This instalment of the Woodworking Blind series will cover tips and techniques for the safe and successful operation of saws. This is not a definitive guide to the use of every saw, as there are plenty of general tutorials freely available governing the use of every type of saw imaginable. This article focuses on the techniques employed to operate various saws with no sight and is intended to offer sufficient description for a blind person to make sense of widely available learning material.
The saw (in particular the powered saw) is the tool most often mentioned in discussions around safety of operation by a sight-impaired person. The two safest saws in my opinion are the bandsaw and the mitre saw, the latter also known as a chop saw. A major contributing aspect the saw safety is the movement direction of the blade, and the angle at which the teeth make contact with the material. A chop saw has teeth that point downwards and towards the fence when the blade is stationary. The blade rotates toward the fence and the rotation of the blade and the pressure applied by the chopping action pushes the wood toward the fence and down onto the table respectively. A bandsaw blade rotates such that the teeth push the wood downwards onto the saw table and as the kerf of the tooth is slightly wider than the steel of the blade the chance that the blade will bind is minimised. Even if it does bind it will only push the wood downward against the table rather than throwing it from the saw.
The table saw is conversely dangerous if operated incorrectly or if used for an inappropriate cut. A table saw blade rotates towards you, with the teeth pointing forwards and cutting down into the material. This is fine at the front of the blade, but at it means that the teeth at the rear of the blade are moving upwards. There is no inherent downward pressure built into the tool itself, unless you have a blade guard installed (which you should in almost every use case). As a consequence of this, if a piece of material binds at the rear of the table saw blade, either between the blade and the fence or through being pushed into the blade by the operator, the blade will quickly pick the wood up and throw it back from the saw, sometimes in a straight line but often in an an unpredictable direction. The only certainty is that the speed of this action, known as a kickback, is faster than you could react and the likelihood of injury is high if you get in the way or try to stop kickback occurring in the split second between the material binding and the blade throwing it from the saw.
Kickback is easily prevented through correct operation as I discuss in Safety First. In essence every table saw should have a riving knife installed. The riving knife is a metal splitter that sits behind the blade and should be of a thickness half way between that of the blade plate and the tooth kerf. It keeps the material parted at the cut line as it is pushed through the blade. The riving knife on most saws also holds the blade guard. If the height of the blade is correctly adjusted for a given piece of material, the guard will be only slightly above the material when it passes through the blade. Because of this if binding were to occur the rising piece of material will hit the guard, and cannot be propelled further upwards and be thrown from the table.
Orientation and posture are also vitally important when operating a table saw. When I was learning I found it easier to use my dominant hand (I’m right-handed) to push the material through the saw. Attempting to use my left hand would usually result in a tendency to twist the material rather than keeping it aligned with the fence. Twisting the material can cause the blade to bind which increases the likelihood of kickback.
That said when you become more confident there may be cuts that require the fence be positioned on the other side of the blade. For example, cutting a mitre on the edge of a board using a saw that can only be beveled one way. In this case the proximity of the fence to the teeth of the blade mean you can’t mount an overhead blade guard from the riving knife, nor do you have a sufficient gap to push the workpiece through the blade at the fence side. In these situations it is preferable to place the fence to the left of the blade, using your right hand to keep the workpiece against the fence (until a safe distance from the blade is reached) and the left hand to push the material. ,
One should always stand behind the table saw at a point outside of the blade path; that is, to either side of an imaginary line pointing from the blade towards the operator. This reduces the risk of injury should a kickback occur as the material will often fly in a straight line until it has a chance to hit something and ricochet. Positioning yourself to the side of the blade minimises the risk of leaning over the blade as you push the material through, and also correctly orients your arm to maximise downward pressure against the table and sidewards pressure against the fence, particularly when pushing with a stick or block. This is general best practice for safe table saw use, but is especially important for the blind woodworker as instinct is to stand straight behind the blade to more easily reference the blade’s location. You should also avoid crossing your arms, especially in the mitre-cutting example situation above, as crossed arms present a perfect obstacle for flying wood to contact with potentially disastrous results.
Handheld power-saws are another matter entirely. The jigsaw for example moves its blade in a rapid vertical motion, and in varying degrees of horizontal motion too if your jigsaw has a pendulum feature which most modern jigsaws do. The action of the blade can cause the saw to jump if it isn’t held securely against the material and with a firm grip. Likewise with a circular saw or track saw, though the rotational direction of the blade and the orientation of its teeth tend to pull the bed of the saw against the face of the material.
The greatest danger with a circular saw is kickback. As with the table saw this is caused when the material binds against the blade which in the case of a handheld circular saw usually occurs when offcuts are improperly supported. For example if you’re ripping a sheet of board down its length with no support beneath the off-cut side, that side may droop as it weakens and bind against the blade. A kickback on a circular saw tends to cause the tool to jump and in some cases be violently propelled towards you. This is easily avoided by properly supporting the material you are cutting using sacrificial scrap pieces, keeping the saw running straight and keeping the bed of the saw pressed firmly against the face of the material. The circular saw and jigsaw are quite safe, though the jigsaw by necessity has no guard beneath the bed so does require more care and confidence.
The jigsaw is often used to cut curves, templates or complex patterns. More often than not a sighted operator would follow a pencil line or a drawing but neither are an option for the totally blind operator. I have seen several methods to follow a line with a jigsaw; some of them difficult and others dangerous. The best is to cut a shape in a thick card and stick it to your workpiece. Then carefully guide the jigsaw along the lines using the front of the shoe (the jigsaw bed) to keep your cut relatively close to the line.
This method requires you first gain a good understanding of the relation of the blade to the centre of the shoe, and the distance from the front of the shoe to the teeth of the blade. Both of these measurements will be specific to your particular model of jigsaw. With this method and a lot of practice you can get very close to a template, and final shaping can be done with sandpaper or a powered sander.
I know of a couple of blind people who operate a jigsaw using a hand beneath the workpiece, which follows behind the blade (or worse, in front of the blade) by a couple of millimetres. This is a difficult and dangerous method as a slip will claim your finger in a split second. It may well be possible to mount a metal guard of the same kerf width of the blade to the jigsaw shoe just behind the blade, but I have never seen this done on a commercial jigsaw. I personally find the method described above the safest way to cut shapes with a jigsaw. For anything more complex or that requires high levels of accuracy, a bandsaw, a router with a template guide or a CNC machine should be used.
The bandsaw can be used to cut templates providing your bandsaw has sufficient throat depth (the distance from the blade to the spine of the saw). Most bandsaws have a vertical guard which incorporates a set of blade guides and should be set to just clear the top surface of the material being cut. Most band saw guards have a slit at the front to facilitate blade changes and give a view of the blade when cutting. These slots are rarely much wider than the kerf of the blade and by aligning the edge of a raised template with the edge of the slot as you cut you can achieve consistent and very accurate results. The accuracy depends on your familiarity with your particular saw, but you will soon learn where the blade cuts in relation to the blade guard and how to correctly position your template. Using this method it is also quite say to follow a line scratched into a piece of material with a knife, awl or centre punch.
The final saw worth mentioning is the oscillating multitool. These are extremely versatile tools that, as their name suggest, employ an oscillating action to move various attachments. They can perform the function of detail sanders, saws, hole cutters and a myriad of other tools with interchangeable attachments. Their primary advantage is their safety. The oscillations are so small and so rapid that they are felt as a vibration should your finger come into contact with the tool. You can therefore place a finger on the front or side of a multitool saw blade to guide it into position, providing your you don’t touch the teeth. The tooth pitch of a multitool saw blade is usually quite fine, so if you do touch the teeth while it is operating chances are you’ll be fine providing you don’t apply pressure against the blade. Nevertheless, used with care these tools have numerous uses including the ability to make cuts in areas where other saws simply won’t fit.
The first saw I operated independently required a different kind of energy to that coming from the national grid. Like most I started with the humble handsaw; a tenon saw in actual fact, which is perhaps the safest saw to start with. The tenon saw features a wide flat blade with a supporting bar across the top to eliminate flex. This reduces the tendency of the saw to jump out of the cut and minimises the potential for binding, but it does mean there is a limit to the depth of cut. These saws are after all designed to cut the notches for a mortice and tenon joint and are not a substitute for the common handsaw. They are however the safest way to get started and I would recommend that any woodworker blind or otherwise cut their teeth (so to speak) using one of these, as you can build your confidence in a relatively safe way.
The common handsaw is perfectly safe to operate blind. As the handsaw has no strengthening along its blade it does flex, especially when pulled fully back with the teeth furthest from the handle in the material. Successful safe use of a handsaw depends on several factors; body position, material support, the length and quality of the saw and the user’s technique. All of these come naturally with practice and experience, though there are a few helpful pointers to keep in mind.
First, start cutting on an edge. If you attempt to cut your material with the teeth flat across its face the saw will likely slide across the workpiece. At best you’ll cause scratches on the face of the material, at worst you’ll start the cut in the wrong place. Angle the saw toward the edge of the material and use short strokes of the teeth closest to the handle to give you a starting cut. Once the saw bites and beings to create a kerf line, you can gradually straighten the cutting angle and lengthen the stroke to cut through the material with the kerf keeping the saw on track.
Use a mitre box. A mitre box is an open-ended tray usually moulded in plastic. The material sits in the open section in the middle, and positioned across the parallel sides are vertical grooves at various angles designed to fit a saw blade. You position your material inside the mitre box, set the saw in the correct pair of angles and slide the material to position your cut. The mitre box then guides the saw to keep the blade perfectly straight, resulting in clean, efficient and accurate cuts. It’s more faff than a powered mitre saw but it’s a useful tool to start out with and to keep on hand for the rare occasion it is more convenient than the powered alternative.
There are other saws too. The coping saw which has a thin blade to get around tight corners and the jab saw which has a long blade and no frame designed to penetrate a surface to cut, for example, socket holes. Hack saws are a stablemate of a school’s workshop but are also found in virtually every home toolbox, with a thin fine-tooth blade perfect for cutting metal stock by hand. These all have their uses; coping saws for example can be used to cut out templates where a jigsaw would be too cumbersome. As the coping saw is moved by hand its blade can be safely touched when stationary, which makes it the perfect tool for carefully cutting around a line scribed with a knife.
We’ve now established that accurate cutting whether by power tool or by hand is not only possible, but need not pose a significant safety risk. The fourth part of this series will cover drilling, screwing, gluing and nailing and the specific tips and techniques therein, so our cut pieces can start to become finished projects.