10 Reasons and Solutions for Circular Saw Smoking – Fixed!

Circular saw is widely used in woodworking. Due to the less weight and size, it can easily use indoors and outdoor. A small size diameter saw blade can use in the circular saw in order to gain the best user experience and handle it easily. But we can see some problems there. Among that, circular saw smoking is one of them.

A circular saw is smoking due to these reasons such as dull circular saw blade, wobble saw blade, misaligned saw blade, higher cutting depth, improper supporting, insufficient saw teeth, lower cutting speed, warped saw blade, worn motor brushes, etc. You can fix them easily after you identify the problems.

When you identify the problem clearly, you can fix it easily. According to the smell of the smoking, we can categorize them into two.

  • Wood Smell – Smoke rise due to workpiece and saw blade
  • Chemical Smell – Smoke rise due to inside motor probelm

1. Dull Circular Saw Blade

When a circular saw is used for a long time, it can be dull easily. You can identify the dull blade by its cutting speed and binding.

Due to the blunt saw teeth, the material will scratch instead of cutting it. Hence it will generate more heat due to friction. As a result of this, smoking can rise and the cutting path is not straight.

If a saw blade cutting speed has been reduced considering its brand new condition, it can be dull. And also, when the saw blade is binding with the workpiece is another sign of a dull blade. And also you can see, chips are not removed properly. This is very important. A brand new saw blade will remove the chips, and when the blade is dull, chips will turn to smaller sizes (dust).

If the saw blade is dull, you should sharpen it using a proper method. Carbide tip saw blades are not dull easily. Those can be used without sharpening for a long time. But due to some unexpected reasons such as cutting nails inside the wood will damage the teeth head easily.

A dull saw blade can be fixed by sharpening it easily by hand or using a sharpening service. Using a high-quality saw blade will minimize the sharpening and avoid smoking and burning the workpiece.

2. Wobble Saw Blade

How to Identify the Wobble Saw Blade?
When you rotate the saw blade by hand, you can see the inclined saw blade positions. When you switch on the circular saw, you can see a wider saw blade than its regular thickness. In order to confirm the saw blade wobble, you can check the distance between teeth and shoe end in two points. If there are different distances, there is a saw blade wobble.

How Does Wobble Affect the Circular Saw Smoking?
A wobble saw blade can cut wider kerf due to its abnormal spinning path. As a result of wobble, the workpiece surface can touch the saw blade while it is spinning. Due to the hard touching surface, its heat can go up, and we can observe smoking from the workpiece. Additionally, we can see burn marks on the workpiece on the cutting surface.

Reasons for Circular Saw Blade Wobble
A circular saw can wobble due to the nonflat flanges, damaged arbors, bent saw blade, etc.

Replace for a new high-quality saw blade

3. Misaligned Circular Saw Blade

The regular saw blade should be perpendicular to the arbor shaft. If the circular blade is not perpendicular, we can consider it as a misaligned saw blade. The circular saw blade should be tight with the proper flat flanges, washers, and nuts. If the sawdust is clogged between the flanges and saw blade it will be misaligned easily.

When the saw blade is misaligned, it can wobble the saw blade. Due to the misalignment saw blade surface can touch the cutting surface tightly. As a result, the workpiece cutting surface can overheat due to friction and then smoke easily.

So you should align the saw blade perpendicular to the arbor shaft well. It will avoid many problems.

When the workpiece is burning, smoking can rise. This is very common for the circular saw cutting process.

4. Dirty Circular Saw Blade

When we use a saw blade long period, dust can toughly adhere to the saw blade surface. This will make the surface rough. Sometimes it can increase the blade thickness due to the adhered sawdust. Not only dust but also rust can cause this problem also.

When the saw blade is rotating, surface dust also can touch the cutting surface. As a result, surface friction will increase, and heat will generate. Hence we can see smoking and burning marks on the cutting surface.

You can use blade cleaner to clean the saw blade. It is better if you can clean the saw blade regularly. It will reduce all problems easily.

5. Higher Cutting Depth

Higher cutting depth with a circular saw

Another factor for circular saw smoking is higher cutting depth. Normally circular saw can cut 2 9/16 inch cut capacity effectively. If the workpiece depth is increased, saw blade needs to spend more time in the workpiece.

As a result of this saw blade, surfaces will touch with the cutting surface much time. Due to the friction, it will heat and then we can see smoking there.

For the most efficient cutting action, set the depth adjustment so that one-half tooth of the blade will project below the material to be cut. This distance is from the tip of the tooth to the bottom of the gullet in front of it. This keeps blade friction at a minimum, removes sawdust from the cut, results in cooler,faster sawing and reduces the chance of kickback.

It is better to use a thin workpiece for cutting circular saw. For the thicker workpiece you can use table saw.

6. Wrong Supportings

Place proper supporting for circular saw cutting path

When we use a circular saw, we should have proper clamps and support in order to have an efficient and effective cutting process. When we use a circular saw we should know how to place supports when we cut.

During the cutting process, the cutting surface should not be bending with the saw blade cutting path. During the cutting process, if the workpiece tends to bend from the cutting path, it will clog due to compression of the workpiece. Hence heating can be generated.

As a result of this, we can see smoking. Sometimes workpiece can kickback due to improper support.

Always keep the proper workpiece supporting as compression is not built towards the saw blade.

7. Insufficient Saw Teeth

Let’s see, how do saw teeth affect the cutting process?. We can cut rip cut, crosscut, bevel cut using the circular saw.

A rip cut is done along the grain path. Along the grain, the path is not strong much. During the cutting process, more chips will remove easily. As a result of this, we should use a lower number of teeth. If we use a higher number of teeth saw blades for rip cut, chips will clog inside due to less space of gullets. When it clogs inside, it will increase the inner friction. As a result of the friction, heat will rise and we can see smoking.

Hence you should use below a number of teeth for each cut.

  • General Purpose of cutting – 18 Teeth
  • Smooth wood cutting – 24-60 Teeth
  • Non carbide, plywood, vinyl siding cutting – 90 Teeth

8. Lower Cutting Speed with High RPM

When the saw blade is spinning, we should move the shoe forward on the workpiece. As I explained above, smoking occurs due to the friction between the saw blade and workpiece cutting surface. When you reduce the tool feeding speed, the saw blade can engage more time with the cutting surface and blade. As a result of this heat can be generated. Finally, we can see smoking due to the heating of the wood workpiece.

  • Use cutting speed and feeding speed of the circular saw according to the workpiece material. If you use hardwood you can use lower cutting speed with hight RPM.
  • For the soft wood you can use lower RPM with lower cutting speed.

9. Warped Saw Blade

When the saw blade is bent or twisted due to any external force we can see smoking from the workpiece. When the saw blade is bent or twisted, it can tightly touch the cutting surface. As a result of this, we can see burning and smoking on the workpiece.

If the saw blade is warped it should be replaced. It is impossible to fix 100% accurately. Even a small edge will gan many problems.

10. Motor Brushes Are Worn

Worn carbon brushes
Worn brushes

If you feel the smoking smell is chemical, there is no doubt check the motor. Normally, most saw motors are brushed. The brushes are touch the commutator in order to supply the current and voltage. brushes are made with carbon, when the armature is rotating, brushes can worn due to friction. When the brushes are worn we can see smoke from the motor.

You must change the brushes when their length reaches 1/4 of their initial length.

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