Official Luthiers Forum!

I'm currently working on the back on my current guitar and started thinking about how to give the back joint reinforcement strip a little visual punch.

Typically we use cross-grained spruce, but it seems like a great place to dress up the innards just a little. I laid some redwood there (the guitar will have a redwood top), but that didn't quite do it. I've though aromatic cedar would be nice for the smell, but so would a contrasting hardwood. I'm using Macassar Ebony for the bindings, and the thought of cutting up a Macassar fretboard for the job seemed like it would be somewhat striking.

Is there a reason we see cross-grained spruce used predominantly other than availablity? Would a hardwood like Macassar be undesirable for some reason? What qualities does the back joint reinforcement strip really need to have?

I should think that any wood with the correct grain orientation should do the trick. Larrivee commonly used mahogany for it. Technically the light weight spruce is better, but it's such a small amount of wood that it likely makes little difference.

That being said, using offcuts from the top is also visually striking, and cheap, cause you don't need to cut into anything else and you're making use of waste.

On 4 piece backs that I have done, many of them, I've used the same material as the backs and sides for the off center joints to make them more subtle and hidden and either spruce or mahogany for the center joint. I don't think it matters really.

Use anything that glues well. I know one maker who masks around the center strip and back bracing and French polishes them to a high gloss. A lot of work but it looks good...

You don't even need to use sawn wood. Sliced veneers will do the trick. Wood is very strong in the direction of the grain, and the back will crack elsewhere long before it could rip a veneer in two.

That said, I usually use spruce or redwood soundboard offcuts and shave them down to 1mm or less, just because I have plenty and don't know what else to do with them.

Here's that treatment...

Any of the soundboard woods work well. WRC can be particularly attractive when given the shellac treatment. Shellac on the centre strip takes but a few minutes, in situ. Shellacking the braces is done before they're glued in.
You can also put the cross-grain on the outside...

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Nice. Thanks, guys.

I've thought about using offcuts from the redwood top, but it seemed a little too muddy when I held it up. Then again, maybe an ebony strip would scream, "Hey! Look at me!" through the sound hole

The guitar collectors and their mirrors would be proud of you guys!
I have a hard enough time making the outside pretty.

On my current build I used a rosewood strip with a small inlay directly beneath the soundhole. I think it adds a nice visual effect when looking into the box.