Have you been using your chainsaw, which isn't quite cutting right? There's a good chance something went wrong when you sharpened the saw.
In this article, I will cover the most common sharpening mistakes. I'll also offer solutions to fix these mistakes.
The Most Common Chainsaw Sharpening Mistakes
There are several common mistakes people make when sharpening their chainsaw. These mistakes will affect your saw's performance, making your work much harder.
The most common mistakes are:
- Using the Wrong File Size
- Using a Dull File
- Filing Backwards
- Not Filing the Depth Gauge Enough
- Filing the Depth Gauge Too Much
- Filing at the Wrong Angle
- Uneven Sharpening
Below, I will explain each mistake in detail. I'll also give you solutions to avoid these problems in the future.
Using the Wrong File Size
Chainsaws come in different sizes, which means chainsaw chains come in different sizes too. Chains suited to fit a larger saw will have large teeth. Likewise, chains intended for smaller saws will have smaller teeth.
As you can guess, sharpening files come in different sizes too. So, you need to match the correct file to the proper chain.
If the file is too small, the file won't reach the top of the cutter. So, the file won't sharpen the whole tooth. In this case, you will have spent a great deal of time sharpening, only to have a dull chain.
If the file is too big, too much of the file will be over the tooth, and not enough will be in the gullet.
The gullet is the bottom of the tooth. It's the part that looks like a hook and is essential for efficient cutting. If you don't sharpen the gullet properly, you will exert more energy trying to cut.
Avoiding this mistake is simple. Use the correct size file. I've included a table with standard chain pitches and their corresponding file size.
To find the chain pitch, check the chainsaw's bar.
Using a Dull File
Chainsaw files won't last forever; they get dull as you use them. When using a file, you should feel the file grab. If the file isn't grabbing and is instead sliding across the chain, your file is dull.
Under ideal conditions, you can get about five sharpens out of a file before you need to replace it.
If your file is dull, it won't sharpen your chain.
When sharpening, you should be feeling the file grip. You should also see tiny metal shavings coming off the tooth as you push your file through. If this isn't happening, you are essentially rubbing your file against the tooth with no result.
To avoid using a dull file, you'll need to keep track of your file use and replace files as you feel them becoming dull. In most cases, you should get around 3 - 12 files per pack.
To extend the life of your files, tap your file on the bench after you finish sharpening each tooth. Tapping your file will eliminate any metal shavings left on your file.
With files being cheap, it's a good idea to buy a few boxes at a time. Having a few boxes means you'll always have a new file ready to go.
To sharpen a tooth, you will need to run the file through multiple times.
The correct way of doing this is to bring the file out, reset and push the file through again
The incorrect way is pulling the file back through the tooth after pushing the file through. When this happens, you are filing backward.
Filing backward is terrible for both your saw and file. The outside of the tooth is made from Chrome. Chrome is stronger than your file. Filing backward is a quick way to destroy your file.
The cutters on your chain will wear a lot quicker if you are filing backward, resulting in a dull chain.
Fixing this problem is simple. Avoid filing backward. Always take the file out after one push through, reset your angle and push through again.
Repeat this process, counting the number of times you sharpen each tooth. Counting how many times each tooth gets sharpened will enable you to sharpen the whole saw evenly. I will touch on this later.
Not Filing the Depth Gauge Enough
The depth gauge is the little bump sticking up in between each tooth. Another name for the depth gauge is the 'rakers.'
The depth gauge on a saw controls how deep the cutters cut into the wood. The depth gauge and cutters are set to the perfect ratio when your chain is brand new.
As you sharpen your chain, the top of the cutter tooth gets lower and lower. If the depth gauge isn't measured frequently, it will eventually become too high for the teeth.
When the depth gauge is too high compared to the tooth, it blocks the cutters from entering the wood. As the ratio becomes more and more unbalanced, it will become harder to cut. If left long enough, you will no longer be able to cut anything.
As you can imagine, using a chainsaw with no result is frustrating.
To fix this, you will need to monitor the height of the depth gauge. You can monitor the depth gauge's size visually. However, visual assessments may only pick up extreme misalignments.
Otherwise, you can buy a cheap depth gauge measurer; this will provide a more accurate measurement. Make sure to check the depth gauge every two or three sharpens.
The depth gauge measurer works by sitting over the teeth of the saw. There will be a hole where the depth gauge is. If the depth gauge pokes through the hole, you will need to file it down until it's level with your measurer.
Filing the depth gauge is a much easier process than sharpening the chain. Run a flat file over the top of the depth gauge two or three times. Make sure you are consistent and file each depth gauge the same number of times.
To check out a universal depth gauge measuring tool, click this Amazon link. The advantage of this tool is that you can use it on any chain brand.
And here is a quick video showing how to file a depth gauge:
Filing the Depth Gauge Too Much
So to avoid under filing the depth gauge, file it every time, right? Unfortunately not.
You only measure and file the depth gauge every couple of sharpens because over filing a depth gauge is another issue.
Filing the depth gauge too much will result in a very aggressive saw. An aggressive saw causes the following issues:
- An overworked saw
- The chain will dull faster
- The saw will become dangerous due to a higher chance of kickback
If the depth gauge is too small compared to the cutter, it will cause the cutters to cut much deeper into the wood. The saw will be much harder to handle.
Don't file the depth gauge every time you sharpen the chain to avoid these issues. Only sharpen the depth gauge as necessary.
Filing at the Wrong Angle
As you will see on your chain, the teeth are at an angle. This angle is 30 degrees. You will need to sharpen the tooth as close to this angle as possible. Too much or too little of an angle can negatively affect your cutting.
Too much of an angle will cause the top point of the tooth to become too sharp. If the point is too sharp, it will be weaker and break easier, becoming dull. Again, this will result in you sharpening your saw more frequently.
Inversely, if you have too little of an angle, your saw will have difficulty cutting. It will feel dull, and you will exert more effort into your work.
To get the correct angle with a regular file takes a lot of practice. On the top of the tooth, there is a diagonal line. This line is the angle you need to be sharpening. You can match your file to this angle, but it will still be hard to maintain as you push the file through the tooth.
There are special filing tools that can assist you when filing. These tools hold your file in a casing that will be at the correct angle once lined up with your saw. Following the tools guide will keep your angle close to the 30 degrees required.
You can purchase one of these tools from Amazon by clicking this link.
I briefly mentioned counting the number of times you sharpen each tooth to sharpen the saw evenly. The saw won't cut well if you sharpen one side more than the other.
Uneven teeth make it hard to cut because there will be a curve. If the teeth are uneven, you will find as you cut, your saw will be curving, requiring you to work hard against the saw to make it cut straight.
This curve happens because one side is cutting more than the other.
To fix this, you will just need to count the number of times you sharpen each tooth and make sure you consistently sharpen each tooth the same. All the teeth on the chain should look the same size.
Another trick to maintaining an even sharpen is first to sharpen with your weak side. If you sharpen with your weak side first, you will be a little worn out when it comes time to sharpen on your stronger side.
Sharpening this way will weaken your strong side sharpening a little bit, hopefully making it even with your weak side.