Using a Table Saw Safely

Recently, a jury awarded $1.5 million to a Boston man after he injured himself on a table saw. Whether you agree with the decision or not, I thought a review of table saw safety would be appropriate.

There are two ways a table saw can injure someone: the putting your hand, fingers, etc. in the blade or having something kicked back at you.

Blade Safety

Let's tackle the obvious danger first -- the spinning blade. Most 10" table saws spin the blade at 3400 to 4500 RPM. This means that each tooth on the blade is traveling at a speed of 100 to 130 MPH. You don't need me to tell you that sticking your finger into the blade is definitely a bad idea.

Most saws come with some kind of blade guard. This is usually a plastic or metal enclosure that rides up on top of the work piece and is intended to be a barrier between you and the blade. Generally speaking, you should try to keep the blade guard on the saw as much as possible. However, there are times when it must be removed.

  • Non-through cuts. Most stock blade guards are attached to the splitter. When using a dado blade or making grooves, the blade guard is in the way and must be removed. Note that this doesn't apply if you have a blade guard that isn't attached to the splitter.
  • Narrow cuts. When ripping very thin pieces, the blade guard can keep the fence from getting close enough to the blade.

In these situations, other precautions must be taken. These are good ideas if you're using the blade guard or not.

  • Use push sticks/shoe. A push stick is another piece of wood or plastic that is used to push the wood through the saw. This is especially useful when ripping narrow pieces, as it allows you to push the piece all the way through while keeping your fingers well away from the blade. If the blade does hit the push stick, you can always make another one. You can't make another finger.
  • Use feather-boards.Using a feather board frees your hands from having to hold the piece against the fence or table, allowing you to concentrate on feeding the piece through the saw and keeping your hands away from the blade.
  • Use a Power Feeder. This is a device that is installed on your table saw and, via rollers and belts moves the piece through the saw automatically.

Whether the blade guard is installed or not, you always need to be aware of where your hands are in relation to the blade. No technology can completely keep your hands away from the blade if you really try to put them there.

In recent years, a woodworker by the name of Steve Glass invented a technology that senses the minute electrical current through a person's hand. When the system detects that someone has touched the blade, it slams a brake into the blade and lowers the blade below the table in a fraction of a second, resulting in only a minor nick instead of major injury. When he found that the major table saw manufacturers were not interested in licensing the technology, he founded his own company, Saw Stop, which integrates this technology. It will be interesting to see how wide spread this or similar technologies becomes in the coming years.

Kickback

When the blade is spinning, the top of the blade is moving towards the operator of the table saw. If the backside of the blade is ever able to grab the work piece, it will quickly lift and accelerate the piece to over 100 mph, "kicking" it back at the user.

There are several ways to keep kickback from happening.

  • Use a splitter or riving knife when ripping. Whenever you are ripping down stock, there's the potential for the piece to twist away from the fence and into the blade. In addition, ripping solid wood can relieve internal stresses, causing the board to move and try to close up on the freshly cut kerf -- pinching the blade. In both cases, a splitter or riving knife keeps the board from coming in contact with the back of the blade. The riving knife is better in this regard since it follows the blade as it goes up and down. A standard splitter stays in one spot and there is a gap between the blade and splitter, depending on the height of the blade above the table.
  • Use feather-boards and hold-downs. A feather-board holds the wood tightly against the fence or table. Again, the idea is to keep the work from drifting away from the fence and into the back of the blade.
  • Don't use the miter gauge and fence at the same time. The off-cut can become trapped between the blade and the fence and thrown back at you. If you're using the fence to index repeated cuts, use a stop block clamped to the fence in front of the blade or slide the fence back.
  • Don't use the table saw. It may be that the particular operation isn't suitable for the table saw. Think about whether the same task can be performed more safely by using a different tool. For example, resawing a board into two thinner pieces is a task better suited for a bandsaw than a table saw.

So how about you? What techniques do you use to keep from hurting yourself on the table saw?

Work safely!

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