Bracing the top and back.

I usually start bracing the back as it's more straightforward than the top.  We want the back of the guitar to be pretty rigid and to not absorb the sound of the guitar.  On the other hand, we don't want to make it too heavy.

My bracing pattern is a simple ladder brace with a center reinforcement strip.  The braces are made from carefully selected quarter sawn sitka.  This means that the grain runs along the braces and the cross sectionally the grain is vertical.  Grain orientation is a subtle consideration, but in creating a great guitar, it's the sum total of little things that makes the difference.

Braces are first radiused by sanding them on a radius disc - a very shallow bowl lined with sandpaper.  This creates a nice curve in the top and the back.  Once they are radiused they are measures and glued to the back.  I am using the "go bar deck" to hold the braces in place while the glue sets.  A strip of cross grain sitka runs up the middle of the back of the guitar for strength. The grain is orientated to go against the center join line to provide extra strength.

The top is a little more elaborate.  Most guitars use the classic "X brace" pattern, which can be traced back to early pre-war Martin guitars.  While there are other configurations, the X brace provides the right balance of stiffness and strength while still allowing the top to "breath" with the sound.

I start out by cutting the braces and radiusing them (on a less deep radius than the back).  They are then glued up using the go bar deck.  Finally, comes one of the most rewarding parts of guitar building - carving the braces.  This involves sharp chisels and small planes and is a process of gradually removing wood to get the right amount of resonance from the top.  Note also the trapeziod shaped bridge plate.  This is made of maple and will sit below the bridge.  

One brace gets special mention - the large fat top brace above the sound hole.  While other braces are designed to allow the top to flex like a drum, the top brace is rigid and designed to hold the wood above the sound hole rigidly in place.  It's over engineered for this task.  Note also the little peice of rosewood glued to the top of the X brace.  This has been referred to as one of the most important bits of wood in the whole build.  It alone greatly increases the strength of this joint.

Finally we have our top and back done.  A tradition is for the maker to sign the back of the top.  

Next job - the sides.

Next up: 

Making the sides.