A steel rod is used for aligning the serrated edge or ‘burr’ and can put a temporary edge on the blade as a kind of quick fix. It's good practice to run a knife over a steel rod every time you use it to slow down the dulling of the blade.
How to use a whetstone to sharpen a knife
It’s a good idea to soak your whetstone in water for about 15 minutes before you use it. The whetstone needs to be kept wet, with ordinary tap water, or if you prefer, sharpening oil. The first thing to consider is the type of blade that you want to sharpen, this will dictate the angle at which you hold the blade. Getting the angle right for your sharpening is probably the most important and difficult element.
Start with your dominant hand, which means, if you are right-handed, you want to have the blade facing away from you. Place two fingers, half on the blade and half on the stone and lift the blade until you feel it flush with the surface of the stone. Place the same two fingers on the side of the blade and apply some light pressure as you pull the blade towards you. Release the pressure when pushing the blade away from you and repeat. Move the blade down the stone starting from the tip and working your way down to the heel of the stone.
Remember to keep the blade wet at all times. You will see a dark residue build up on the stone, known as 'slug', this is made up of microscopic steel fibres that the stone is removing from the blade, and is what will sharpen the blade so try and use it in contact with the stone.
Flip the blade over, and repeat the process in reverse, this is your non-dominant hand so you will need more reps. The aim is to create a fold of microscopic teeth known as ‘raising a burr’. When this forms, it is time to flip the blade over and sharpen the other side.
The next stage in the sharpening process is to refine the edge with a finishing or polishing stone. Repeat the process as before, but with a lighter touch. Wipe the blade clean when finished.
How to keep your knives sharp
All knives will dull over time, but there are a few things you can do to slow the dulling of the blade. Wash the knife immediately after use and dry it with a cloth, before putting it away. Leaving a high-quality knife in the sink or submerged in water is a sure way to take the sharpness of a blade and never, ever put your chef’s knife in the dishwasher.