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"Prescott" Double Bass, c1830
Every pet owning bass players worst nightmare! Dog hits
bass A, knocking it over. Bass A hits bass B. Bass A's scroll ear
smashes into bass B's upper ribs. Bass A (German factory bass) is fine
while bass B (1830's "Prescott") takes a ride to our Mystic, CT shop to repair the
damage.
In repair page one we
repaired a smaller rib hole/crack very successfully. This is a much larger
hole, but it will blend quite nicely. All the pieces were there and went
together without too much convincing. A maple veneer along the inside will
give all the support it needs. Touchup was a bit of work mainly because we
had to make our existing varnish opaque to match the surrounding varnish.
The real problem is the scroll. Upon first inspection it
was deemed by us to be unstable. The owner bought this bass 18 years ago
and noted the cracks and brass pins, so he put some pencil lines to see if the cracks
would travel. Eighteen years later, the pencil lines show the cracks have
not traveled. But when we took off the plate tuners, everything just started
falling apart! It is a miracle that 1) this scroll was not buzzing beyond
belief in the owners ear and 2) the scroll has not just snapped off! This neck and scroll
though are what we call "Frankensteined" together. The neck length was
shortened by way of a lap joint and hardware. The neck heel had been
lengthened to ad more over stand. The fingerboard had been reverse shimmed
to decrease the projection. The neck heel has been shoed twice in attempts
to raise the projection. The neck set mortise is very shallow and only lag
bolts hold it into the block.
Obviously years of repairmen have brought this neck back and
forth. It is time for a new neck and scroll graft!
We x-rayed the scroll to see just what we
were in for. About 35 nails will need to be removed before we start to
carve, if we go that route. There are two possible repair route's to take:
#1)The scroll will need 8 bushings and cheek grafts. The inner
wood of the peg box walls will be replaced with the neck graft, and the outer
portions of the peg box walls will be replaced with the cheek grafts. Just
a thin amount of original wood will remain in the middle (although most of this
wood will be bushings). In the end the scroll will have maintained our goal of conservation of original material when
allowable.
#2)The volute will be grafted onto a new neck &
pegbox.
Our goal is always the preservation of original material.
Even though this scroll shows much evidence of not being original to the maker,
we decided to preserve the story it tells, and have elected to proceed with
repair route #1.
The string length is currently set at 42.5" and we shortened
it a bit to 42".
The projection is about 7 inches and that too will remain. The over stand
is currently 6.5mm (this is spec for a violin, not a bass) and that will be
corrected to 25mm. This will change the angle of the strings over the
bridge and thus reduce some of the string tension on the top, as well as make
for a more comfortable playing instrument. A new neck block will allow us
to set the neck deeper, thus adding the strength to the mortise that is needed
so that the lag bolts can be abandoned. Originally the pegbox walls were
too thin at the base and were not load supported by the neck. This caused
the pegbox to crack along the floor. The scroll graft will allow us to
carve thicker pegbox walls that (inside edge) extend into the neck. This
will put the load of the pegbox walls onto the whole of the neck and help to
prevent future failure.
At the last minute we decided not to install the original tuners
back on the bass (they were brittle and had as many repairs and patches as the
scroll had). Not enough time (and money) were left, so standard German
plate tuners were installed with an offset orientation to take some pressure off
the scroll.
The bass finished out very well and was out to gig with the owner
the first day it was picked up!
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