Many people think they are qualified to sharpen the chain saw chain and that is perhaps very true in most cases. However, I will attempt to show the proper way and the reasons that are important for doing it my way. The manufacturer designed the saw tooth, of the modern chain saw chain, to cut in a very specific way that would allow it to cut faster and last longer before any sharpening is neccessary. I have had people ask how offter a chain needs to be sharpened. That is the same as asking how long a piece of string is. It will need to be sharpened when it does not preform as a new one would. It may be ten hours or ten minutes, depending on what is being touched by the cutter tip. If the log has any dirt in it's bark then with each cut there will be a little ware and the operator will notice the difference in the cutting ability. When the chain was first used, whether brand new or just sharpened, it cutting ability was able to penstrate the log very easily with no use of the dog (spike) to make it cut. As the chain's cutting tip wore than it soon became more likely to dig the spike into the log and use the saw's leverage to make it cut better. This is when the operator has to use good sense as to how much pressure to apply by the spike leverage. Because when it becomes to much pressure. this is when severe wear on the bar and chain takes place, Forcing the dall chain against the bar makes heat, and heat causes wear. It also causes the bearing joints in the chain's links to heat up and wear that part also. This is what is known as "stretch". While I'm talking about stretch, I want to address one thing that I have leaarned about cutting slab wood. I have noticed that the chain stretched at a rate of about %50 more then when cutting regular pole wood or trees. This is because there is much more bark to be cut on slab wood, then other wood, and the bark is where the sand lodges, as the wind blows it around, and also as the wood is dragged on the ground.

One of my customers was having a problem with keeping his chain tight, as he thought it was, and he came to my shop to talk to me about the problem, thinking the bar was not staying tight. This was on an 041 Farm Boss with "20 bar and chain. I first examined the saw to see if maybe something was causing the bar to slip but soon ruled that out. I have never seen a bar slip on any saw where the bolts were tightenen to specs. To tell the truth I didn't have the answer to the problem at first but somehow the chain had to be the problem due to unnatural wear on the bearings in the chain's joints. Then it dawned on me. This man lived on the CaCapon river bank and had a farm there. I then asked if he was cutting timber along the river. With a slow and searching look at me.--he said yes. He said, with a puzzling look, what does that have to do with it? I began a little teaching topic to explain just what was happening to his chain saw. That CaCapon River overflows every year and some years the water reaches thirty feet above it's natural flow. When this happens the water carries hundreds of thousands of tons of sand laden topsoil with it down through the trees and deposits it in the bark of every tree along that river. So, over and over with every flood more sand gets grown into the bark of the tree up to the highest flood mark which may be thirty feet above your head. That means that not only the first cut but the second and maybe the third cut will have sand in the bark that you will be cutting through. Your bar is not slipping loose but your chain is wearing which is stretching and it appears to be loose. As I was explaining this his hands went up in the air, as he made a rotation, and with an exasperating look said: I don't know why I didn't think of that, since I have lived there some 70 years.

What is the best type of chain to buy? This all depends on the application it is to be used in, the size of the saw and the person using it. If we are talking about a person that is experienced in the use of a chain saw and he is cutting timber or fire wood, and the saw has signficient power, then I would suggest what is commonly known as a flat top chisel tooth cutter without the super duty antikickback. However I would always reccomend the ramp type antikickback on any chain you purchase. It is only good sense to have some measure of protection to keep from getting into trouble when you are using one of the most dangerous pieces of machinery know to man. Any device or mechanism that will ward off potential injury is always a good thing.

If you are using a small saw with power designed to cut small trees or pole wood, then the saw will have a smaller designed chain and it really doesn't require a particular type chain to enhance it's preformance. If it is a mid-range saw, then use the guide above.

What is the best angle to file the chain? This is perhaps the most often asked question I receive. The "angle" refers to the slant to the cutter link. All new chains come with a 30 to 35 degree angle right from the get-go but that does not mean that is the gospel. I prefer a 25 degree angle. I find that this seems to work best for most woods. The reason for a lesser angle goes like this. The greater the angle to the cutter the greater the side pressure on the cutter link and, the greater the angle the longer the cutting edge and thus more power is required to pull it through the wood. So, by reducing this factor by the number of teeth on the chain, that are in the curf, (section of wood being cut and the width of same) faster cutting action is achieved with less fuel. Might not be a drastic amount to think about but in a day to day situation where it is uses in a commercial application, it could amount to big savings. There is also the type of wood being cut to consider in this "angle" thing. If I am going to be cutting dead loucust, which is very hard wood, then I would go with the greater angle and forget the above. But don't change the angle for one tree. One other factor is, make sure both sides are exactly the same angle.

One of the biggest mistakes I find in chain sharpening is the the depth and undercut. This has to be correct for the cutter to preform at upmost. If the undercut is not enough then the cutting edge will be blunt and not chisel acting in it's cut throught the wood. This tends to push the cutter out of the wood because the wood being cut is piling up against the cutter and raising it upward. When the undercut is to great it tends to cut very fast but only a short period of time. There is not enought metal to hold an edge and if it hits a hard knot it may even bend the top edge down which will simulate a dull chain. What make for a proper undercut is when only 1/4 of the file goes under the tip of the cutter. As far as the depth is concerned, that will correct itself when the proper undercut is achieved.

How do I know when the chain is dull? When it won't cut or cuts to one side.

How many strokes do I make with the file? Again this is all proportionate to how dull it is. File it back until no scruff marks are left on the top edge of the cutter. Pay particular attention to the angle and undercut as you file it back to sharpness. One good suggestion I can make for anyone filing a chain. Find a way to hold the saw firmly. I sometimes cut a groove in a stump top to hold the bar from moving around and sometimes I just hold the saw against the tailgates holding cable, first one side then the other, using my body to supply pressure to the powerhead while pushing the file through.

How much do I take off the depth guages and when? Usually they don't have to be adjusted untill about 1/2 of the cutter is filed or ground away. What you have to see in your mind is the design of the cutter tooth. As the cutter is filed or ground back, the depth of cut lessens. As you look at the side view of the cutter you will see that the cutting tip is higher then the tail of the cutter. Out in front of the cutter is the depth guage which is somewhat below the top of the cutting tip. This difference is the amount of cut allowed. About 1/8 inch. If your saw has the bigger powerhead then you may want to adjust this cutting amount to a bigger bite. Bear in mind as you do so, you are inviting your saw to climb, pull, kickback and be much more aggressive.

Of course the best way to sharpen a chain, by far, is with a chain grinder, and I mean one that has the proper grinding wheels to do the job, with an experienced operator.. I have ground many thousands of chains and can make a chain cut above standard until it has very little tooth left on the cutter. I have people that bring me as many as sixteen chains at one time to sharpen, on a repeat basis. I have had chains brought in that others have ground on their machines and I can tell by looking at them who has ground them, usually. If the operator has not the experience in grinding chains , then they need to have someone teach them the proper way to do the job. The machine also has to have the proper grinding wheels to achieve the proper grind for the particular chain being sharpened. That seems to be the biggest shortfall of all places that grind chains. They try to do all types of chains with only one size grinding wheel and usually don't even have the grinding wheel to do the depth guages.

There are many other things to consider on a chain saw chain. I'll just go through some. If a chain has become dull on one side, from hitting a stone or metal or whatever, and the operator continues to use the chain to cut, probably because they don't have an extra chain or even a file with them, the chain tends to lean to one side which causes wear on only one side of the bar and chain. This chain will probably not be much good again because it will be leaning forevermore causing it to cut to one side. I always (always) check the bar when grinding a chain, if the saw is brought in with the chain. If the bar looks like it is worn on one side, I grind it back to specs to make it flat. If the bar has worn to the point that the wear has erroded the metal from the inside of one side, making one side thinner, then the only solution is to turn the bar over or put on a new bar. I will also taper all sides of the bar on the grind wheel, just a little, to reduce the possibility of the bars edge snaging on the precious cut mark made on the tree. Didn't think of that did youi? Makes a wonderful difference.