In response to finding so many fantastic sets of chairs that are missing individual chairs or have poor repairs, I have decided that I might try to give some tips to the DIY folks.
Most sets of chairs we get have at least one chair that has loose joints which we need to repair before sale which means most sets at home are probably showing up with similar problems. Getting to the repair early can also save bigger repairs later. Dowels can break and tenon joints can move around widening the corresponding mortice that it sits in if the are not re-glued in time.
Never throw away parts of sets of chairs, nearly all can be fixed no matter how damaged. Full sets of even numbered chairs are always easier to sell.
To repair dining chairs successfully you will need someway to clamp the joints. Clamps can be purchased really cheaply from chain hardware stores or online. The main thing to do before purchase is to check the opened width of the clamps jaws will fit the largest of your chairs spans. If you can’t afford the tools the old way to do it was to tie a loop of rope around the chair and tighten it up with a lever of wood twisting the rope up. Be careful if your crazy enough to try it as this is a great way to have it unwind fast and injure you.
Other than a clamp you will need:
Wood glue Aquadere, PVA etc
Mallet a big headed wood or plastic hammer (a claw hammer with a piece of scrap wood between the chair and the head can be used)
Stanley knife
Chisel
Rags
Possibly drill with bits
Dowel jig
Dowels
Now usually the joints that go first are the back where it meets the seat support rails. To get at the dowels or tenons you need to knock apart the joint with a mallet being careful to not bruise the wood. You can use a piece of wood between the hammer and the chair and some masking tape over the strike are might help protect the finish. Once apart you can see if any dowels are broken.
If not you need to remove as much of the old glue as possible to allow the new glue to stick. This can be carefully done with a stanley knife used to scrape along the dowels. A small piece of very course sandpaper can be used to rough up the surfaces that touch inside the joint. A drill bit the same size as the hole can be used turned by hand to break away old glue.
Next use the glue to cover the areas that touch including the dowel hole. Immediately put the chair back together and get the clamps on to close up the joint making sure the joint is square. Placing the chair on it’s feet on a very flat surface helps them stay square. Wipe away the excess glue with a damp rag and then a dry one. Leave the clamps on while the glue dries.
If the dowels are broken you need to drill out both sides before replacing the new dowel. It is really important to stay in the original centres of the old dowels so using several sizes of drill bits starting small and getting up to the size of the new dowels. Using a dowel jig helps keep the dowel straight and again these are available cheaply and easily.
Once you have the holes drilled you follow the above instructions and should end up with solid chairs that will last years.