How to Measure Wood Successfully
Measure. Cut. Measure. Cut.
That doesn’t sound like the typical advice of “measure twice and cut once,” but it is just as important to “measure, cut, measure, cut.” Often, people do not realize that they need to allow for the kerf, or width, of the saw blade when they measure. Saw blades can vary from 1/8″ (0.125″) to about 3/32″ (about 0.091″), and some of the thinnest blades are 1/16″ (about 059″) thick. Other factors, such as pencil width, also affect the final results.
Measure your first piece and then cut it. Measure the next piece from the newly cut edge or the other edge and then cut it. You can measure two pieces on the same piece by measuring in from each of the board’s ends. The remaining piece in the center will be your “waste” piece because it will have the kerf widths cut out of it.
Precision Marking
Making a precise mark on your wood is important. The standard carpenter’s pencils and chalk are sturdy, but they can leave wide marks that can distort your measurement. Use a sharp #4 pencil or a knife, such as an X-ACTO®, to mark your wood. Put an X or scribble on the scrap, or unmeasured, side, even if you will use this wood for another piece.
Why Not Measure All the Cuts First?
Many people measure all of the cuts before sawing the wood. If the size does not have to be important, you can do it this way. However, if you need to fit these pieces together and measurements matter, then you should not do this. Consider that a saw blade can have a kerf of 1/8″ and four cuts in a board can eat away 1/2″ of wood.
Measuring Your Cut Width
It is important to measure the width of the cut when you are doing detailed work, such as inlays, fine cabinetry, and other work. A blade that has a slight warp or other imperfection can affect the width of the cut. Set up your saw with the blade you intend to use and make a two or three inch cut into the type of wood that you are using. Do not cut the full way through the piece of wood. Measure the width of the cut and use this as a rough estimate of the amount of wood that will be lost in cutting.
Precision Cutting
You can foul up your precise measurements when you cut your wood if you line up the blade on the wrong side of the mark. Line up the blade on the “waste” side of the mark. Practice on scrap wood until you know how to precisely cut wood on your saws, such as table saws, circular saws, jigsaws, and others.
Use the Right Saw for the Blade
Another factor in wood loss is the saw. A low-powered saw, such as one under 3 horsepower, will force thicker blades to grind at the wood instead of smoothly cutting it. Use one of the thinner saw blades in low-powered saws. Generally, these saws are circular saws, but you should check the motor size of your table saw, too.
Putting It All Together
When you understand your saw, the blade’s kerf, and your own sawing habits, you will be more successful in achieving your woodworking goals. Many of these tips work for other materials, such as plastics, metals, and more. The success of your project depends upon having the right measurements, the proper-sized saw, and suitable blades.
Resources: http://www.circularsawblade.net/kerf
http://www.rockler.com/articles/saw-blade-selection-guide.cfm
