Prepare The Moulding
As with any remodeling undertaking, the first step – and the most laborious – is preparation. Surfaces upon which moulding is to be installed need to be clean, dry and smooth. The moulding itself may need to be cut, sanded and finished.
To prepare the moulding, you’ll need a mitre box, a cope saw, clamps and any needed finishing materials along with a box or two of 1/2 inch finishing nails.
Mitre boxes come in various shapes and sizes, but they all serve the same purpose: to hold pieces at the correct angle for cutting. Even with pre-molded trim you’ll need to make several joint cuts, usually at 45 degree angles.
Take Good Measurements
Measure the room carefully, then allow a slight amount extra for losses from cutting. You can always make the piece shorter. Making it longer creates a seam. Pieces will usually be joined at 45 degree angles either at a corner or where a moulding piece doesn’t extend the entire length of room.
Extra care needs to be taken at corners, where any errors are the most visible and exact joins are hardest to make. There are several ways to help yourself out. One technique involves deliberately making pieces end shortly before the corner.
Corners can then be finished with small, pre-made pieces, often rounded. Another option is to make pieces fit as carefully as possible and then fill with wood putty at the corner and sand carefully.
Keep in mind that houses are never constructed precisely, nor ever exactly level. Allow for small irregularities.
Install The Moulding
Joining pieces together can be done with finishing nails hammered in near the ends and/or with glue on the joining surfaces. When using nails, be sure to hammer them in at slightly different levels on the adjoining trim pieces. This ensures that you’re not hammering a nail on one piece into the nail on the adjoining piece. That can lead to cracking the trim.
Trim cracking can occur in any case. Minimize the risk by pressing on the surface with a piece of wood or plastic while nailing. That allows the nail to compress the wood internally, rather than crack outward.
A cope saw will allow you to make free hand or clamped cuts to make small adjustments. Professional-looking moulding installations always have very precisely fitting pieces. Nothing says ‘amateur’ more than gouges, incorrect angles, gaps and bent nails. Stain can only cover up so much.
Minor Adjustments May Be Needed
Depending on the kind of trim purchased, you may need to sand the pieces. Obtain several grades of sandpaper, including very fine grit. Always sand with the grain of the wood and carefully remove fine sawdust afterward. Wiping with a slightly moist, small towel helps get the surface prepared for staining.
It’s usually best to finish pieces before installing. Ensure that any nicks and irregularities have been puttied. Let dry, then sand the putty
down even with the moulding surface and wipe with the moist cloth. Allow to dry completely.
“Finish” Your Project
Finish can be stain, varnish or paint depending on taste and room décor. Check the guidelines on the container to find out what kind of wood is best with what kind of finish. Oak, for example, isn’t generally painted but stained or varnished. Painted moulding will usually require at least two coats, one primer, one final.
When planning your project you may want to get a few weather reports. Aim for days of moderate temperature and low humidity. Glues and finishes will dry best under those conditions. Also, you’ll want to allow for plenty of ventilation during the project to prevent unpleasant and potentially harmful odors.
Good Luck with your project!