FASTENERS

    The types of fasteners typically used to install trim include nails, staples, and screws. Traditional hammer-driven finish nails are categorized by "penny" size-the larger the penny number the larger the nail. Pneumatic-driven nails are identified by gauge and length. The larger the gauge the smaller the diameter of the nail will be. Pneumatically driven staples work well for attaching plywood; however, due to the large hole created in the face of the material they are suitable only where they will not be visible.

GLUES

    In trim work, glues are used to secure joints, especially to keep miters tight. While there are many types of glue available, four types are especially useful.
    Aliphatic resin ("yellow") glues have become the most commonly used woodworking glue. As a rule they are stronger and set up faster than the white glues. However, white glues set up more slowly than yellow glues, allowing a little more flexibility and a more relaxed pace when gluing up large or complicated assemblies.

LUMBER AND SHEET GOODS

    If you choose to paint your trim, it is cheaper to use manufactured substitutes than solid wood. Keep in mind that wood is stronger and more rigid (making it a better choice for window jambs and stools) and its dust and fumes during milling processes are less toxic. If you do want to use solid wood for painting choose stable and relatively inexpensive woods such as poplar or pine. After the piece has been molded it is then preprimed. This produces a molding that is straight and free of defects-though the glue joints may transmit through the paint requiring some filling and sanding.

    MDF is also a good choice for paint-grade millwork. It paints and machines well and it has a hard surface that resists dings and dents. It's also less expensive than solid wood. Its disadvantages are its weight, lack of stiffness, and susceptibility to moisture. If MDF gets wet, it expands, never to return to its original shape. I don't recommend it for window extension jambs or for stools. MDF also offers poor purchase for screws along its edges.

MOLDINGS

    You will find that most lumberyards and building centers carry a wide selection of the moldings that are normally being used in any particular region. You should, however, be sure to check that you can obtain the moldings you want before getting too far into the design and planning process. Sometimes the material will have to be ordered or specially made, which will add Router bits can shape simple profiles or be combined to make an infinite number of custom moldings.
BUILT-UP MOLDING STACKED ON EDGE
to your project's time and cost. Moldings are priced by the lineal foot-the more complex and the larger in size the molding profile, the higher the cost per foot.

CHOOSING A STYLE

    If you are remodeling or adding on to an existing house that was built in a distinct architectural era, it's likely the decision about style is already made for you: you will simply match the new trim with the old. If you are not constrained to a particular style period, however, the design options are wide open. To narrow down your choices, first decide whether you are looking for a formal or informal look. Formal trim tends toward ornate, complex profiles and is often painted to put the emphasis on its form rather than the material itself. Informal trim, on the other hand, tends toward simple profiles and is often finished clear so that the grain of the wood is visible.