Construction - Carving 2

With highly figured maple, scrapers are a must. No matter how sharp the plane, some tear-out of grain is bound to occur. Unlike with spruce, where course sandpaper and a good sanding pad suffice to even out the contours, scrapers do the job on maple.



It is probably best to finish off the scroll once the top and back are glued to the rims and the binding is installed. 
Approaching 90% of the final shape is a good target at this point.

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Final sanding smooths out the contours: 60, 80, and 120 grit.  Folding up several thicknesses of old terry cloth
makes a good sanding pad, which can be formed into whatever shape is needed.
Dealing with Runout

The angular pattern created when routing off excess material from the top shown here is a result of compensating for runout.

Spruce often grows in a spiral pattern, in which case the alignment of wood fibers is at an oblique angle to the vertical axis of the log. If billets are split from a round of wood, and top blanks are then cut in the same plane as the split face, there should be no runout.

If the tops are simply cut from the round along the vertical axis, though the wood may be perfectly quarter-sawn, its strength-to-weight ratio could be severely affected by runout. Unfortunately, this condition is not obvious. Not surprisingly, violin supply houses charge higher prices for split tops.

One way to check for runout is to insert a chisel at the end of the top blank and split off a thin piece. If it splits parallel to the face, there is no runout. If it splits out of or into the face, runout exists. I do this at both ends of both halves of the top to makes sure I understand how the grain is running. Doing the same for tone bar blanks is equally important.
Once the grain is known, the two halves of the top can be glued up in a fashion to eliminate or at least minimize runout. During glue-up, the two halves may look more like an X than two parallel lines. Of course there needs to be enough wood to maintain the final thickness. The top shown above was milled from a 3½” blank with such extreme runout that it barely resulted in a 5/8” top.

The further north the wood grows the more likely spiral grain exists. Studies have shown that left-hand spiral growth undergoes more severe distortion during drying than right-hand growth. Log home builders will reject or limit the use of these logs, as they tend to be weaker than straight or right-hand spiral grained logs. Left-hand grain is not nearly as common in the northern hemisphere as right-hand, so hopefully little of this wood enters the instrument-wood market.