Sawing

 

Accurate sawing is very important for us because it influences the later phases of our work to a great extent. Before starting sawing, check the markings once again. Check whether you have to saw along the line or near it so as to keep the line. It is easy to make your workpiece a saw blade longer or shorter.
For sawing you need a stable, not wobbly table to which you can fix the piece of wood to be sawn. When fixing your workpiece, try to fix it as close as possible to the surface to be cut in a way avoiding knocking your hand against it and preventing the wood to be sawn from swinging out. With some practice you’ll surely be able to do it right! Those who are fortunate have a carpenter’s workbench; I do not have one myself but my modelling workbench was manufactured based on the same pattern.


A modelling workbench

(A modelling workbench)


A normal table, too, is perfectly suitable for our work. You can fix the wood to the table using two fast screw clamps.


Wood fixed to the table

(Wood fixed to the table)


A foldable workbench may come in very handy around the house, too.


A foldable workbench

(A foldable workbench)


A strip of wood fixed into the workbench

(A strip of wood fixed into the workbench)


Bumpers and a mitre box screwed onto the workbench
A foldable workbench is perfect to be used for our work. The only disadvantage it has is its light weight. Yet this shortcoming is easy to handle by hanging two sandbags of 5-10 kg on the bottom rails of the workbench.


A workbench with sandbags

(A workbench with sandbags)


When you have more practice, it will suffice to keep the strip firm with your hand, without the extra support of the sandbags. But do not throw the latter away; they may come in handy later on for carving, engraving or planing.
If necessary, various accessories can be fixed onto the workbench.


A bumper and mitre box screwed on the workbench

(A bumper and mitre box screwed on the workbench)


A vice may also come in handy, although you can cope without it, too. The vice, just like a clamp, may leave marks on the wood. So as to prevent this, use both with pads.


A vice

(A vice)


Fixing strips with wooden pads

(Fixing strips with wooden pads)


In what follows, let us learn the essentials about saws.
Saws are cutting tools with smaller or bigger teeth. All saw teeth have cutting edges. These edges cut tiny pieces one by one from a piece of wood. To put it simply, the bigger the teeth of a saw, the softer the wood to be sawn, and vice versa: the smaller and denser the teeth, the harder the wood to be sawn should be. The sharper its teeth, the more a saw bites (cuts) into the wood. The tasks a saw is to be used for determine how its teeth are designed. Therefore there are lots of different types of saw available in trade. Saw blades are characterised with a TPI (teeth per inch) number, which indicates the number of teeth per one inch. You can categorise blades according to their TPI numbers. Rough saws have a TPI number of 14-17, medium saws of 18-24 and fine saws of 25-32.
Foxtail saws have teeth with sharp cutting angles (δ). The average value of δ is between 80~90º.


The cutting angle of a foxtail saw

(The cutting angle of a foxtail saw)


A foxtail saw and a replacement blade

(A foxtail saw and a replacement blade)


The teeth of a foxtail saw

(The teeth of a foxtail saw)


A foxtail saw is excellent for vertical cuts, but if you cut horizontally, against the grain, you will get a lot of splintering. For cross-cutting use a dovetail or a mitre cut saw. Thanks to the rigid blade your cross-cutting will be accurate and with the obtuse angled teeth splintering can be avoided. The cutting angle is approximately (δ) 120º.


The cutting angle of dovetail saws

(The cutting angle of dovetail saws)


A dovetail saw

(A dovetail saw)


The teeth of a dovetail saw

(The teeth of a dovetail saw)


If you saw in curves, along small arches, use a coping saw. Unlike other saws, you can use this while comfortably sitting, taking care to keep the saw vertically. The 300 mm and 160 mm coping saws are the types most widely used.


300mm coping saw

(300mm coping saw)


160mm coping saw

(160mm coping saw)


Actually both types are suitable for us. It is probably easier to cut with the smaller one, while the 300 mm coping saw is better for shaping bigger shapes. When cutting curves and arches, turn your workpiece instead of turning the saw in the right direction. When sawing patterns with various inner holes, make a drilling where you can pass the blade of the saw through for sawing.


A saw blade passed through

(A saw blade passed through)

 

There are several types of blades to use with coping saws.


Various coping saw blades

(Various coping saw blades)


I do not recommend the spiral blade; even though it cuts faster and you do not have to turn your workpiece so frequently, the cutting surface is not really nice. The workpiece requires more sanding.
Coping saws work by pulling. Therefore, the teeth of the blade must point towards the handle.


A correctly fitted coping saw blade

(A correctly fitted coping saw blade)


After some practice, you can work with it very nicely. In the beginning you are sure to break some blades, but later on you will be surprised to find how long a single blade can last.
When replacing blades, you must press the frame. After fitting in the blade, release the frame and the frame will keep the blade tight. You can make a fitting aid device for it, too, in the edge of the coping saw table for example.


Replacing a coping saw blade in the coping saw table

(Replacing a coping saw blade in the coping saw table)


A coping saw table is very useful. We can fix it to the table with a shackle. The wood to be sawn is to be fixed to the coping saw table and is supported by the table from all sides.


Coping saw table

(Coping saw table)


These three types of saw are sure to be required for your work.
You can work very fast and nicely with what you call Japanese saws. They work by pulling, which makes it possible to use very thin blades of approximately 0.5-0.7mm. They have very tiny and specially designed, sharp teeth.


Tajima pull saw and replacement blade

(Tajima pull saw and replacement blade)


Another type of pull saw with replacement blade

(Another type of pull saw with replacement blade)


Japanese saw teeth

(Japanese saw teeth)


In the longer run, it is worth buying one by all means. You can really grow fond of it. If you are careful with the blade, it lasts very long. Unfortunately, if it gets blunt, there is no way to sharpen it; you have to buy a new blade.
When cutting larger pieces of wood, you use a frame saw. You will probably not need one if you make small objects.


Frame saw

(Frame saw)


Various teeth sizes and profiles

(Various teeth sizes and profiles)

 

Saws must be regularly maintained. I will describe their maintenance in the chapter about sharpening tools.
Sawing correctly:
Sawing is a process for which you need practice. The condition of you tool influences how easily you saw to a great extent. The blunter your saw, the more you need to press it. The harder you press it, the more easily the saw slides out towards the side, getting stuck in the wood. After some practice you will feel the right movement. When starting sawing, use your thumb to keep the saw in the correct position and make repeated small movements to assist it into the wood.


Assisting the saw into the wood

(Assisting the saw into the wood)


Considering the Japanese saw is very sharp and requires a movement you have to get used to first, it is a tool requiring greater care in the beginning. My son used a piece of wood to replace his thumb until he got used to this saw. When the saw is in the wood already, you can remove your thumb. Use your other hand in which you hold the saw to assist the saw with fine movements into the right position. If you have the right direction already, pull and push the saw in the direction of sawing, avoiding shaking movements, keeping the direction and the angles.
As you get closer to the end, make increasingly fine movements and, if possible, support the falling out piece to avoid breaking the edge of the strip.


Broken edge of the strip

(Broken edge of the strip)


A mitre or sawing box may also prove very useful for our work. It is very easy to use. In the case of a traditional saw, place the strip into the box and press it against the side further from you. In the case of a pull saw, press is against the side closer to you. The guide slots cut into the mitre box guide the saw properly. 90º and 45º degrees are sure to be pre-cut in the box. You must be careful in order to prevent that sawdust could hinder precise movement. Clean the box regularly during your work.


Sawing in a mitre box with a pull saw

(Sawing in a mitre box with a pull saw)


Sawing in a mitre box using a traditional saw

(Sawing in a mitre box using a traditional saw)


Sawing in 45ºdegrees

(Sawing in 45ºdegrees)


Mitre cut handsaws can also be well used. They come in many types, with various blade lengths. Their advantage is that you can set several angles in a simple way. Mitre cut handsaws that guide the saw very well and for which good quality replacements are available are unfortunately somewhat expensive. If you want to cut cross-cut a 100 mm strip in 45º, a saw with a blade length of at least 560 mm is required.


A mitre cut handsaw

(A mitre cut handsaw)

 

Sawing defects:


Sawing defects may be caused by insufficient practice or defects in the tools.
One such defect may be the bluntness of your saw. The saw proceeds very slowly in the wood and goes out of square. This makes your job, too, very difficult.
Another defect that makes your saw drift is incorrectly performed setting, which is outlined in detail in the part about sharpening tools.
If the saw blade is twisted or warped, the saw once again goes off the line. It is impossible to saw straight in any of these cases.

 

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