As usual,
Dana Emery strikes again !
Excellent post .......
excellent post.......
Sonically too, Ebony is not the most musical of woods and while I have
retopped a beautiful archlute for a player out here which had ebony
staves, one could lightly sense the enharmonic character of ebony in its
sound... now for bridges, Dana is right with respect to correct build
procedures ......But if our mystery bridge turns out to actually be
ebony ( and I have seen some pretty strange stuff done in our modern era
with lutes) now would be the best time to replace it
I especially like Dana's suggestion to check all joints !!!!!
In the retopping of the archlute I mentioned above MANY braces (well
over half!) had crystalized glue joints and so I had to re-brace the
entire instrument..... This instrument which was made by a pretty well
known luthier was built in the late 70s.
AND if the top is pushing 20 plus years , Dana's additional suggestion
of simply putting on a new top is indeed called for...............
A last note to Dana's post....
some years ago i posted a quick observation on cracks, and its worth
mentioning it again.
And Dana is yet again right on target....
The Spanish masters of lutherie during the mid 60s many of whom I had
the great honor to know , were absolutely firm on this issue.. We are to
brace perhaps 5 or 6 percent LOW with respect to the expected humidity
the instrument is going typically see.... This is to insure the health
of the top and to make sure the top sounds well too.
BUT there is another monster lurking here......
If the players don't also agressively monitor EXCESSIVE HUMIDITY as when
when the relative humidity is in excess of say 20 percent of the build
target, then the wood will expand accordingly ... Now since the
plantilla or shape of the instrument is fixed by the braces and bowl ,
the softer top, as it expands, has no where to go...
What happens then is that the wood first bellies upwards and then starts
to crush itself, under these high humidity conditions and then, when the
humidity drops , the top can REALLY crack, and whats worse, at a higher
level of humidity even than the target build point!
This occurs because by virtue of have been laterally crushed, the top is
fundamentally NARROWER than before. When the humidity drops and the top
shrinks even further, these catastrophic failures can occur.
I restored several German harp guitars like this... The back of one of
them, a Haberman instrument, had shrunk so badly that it lost over1/4 of
an inch in width relative to plantilla so that when I removed the back
you could hear the instrument groan as the stresses were relieved and
the sides started to reconform .
If this is what has happened to Sterling's lute, then i am afraid a new
top is indeed in order......
Richard Lees
On 6/18/2012 3:32 PM, Dana Emery wrote:
First point, much of that which is black on musical instruments is
dyed maple and not ebony proper. The wood used for a lute bridge does
need to stand up to the strings, but need not be as stiff as ebony,
fruitwood (pear, plum, apple) are recomended from what I recall.
As has been pointed out your enemy is thermal mass. A replacement
strategy allows destructive removal. Working on the naked top will
allow the other repair you want to do, and in general you can
rejuvinate all the joints as you wish.
cracks in the top of a lute are troublesome, and likely when an
instrument travels to a drier climate than that it was built in (er,
designed for). A piano top is designed to have a slight but crucial
arch that keeps all the joints in compression as it dries out. lute
tops are flatter than can allow that, and actually cave in in places
(especially between bridge and rose); rising in others (below bridge).
An entirely new top might not be a bad idea at this point, but you
seem inexperienced for that, still should you have the resources, it
might be an opportunity to consider exploring. You will want to make
thickness measuring calipers as well as a go-bar deck and perhaps some
other specialist tools. The scrape of the present instrument can be
used for a model. You might look for a violin maker in your area to
share a brew or two with and get some informal counseling.
Good luck
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