Repairing the Bulging Top on an Old Classical Guitar [Pictures] - created 11-19-2008

Thorne-Thomsen, Eli - 11/19/2008.16:57:22

A friend has asked me to try to repair the bulging top of her classical guitar, and I really don't know where to begin. Years of string tension has caused to top to bulge fairly dramatically at the bridge. thus, causing the action to be very high. I would like to reduce this as much as possible to make the guitar more easily playable. Any thoughts?

Eli

She hasn't been using steel strings on it, has she?

How bad is the action now?

A couple of pictures might be helpful.

Because of the classical guitar bracing, repairing a bulge may be more difficult than on a steel string. Usually it is not as much of an issue unless, as Deb suggests, it has been strung up too heavily. I start with heating and pressing the top but you need to have a good peek around the inside with light and mirror to check for split or loosened braces.

The action at the 12th fret is a 5/16th of an inch. I will post pics as soon as I get a chance.

Th guitar may have been strung with steel at some point, but when I got it it had nylon. The bracing seems to be sound. Nothing loose as far as I can tell. I can't believe how lightly this guitar is braced(I am used to steel strings). When applying heat and pressure, how hot and how much? And, do I need to remove the bridge?

Eli

If this is not an expensive guitar, it might be a good candidate for a JLD Bridge System (formally known as a Bridge Doctor).

I believe it has some value. It is a Vicente Tatay. I don't really know anything about it's history. But, it was made no later than 1942?

There are Tatays made in the factory and hand made guitars by the family. The factory guitars are not that bad. They are built lightly. Check the label to make sure of the date and see if it was built by Vicente himself or one of the sons, or if it's a factory guitar. The factory guitars are not that valuable, but hand made one might be worth more. Some of the factory Tatay's are really charming, they still had some folk art qualities to them and were not totally mechanical looking like factory guitars now.

I am not sure how to tell if it was made by the factory, but I believe it is hand made. It is not an "Hijos de Vicente Tatay." The label reads "Fabrica de Guitarras, Bandurrias, y Laudes. Vicente Tatay, Literato Azorin No. 13. Valencia(Espana)

Regardless of age, I just want to figure out how to fix the bulge.

Eli

Eli, I've mostly done this on steel string guitars, with the bridge removed I heat the top. I use a heat lamp, moving it around, and I watch it like a hawk every second. You want the top to get really warm, so that you can touch it with your hand but just barely. A tiny bit too much and you can have finish damage. Then I clamp the top with a very straight board and let it cool. Make sure that you check for any loose braces before and after this procedure.

I can't help in the least but curiously when I am in Valencia I useally stay wih a friend who lives on Literato Azorin. Don't ever recall seeing a guitar place there however.

Amy, Thanks for the advice. I will try it. I will have to get my wife to test the heat. I am a chef and my hands are fairly desensitized to heat. I will post results and/or more questions.

Are you sure top doming is the culprit?

Is the soundboard region in front of the bridge concave?

It's very possible the neck has pulled up. You might consider slipping the foot, unless it's a dovetail neck.

You might want to remove the bridge before trying to iron the soundboard straight. Then replace bridge or stiffen the old bridge with rosewood veneer.

If yellow glue (tightbond) was used, heat is all you need to lift the bridge and separate the back and foot. If it's hide glue, you'll need steam.

Careful with old lacquer, it ignites at low heat.

Thanks for the advice, Amy.

What to do with depressed tops (instead of bulged) on floating bridge guitars?

Pretty much the same only in reverse ( I sound like Yogi Berra) It needs to have the bracing re-enforced, a good look around inside to see what is actually sagging and/or perhaps loose.