Some of the possible reasons behind the smoking of the circular saw include a wobbling saw blade, dull saw blade, misaligned saw blade, improper support, wrong cutting depth, wrong tooth set, warped saw blade, slow cutting speed, and many other causes. Of course, you can’t fix the smoking issue if you fail to zero in on the real cause of the problem. So, at the onset, it will help to know the potential causes of a smoking circular saw.
Possible Reasons Behind Your Circular Saw’s Smoking Issues
There are many possible reasons behind the smoking of your circular saw. Knowing these possible reasons will help you troubleshoot this smoking issue. Below is a shortlist and explanations of each of these reasons:
Dull Saw Blade
A dull saw blade can cause your circular saw to smoke. You might start with a very sharp saw blade. But after many and continuous cutting, the saw blade becomes dull. Then, suddenly, the saw begins to emit smoke, and you’re taken aback by the appearance of smoke.
To remedy this issue, you can check the teeth of the saw to see if they are dull. If you’re an experienced circular saw user, you will readily feel that the teeth are dull. To check on the saw’s teeth, you can unplug the circular saw and inspect the teeth’s edge.
If you’re not experienced, you can check the sharpness of the circular saw blade by making another cut. If the saw exerts too much effort in cutting, the teeth of your saw blade are dull and blunt. You can either replace the saw blade or sharpen the saw blade.
Incorrect Tooth Set
An incorrect tooth set might be another cause of saw smoking. Yet, you will seldom think of this cause as the reason behind the saw that smokes. Saw blades come in different sets of teeth. So, you might be using the saw blade with the wrong tooth set.
Some saw blades come with teeth that have alternately pointed teeth. This tooth set allows the saw blade to cut thicker than the blade’s actual thickness. Such teeth arrangement lets the saw blade cut without letting the flat blade part contact the timber. Thus, you can avoid binding of the saw blade.
However, if you use a saw blade with no set or little set, the blade’s flat part would rub with the wood, burning the wood. This burning of wood can make the saw smoke.
Incorrect Saw Blade
Another reason behind the smoking of the circular saw is the incorrect saw blade. As mentioned above, circular saw blades come in different types with varying tooth sets. Using the wrong blade type might cause the saw blade to bind and burn wood.
To make fine cuts, you need to use a saw blade with many teeth. If you want to make a quick rough cut, it will be best to use a saw blade with fewer teeth.
You can also use this blade type when cutting thicker lumber. As a circular saw user, it will help to know the ideal type of saw blade for the kinds of cuts you would like to make.
Dirty Circular Saw Blade Filled with Saw Dust
As you use your circular saw more often, dust and debris might lodge into your circular saw motor. You will also see pitch buildup over time, making the thickness of your saw blade a bit wider. Moreover, your saw blade might rust over time. If you don’t remove these buildups or clean your circular saw regularly, there will be increased friction when you use the circular saw.
With more friction, more heat will get generated when you cut. This increased heat will cause the wood to burn, causing burning marks and smoking while you cut. So, you must clean your circular saw and saw blade regularly to prevent smoking and burning.
Cutting Damp Wood
Another reason behind a saw producing smoke is when you cut damp wood. If the wood is moist, it will be more challenging to cut. Your saw blade will need to run faster at a higher speed when the wood is wet. The saw blade will also heat up and oxidize the wood’s moisture. This oxidizing of moisture will produce smoke.
Cutting Too Much Wood in One Go
If you would cut a thick timber, you might aggressively cut because you want to cut as much at once. If you do this, smoke might ensue from the circular saw while you cut. This smoke will emanate from the cut fibers that can’t escape with ease. Since these fibers are stuck, they would cause too much friction, leading to smoking.
You can avoid this predicament by reducing the cutting depth of your circular saw blade and engaging in multiple passes. If you do so, you can make the cutting process easier while giving your circular saw blade a reprieve.
One of the essentials of cutting using the circular saw is the use of clamps. Another essential is the use of proper support. As a woodworker, you need to support your workpiece while you cut. With the correct supports and clamps, you can cut effectively.
If you don’t support the workpiece, there is a big chance that the wood would bend, causing binding and blade pinching. As the circular saw blade gets pinched by the wood, heat will get generated, causing smoke to emit from the wood. In the worst case, it can cause kickback likewise.
Cutting at Lower Speed with Higher RPM
When using the circular saw, you need to move it forward while the saw blade is spinning. If you run your circular saw blade at a higher RPM, but you are not moving the circular saw forward or moving it slowly, friction might increase, and heat buildup happens.
If you feed your saw blade slowly at a higher RPM, heat will get generated, causing the circular saw to smoke. So, when cutting using the circular saw, you must match the circular saw’s feeding rate with the saw blade’s RPM.
An Issue with the Motor
If you’re an expert in using the circular saw, you can distinguish if the smoke emanates from the motor or burning wood due to friction. With the determination of the type of odor, you can quickly figure out the source of the issue.
For example, if it smells like burnt wood, the smoke is caused by the friction between the wood and saw blade. If the smoke smells differently, it might be an issue with your motor. It will be best to repair your motor or replace it altogether in such a case.
Worn Out Motor Brushes
If you think the smoke smells like that chemical, it is undoubtedly a problem with your motor. Most motors are brushed motors. These brush motors come with brushes that touch the commutator to supply voltage and current. Carbon usually makes up the brushes.
Once the armature rotates, the brushes might wear because of friction. When these brushes wear, they will emit smoke, and you will see this smoke emanating from the motor. So, you need to replace the brushes when their length gets reduced to a quarter of their previous length.
A smoking circular saw is not only frightening to look at; it also indicates a troubled circular saw motor or troubled saw blade. If it is caused by friction, the smoke, of course, will smell like burnt wood. If it is an issue with the motor, the odor will be more pungent and stinging. Thus, you can determine with ease if the smoke is due to excessive friction or motor issues.
Knowing the cause of the smoke will enable you to troubleshoot the issue immediately. In the worst case, you need to replace your motor if it is badly damaged. Yet, in some cases, you only need to adjust or you only need to clean the saw blade to remove pitch buildup.
Jason is a 40-year-old woodworker, carpenter and author who have been involved in the woodworking and woodcraft industry with 17 years of experience. He is expertise in technical aspects, woodcraft and furniture building projects.