Dado cuts are important part of cabinet and furnitures work because dado cuts allow the pieces of wood to lock together. A dado cut can be strong and clean when proper made, but a dado cut can also split the wood if the blade are not set up properly. Knowing how to properly setup the dado set will allow the craftsman to create a joint that will allow the pieces of wood to lock together cleanly.
There is two main types of dado sets: stacked sets and wobble blades. A stacked set use two outer blades and several chippers that is placed in between the outer blades. The teeth of a stacked dado set will always remain in the same plane so that the dado cut leave a flat bottom.
How to Set Up and Use a Dado Set
A wobble blade dado set feature two blades that tilt from side to side on a central hub. Wobble blades will leave a slightly curved floor for the dado cut because the tilting of these blade during the dado cut. A person may use a stacked dado set if they needs strong, aesthetically pleasing joints and may use a wobble blade dado set if they are making a quick housing for a drawer or another temporary jig.
The width of the dado cut must match the thickness of the material that is to be use in the joint. A quarter inch dado cut is used for thin back panels and dividers. Three eighths of an inch and half inch dado cuts are used for most shelves and partitions.
A three quarter inch dado cut is used for most plywood shelves. You can adjust the width of a dado cut by adding chippers to a stacked dado set. Each chipper that is added will add one eighth of an inch to the width of the dado cut.
The depth of the dado cut is very important in the formation of strong joint. A dado cut should not be deeper than half the thickness of the board that is being cut. If a dado cut is deeper than half the thickness of the board, the wood will split due to the removal of too many of the wood structure.
A one quarter inch dado cut and a three eighth inch dado cut are used for cabinet backs and for light shelves. A half inch dado cut is used for structural connection in hardwood furnitures. If a dado cut is too deep, the wood may tear out on the exit side of the dado cut.
There are three common type of dado cuts that are used in making furniture: dados, grooves and rabbets. A dado cut run across the grain of the wood and is used to lock a shelf or a divider into the case. A groove cut runs with the grain of the wood and is used to capture a panel or a cabinet bottom board.
A rabbet is a dado cut made on the edge of a board; this cut allows another piece of wood to overlap the cut on that edge to create a flush joint between the two board. The thickness of the material that you are use needs to be considered when setting up a dado cut. Although plywood may be sold as three quarter inch in thickness, the actual thickness of three quarter inch plywood is twenty-three thirty seconds of an inch.
To account for this, shim can be used to even out the difference in thickness. A single paper shim can be placed in between the chippers of a stacked dado set to make the joint between the two boards become a snugger joint. Always cut a test dado cut in a piece of scrap wood before you cut your final workpiece.
This will allow you to test the depth of the dado cut. The type of wood that is used in your joint will change the way that a dado set work. For instance, dense type of wood like oak and maple will burn if they are fed into the dado cut slowly enough.
Soft wood like pine can result in a dado cut with fuzzy wall. The veneer on plywood may splinter on the exit side of the dado cut. MDF contain resin that will dull the carbide blades of a dado cut faster than solid wood will.
Some of the most common mistake when setting up a dado set include not using the dado insert in the saw to replace the throat plate, stacking the chippers such that all of the teeth point in the same direction and simply setting the depth of the dado cut by eye instead of on scrap wood. Each of these mistake can cause the saw to split the wood or the depth of the dado cut to go all the way through the workpiece. You can avoid these mistakes by properly setting up the dado set prior to cutting your wood.
