posted on April 29, 2013 13:48
by William Zuppann, President, Wood Innovations, Inc.
Architectural wood molding in a historic house is usually more elaborate than molding in modern homes, where simplicity of line and easily available ‘standard’ designs are favored. In older homes the standards differ from today’s standards, and in more expensive homes the molding may have been created for that house alone.
Any molding profile can be duplicated exactly using modern techniques and machinery. The shape is transferred from an original sample or drawing to a template, which is then put into a knife grinding machine, which works like a key cutter, to create a steel knife (or in some cases a series of knives) which is hard enough and sharp enough to cut wood. These knives are then put into cylindrical heads which are installed in a specialized molding machine which may spin the cylinders at 6,000 rpm; a complex molding machine permitting five or more of these cylindrical heads to be used at a time.
Costs associated with this process include the cost of the knives, the time involved in setting up the machine to install the specialized knives, and of course, the cost of the wood itself. The wider the knife, the greater the cost; set-up costs tend to be fixed; and the wood cost will vary with the size of the molding and the number of lineal feet needed.
Where the number of lineal feet needed is large, the cost of the knife and the set-up becomes small per lineal foot. But where the project is small, cost considerations come into play. Companies like Wood Innovations, which specialize only in architectural wood molding, accumulate a wide variety of knives over the years, and it may be possible to avoid the cost of the knife by using an existing knife from our inventory of knives. Some modifications are possible by altering the spacing of the knives within the heads, creating acceptable results at reduced cost. Use of our full line of stock moldings is also a possible means to avoid both knife and set-up costs.
Another caveat for purchasers of wood molding is to be aware of the quality of wood used. Lower grades of lumber can result in apparently low bids for your job, but this is a false economy if knots and other imperfections result in material waste, and in an unprofessional result where many short pieces break the visual pattern across the span of a room.
Wise contractors habitually avoid cut-to-order lengths for wood molding and also order 10% more material to avoid the embarrassment of a new set-up fee for a short run at project completion. Because hardwoods come in variable lengths (seldom in lengths greater than 16 feet), a good carpenter will be sure his cuts take into account the entire job, planning in advance so that the last three feet installed is a single piece, and not three short pieces.
Selection of wood species is also significant. Poplar is often a good choice for interior molding, and paints well. Where the warmth of wood is a design feature, the more expensive choices of Oak, Maple, or Cherry may be best. Fir is generally preferred for exterior work since it is generally cheaper than Redwood or Mahogany, which also perform well outdoors.
Three piece bases (the base, a cap and a shoe), wide butterfly casing, corner blocks (rosettes) and plinth blocks in compatible designs are the hallmarks of a quality job. All of these are available in stock and by custom order at Wood Innovations.