It is not rocket science to sharpen a chainsaw chain, but it can be one of the most frustrating experiences. To begin with whenever you sharpen a chain you need to make sure you get all the dull spots sharpe. This includes the top of the tooth, the side cutter, and the point, this is the place where the side and the top on the tooth meet. Once a chain has been sharpened a few times the rakers, that little thing that sticks up in front of the tooth, have to be filed to the proper height.
The most important thing is to keep the angle the top of the tooth is filed at close to the same from tooth to tooth and from side to side. The length of the tooth from front to back is not as critical as the angle so if you take one tooth back a little more than another don't worry. The type of chain you are trying to sharpen will determine at what angles you need to file them at. Most file guides will give you suggestions as to what they should be.
You don't have to worry about the side of the tooth as that will get dressed as you sharpen the top of the cutter. Make sure you get the top of the tooth sharpened evenly, most people pay more attention to the point of the cutter than they do to the opposite end. When you look at the top of the cutter from the nose of the bar you want to see and even edge across the top cutting surface. File until all the shiny spots are gone, some times you will see a small burr rolled up along the top of the cutter.
One side will be easier to sharpen than the other the side will depend whether you are right handed or left. Try to keep the same angle across the top as the chain had when it was new, some brands of chain have a line scribed on the top to give you a guide to go by and to tell you when the chain is out of life.
The proof of how you did will be when you make your first cut. The saw should cut straight and you should not have to push the chain through the wood. When it cuts off to one side either you did not get the top angle quite right or one side is still duller than the other. Keep at it and pay close attention to what you do so you know the cause and effect. Some of the manufacturers of saw chain have good website instructions on all the aspects of chain sharpening.
I made a fixture to hold my chain in a vise which makes it much easier for me. The trick is to sharpen the chain a little more frequently as you will have less dull to remove, and when you do hit something take your time and get it back into shape. When you try to cut with a dull chain you can heat up the chain to the point where you take the temper out of the steel and it will never stay sharpe like it did before.
Randy
