to cove and bead?

[fubar]

Gday All,

I am contemplating starting a kayak or canoe build.

Its Bob the labrat fault his flathead kayak really caught my eye (lovley slat built kayak).


So I,ve started doing the research and this is first of the questions (as usually I start and then ask after I bggered up trying to be different this time).


I am probably using 1/4 inch thick stips not sure of width but on a lot of the vids they seem to use the cove and bead edges is this really necessary or can a staight edge work OK if the strips are a soft timber like WRC.

Thanks Dennis

[tony_A]

G'day Dennis
I am 80% of the way through building a laugingloon double kayak Twin Star tandem baidarka design wood strip sea kayak by Laughing Loon (http://www.laughingloon.com/twinstar.html) I used western red ceder on the sides of the hull paulowina on the bottom of the hull and californian redwood on the deck. Didn't use cove and bead rather fitted each strip by hand using a block plane. The technique is described on the website, Hand Beveling wood strips for wood kayak canoe tablesaw set-up safety (http://www.laughingloon.com/shoptips3.html).
I found fitting the strips OK but there is a lot of work in building one of these. While I dont consider my self a perfectionist I am a prety darn goodist!
If you decide to go down the hand fitting rather than bead and cove send me a message and I can give you a more detailed descritpion of the process and pitfalls that I found. May do a summary of the build on this site when I'm finished (hopefully this summer)
Tony

[whitewood]

I hope Allan Newhouse comes into this thread discussion. He has built at least 5 kayaks with mostly Paulownia and does not use B & C. His crafts are a pieces of art but equally functional.

Whitewood

[PAR]

The cove and bead method can eliminate a lot of fiddly bit of fitting planks, but isn't without some trimming to get bright finish fits. If shaping the strips by hand you can get just as nice a job, if a bit more effort. In reality, they both are about the same if you want a bright finish. If on the other hand you will paint it, then hand fitting without bevels will do just fine, filling with thickened epoxy afterward, then fairing her smooth. Ultimately it depends on what you want. If you want a bright finish, the fits have to be tight. Cove and bead can help in this regard, but you'll feel bad about the amount of wood left over after you made the beads and coves. On an average canoe build, 1/5th maybe even as much as 1/4th the strip material is shavings on the floor after beading and coving the strips. With hand planed strips, you'll have much less waste. If it's a painted build, then you can compensate for terrible fits with thickened goo and paint.

[fubar]

It will be a bright finish as I love the look of the timber kayaks and canoes I've seen . I thought it would be a quicker and easier process for a first time build not having to plane the majority of the edges to a tight fit
thanks for the replies more questions will be forthcoming

hooroo dennis

[ian]

if you go with hand planing, a pair of edge trimming planes might prove very useful
Veritas Edge trimming plane (http://www.leevalley.com/US/wood/page.aspx?p=54862&cat=1,41182,48945)
and
Bronze Edge Planes (http://www.lie-nielsen.com.au/catalog.php?grp=1225)
from the Veritas blurb ...

The fence is drilled to allow blocks to be added or to affix a wooden wedge for cutting controlled bevels, such as in boatbuilding.the Lie Nielsen's also have drilled fences

[tony_A]

I found the standard block plane to be fine. The angle of bevel changes a bit along the length of the craft due to the changing shape of the hull. Less on the flatter sections and more on the curves areas. The bow of my craft has a bit of reverse curve which required reverse bevel and tapering ends on some of the strips. I think B&C would have been difficult in this section I milled the strips for the hull with a 3 degree bevel on one edge and this was a good start. Hand plane for the fine adjustment there after. I routered a 6 mm wide slot 12 mm deep in a 4 m length of 50 by 200 pine and could sit a strip in the slot if I needed to plane the whole length.
Tony

[whitewood]

Par has made a point about the loss of timber during the B & C process. If you are buying your strips with B & C it will cost you about 50cents extra per L/M and you will have to buy more metres of timber to cover the same hull. Allan Newhouse finishes his bright from the regular strips of 6 x 20 mm.

Whitewood

[fubar]

I can cove and bead and I will be cutting my own strips so not too worried about the waste just really wanting too know if its demonstrably better system . The wife has expressed an interest so looks like it will be a canoe build.
Now regarding timber I have access to some rather nice tight grain douglas fir its at the moment would that be suitable for canoe buiding?

[whitewood]

I can cove and bead and I will be cutting my own strips so not too worried about the waste just really wanting too know if its demonstrably better system . The wife has expressed an interest so looks like it will be a canoe build.
Now regarding timber I have access to some rather nice tight grain douglas fir its at the moment would that be suitable for canoe buiding?

It seems to be accepted that the lighter the craft the easier / quicker it is to paddle. Many of the strip planked kayaks /canoes are made out of Paulownia or WRC or a mixture of both if your going for appearances as well. You can source your Paulownia on the net or just contact Port Phillip Plantation Shutters at Mordiallic. (Not connected)

Whitewood

[fubar]

Thanks whitewood I have read your previous posts and will be in touch with plantation shutters regarding the paulownia but
why is lighter better? portage ? speed ? does it make a difference at the end of the day paddling a 20 or 40 kilo canoe?
Its been 30 odd years since I last paddled and that was in plastic always down river.
lots of beer and red wine consumed since then so really cant remember.
again thanks for replies

[ian]

why is lighter better? portage ? speed ? does it make a difference at the end of the day paddling a 20 or 40 kilo canoe? all other things -- length, beam and hull profile -- being equal, a 40kg vessel (+ you) will sit deeper in the water than a 20kg vessel
resiatance to paddeling is a function of wetted area -- ie the area of the boat's hull sitting in the water -- the greater the wetted area the greater the paddeling effort -- so the higher out of the water (= lighter) is better

[b.o.a.t.]

to add to Ian's reply...
Every boat-length you travel, you displace a weight of water equal to the total boat & passenger weight
an average of about 6" to the side, and move it back again behind you.
You do this with the sweat of your brow & the blisters on your own two hands.
If the boat weighs an extra 20kg & is 5M long, for every km you paddle, you manually
move 20kg x 200 boat-lengths (4 Tonnes) of water 6" to the side, & 6" back again.
For ever and ever, amen.
Then there's the carrying it from the car roof to the water.
The cool thing about a canoe is you don't have to park right next to your put-in point.
200M away is ok. Unless your canoe is 20kg over-weight...

Hence Pawlonia & western red cedar being the preferred timbers for strip planking.
best regards
Alan J

[fubar]

thanks for the replies looks like it will be paulownia with small amount of other species used for highlights
again thanks for the sharing of knowledge

[whitewood]

I typed an answer 3 times yesterday only to find they did not transfer to the forum when I submitted the reply. Don't know if it was my new windows 7 or the new forum. In the end you have had 2 responses from persons who explained the theory. All I remembered was a post by a naval architect, (MIK I think) who explained the theory. I didn't remember the reasons just the response as I was selling Paulownia at the time and it was the best response to further sales of my timber. All I'll add is sailing and rowing place a lot of importance on light weight hulls so it must make a significant difference to performance.
Good luck with your build. If you visit Allan Newhouse's posts you may get some ideas on design and appearances of kayaks. If not send me an email and I'll reply with some photos of his craft.

Whitewood

[anewhouse]

Sorry about the delay in responding. I've been away racing my strip built K1. :)

I am currently building my 9th strip built kayak and have not used bead and cove for any of them. I am quite satisfied that there is no benefit, either in time or the quality of the job.

I use the method described by Rob Macks in the link provided earlier.

Apart from my first two kayaks, which were WRC, I have used mostly Paulownia with WRC accent strips. I have found the Paulownia very similar to the WRC as far as bending, cutting and sanding goes, but it is roughly 20% lighter.

I am very keen on the idea of light kayaks and that is just one part of the reason I use so much Paulownia. After the first two kayaks, I also became convinced that 5mm strips are better than 6mm and I notice that Rob Macks is also a big fan of the thinner strips. He explains why here. Laughing Loon Shop Tips (http://www.laughingloon.com/shop.tips.html)

All my kayaks since the first two have been 5mm strips except for my to racing kayaks that are 4mm strips.

Fortunately I paddle my kayaks in water that doesn't involve bouncing them off rocks, so I don't need a bullet proof layup. Consequently my 4.5 metre sea kayaks weigh about 13kg with bulkheads, hatches and seat fitted and the 5 metre one is less than 15kg. The 4.5 metre TK1 is under 8.5 kg and my 5.2 metre K1 is exactly 10.8kg. The K1 is about half a kg over what it might have been, but I was building it from left over strips and a lot of the deck is WRC.

Others have explained the theory behind the advantages of a light kayak. if you want evidence of just how much difference it makes, go to the Blue Heron website, download the free kayak designing software, check the drag on the default design (or your own), then move the waterline up so that the Design Displacement is about 10 or 20kg heavier. Then check the drag again.
Blue Heron Kayaks (http://www.blueheronkayaks.com/kayak/index.html)

One other advantage of the thinner strips that Rob doesn't mention is that when you bevel the strip, you don't have to take as mush off. The gap you are trying to get rid of is about 20% smaller than if you used 6mm strips.

My reading on the subject of bead and cove suggests that if it goes well, it does a good job, but if things don't go well, there are a few reasons why it will look significantly worse than bevelled strips.

There are few photos of my kayaks on this forum and on the Blue Heron forum if you want further evidence that bevelled strips can produce a tidy job.

[whitewood]

Allan it's nice your still going strong both on the water and in the forum. I feel your the most experienced amateur builder around and your opinions are worth reading.

Whitewood

[labr@]

I've only just noticed this thread - lots of good replies there.

Dennis, like Tony A I would go with the straight edges and hand bevel with a block plane - possibly because having done it once it would be a familiar process. I'm not sure that an edge plane with a guide block would help because the bevel angle varies along the strip.

AJ is right about the importance of weight in getting to the water - a heavy boat is less likely to be used and it would be a shame not to use it as often because of this.

I am just getting started on a skin on frame using paulownia for the stringers and purchased enough to do another strip build as well. Have only ripped and scarfed the stringers so far but it seems a nice timber to work with and has a nice pattern, although subtle due to the pale colouring.

What design are you going to build - or haven't you chosen one yet?

Tony A - how about starting a thread to show your build. The Laughing Loon designs look fantastic and there may be a few people on here that would like to see how to go about doing a baidarka. Shooting Star is definitely on my wish list.