Some chairs and tables are fitted together with a dowel rod that runs from one leg to another. The dowels are glued into holes cut into the legs. Wood dries out and shrinks with age.
If your dowel is now too small for its hole, wind cotton or linen thread around the tip of the dowel to make it thicker. Then coat the wood and thread with glue, and reassemble.
Another way to fit a shrunken dowel into the hole is with a shim. Shims can be purchased where wood is sold. If you want to use a shim, look for a small shim no wider than the tip of the dowel. Now follow these steps:
Cut a small slit in the end of the dowel with a sharp utility knife.
Try to center the cut so that each side will be equal in size and strength.
Carefully slip the small shim into the slit, the pointed edge first.
Gently push it in so that it expands both sides of the tip.
Don’t worry if a little of the thick edge of the shim protrudes from the dowel. (Too much wedge sticking out, however, will prevent the dowel from fitting in all the way.) When you insert the dowel into the leg, the shim will continue to work its way down into the tip.
Toothpicks and wooden matches with the heads broken off can also be used to fill enlarged holes.
Insert the dowel tip into the hole in the leg and tap it gently into place. The dowel should now fit tightly.
Never use too much force in getting the shim into the end of the dowel and don’t use a shim that is too large. If you do, you can easily crack the wooden tip. Yes, you can glue the pieces back together, but the joint will be weak unless you use epoxy glue.
Remove the dowel and shim.
If the dowel isn’t tight when tapped in (step 4), that means the shim is sticking out too far and bottoming in the hole before the dowel gets tight. If that happens, you can trim a little off the blunt end of the shim.
Glue all surfaces of the tip and the hole and push the dowel back into the hole.
Putting pressure on the joint strengthens the glued bond. But don’t apply too much pressure, because you don’t want all the glue to seep out. That weakens the joint. Too little pressure also results in a weak joint, because the glue isn’t as effective. If you wind up with a weak joint, you may have to disassemble the pieces and reglue everything.
If, after you’ve glued the dowels into place, you’re still uncomfortable about the joint’s strength, you can use small nails or screws to reinforce it. The trick here is to place them through the dowel and leg joint in an inconspicuous position; the backside or underside of the furniture works best:
After the glue has dried, drill a small hole at an angle through the dowel and into the leg.
The glue must be dry so the pieces don’t move around; if they do, the wood may crack or split.
After the nail or screw is flush with the surface of the leg, countersink it.
Place a nail or screw that’s the same size as the head of the nail on it and tap it with a hammer. That will drive the nail further down.
Fill in the indentation with plastic wood or a wood patch in the same color and shade as the chair’s finish to make the depression undetectable.