Now the crucial part. This is the part that makes or breaks the guitar:
(usually referred to as the 'top' in the USA)
There are many variables to be considered (thickness, doming, bracing...), and depending on how this is done, the guitar could have the voice of an angel (consistently achieved only by great guitar makers) or sound like an inexpensive ukelele.
When purchased from the supplier (there are wood dealers that specialize in cutting wood specifically for musical instrument builders), the top comes as two pieces (trees are not wide enough for a one-piece top). This is a set of Italian alpine spruce (picea abies) that I purchased from a wood harvester/dealer in Italy.
As received, the wood is usually 4mm to 6mm thick. The soundboard typically ends up in the range of 2mm to 2.5mm thick.
The first job is to glue the two pieces together. The edges that will be glued (the center seam of the top) need to match perfectly so there is no gap in the seam.
The two halves are glued together. I use a 'plate joining jig' purchased from Luthier's Mercantile, Inc. It makes the job almost foolproof. The key to success is to apply downward pressure while pressing the two halves together.
Now the joined top needs to be thinned considerably. To avoid tearing the wood, I use a toothed blade in the plane. Removing 2mm - 3mm of wood is a lot of work.
With the top thinned (at least in the ball park - fine tuning will come later) the shape of the guitar is cut out and it's time to install the rosette. A channel around the sound hole must be removed for the rosette to fit into.
Here are two tops with rosettes installed.
Now the sound hole is cut out. Don't worry - the gap at the top of the rosette will be covered by the fingerboard.
Next post: Bracing the top.