When a part of a frame has gone bad, one alternative is to replace the wood in a part of the frame, instead of replacing the whole frame. For example in windows and doors, this is often a good technique. The wood in the bottom part of the frame catches the most moisture. Often the rest of the frame can be good, but a portion of the bottom frame has some bad wood that need to be replaced. If your wood is old and well grown, such a repair might be much better than replacing the whole frame. Basically there are four ways to exchange a piece of wood in a frame:
- Drill a round hole, and insert a round wooden plug (this is the easiest exercise, requires only a drill and a plug)
- Use a special purpose router like Domino to route away a bit of the frame, and insert a special plug in the hole (fairly easy, but requires a special purpose router, does not solve much more than the drill method)
- Route a hole in any shape, and insert a suitable plug made through a router guide bush set (this is the easiest exercise when round plugs as per first method is not an option). The other major advantage compared to a drilled bit is the possibility to adjust the inlayed piece of wood to have its fibers in the same direction as the piece it is inserted into. An example of such a job is given here.
- Make a hole in any shape using a mortise chisel and then insert a suitable plug created with help of saw and chisel (this is not as easy as it sounds)