The True Angle tool is a protractor used to measure the exact angle of the inside of outside corner where two walls meet. That measurement allows you to set your miter saw to the exact degree and angle required to make a perfect crown molding cut for the wall. The protractor looks like two rulers attached at one end with a wing nut. The attached end has a degree scale printed around it to capture the measurement.
Things You'll Need
True Angle protractor
Crown Molding & Trim: Install It Like A Pro (book)
Hold the True Angle protractor so that each piece of the protractor is placed against one side of the walls for the corner to be measured. The protractor will form the angle of the corner.
Twist the wing nut on the attached end of the protractor to lock the protractor in place and remove the protractor from the wall.
Locate the guideline on the protractor and read the degree indicated for the wall angle. Compare the degree to a True Angle tool chart that is provided in the instructional book, Crown Molding & Trim: Install It Like A Pro!, to get the exact settings for a miter saw or compound miter saw.
Set your miter saw according to the indications on the True Angle chart and proceed to make the perfect cut for that corner. Refer to the book for the proper placement of your crown molding in the saw.
Always wear safety glasses when operating power tools.