How to Repair Wooden Chairs and Fix Broken Stools
If you look at the discards out by the curb on trash pick-up day, you’ve probably noticed broken wooden chairs and stools awaiting their one-way trip to the municipal landfill. It’s a shame how frequent this sight is, since in many cases a simple, basic repair could put these items back in service for many years. In this article, I’ll show you how to do the most common repair, which is the replacement of a broken brace.
Design of Wooden Chairs and Stools
Most wooden chairs, and nearly all bar stools, have legs which are connected by braces to form a rigid structure strong enough to support us safely. These braces are vulnerable—they are exposed to all sorts of accidental impacts, and it’s easy for people to put their full weight on them. They are not designed to withstand that! But if a brace does break, the legs will soon follow suit unless the brace is repaired or replaced--the legs by themselves are not strong enough, nor rigid enough, to withstand sideways stress.
Tools You'll Need
The chairs illustrated in this Hub are particularly easy, for a couple of reasons. (I've fixed two of them now.) First, the braces are simple, plain wooden bars which are easily replicated by the home handyman. The finish helps, too; the black paint is easy to match and covers up wood filler and screw heads admirably.
Conversely, ‘spindle’ braces need a wood lathe to duplicate, and stain finishes can be harder to match, as well as requiring more refined woodworking to achieve 'invisible' joinery.
How to Repair Wooden Chairs and Fix Broken Stools
Begin by removing the remains of the old brace. In this case, simply sawing them off flush with the leg was sufficient. I had decided that for such a utilitarian chair there was no need to attempt an exact repair, which would involve crafting a brace with peg ends to insert into the legs. Rather, I planned to use deck screws to make a simple yet strong joint.
1. Use a good woodworker’s glue.
Unfortunately, the chair had been used for some time after the brace broke, so the leg itself was also damaged, as shown earlier. This damage was addressed by gluing the split wood at the top of the leg. I used a good woodworker’s glue, fitting the damaged areas carefully back together and clamping the leg back in the correct position.
2. Make the replacement brace.
The next step was to make the replacement brace. I used a scrap piece of pine, already the correct width and thickness. The undamaged brace on the other side of the chair provided a handy template, allowing me to simply trace the necessary cut lines for correct length and angles for the ends. No measuring required!
3. Drill pilot holes for the screws.
With the brace cut to size—and the glue on the leg repair fully cured, of course!—you are ready to proceed with installation of the new brace. Start by drilling pilot holes for the screws. It’s best to drill from the inside of the leg out. That lets you accurately match the location of the holes in leg and brace, even if you drill the hole in the leg at an angle that's less than perpendicular—and if you don’t match those holes, the brace won’t be centered in the leg.
By the way, if you haven’t done this before, a good rule of thumb is that the pilot holes should be roughly the width of the shank of your screws—that way, the hole is small enough that the threads of the screw have wood to ‘grab,’ but the large enough that the solid central part of the screw won’t have too much wood to ‘push aside.’ Pilot holes increase accuracy of placement, decrease the effort to drive the screw, and greatly decrease the risk of splitting the wood.
4. ‘Countersink’ the screws in the legs.
You may also wish to ‘countersink’ the screws in the legs. If you countersink them deeply, so that the screw heads are, say, a quarter-inch or more below the surface of the leg, you can fill the hole with wood filler. When sanded and painted, this is basically an invisible repair. In the case of this basic utilitarian chair, I was content to countersink so that the head of the screw was flush with the surface and simply paint the screw head.
To countersink deeply, use a regular bit a little larger than the diameter of the screw head—the exact dimension isn’t critical, as you are going to fill the hole anyway. If you are countersinking flush, you can use a bit specifically made for the purpose, or you can use a regular bit of the same diameter as the screw head. (If you do the latter, I’d suggest running the drill in reverse to allow a more gradual and controllable rate of wood removal. Otherwise, you will likely find that you are countersinking deeply after all!)
No style points for you if you countersink simply by overtightening the screw so that it digs itself into the wood! This tactic can work if the wood is soft enough, but runs the risk of splitting the wood, or of stripping the hole so that the screw threads no longer hold. Trust me on that!
Be careful that the brace is solidly against the leg as you screw the joint together. You don’t want any gap between the two pieces, as it will compromise both appearance and strength. I like to add a little supplementary strength to the joint by gluing. I really don’t think it contributes all that much--but the glue should help keep the brace from rotating, and requires nearly no additional effort or expense. So why not?
With the new brace in place—and the glue cured, if you’ve chosen to use it—you’re ready to finish the repair. Sand carefully so you have a good surface to paint or stain, and apply the finish of your choice using a small brush. (Alternately, you might choose to repaint the whole chair, in which case spray-painting becomes an option. But that would be a subject for another Hub!)
Ah, the satisfaction! An hour or less of pleasant work, all told, and you saved yourself maybe twenty to fifty bucks (plus environmental costs.)
And it's not as if you have to tell everybody just how easy it was!