In my previous post i discussed the uses and benefits of the Round Knife. In today’s post I would like to continue discussing the round knife, but this time give you all the info relating to sharpening a round knife. As it’s essential to keep your cutting tools sharp i thought this post would help those who are new to leathercraft and sharpening knives.
What tools are required for sharpening.
- Sharpening Stones or Whetstones or grit stones.
- Lubricant such as oil or water
- Leather strop
- Jewellers rouge
- Cloth for cleaning and wiping your blade
- Round knife
- A firm work surface to work on.
In this post i walk you through the various steps to sharpening a Round knife, what tools are required and a general outline of the process. There seems to be plenty of misinformation out there so i have compiled all the helpful info into one post. Read on to find out more.
What are Sharpening or Whetstones?
The term “Whet” ‘means to sharpen’ and does not mean to moisten or make wet. Whetstone therefore literally means sharpening stone. Whetstones are also called Sharpening stones or Grit stones and they are used to sharpen knife blades. The knife blade is rubbed against a whetstone of a certain coarseness or grit which gradually sharpens the blade.
Whetstones are normally flat rectangular blocks, but they also come in round stones or in the form of rods.
What types Of Whetstones are available.
Oil stones – these lubricated with oil. Generally well priced.
Water stones– are lubricated with water. Usually soaked in water prior to use. Generally well priced.
Diamond stones – Made from a coating of diamond chips bonded onto a metal plate. Don’t need lubrication, but can be lubricated with water if necessary. More expensive stones.
Ceramic stones – Don’t need Lubrication, but can be lubricated with water. Generally well priced.
Whetstones occur naturally in nature but can also be manufactured. They are commonly made from Novaculite (Arkansas Stone), Aluminium Oxide (India stone) or Silicon Carbide (Crystolon stone). The stones are used with lubricants such as oil or water and are therefore referred to as oil stones or water stones.
Generally you can use oil or water as a lubricant on most types of stones but once a lubricant is used on a stone you have to stick with it. You can’t change from using water on a stone to suddenly using oil as the stone will become unusable.
The manufacturers specification of which lubricant to use on a particular stone is usually provided when purchasing your stones.
A Diamond stone can also be used to sharpen knives. These stones don’t require any lubricant to be used, although water can be used if needed. They are generally harder than oil and water stones and due to their hardness they last much longer. Diamond stones don’t come in a high enough grit to achieve a highly polished finish. They are also more expensive than oil and water stones.
Ceramic stones are much harder stones and are mostly used for polishing finer edged blades rather than the rougher low grit work.
Water stones are soaked in water prior to use. Generally anywhere from 5 to 15 minutes is enough of a soaking to allow you to use them. Generally water stones are cleaner and easier to use for beginners. Oil stones are a little bit more messy.
Whetstones come in differing grades of coarseness or grit, ranging from 100-10000 grit. A lower grit stone is usually used to repair knives with chipped edges or with slight damage to their edge.
The higher grits allow a finer more polished blade to be achieved. An 8000 grit stone will be used to finish or refine your knife edge giving it a polished mirror finish.
Start sharpening with the lower grit stone and then work your way through the varying coarseness until your blade is finely honed and polished.
What does the lubricant do?
Lubricant has two functions. It reduces heat build up when sharpening, but also helps to move away the particles or swarf that are produced while sharpening. This way your knife is sharpened quicker and the life of the blade is protected.
Where can i buy a Whetstone?
Whetstone kits are available from Amazon. Some kits come with a variety of different grit stones as well as the leather strop and jewellers rouge and lubricating oil. If you would like to see an example of sharpening kit i am referring please click this link to Amazon to see what’s available.
How to sharpen your Round Knife.
I have included a video from Tandy Leather below which explains the sharpening process very clearly.
Sharpening a blade is a 4 step process which involves using differing degrees of coarseness grit stone in order to sharpen your blade. You can break the sharpening process into fixing, sharpening, finishing and stropping phases.
Sharpening a round knife involves rubbing your blade against a whetstone at a 15 to 20 degree angle. The angle that you sharpen your blade is very important. If your angle is incorrect you can end up with a blade that isn’t sharpned.
Less than a 1000 grit stone will be used to repair knives with chipped edges – This is referred to as a fixing stone as it fixes and repairs damaged blades.
1000-3000 grit stones are used to sharpen dull knives – This is referred to as a sharpening stone as it does start the sharpening process.
4000-8000 grit stones are used to refine your knife/ blade edge to near mirror finish. These stones are commonly referred to as finishing stones as they are used to get a nice smooth finish on your blade.
After this process of sharpening with stones is complete you can use a leather strop and jewellers rouge to strop your blade to give it its final finish.
The Leather Strop
The final phase after sharpening with your whetstones is to use a leather strop to polish the edge of your blade and work off any burr left behind from the whetstones. This step is very important as the strop is used with a very fine abrasive called a honing compound.
In Leather work the compound that’s usually used is called jewellers rouge. This honing compound is applied to the surface of the strop. These abrasives help to give a mirror finish to the edge of your blade.
Strops can be rigid or flexible. I prefer to use a a rigid leather strop which is just a piece of leather glued to timber. Your blade is then rubbed against the strop to refine/ shine your edge.
How long does it take to sharpen a knife.
Sharpening your blade is a bit of a process depending on what kind of condition your blade is in. If your blade is really dull or blunt it will take about of half an hour to 45 minutes to sharpen. It’s important not to rush so take your time as you want blade razor sharp.
Important note: Be careful when sharpening your round knife. Always keep your fingers out of the way when you sharpen your knife.
Once your Round knife is sharpened and not being used its best to store them in a sheath so that the blade edge doesn’t get damaged or cut you.
Conclusion
Hopefully the above info has helped you understand the difference between oil and water whetstones and the sharpening process in general. You can apply this sharpening technique to just about all your blades that need sharpening. Good luck and please check out my post about the Round Knife if you haven’t already seen it. Thanks.