My friend Yang asked me to fix a chair for him, as its leg is broken. The chair belongs to a furniture set with a total of three identical chairs and a table. The furniture is in an antique style with a paint in patina color.
The leg is broken in a 30° mitered angle along its length. Apparently, at the same location, the leg was broken before; the previous owner has tried to fix it by simply gluing the broken piece back (From the above picture, we can see the yellowish residual dry glue used by the previous owner.) Gluing the piece back is similar to gluing a miter joint when making a picture frame; a miter joint is inherently a weak joint due to the end grains of the wood; even though the leg may work ok right after gluing, after a few years of use, the leg was broken again. The below picture shows the leg is supposed to look like, by clamping.
To fix it, I drilled holes from the back of the leg for putting dowels and screws in place; these dowels and screws are perpendicular to the break line; the shear strength of the dowels and the screws will prevent the detachment of the leg, on top of the gluing. Drilling from the back of the leg is to limit the cosmetic damage as the holes are almost invisible looking from the front. BTW, I have to use an egg beater to get into the tight space for drilling the holes.
Glue will have to be used to attach the two pieces together; for this, I chose epoxy glue as it is very forgiving for the materials to be glued together. I also cleaned the residual yellow glue, using a chisel, before putting the new epoxy glue so that the epoxy has clean surfaces to work with.
Finally, sanding the leg using sand paper of various grits (p80, 100, 120, 150) and then putting paint of similar color complete the work.