10 March 2015

The Floating Brace

Floating brace inside a
Miguel Rodriguez guitar
This January I was asked by a customer to install a floating brace into a couple of his guitars (which were built by different luthiers, not me)...

What the heck's a floating brace?

Brace in Rodriguez guitar
The first time I saw a floating brace was in 2004, inside a 1980 Miguel Rodriguez guitar that I was studying. These photos I took of the brace inside that guitar. The brace appeared to be original and after a little research I discovered that Mr. Yuris Zeltins, a guitar repair/restoration specialist in San Diego, was probably the originator of the idea.

Brace in Rodriguez guitar
I'm grateful that Mr. Zeltins was willing to speak with me on the phone in 2004 to answer my questions. The way I understood it, Zeltins invented the floating brace in the 1970's as a preservative measure to prolong the life of guitars who's soundboards were seriously dipping between the bridge and soundhole. Rodriguez, during the 1970's, was gradually making his soundboards thinner, and got the idea from Zeltins by about 1980 to incorporate the floating brace into the design of his guitars (I believe Zeltins said Rodriguez instruments were the first ones he installed the braces into - but don't quote me...). It's fairly common to see soundboards of old guitars, and yes, of plenty of new guitars too, with pretty dramatic concavity in front of the bridge. Since Zeltins's solution is non-intrusive and easily reversible, it's an effective, elegant way of keeping some of those instruments playable for longer without diminishing their value. In fact, if done conscientiously, I've personally found that a floating brace may actually improve the sound of some guitars, and can be used to help eliminate wolf notes.

Brace inside Dammann guitar
Brace ready to install
Brace in place
At left is another guitar that I studied in depth. It's a 1990 Matthias Dammann, one of his early double-tops in which Zeltins installed the floating brace in the early 1990s.

To the right are a couple of photos of the floating brace that I just installed into my recent customer's instrument built by a different luthier in 2014.

How do I know if my guitar could use one??

Think of it first and foremost as a preventive measure. To slow down an under-built guitar's gradual swallowing of itself under string tension. If your guitar needs the extra structural support, then here are a few more considerations:

  • By preventing soundboard deflection, a floating brace raises the action height considerably. Your guitar must have sufficient saddle exposure and break angle to allow the saddle to be lowered enough to compensate.
  • Furthermore, the main soundboard resonance is going to be raised by the brace. You want to be sure that raising this frequency is a desirable consequence, and you should have a clear idea of exactly what your target resonant frequency is. This way you can fix any existing wolf notes and avoid creating new ones.
  • Be aware that the floating brace also increases the sense of string tension for the right hand
  • And be prepared for a deleterious effect on the guitar's sound, just in case. Although, you'll probably be surprised how little it seems to change the sound. 
  • Finally, will the guitar's soundboard bracing, linings and sides facilitate this kind of thing being installed?

As always, thanks for reading. I hope you found this informative, have a nice day!