Humidity Discussion

What happens to a guitar when it's dried out?

Here's one example.

The critical geometry is completely affected. Setting up the guitar is difficult. In addition to this, the entire structure of the instrument is under abnormal tension. There are many different pieces of wood glued together inside a guitar, different types of wood, with grain lines pointing in all different directions; when these various components of the instrument dry out, they contract in different directions and to varying degrees of subtlety. This creates undo tension throughout the structure of the instrument and it therefore doesn't play the same, and it doesn't sound the same either.

It's true that not all guitars or like instruments need the be humidified to prevent cracks or "visible" damage. However, when someone brings me a guitar that is dried out, even if they are happy enough with it's playability, the damage is visible to me.

I've also seen many older instrument that have been dry for a long time. Some say the guitar has been "acclimated." Rarely is a guitar properly "acclimated," and some guitars refuse to "acclimate." Some of the older instruments don't show much extreme trauma, but none are in pristine condition. Most have had crack repairs and other work done to remedy the effects of being turned into guitar-jerky.

Keep in mind, a guitar with the correct geometry, kept at the right humidity, plays and sounds the best. Too much humidity makes the guitar play and sound horrible as well. However, too little humidity is generally more detrimental to the structural integrity of the instrument. And besides, you will never have a problem with excessive humidity if you live in northern Arizona. So get a humidifier already!

My next post will discuss how to properly humidify your instrument.

Glue that Back back On

You may be wondering, why so many clamps?

I had to remove the back (which was already lifting in various places around the seam) on this Kamaka ukulele to replace a back-brace and reglue another brace on the underside of the top. This is a small soprano uke, so the only way to get inside was to remove the back. The problem was originally caused by dryness. Coming from Hawaii, the instrument did not take well to the dry climate of northern Arizona. Because the instrument had been dried out, braces were lifting and the body was slightly warped.

So, this is why I needed so many clamps to properly glue the back in place. Four of the clamps are being used to simply hold the sides in the correct shape to accept the back into proper position. Because the wood had dried and warped, after the back was removed the sides didn't stay in the same shape... i.e. they were being held in place by the back prior to its removal.

As to why so many different types of clamps were used... I didn't have enough spool clamps for the entire job... also, spool clamps would've gotten in the way of the the clamps that were used to keep the sides in the correct position.

This was a beautiful, authentic Hawaiian uke with some great pieces of koa wood. It was a pleasure to bring this instrument back to life. After the structural work, I did some minor fret work and made a new bone saddle.

-- Ryan Elewaut

The Worst Headstock Fracture... Ever

So, I'm going back through some pictures of past repairs and finding content for the new blog. Here are a couple pics from the worst headstock fracture I ever had the pleasure of repairing. This was a Gibson acoustic with a headstock break completely perpendicular to the neck and just behind the nut. There was virtually no surface area for a sound glue joint. The guitar had been broken at the head stock twice prior.

I applied wax to the exposed truss rod with a burning candle. I wanted the truss to still be functional... i.e. not be seized by the first glue job. The first glue step was to simply get the headstock back on the neck of the guitar. I knew this step would be structurally useless, I just needed to get the head back in place to begin the reinforcement.







Below you can see all the various glue joints showing the various reinforcements made during the repair. There are two mahogany splines inlayed parallel to the neck, on either side of the truss rod. Then a disc planer, mounted on a drill press, was used to thin the back of the headstock down to create another gluing surface... which created addition strength. Epoxy was used during all glue procedures for the additional strength provided by the adhesive.

Again, I don't have pictures of the completed project. The repair turned out clean, especially after refinishing the neck with dark stained lacquer. It was nice to be able to hide these (great looking) glue joints with the dark finish.




--R.E.