As a woodworker, you are likely to spend considerable time working with circular saw blades. Occasionally, you may come across a dull saw blade. How do you deal with it? You need to decide on whether to sharpen a blade or replace it.
Can circular blades be sharpened? The answer to this question is, yes. But first, you cannot sharpen all circular blades. Further, you need to equate the cost of sharpening against the cost of a new blade. Sometimes it’s cheaper to replace and other times, if you have the tools and the know-how, you can sharpen them.
Background
When it comes to circular blades, the sky is the limit with regards to the types of circular saw blades that you get for various purposes. When your blade becomes dull, you might wonder what action you need to take – to sharpen or replace?
Some blades, especially the carbide-tipped variety can be expensive – perhaps $50.00 to $100.00. In such a scenario, it makes sense to sharpen them to extend their life. But you can replace cheaper circular blades.
If your blade is dull, it becomes inefficient and slow. It can also be hazardous, as it can overheat, impart a rough finish, and jam causing kickbacks. If you have the right tools with adequate knowledge and experience, you can sharpen your dull circular blades.
Circular blades with teeth that do not have a carbide tip are generally cheaper than those that do. As we mentioned above, it is more practical to replace the cheaper blades.
For example, a masonry blade cuts using its face. These blades typically have flat teeth, wear out faster, and work out cheaper than carbide-tipped blades. We use masonry blades to cut tiles, cinder blocks, and concrete.
Carbide-tipped blades on the other hand have a much longer life. You can use them to cut various materials of multiple thicknesses and hardness.
Signs of a Dull Blade
Even the sharpest and most resilient blade finally gets dull after using it for a while. Although carbide-tipped blades make for many years of sustained use, they will ultimately become dull and you will need to sharpen them.
But what are the signs of a dull blade? Well, to start with, you will start noticing cuts that are not altogether clean. The transition is slow, but you will gradually see that the cuts aren’t in the straight, clean line that you used to get when your blade was new.
If you take a photo of the way your blade cuts when you first start using it, you can compare it with a recent photo. You can compare the photos in the “before” and “after” photos to check for deterioration in the quality of the cuts.
You will also notice extra load on the motor as the machine cuts through the material. As the blades become duller, the blade generates extra heat due to the added friction.
If you see the warning signs mentioned above, the time has come to sharpen or replace your blade. If you plan to sharpen it, you can follow a few simple steps if you have the know-how and the required tools.
Price of Sharpening a Circular Blade
When the question of replacing vs sharpening comes up, it all boils down to the cost. As mentioned above, if your blade costs a few dollars, say $5.00 to $10.00, then you would probably do well to replace the blade – it’s not worth the time or effort involved in sharpening it.
But for the more expensive blades, you can save a tidy sum by sharpening them or getting them sharpened. If you are going to get your blade sharpened, you can either get it done by a professional or do it yourself.
Whichever way, the cost of getting a circular blade sharpened can be between 25 to 50 cents per tooth. So, for example, a 40-tooth blade at 25 cents per tooth blade will cost you (40X0.25) = $10.
If you paid $50.00 for your blade, it is worth spending that money. Your sharpened blade will work as well as a brand-new circular saw blade.
Circular saw blades, especially the carbide-tipped variety, are the more expensive types. You will get blades with carbide tips for $50.00 or above, even over $100.00, which you would definitely want to sharpen or get sharpened.
Handy tip: Instead of disposing of your cheaper blades when they become dull, you can save them for demolition and remodeling work. They can prove to be especially useful while cutting wood that might contain blade-damaging hidden nails and screws.
How to Sharpen a Circular Saw Blade
It is a common practice to replace circular saw blades when they become blunt. However, if you have the knowledge and tools to sharpen them, you can save a tidy sum of money over time by doing so. Here are the basic steps involved:
Step 1: Dismantle the Blade
Remove the blade from the machine. You can do this by using the appropriate spanners.
Step 2: Fixing the Blade
You need to fix the removed saw blade on your workbench. Use two screw clamps and ensure that you clamp the blade tightly. It will prevent it from vibrating as you work on it.
Step 3: Mark Your Starting Point
You need to record your starting point so you know when you have come back to it. For this, you can use a permanent marker or make a small scratch with a scriber.
Step 4: Trim the Saw Teeth
The teeth of circular saw blades do not wear down evenly. Using a flat file, trim down the unevenness on the teeth until they are all the same height.
Step 5: Set the Teeth
You now need to ensure that the teeth are bent or skewed slightly to the left or right. It enables the teeth to create a kerf slightly wider than the blade thickness. You will need a plier to perform this function.
Step 6: Sharpen the Blade
You will need a triangular file for the actual sharpening operation. Rub the file over the face of the teeth, ensuring that the teeth are similarly shaped and identical to the original shape and angle.
You can start with the “left-hand” tooth row, and then move to the “right-hand” tooth row. Use three to four strokes of your file for each tooth. This stage needs a bit of practice, so be patient.
Step 7: Reassemble the Blade
Now that you have sharpened your blade, you need to reassemble it. Ensure that you fit it tightly and firmly on the machine.
Step 8: Test Your Newly-sharpened Blade
Locate a test block of wood. As you cut the wood, ensure that there is no undue noise or vibration. Also, observe the quality of the cut. It should look better than the cut that the blade produced when it was dull.
Also, check the alignment of the teeth and ensure that they are uniform in height and orientation. If you have done it right, your circular saw blade should be as good as new!
Conclusion
We always prefer a sharp and efficient cutting blade whether circular or straight. You can get the best performance out of a sufficiently sharp blade. A dull blade will cause all sorts of issues like burnt wood, undue splintering, and even a jammed blade that can result in kickbacks.
However, you need to decide whether you want to go in for DIY sharpening or get your blades sharpened by a professional. Although the process of sharpening circular saw blades may appear to be simple, it is not.
To sharpen your own blades you need appropriate tools, adequate experience, and knowledge. If not done correctly, you may end up wasting time and money and being worse off than you were, to begin with. But if you know what you are doing, it can be a worthwhile experience.
In any case, create a preventive maintenance schedule for all your machines with circular saw blades. You will experience great satisfaction during your cutting operations in your woodworking workshop.
Happy woodworking!
