :-)

The Greenland Paddle.. the latest iteration has proven to be the nicest paddle I have ever used I think.. the word that sprung to mind while out testing it on a choppy day was “silky”.. the blade is wonderfully well behaved in the water and appears to be very efficient. I’m enjoying the wing-paddle effect one can get with a greenland stick with the right stroke. Effortless :-) The 600g weight is thoroughly spoiling me.. I have continued to use my euro-blades with my Tiderace just so I can enjoy the Greenland all over again when I get back in the skinny Tahe boat.. hence this picture taken by a friend last weekend while exploring the nooks and crannies of Godrevy Island on a rare perfect summer day. Nooks and crannies of a different kind appeared to be on offer when our planned lunch stop turned out to be a secret nudist beach… we didn’t stay long.

black paddle.. black boat

perfect match for the Tahe Greenland

I’m happy enough with the design that I think I’ll offer it for sale later this year…. drop me a line if interested.

Fins then.. I didn’t really plan to write any more about these but I feel compelled to. I have a couple of sets of 3.5″ fins in use by friends and the feedback has been of the <quote> “.. fu**ing fantastic..” and “amazing” flavour.. Modesty suits me I think… <cough> One of my friends has been selected for the GB team at this years surf kayak world champs.. and he’ll be using my fins which is a very cool thing :-) The performance of them as compared with commercial glass fins does appear to offer a significant improvement in speed and responsiveness. Durability appears to be excellent too. Now that I refined the construction I might just have to start offering these for sale (to order) as well. Price I think will be £70/set, a price that compares very favourably with Rainbow glass fins, generally considered to be a very good fin. I think it is fair given the cost of carbon and the amount of work in a set. There is the added advantage for the owner in that damaged fins can be returned to me for repair and should one get broken or lost I am happy to make single replacement fins.. which is something you definitely don’t get with standard commercial fins. Later this year I’ll get around to developing some more templates.

mmmm

All of that, and the ongoing Boatbuilder’s Story project is going to have to wait until the fall.. sorry, autumn. You see in 10 days time I’m off up to the Outer Hebrides to pick up a job working as a sea kayak adventure guide. A summer of week long kayak/camping adventures among the wild coastlines of Barra, Uist & Harris. Can’t wait.. but it is also going to be the longest period away from my bike and riding for, oh.. 15 years or more . Hmm.. will probably do me good :-)

another carbon Greenland paddle

I’ve just finished making myself a second carbon Greenland paddle. The first one has been a great success, very nice to use – comfortable and very efficient, and has proven itself more than tough enough. The reason for this new one is that I wanted to modify the blade profile slightly and vacuum bag the components rather than just rely on a hand layup.

Rather than start again from scratch I simply modified the original plugs and made new moulds. Saved me a lot of time. The vacuum bagging of the components has resulted in quite a significant weight saving, this paddle at just 600grams for a 2.19m paddle is noticeably more feathery than the last but using the same number of plies (4 of 200g/sqm twill carbon) ahould be easily as strong, probably more so thanks to better consolidation of the laminate. The only ‘issue’ I found using a vacuum bagged laminate is that the thickness is noticeably less than before, joining the blade components was an exercise akin to gluing paper sheets edge to edge so rather than joining using an internal fillet of epoxy/microfibre paste I’ve used an external wrap of bias cut carbon over the join. It looks fine but not quite as tidy. Still, it is a handmade thing and the delight of it is more in the using of such a light blade rather than the admiring of it… though that is nice too :-)

I'll get better pictures next time I head out on the water.. The black fade on the loom looks rather nice I think. Unnecessary but nice..

While I’m on.. an update on the carbon fins.. they are proving themselves more than up to task of withstanding rough launchings and landings and the performance improvement on the boat is noticeable. I’m very happy. I’ll write more about those shortly.. stay tuned!

p.s if you want to know why I’m not using the arguably simpler route of carving a foam core and laminating directly on that… it was simply an issue of cost, locally I could not get the styrofoam I wanted in quantities less than 70 or so sheets, and mail order courier costs plus small quantity orders were not economical.. so I made it hollow again. It makes a lovely paddle but is more work.

making a carbon Greenland paddle.. part 3: the paddle

Ok, here it is.. finally got around to writing up last bit, sorry for the wait.  I must also apologise for being something of a dummy and without thinking erasing the card that all the construction photos were on… so I only have a couple of pics plus the finished product. I’ll be making another incorporating lessons learned on this one however so I’ll take more pictures then… sorry :-(

To make each blade half then the moulds were prepared with a few coats of wax plus a coat of release agent. I used 4 layers of 200g/sqm twill cloth to make the laminate. The layers of cloth were wetted out using a plastic roller and layered together flat on the benchtop on a layer of taped down wax paper rather than laying each layer in the mould separately.. doing it this way ensures better wetting out and improved consolidation of the laminate as well as making the cloth easier to handle. Once wetted out the combined layers were peeled off the paper and laid in the moulds. I probably spent at least 10-15 minutes on each blade half coaxing the cloth into the contours of the mould and doing my best to ensure no trapped air bubbles. The wet laminate was then trimmed roughly with a pair of sharp scissors to around 5-10mm above the mould flange. After a couple of hours when the resin was ‘green’ – i.e going off but still pliable I trimmed the cloth flush with the mould flange using a sharp blade.. and then after a further 12hrs or so cure time the blade halves were popped out of the moulds with a sigh of relief :-)

I wanted to avoid external reinforcement of the seam between the blade halves so after sanding the joining faces flat on the benchtop I joined the matching pairs using a thick paste of epoxy and microfibres.. the idea being that, in theory, the excess paste squeezes out of the joint and forms an interior fillet on the joint. So far so good, whether or not it proves durable enough in practice remains to be seen… made a nice tidy, practically invisible joint though :-)

To join the completed paddle halves I carved a rigid foam ‘spigot’ (an offcut of that foil-covered foam insulation board) about 1.5mm smaller in cross-section all-round than the internal cross section of the loom (shaft). That was wrapped in 4 layers of wetted out unidirectional carbon tape with the fibres running longitudinally. The whole thing was then wrapped tightly in polythene and gaffer tape to add some compression while the epoxy cured. Luckily I have a picture of the spigot  on another camera… voila!

The paddle halves were glued together on the spigot using more of that epoxy/microfibre paste and the whole clamped down to cure.. making sure of course all was aligned properly. Once cured I also wrapped a layer of cloth around the outside of the joint extending about 2″ each side of the join.

I had a tidy up so I could take this picture... it was a veritable dung-heap of disposable gloves, mixing cups, paper towels, brushes, scraps of carbon etc...

After final rubbing down the whole lot was given 4 coats of polyurethane lacquer .. semigloss as I find it hides the scuffs and scrapes of everyday use better.. The finished paddle looks pretty nice and in use has a very pleasing degree of flex. It weighs about 650grams, a bit more than half that of a similarly dimensioned wooden paddle.

So.. in summary, I’m pretty happy with the finished product. It is a prototype however and is not flawless. I learned loads along the way so the next paddle will of course be perfect.. and it will be vacuum bagged rather than laid up by hand ;-) Purely in terms of the material cost and time expended it probably is not a particularly worthwhile project.. but in terms of the satisfaction of making something cool, the lessons learned and the pleasure of paddling with something pretty unique.. very much worth it, and at last I have a paddle that properly matches my Greenland boat :-)

kind of a hard to thing to photograph in an exciting manner, and the weather is hideous today so the boat shed will have to do...

(For reference parts 1 and 2 of this project are here & here respectively)

making a carbon Greenland paddle.. part 2: the mould

As I write I have just finished laying up the carbon cloth to make the first section of paddle… if you want a stress free life I wouldn’t recommend this project… I’m well aware as I work that mistakes/problems are going to be expensive in both time and money invested and it is proving to be a devil of a job to get the cloth to conform to the mould without a vacuum… I’m not keen to fork out a wedge for a vacuum pump but if what I have just done does not work out I may have to.  Aside from that the twill cloth is very delicate to handle and of course it is a super messy business… Writing this up as I go means that I can’t hide any cock-ups either.. still, at least you could learn from my mistakes :-) I have been wondering why I couldn’t be happy with simply carving myself a traditional wooden paddle from some beautiful red cedar or something….

Anyway, I digress… at the end of part 1 I had a pair of nicely carved paddle sections. From that point then the procedure looked like this…

The blade halves were coated in epoxy and then, once cured, cut back with progressively finer grades of wet and dry paper.. from 240grit to 1200grit. I spent a lot of time over this as the effort invested now will be directly reflected in the quality of the finished paddle.. The epoxied blade sections were then glued to base-boards.. these were not epoxied until after the mounting as I could then carefully flow the epoxy coating right up to the junction between blade and baseboard to ensure there was no gap for the moulding gelcoat to seep underneath…

warm and sunny October weather continues :-)

The epoxy coating on the base was then cut back but with less care as it’s not going to be represented in the final paddle. The whole lot was then given 5 coats of paste wax, allowing to dry between each coat, and polished between each coat. The plugs looked pretty nice after that :-)

the finished plugs

The moulds themselves are made relatively cheaply using polyester resin and chopped strand glass mat. After applying a layer of PVA mould release to the plugs a thick layer of gelcoat was applied, this forms the surface of the mould and also serves to form a fillet between the blade and the baseboard. Once set, but still ‘green’ to ensure a good bond 3 layers of chopped strand mat were applied. The first layer being a light-weight mat to better conform to the plug, the next two being a heavier weight cloth for stiffness.

cutting chopped strand mat (CSM) to size, gloves essential when handling..

active ventilation (fan) to keep fresh air moving through essential with polyester-based materials.. fumes not good for your brain cells..

the finished lay-up of the mould

After allowing to cure for 24hrs or so fingers were crossed and the moulds popped off the plugs….

hurrah! It worked :-)

It seems to have taken forever to get this far… I am so hoping the next stage goes as well… stay tuned  to find out :-)

Carbon Fairy comes.. (again)

progress on the paddle project has been slowed somewhat this last few days by a spell of fine weather, the Cornwall Sea Kayak Symposium, some bike riding, getting mashed in some large surf and essential outdoors work on my house… It’s not stalled completely however, a large roll of the black stuff arrived today, yum, and the plugs are just about finished.. I just have some final cleaning up and polishing to do before I bite the bullet and start making the moulds…. all will be written up in due course.

 

mmmmm :-)

 

 

plugs epoxied and on their base boards. Final cleaning up and polishing still to do

 

 

making a carbon Greenland paddle.. part 1: the plug

I had planned to present this all in one go, but it’s quite involved and time consuming so I decided to break it down into stages instead… gives me something to write about :-)

This project is something I’ve been meaning to get around to for over a year, using my traditional wooden Greenland paddle with my carbon Greenland boat doesn’t feel quite right but the only commercially available carbon version I know of costs around US$500 plus the cost of shipping across the Atlantic… I was never going to fork out that much for something I could make myself.. I just needed the time…

There are a few basic ways of making such a thing.. the quickest and easiest is to carve a foam core and simply vacuum bag a carbon (or carbon/kevlar) ‘sock’ onto it.. perhaps with some additional unidirectional carbon under the skin to modify the stiffness characteristics Job done. A variation on that would be to cut a wooden stringer and laminate foam or balsa around that, carve it and vacuum bag as before.. this way would make it easier to carve a symmetrical paddle with the stringer acting as a guide. The third way which is also the most time consuming is to make a plug, take a mould from that and then use that to mould the blades in carbon. This last way makes for a very symmetrical paddle as each blade half comes from the same mould but the downside of that is that there are longituduinal seams in the final paddle that need reinforcement. There is a less obvious advantage I think in that the natural joint in the centre of the shaft opens up the possibility of making a two piece paddle quite easily. Of course once I have made the mould I can churn out multiple copies too… I may be able to sell a few.. but that is not my primary motivation. Yet.

I chose the third way.. not because I like making life hard for myself but because I gain a great deal of satisfaction from working with wood (to make the plug) and the design for a two piece Greenland paddle is something I definitely want to play about with once I’ve made myself a couple of one piece blades to use.

The basis for my paddle pattern is the West Greenland style described by Chuck Holst here. In my case I’m making an 86″ long paddle with a maximum width of 3.5″.

The plug is made from a slab of 4″ x 1″ x 60″ pine I found after some rummaging around at my local builders merchants for a piece free of knots.. this is important. I envisaged making two moulds, one for each half of a blade . or for each quarter of the paddle if you like. I could have done the job making just one mould for a half blade but in this case the plug would need to be perfectly symmetrical to guarantee a perfect join once each blade half is mated to its opposite number.. so rather than faff about with fraction of a millimetre accuracy I cut two blanks and spot glued them together for shaping. This way I could carve a complete blade/paddle half and then split the plug down the middle and create two moulds, one for each side of the blade.

The most tedious part of the fabrication is cutting the basic taper into the blanks, longitudinally with the grain.. it’s necessary to use a fine toothed saw to avoid tearing the wood and take care to keep the blade perpendicular through the blank.

cutting the longitudinal taper for one blade half

a small surform worked well for cleaning up the saw cut to a smooth taper

Once that was done for each blade half I glued them together and cut the basic blade plan-form, again using a fine tooth saw.

The basic blank was then marked up with guidelines for the various bevels and tapers before I set to with a spokeshave.. with a sharp blade this is possibly my favourite tool, I can feel the blade cutting the wood through my fingertips, feel the texture of the wood.. it is most satisfying to gently peel away the layers of timber to reveal the 3 dimensional shape of the paddle..

beginning to carve the 3-dimensional shape

Final finishing was done by eye with 60 grit and then 100 grit sandpaper.

coarse grit sandpaper wrapped around a long block for finishing the tapers

finished blade halves ready for an epoxy coating, polishing and then creating the moulds

The next stage is to glue each blank to a flat baseboard and lay on a coat of epoxy, cutting back for a perfect finish.. and then I’ll make my moulds. Stay tuned…

yes I know the grass needs a cut... nice log pile though eh?