Prints, photos and paintings can add interest and style to a home. Often, picture frames are as decorative and interesting as the items they house. Unfortunately, over time, and with lots of roughhousing by kids and grandkids, wooden picture frames get knocked around and become square and beat up; miter joints can open up and glass can become cracked or chipped.

Rather than replacing an otherwise good frame with a new one, we suggest you make the repairs yourself. You will find that the frame will be as good as new for a modest investment, and you'll be glad that you didn't toss that favorite frame.

There are several means of reinforcing the joints of a wood picture frame. The appropriate method depends on the extent of the damage and the size of the frame. Larger frames require more reinforcement.

In all cases, the first step in the process is to remove the frame from the wall and carefully remove the contents—glass and all. If the glass is damaged, look for a replacement at a local arts and crafts store that sells frames. Nonstandard size glass can be obtained from a local glass company.

You'll need a clean, stable work surface such as a work bench or counter. To avoid further damage to the frame and to prevent it from slipping during the repair process, we suggest covering the work surface with a small piece of rubber carpet pad. It's great for other woodworking projects, too.

Before reinforcing the picture frame, use a speed square or triangle at the corners to check that they are 90-degree angles. Another means of determining that the frame is square is to use a tape measure to measure diagonally from outside corner to outside corner. When both measurements are the same, the frame is square.

Once the frame is square and the mitered corners are closed, you can use one of the following repair methods:

One of the simplest and most effective means of reinforcing a frame joint is with a mending plate. It's essentially a dog-eared metal triangle with small return flaps at either end. The flaps are designed to wrap the outside edge of the frame and to further ensure that the frame is square. Mending plates contain several holes through which wood screws are inserted into the frame. Use a driver drill along with a small bit to drill small pilot holes before driving the screws. Be careful not to drill through the face of the frame, and use screws that are not too long so they won't penetrate the face of the frame. Mending plates come in many sizes to accommodate various size frames.

Joints for small to medium-sized frames can be reinforced using four- to sixpenny finish nails. Drive the two nails into the corner of the frame at a 90-degree angle for the most secure connection. Wherever possible, the nails should be driven into the top or bottom (rather than the sides) where they will be less visible. As with mending-plate installation, pre-drill small pilot holes to prevent the wood from splitting. Use a punch to slightly countersink the nail heads to allow for puttying. Use a vinyl spackle for painted frames and a putty stick or wood dough for stained or decorative ones. Repairs can be touched up using an art brush and a dab of matching paint.

Reinforcing joints on larger frames can be a bit more daunting. The process is similar to that of using finish nails, however, instead of using nails, we suggest using short pieces of half-inch diameter wooden dowels or "pegs."

Begin by drilling a hole at a 90-degree angle into the corner of the frame. When possible, the holes should be at the top or bottom of the frame where they will be less conspicuous. Be sure to use a bit that corresponds to the size of the peg. Drill a test hole into a scrap piece of material and test the fit. It should be snug—but not too tight. Drill the hole approximately 1-16th of an inch deeper than the length of the peg so that it can be countersunk to accept putty.

Thoroughly coat the peg with carpenter's glue before inserting it into the hole, and carefully tap it into place using a small finish hammer. Countersink the peg by inverting a punch and tapping on the narrow end, or you can use a hinge pin to sink the peg. Wipe up any excess glue with a damp rag and fill the small void at the end of the peg with spackle or wood dough, depending upon the desired finish.