onsdag 3 december 2014

Tar and shellac finish on canvas canoe

I don't see this very often on the net but it's pretty comon here in Sweden so I thought I should mention it.
I started canoeing during a 2 years course at Sjöviks Folkhögskola in Sweden. It was a bushcraft course with very big emphasis on canoeing. That said, we used the canoes A LOT, so they needed to be strong but still light enough for the average person to portage.

Applying it
The solution is to treat the canvas with about 3-4 coats of tar, applied in spring when the sun is strong but before it's too hot so the tar starts dripping. It needs to be rubbed in deeply in the canvas. We usually did it with big brushes. But be careful not to put too much, it will take forever to dry. It's okay if the first coats look uneven. Depending on the weather you might have to wait between 5 days and a few weeks between coats. I would say usually around 1 week. Let it dry by a south wall outdoors for quickest drying.
When the tar has dried you're ready to apply shellac. The best is to use "orange shellac"-flakes which are not dewaxed. Then mash them up into small pieces and mix them with denatured alcohol (one third shellac flakes to two thirds of alcohol). It takes a while to dissolve and you need to shake it from time to time. When it's all liquid you're ready to go.
Apply it under the water line. I recommend taping the water line for a straight line. You will see that it dries very quickly. And for each layer it will be quicker and quicker. But don't stress it. For the first 4 layers you should do just 2 a day. Then after that you can do a few more per day, especially if it's sunny. It's good to sand it a bit with 100 grit between coats so it mixes up instead of creating layers. After about 8 coats you should be fine. Then you have to wait at least 24 hours before putting it in water. If the shellac comes in contact with water before it dried it will turn white. But do not fret if this happens. All you have to do is wait and let it dry completely then apply another layer of shellac and the white will disappear like magic.

What's good about it
When you apply a new layer of shellac it will merge with the old one. So if you get a scratch on the canoe you can just put one stroke of shellac and it will be gone. If you get a rip in the canvas all you have to do is put on a piece of fabric, or even better, leukoplast, and then just put a few coats of shellac. Duct tape attaches too and works in emergencies, but it won't take on the shellac.
Over time the shellac will crack up a bit (though not take in water). But all you have to do then is apply another coat. Even if you aply shellac to just a small part of the canoe it merges seamlessly with the old one so there is no need to do the whole thing every time.
Oil colors attaches nicely to both the tar and canvas.
It's lighter than a filler-coat and completely decomposable.

Here's a photo of my canoe, coated with tar and shellac.

The name comes from the worlds oldest tree, Old Tjikko, a spruce close to where I built the canoe (the canoe is also made of spruce).

söndag 30 november 2014

Open canoe paddles 4: The blade

The blade is truly the most important part of a paddle. There is a lot of things to think about when choosing the blade. Not just the size but also the profile shape and the spine affects it's usage greatly.
I will list a few comon blade shapes and talk about their good and bad sides.

Sugar Island
The Sugar Island shape is the one you find on most cheap paddles and almost every plastic one. It's a wide blade with even width all the way to the tip where it ends abruptly. Why this shape has gotten so comon is a mystery to me. The great width and blade area makes it very heavy to paddle with compared to a narrower blade. The only place it really excells is in shallow water where you want lots of blade surface near the tip to scoop more water. And in rapids where you need lots of blade area because of all the air in the water. They can also break easier since the wide tip easily gets stuck in between stones and breaks off a side of the blade.

Beaver Tail
This is probably the most comon shape among more experienced paddlers. It's a great blade which works in almost all situations. It is narrow near the shaft then widens out towards the rounded tip. The wide tip makes it good in shallow water and gives some extra power while steering. Because it is narrower near the shaft it's possible to do very effective C-strokes and bends really close to the canoe.
The biggest drawback of the beaver tail is that it's hard to balance the paddle since there is a lot of material out at the tip. It can also get tougher paddling with a beaver tail because the wide area of the blade is so far from the pivot point.

Otter Tail
My personal favorite. The blade is pretty much the opposite to a beaver tail. It's wide near the shaft and then narrows toward the tip, which is usually rounded on these too. With a narrow tip it's very easy to paddle for great distances, the resistance is very low. And balancing the paddle is usually not too hard for the maker. The wide part near the shaft can get in the way when doing C-strokes sometimes. And on shallow water you don't have a lot of blade surface to use.

Pointy tip blades
I find these blades the most interesting ones. I do not know of a name for these paddles but they are historically very common. They exist in both otter- and beaver-tail forms. Some say they used the pointy tip as a weapon for spearing fish and for fighting against neighbouring tribes. While the fish-theory sure could work for some of the blade designs, that's definitely not the case for all. Some have the tip in a very wide angle which makes it pretty much impossible to spear anything with it.
My personal theory is that a pointy paddle blade lasts longer. It might seem strange at first. Won't a pointy tip take all the tear and wear and be weak because there isn't a lot of material? Yes true, but some wear on the tip is not really a problem. Sure it will get blunter over time but who cares? The most comon ways for a paddle to break is either the shaft breaking or one side of the blade splitting up. On a pointy paddle this isn't very likely since the wear will be in the middle where the fibers go all the way through the paddle. And there are no sides that can get stuck between stones and force it to break.
It's said that the pointy tip will enter the water quieter. That may be true if you really put down the paddle carfully but during normal paddling I don't see a difference.
The obvious drawback of a pointy paddle is steering. J-strokes don't give very good response. But Canadian- or northwood strokes works fine as you steer with pretty much all of the blade.

Of course there are more blade types than these but I think these cover the main forms and from this you can figure out the effect of other shapes. Now for the size..

Blade size
A narrow long paddle will go easier in the water than a wide short one with same blade area. But the wider one will give more power. This is because the narrow one have longer edges where the water can slip by.
In many cases though, the long narrow one is to prefer. it puts less strain on your body and you can move it faster in the water which produces more speed.
There is a formula which says if you double the speed of the blade in the water it has the same effect as paddling at normal speed with a 4 times bigger paddle blade. This means you can sometimes increase your speed by making the blade smaller. (For more information on this I recommend a look in "Sea kayaking: A guide for sea canoeists" by Philip Woodhouse. You can read it for free by pressing the link. It's on page 27 and of course applies to Open canoes as well.)
Bigger blades are preferred when doing Freestyle canoeing (For better steering) or paddling rapids (Because there is a lot of air in the water.).

The spine of the paddle is the part where the shaft extend on the blade. It usually covers about 1/3 of the length of the blade. It's main purpose is to make the blade stronger and not too flexible. The spine can either be an even bevel from the middle to the edges or a visible bump in the middle that looks like the shaft continues into the paddle. The visible spine saves some weight as you can remove more material from the blade. But it can also make it a bit wobbly in the water.

Now that's it for my Open Canoe Paddle series. I hope you enjoyed it! Please leave comments and let me know what you think.

fredag 28 november 2014

Open canoe paddles 3: The grip

The grip is truly the part where you can make a paddle personal. It's the best spot for a paddle maker to let loose their creativity. And it serves as an important balancer for the whole paddle.

There are some different kinds of grips out there. The most comon nowdays being the pear grip, called so as it has the shape of an upside down pear. It's a grip which makes it easy to slide the hand around when doing the indian stroke or a C-stroke or any other manuever where you don't want a fixed grip. And it's very comfortable for forward paddling as you can press the palm of your hand on a wide surface.
The T-grip is pretty much the opposite. It gives you a firm grip which is excellent in whitewater where you want total control of the paddle.
The third one, the Northwoods grip which is wide and long, allows you to either have the hand on top as with the T- and pear-grips or hold the hand in the same angle as your lower hand, making it possible to adjust the "shaft length" whenever you want. For the paddle maker the northwoods grip is also a great way to balance a paddle as it adds a lot of material on the grip side.

Historically it was quite comon with gripless paddles too. These were mostly used in big canoes powered by many people. Where only the stern and bow paddler needed the ability to steer. Nowdays I don't see anyone using that kind of paddles. But if you do know any please let me know!

torsdag 27 november 2014

Open canoe paddles 2: The shaft

The main purpose of the shaft in a paddle is to act as leaverage to transfer the force from the upper hand to the blade. The lower hand should mainly act as the pivot. Therefore the length of the shaft has a very big effect on the paddling. The other things which should be considered is the form (round or oval, or a combination of both) and thickness.
I've split this article into 3 sections; Length, Thickness and Form.


'Shaft length' extends from the top of the grip to the throat of the blade, just where it starts widening.
The most common way to decide if a paddle is the right length is to put it on the ground and see if it reaches somewhere around your mouth. This way of measuring the paddle isn't really correct. Since what matters is the shaft length, not the paddles total length. You want a shaft length where, when you sit in the canoe and the whole blade is submerged, your upper hand is at about the height of your eyes. If the shaft is longer you have to stretch out your upper arm which forces you to use your arms instead of your torso. The right shaft length makes it much easier to use the torso while paddling. And with a long blade youre forced to make longer strokes. If you start the stroke far towards the bow you're just pressing water downwards, moving the canoe up. And similarly if you end the stroke far toward the stern you push water up, pulling the canoe down which just raises resistance.
A too short paddle on the other hand will lessen the leaverage which makes it harder to paddle. And the blade will also be partly above the water which creates "ventilation". The blade pulls down air behind the paddle which makes the water you press away in front of the blade fall in behind the paddle. So you lose power in the stroke.

So summarizing it, the better you are at using the torso (efficient paddling) the shorter shaft you'll want. And the shorter shaft you have the easier it will be to paddle efficiently. But if you paddle incorrectly with a too short shaft you'll get tired really fast.

Now that's the basics. But unfortunately, this isn't all there is to it. Which canoe you paddle matters, since the seat height and gunwhale height over water varies in different canoes. And if you tilt the canoe while paddling or sit on your knees that also changes your distance from the water. Your technique also affects the length. If you do short quick strokes rather than long ones you need a shorter shaft. And if you're stern paddler you might want a little longer shaft for more effective steering strokes.
The method I use to find out correct length is to try a paddle and analyze my stroke. At the point in the stroke where the paddle is at the deepest I want the blade to be just below surface and the upper hand in height with my eyes.
The easiest way to find this is with a paddle with adjustable shaft length. If you don't have one you can try with a slightly too long paddle and see how far under the surface the throat of the blade is (when at the deepest part of a stroke which has the grip at eye height) and remove that length from the shaft when you make or buy a new one.
But generally people use too long paddles. So my personal recommendation for you is to get a paddle just a little shorter than you think you need. The latest solo paddle I made has a shaft length of just 56 cm (22") and I feel I could cut it down by an inch or two still.


Thickness is mainly about strength. A thicker shaft is obviously stronger. But it's also about balance, weight and comfort. A thinner shaft is lighter and easier to grab since you hold it in a loose grip. While a thicker shaft aids in balancing the paddle as it puts more weight on the grip side.


An oval shaft is perpendicular to the blade for strength and comfort.
The form of the shaft is either round or oval. A round shaft is easier to flip when for example doing j-strokes. While an oval shaft gives a better grip and feel of orientation. An oval shaft is perpendicular to the blade to maintain the strength of a round shaft and to fit better in the hand. This means that by using an oval shaft you save some weight without losing strength. But for a paddle maker this makes it harder to balance the paddle (see previous post on balance) since you remove weight on the shaft side, which is already too light. A solution for this problem is to have the shaft round near the grip and then bevel it to an oval shape towards the blade. The thinner shaft near the throat also lessens the ventilation (see above).

fredag 11 juli 2014

Open canoe paddles 1: The paddle and materials

The choice of paddle is just as important as the choice of canoe. It greatly affects your paddling and could be the difference between a stiff neck with headache as a result or a fantastic day on the lake. 
This is the first part in a series of 4. In this part I'll talk about the different parts of the paddle, materials, balance, weight and flexibility.

This picture is from the book "Canoe Paddles- A complete guide to building your own"  by Graham Warren and David Gidmark. It's a great book if you want to learn more about paddles and especially if you want to make your own.
In the next 3 parts of this series I'll go into detail on the shaft, grip and blade. For now I'll focus on the paddle as a whole. There are 4 things to think about here, material, balance, weight and flexibility. And I won't say the cliche phrase that it's all about compromises. You can actually combine all these 4 attributes quite well in a wooden paddle. Though lighter weight will obviously make the paddle weaker in most cases. Well, I'll go through these attributes one by one.
The things you should consider when choosing material is; hardness, weight, feel in hands, toughness, environmental impact, flexibility, maintenance and price. 
The most common materials in paddles are aluminum, plastic or wood. Then there are more high tech materials like glass fiber and carbon fiber.
It's a good idea to have a paddle which matches the gunwales on the canoe in hardness, otherwise if the paddle is too soft the abrasion will wear it down eventually, or if it's too hard the gunwales will be worn down. So for an aluminum canoe you'll want an aluminum paddle, unless of course, the canoe have gunwales in another material.
Wooden paddles have imo hands down the best feel. Even when paddling in winter they feel warm in your hands and if the shaft is just oiled and not varnished you won't have to worry about blisters when paddling. Aluminum are probably the only paddles which you want to avoid using. Even in summer they feel cold and in winter they could cost you your fingers. Most other paddles will feel okay but maybe give you blisters if you paddle for too long. 
Toughness is not the same as hardness, though a harder paddle will be tougher than a soft one. A paddle with thicker shaft and blade will be tougher. But also heavier and not as smooth on flat water. More on this in the "blade" post.
If you want an environment friendly paddle, which I think should be highly prioritized since we paddle and enjoy the nature. Then take one in wood. The other ones require lots of processing with toxic rest products, and if lost when paddling they won't decompose.
Wooden paddles probably require the most Maintenance. If they're oiled you should re-oil them at least once a year, but more can't hurt. But make sure to wipe them off about 30 min after oiling, otherwise you'll get a sticky surface which isn't nice. Varnished paddles don't need maintenance as often, but it's more work when you actually do it. Non-wooden paddles don't really need any maintenance at all.
Plastic paddles are the cheapest, but they usually have poor design, especially the grip. They are also quite heavy. Cheap wooden paddles usually lack good design as well, though they are usually a bit better than the plastic ones. Carbon fiber and good laminated wooden paddles are the most expensive, but well worth the price.
Most of the time while paddling you're holding the paddle in air or water. If we say your paddle weights one kg (35 oz) and you paddle for 3 hours that's like walking for 3 hours with a 1l pack of milk which you constantly move up and down. Gets quite tiring after a while... So a lighter paddle will make it more fun and less tiring to paddle. But don't get too stuck on the weight. A well balanced paddle will have a much bigger effect on the paddling than a light one. Carbon fiber are the lightest paddles you'll find and quite hard too for that weight. Wooden paddles are also unexpectedly light, especially laminated ones can get a really good weight to toughness ratio.
The balance is what really makes the paddle feel light. If you ever try a well balanced paddle you'll never again want to use one that is not.
Generally it is said that you want the balance point, with waterfilm (more on this soon) to be at the paddles throat. However I personally disagree with this. I think the balance point should be where you hold your lower hand when you lift the paddle since that is the point you pivot the paddle on. This though, is quite hard to accomplish on a wooden paddle without lamination.
Since the blade is usually much heavier than the grip, the balance point tends to go towards the blade. Especially on shorter paddles where the grip isn't as far away. To complicate it further a water film is added to the blade while paddling. When you lift the paddle from the water a film of water remains on the blade, adding weight towards the blade. To compensate for this the initial balance point should be 2-5 cm (3/4" - 2") (depending on blade area and paddle length) closer to the grip than the final point.
A little flex in the paddle saves your body from shocks when you hit a stone or accelerate too fast. It also makes the paddle feel more alive. Too much flex however, will take lots of power just to bend the paddle. And the water will just slip off the blade if it's too flexible. Trust me, I once made a paddle with too much flex in the blade and it's quite heavy and unresponsive when paddling.
To complicate it a bit it also matters where the flex is in the paddle. There isn't a lot of research done on this so I can only talk from my own experience. As I mentioned I made a paddle with lots of flex in the blade and it didn't work very well. So I'm of the opinion that there should be a little flex through the whole paddle instead of lots of flex in one part.
To try the flex in a paddle, put it against the ground at about 45 degrees and hold the grip with one hand and push with light force on the middle of the paddle. It should flex around 2 cm (3/4") at the spot you're pushing.

In the next part: Open canoe paddles 2: The shaft, I'll talk about what you need to consider when choosing shaft form and length.