Top Separation Repair on 'Bowl-Back' Ovation

If your acoustic guitar top is starting to separate or lift a little from the guitar sides, it’s usually a reasonably straightforward job to repair.

Basically speaking, it’s a matter of some glue and some good clamping. Good clamping is the secret to all good glue jobs and it’s not too much hassle to clamp most acoustic guitar tops.

However, on a guitar like an Ovation—with a moulded, curved back—things are a little less cut and dry. Applying pressure along the edges of the top is a bit more tricky.

Hence, this monstrosity.

Crazy clamping on an Ovation

Crazy clamping on an Ovation

The guitar’s neck is held in my vice.

I’ve a couple of mats below to cushion it and conform to the shape.

The other side is held in place so it doesn’t start to ‘flip’ when I…

Clamp the top using my workbench as a clamping point.

This way, I can get a decent, downward pressure on the top so it’ll re-glue to the sides. We’re not talking tons of pressure here—this is a fine (if less than graceful) solution. 

Repairing Loose Acoustic Guitar Braces

Visible gap on loose acoustic guitar brace

Glued inside the top and back of your acoustic guitar are braces. These are wooden support beams* that provide strength to what are, otherwise, relatively thin pieces of wood. 

Sometimes a brace can become loose. This could be because the guitar gets a knock but, often, some or all of the glue can just fail for a variety of reasons. 

A loose brace can be a pain. If part of the guitar isn't properly supported, it can pull and warp in unpleasant ways. That's generally not good. In addition, one symptom of a loose brace (and frequently the one that leads to its being discovered) is a nasty buzz or even a rattle when some or all notes are played. Often this buzz is located around a certain note (a tone or so either side) as the loose brace vibrates in sympathy. 

These can be an incredibly frustrating thing to track down. Sometimes you'll get lucky and be able to see the gap between brace and top/back (like in the photo at the top—the shadow beneath is clear) but, more often, you'll end up, up to your elbow in the sound-hole, poking at joints with a feeler gauge, trying to find a tiny gap. It's a real pain. 

When it's found, the gap should be cleaned and the old (failed) glue removed. Then, fresh glue is worked underneath the brace and the repair is clamped up to cure. This sounds straightforward until you try doing it, at the limit of your reach, blind (or, with an obscured reflected image in an inspection mirror).

Loose acoustic guitar brace

Find loose guitar brace

Not so with this one, though. These are back braces and they're relatively easy to get at. This particular guitar did actually get a knock and has had a previous repair for a back/side separation. I can't be certain that these braces were knocked loose at that time but it seems likely. Maybe not, though—benefit of the doubt for the previous repairer.

You can clearly see the feeler gauge poking under the braces in the photos. The blue tape is something I've put in, by the way. It keeps the mess down when working glue under the brace. 

Once there's a good smearing of glue in there (and it needs to be worked well under to get a good joint), a bit of a wipe up, and then it's clamped (see below). The little scissor-jack thing is a god-send for these jobs—it gives decent clamping pressure and I can wind it up from outside the sound-hole. 

On this particular instrument, this has to be repeated a few times as I found four loose ends. But not any more more. All re-glued and sorted. 

Glueing and clamping loose back brace on acoustic guitar

*I think 'beam' is the correct structural term for guitar braces but any engineers can feel free to correct me. Beam tends to make most people think of massive steel joists, however, while guitar bracing tends to be a little smaller. And wooden. 

So, How Do You Damage A Hole?

Acoustic guitar top repair

Or, more to the point, how do you repair a hole?

Damaging this was the (relatively) easy part: the owner is a 'big hitter'. I've worked on some of his other guitars and, actually, this one isn't bad. We've caught it reasonably early. This guitar is one of the owner's favourites though and he wants to do something before it disintegrates into tonewood-sawdust.

As it happens, we're in luck on this. The majority of the damage is inside the soundhole rosette. This gives us a natural break-line for a repair. It's much easier to affect a discreet patch with that division between the existing soundboard and some newly-added wood.

With that in mind, I figured the best, and least obtrusive, way to manage this was to replace the entire circle of wood inside the rosette.

Cutting cedar to repair acoustic soundboard
soundhole repair acoustic guitar

Using a trammel and my Dremel-type router, I can cut an accurate circle to replace the damaged part from a cedar board. Then, carefully, I remove the damaged wood right up to the rosetted edge and from underneath the fingerboard extension. The fit for the new wood was perfect first time (hurrah). All I needed to do was to square off the edge that butts against the shoulder brace.

Patching acoustic guitar top
fix acoustic guitar soundboard damage

Time for a little support. Effectively, what I'm doing in the photo on the left, above, is 'extending' the soundhole braces to support the new wood. This area contributes hardly anything to the overall tone of the guitar so I'm not worried about altering its sound by adding reinforcement here.

And, speaking of reinforcement, that's what's happening in the photo on the right. Not only will these shaped pieces of wood help to support that newly glued soundhole edge, they will also strengthen it against future, vicious, pick attacks.

Once it's all glued up, I can shape the edge of the soundhole and round it over. That narrow circle of cedar would have been far to delicate to survive my doing that before it was part of the guitar.

Time for finishing. I'm doing something a little unusual here. I've finished this patched-in soundhole with cyanoacrylate (effectively, Super Glue). I wouldn't normally use CA for something like this but, in this case, it will soak into the wood and harden it. This will help it withstand all that pick-punishment in the future. I can tint it to better match the colour and, once built up and cured, it can be buffed to a shine (or in this case, a satin sheen).

Last step is to add a custom-shaped, clear, mylar pickguard to a wider area of the guitar. Again, this will give a little more protection to the top. I've replaced the existing pickguard on top of that to keep the guitar looking original and give one more barrier against future damage.

acoustic guitar repair ireland

acoustic guitar repair ireland