A few minutes spent touching up a scratch or tightening a loose joint in a chair or table often makes the difference between saving that piece of furniture or having to discard it.
Fortunately, there are a number of easy-to-use products available in most paint and hardward stores for touching up or filling is small scratches and dents. Small bottles of stain can be used to color the imperfections. But for actually filling them in and smoothing them over there are special wax-base sticks or "pencils" to make the job easy.
The directions supplied with these wax pencils or sticks generally tell the user to rub them back and forth over the crack or hole to fill it in, but better results will be achieved if the wax is "buttered" into and over the defect with a heated knife blade or small spatula (an artist's knife is ideal). dWarm the blade in the flame of a cigarette lighter, then use it to scrape wax from the end of the touch-up stick and smooth it on over the depression. Remove excess by scraping with the back of the knife, or with a piece of stiff plastic, then allow to cool before applying furniture polish to restore the gloss.
When a chair or table starts to wobble due to a loose rung or glued joint, the trouble is that either the glue has dried and lost its bond, or the end of the rung has shrunk so it no longer fits snugly inside its hole (or it could be a combination of both).
The best way to reglue one or more loose joints in a wobbly table or chair is to take the piece completely apart and clean all joints before you reglue and reassemble them. On older pieces that have no nails, screws or other fasteners, this may not be as difficult as it sounds. Most glues used years ago were water soluble and can be loosened by soaking with hot water, or by use of a vinegar-and-water solution.
Where this is not feasible, or where there is only one joint loose and it does not seem practical to take all the other joints apart, it is usually possible to pry the end of the loose rung most of the way out of its hole without taking everything apart -- or at least prying it out far enough to permit reaching in with the point of a knife reaching in with the point of a knife reaching in with the point of a knife or narrow blade to scrape out most of the old glue (a stiff peice of strong wire will often work well for this job).
After scraping out as much of the old glue as you can, do the same with the outside of the rung where it fits inside the hole. Try sliding the rung end back in and pull it out again to see if it fits snugly. If it doesn't, you can use the method shown in the drawing to increase the diameter of the rung slightly to make it fit snugly.
This involves wrapping a layer of thread around the end of the rung before gluing and reassembling the joint.
To keep the thread from unwrapping or bunching up when you do this, start by running the thread lenthwise over the inside end of the rung, then make the first wraps over this to keep the end from working loose.
In those cases where you cannot pry the joint apart enough to get at the end of the rung, pry the joint opens as much as you dare, then push thin slivers of wood in around the outside fo the rung.
Start by scraping out as much of the old glue as you can, using a piece of hanger wire that has been hammered flat at the end (to create a sort of miniature chisel). Then squirt glue into the hole, using a hypodermic-type glueinjector (sold in many hardware stores) or a narrow nozzle on a plastic bottle. You may also be able to poke the glue in with a toothpick or small nail. Then, while holding the joint open as far as it will go without too much strain on the other joints, start pushing the slivers of wood in around the outside of the rung. Use a wood mallet, or a hammer and a block of wood, to gently tap it the rest of the way in.
Use a strong piece of plastic clothesline or similar rope, and wrap it twice around the chair or other object, then tie a loose knot that still will leave a slight amount of slack. Insert a stick between the two wraps, then twist to apply the needed amount of pressure and secure the stick.
Be sure to place thick cardboard pads at the corners or wherever the rope could dig into the wood. Also, remember that you don't want to squeeze all the glue out of the joint and you don't want to distort the piece: Apply a moderate amount of pressure and don't twist too tightly.