Learn how to sharpen your knife or axe
Learning how to sharpen your cutting tool is an essential piece of maintenance that you should learn. This article will be made for the beginner yet it will hold a lot of information that I am sure anyone will find useful.
Understanding What You Are Sharpening - The Grind
Firstly you must understand what type of blade you will be sharpening. Knives come in all different shapes and sizes and their type of edge also varies, the different styles of edge are often referred to as 'grinds'. It is important that you understand which type of grind that you are dealing with, this will determine how you will sharpen it and what tools you will use in the process.
So what's the most popular grind for a bushcraft knife? Well a poll taken on BushcraftUK asked exactly that, there was five different grinds to choose from and 93 Bushcrafter's voted, 60% of them choose the 'Scandi' grind as their favourite choice, making it by far the most popular choice. If you have something different that's not a problem at all, its all a matter of preference and they can all perform great for certain tasks.
Illustrated on the right you can see four commonly used knife grinds.
Blades are also produced in different materials, most commonly used are high-carbon steel or stainless steel. High carbon steel blades supposedly hold a sharper, stronger edge for longer, but as a result of their high-carbon content they are prone to rust, so will require more care and maintenance if you want to keep your tool rust-free.
Stainless steel does not hold a superior edge however it is resistant to rust.
Sharpening Tools and Techniques
Something to note about sharpening tools; whether its a oilstone, water-stone or wet'n'dry paper, they are all rated in 'grits'. The 'grit' number is a grading of how coarse the stone is, the higher the number the finer the stone will be, the lower the grit the more coarse the stone will be. A coarse stone of say 240 grit will remove dinks and sharpen your steel blade a lot faster than a 800 grit would.
Benchstones - Waterstones, Oil Stones & Diamond
Below I will give you a introduction to just a few sharpening tools you may come across, the technique in actually using the different sharpening tools can be very similar, however each requires different preparation and they each have their own pro's and con's.
Japanese waterstones
... are my personal favourite, in my opinion they are clean, efficient and require next to no maintenance. Waterstones just need a little lubrication, its easy just soak the stone in water for 10-15mins before you use it, then a squirt of water every now and then if the stone gets a little dry. There's no messy oil's or cleaning to do and they don't clog up as easily as oilstones do.
When purchasing water stones to sharpen your knife you will probably want to get two different grit stones. You can sometimes get double sided stone with different grits on either side, or you can often buy a set of different stones. I get my waterstones from Axminster Tools, they are fast to deliver and often reasonably priced. To the right you can see a waterstone set that I purchased from them a few years ago and I notice its still available; the 'Ice Bear Waterstone Sharpening Kit' contains a 800 grit stone for initial grinding and sharpening, a 6,000 grit stone for a fine polished finish, a rubber & metal non-skid stone holder (which is handy when your stones are wet!) and a Nagura stone for cleaning the glazed surface of the fine stone. This is a great set to start with, it has lasted me a few years now and is still going strong.
I recently purchased a coarser 240 grit stone, I wanted a coarser stone that would remove dinks and damage from a damaged blade quicker than my 800 grit stone and it certainly does the job.
So any downsides? Waterstone's can be considered a little cumbersome and considered more of a home/shed tool as oppose carrying one for use in the field. However having said that I know there are smaller double-sided waterstones available, although I've personally never needed them or tried them.
Also waterstone's can loose their true flat surface faster than other tools, however this is no major problem and can be easily remedied by rubbing the stone's surface on a harder flat surface like a paving slab etc.
Oil Stones
... are very common and cheap, found in any hardware store and are often double-sided with a coarse grit and a fine grit. Easily poached from father or grandfathers shed! Lubricated with oil (WD40 etc.) they can do a good job and fast but some consider them to be a little messy and the surface-pores can clog up with the steel from your blade and after a lot of use they may need de-oiling, soaking them in chemicals for long periods.
Diamond sharpening Kits
... consist of a thin synthetic board impregnated with 'precisely sized Monocrystalline diamonds permanently bonded to nickel.' The company DMT pioneered this sharpening technology. Diamond whetstones have two advantages over waterstones and oilstones. They cut more quickly and stay flat. You can even use a coarse diamond whetstone to flatten the edge of your waterstone if it has become misshapen through hard use.
Diamond impregnated boards do not require any prior preparation to use (no oils or water etc.) they can be really thin, light and portable.
I personally don't have much experience using Diamond sharpening techniques, however a blacksmith friend of mine did tell me that for very frequent use (when sharpening is your job!) they don't stand up to the task and the diamonds simply ware away to quick, so they could be potentially be expensive and not really last a long time.
[If you would like to contribute more information on Diamond Sharpening please contact me]
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For expert advice on sharpening |
Now here's a question! How do you sharpen your Crook knife, hook knife, spoon knife, or wharever it is called?
I have tried and failed, but , i keep trying
Mike