Laminated bracing - What do you think?

[tippie53]

this can be an interesting discussion , the thing is stiffness to weight ration. When you think about it , making it all out of spruce but cross graining the middle section would increase the stiffness considerably without adding mass. It may be a good topic to see what the true end results are .
I would think a mid of carbon fiber would be stronger and more stable than different , and it would be an interesting experiment . Often "new discoveries" are found old ones.

[darren]

Ken H builds with spruce/wenge/spruce braces (IIRC) and is influenced by McPherson... bet he'll be chiming in here on his strength/weight testing.

[kencierp]

Note the term --"we feel" -- its subjective -- pretty cool -- but not a good choice for a first or second project.

http://mcphersonguitars.com/beta/technology/

scroll to bracing

[tippie53]

Balsa does have a high dampening value not sure what the weight to strength ratio would be. The vibrations of the top would still get sucked out from the Balsa . It sure makes for good airplanes

[Jim_H]

My approach to building guitars is very non-scientific. In fact you might say it's even anti-scientific. I hate getting distracted by things that over complicate what I'm doing.

As it stands, I'm barely able to consistently and accurately build a guitar *at all*. My first effort sounded terrible (until I re-topped it with lighter bracing).

My goals for building gutiars center around being able to build to a certain characteristic. i.e. The objective of building a bluegrass banjo killing boom box dreadnought requires an understanding of what types of materials are ideal for this. Bridge material and weight, top thickness and weight, bracing materials, patterns, shape, and weight, etc.. Alternatively building a jumbo strummer for playing John Denver songs, or a small body ultra sensitive finger style guitar all require different strategies when it comes to materials, construction, and setup.

Additionally, being able to customize a guitar to suit a specific player. Fingerboard radius, nut width, string spacing, fret height, and the corresponding setup stuff.. nut action, relief, saddle height, etc...

I have a lot to learn about how a guitar works, and what makes a 'good' one (relative to the stated goals). My current efforts are centered towards building with fairly standard materials, using basic 'baseline' dimensions for plate thickness (stiffness?), weight, etc.. and using fairly traditional woods (mahagany, rosewoods, etc...) to try to develop an organic feel for the process. Once I feel I have developed a sense of how to do these things, I might start venturing off into exotic and expensive woods, and using different bracing patterns, etc...

Bottom line is, other than what I've read in books and on the Internet, I don't *really* understand what makes a good or bad guitar. Until I can reliably and consistently build them to a stated goal for tonal and sound characteristics, playability, and reliability/durability, I'm not going to venture too far off the reservation.

[Darryl Young]

The thing that peaks my interest about a laminated brace (even if the middle layer is a heavier hardwood) is the possibility to resist creep. Maybe even a hardwood layer in the middle would help this some (can't say for sure). But if I were going to all the trouble to laminate, I think I would use carbon fiber (CF) for the middle layer. It could be lighter and stronger than spruce. I think Mario Proulx builds this way and chooses a thickness for the CF layer that matches the strength of balsa (probably sheds some weight......which the glue might add back in, not sure). His reason for doing this is to push the edge on strength yet retain creep resistance. Trevor Gore just adds CF in strand form to the top and bottom of the brace. It's more effective in this location but then you can't shave the top of the brace to tune the soundboard. It would be no picnic trying to shave a brace with a middle layer of CF so it's not the perfect situation either.

Keep in mind that while a laminated brace is stronger, the glue adds weight so the stiffness to weight ratio may or may not have improved.

[KyleColdren]

Darryl,
Here is what Trevor Gore's braced tops look like. You can see the CF on the tops of the braces. Very interesting.

[Jim_H]

Greg Smallman is a highly regarded classical builder who uses balsa in his bracing. There is a lot of debate in that community about his results. Some love it, some hate it (mostly traditionalists).

[deadedith]

Why not all-carbon fiber braces? And bridge plate? Are we really saying that we can improve that much over the GREAT sounding guitars of today and yesterday that are built traditionally?
I'm just wondering what the goal is. Then again, I'm an old fart and don't have a lifetime of experimenting in front of me, so maybe my viewpoint is influenced by that. :-)

I'm not negative on the idea of carbon fiber, or even the rather grotesque Gore bracing pattern; just really trying to understand if there is a CLEARLY demonstrated positive effect of these proposed methods. They are interesting, for sure..

[Kevin Sjostrand]

TRADITION!

I will stick with what has worked for eons, and save my brain power for more important things, like, hey, "what am I having for lunch today?" :>)

Kevin