A broken x-brace is a serious matter.
Inside most steel-string acoustic guitars, there are a number of braces. They’re glued to the top (and the back) to provide strength—without them, the string tension would just pull the guitar top apart.
Most guitars these days (and for some time) are ‘X-braced’, so called because, as you can probably imagine, the two main braces intersect around the bridge and form an X shape. While there are a number of other, smaller braces on the guitar top, it’s the two x-braces that do most of the work.
When one of these breaks, it’s a big deal. Your guitar top can deform, your bridge and bridge pad may become loose, and your guitar can be ruined.
In an ideal world, a broken x-brace would be removed and a new one installed in its place—it’s under a lot of stress and ‘new’ is preferable to ‘glued’ in this instance. However, it’s not usually possible to replace an x-brace through the sound hole since they’re too long. This makes replacement a pretty massive job involving the removal of (probably) the guitar’s back. It’s not something that is done lightly and the cost may be hard to justify for many instruments.
Sometimes you can get lucky, though. While a repair to an x-brace isn’t always possible or advisable, some breaks lend themselves to repair more readily.
This one, for instance.
The break is long and easily accessible from the sound hole. The brace is relatively wide and provides a fair amount of glueing surface.
And, the icing on the cake, there’s a flat top on the intersection. This means I can add a little patch there to provide some extra insurance that the repair will hold.
Glueing and clamping the split is straightforward. I want to show you that patch I mentioned.
Many guitars already have a patch like that shown above on their X intersection. I’ve left one ‘leg’ of the patch a little longer. This will extend a little farther down the broken brace. The pencil lines show how it will sit on the braces.
Working through a sound-hole is frequently a fiddly job but things are nicely within reach here. A regular G-cramp does the trick. You might see a little bit of tape on the patch. That was just to keep it in place and aligned as I clamped it.
And here’s the finished article. Brace glued, patch applied, and new life for this guitar.