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.

Vintage Restoration

This is the introductory post to what will be an ongoing restoration project. I will be making various posts throughout the process. The series of posts will show:

-Full dovetail neck reset.
-Complete re fret
-Remove and replace pickguard
-Remove and re glue the bridge

In addition to these topics, I will be showing and exploring many other general setup procedures and restoration topics... and other things that happen along the way. With a job like this, more things easily come up along the way.



This is a gorgeous, vintage 1962 Martin D12-35. I bought the guitar for the shop with the plan of restoring it. I haven't decided whether or not to keep it after the restoration is complete. The Brazilian Rosewood is beautiful. Below you can see the three-piece back with the Indian Rosewood in the center.














Look at the way they matched up the wood figure at the heel. This is a really great looking piece of Brazilian.













Here you can see how the bridge is lifting, and the pickguard. The bridge isn't too bad, but since we're resetting the neck angle it'll be best to fix this so as to correct the overall geometry of the guitar. I'll be using hot hide glue for the two major glue joints... the bridge and neck joint













-R.E.

Mando Acclimation

Here is a repair I did about a year ago. I replaced the bridge foot on this Stiver mandolin with one I fabricated from an ebony blank. The need for this repair was due to a typical northern Arizona instrument problem. The mandolin had dried out and "acclimated" to our dry environment, which altered the geometry of the instrument. The neck angle was so high that the original bridge could not be raised tall enough to yield appropriate playing action... strings were too low to the fingerboard and it was buzzing like crazy. While I was at it, I leveled frets and setup the mandolin as perfectly as possibly with a new bone nut.








After making the new bridge foot, it was important to sand the bottom of it to precisely match the contour of the mandolin top.








This enables the best transfer of sound vibration from the strings, through the bridge, and into the body of the instrument. Anything other than an absolute perfect fit is unacceptable in this case.









Here you can see the old bridge foot,














the new one made from scratch,














and both side-by-side.



The new bridge foot is almost 1/4" taller than the old one. I made it just tall enough for the strings to setup at the proper height once the bridge saddle was put into place on the posts. I didn't want to make the new piece any larger than necessary. By making it as close to the original size as possible the original sound of the instrument would be preserved as much as possible.




I didn't take any final pictures of the completed project. But this repair was a complete success and the customer was extremely pleased with the renewed playability of the instrument.

(Post Script) It should be noted that trying to purposely acclimate a fine instrument (such as this one) to the dry humidity of Flagstaff is usually unrecommended, if not highly discouraged. It is much easier on the instrument, and on you as the owner to simply invest in and learn how to use the appropriate humidifier, and more importantly get in the habit of keeping the instrument properly hydrated. The owner of this instrument was lucky we didn't have cracks to fix or any major structural repair, worse than what we saw, anyway.

-R.E.