Sterling,
I'm sort of a lurker on this list, I had started building a lute some
years ago - after getting interested by making the Music Maker's flat
back to see if I could handle the play. Medical matters have taken me
away from the lute, but I retain interest. I still play, and sometimes
repair, harps and other stringed instruments.
You say that the split in the soundboard doesn't affect the playability,
but it could in the future if it widens. May I make some suggestions
from one who deals with wood (I am a wood turner). And if my suggestions
are totally out of line in dealing with a lute may I ask the more
knowledgeable on this list to say so.
Removing the top and replacing it involves a certain amount of work and
expertise. I make very thin hollow forms on my turning lathe, and as
they are usually of relatively green wood they often split on the end
grain. I rub sawdust into the split, then drip in thin CA glue. This
effectively makes new wood as the sawdust and the CA glue meld (not
really new wood, but better than glue alone). If you are thinking of
removing the top/soundboard anyway, perhaps you should try this first.
As to the ebony bridge, someone suggested grinding it down rather than
taking it off. That also sounds like a "good fix" to try. You could make
a new bridge and glue it on top of the ground down ebony.
Let me stick my neck out now, in this community of luthiers. There are
two basic forms of stringed instruments. The harp is one in that the
strings pull directly on the "soundboard". The other form has the
strings parallel to the soundboard, and pressing on it over a bridge.
That form is separated into two sub-groups - the lyre, psaltery, cithera
(zither) is one group and the violin, guitar, lute, etc. is the other.
The former have a string for each note, and the latter have a neck and
fretboard (whether fretted or not) that allows for fewer strings to make
the notes.
These differences are important in the production of the sound. Musical
sound involves the overtones of the plucked or bowed string (or for
woodwinds and horns, the shape of the air column - but we are speaking
of stringed instruments). I'll address the harp first. Contrary to the
opinions of most of my harping friends (pun intended) the construction
material of the harp body has little effect. The harp strings sing to
the open air, and the fullness of sound comes from the direct vibrations
that the soundboard, under tension, passes to the sympathetic strings.
The harp body is not a resonating chamber, except to the extent that it
enhances the vibrations in the soundboard that are passed to other
strings. I.e., the soundboard is not a transmitter to the sound in the air.
Now to the bridged instruments. Here the resonating chamber of the body
has more effect, and is more integrated into the sound transmission to
the air. At the extreme we have the violin bridge, a complex shaping
with cutouts so that the bridge itself affects the passing of the direct
vibrations of the strings to the soundboard, and therefore the
resonating chamber that is the body. At the other end we have psaltery,
lyre, and zither - where the body is not so resonant. A solid bridge,
and a high tension, and less resonance.
In the middle is the lute group, the plucked instruments with a neck and
fretting (in the sense of finger pressure on the string to change the
note, not the actual frets). The entire combination of body and
soundboard are a resonating chamber, but the bridge is a "passive" pass
through (in contrast to the violin bridge). Where the violin is made as
a body of the same material the lute group has a body and a soundboard
of different material. The goal of the bridge is to pass the vibrations
to the soundboard, but it is also needs to be of a harder wood to not
wear away from the movement of the strings in tuning.
Perhaps the ebony is too hard, vibrations move at different speeds in
different woods (or materials, depending on the density). But I wonder
if there is any need to replace the ebony bridge with a more traditional
material - it seems to me that it would make a good bridge. Perhaps the
amplitude of the vibrations in the wood is reduced with the harder wood,
perhaps there is a compromise that resists wear but also retains
amplitude. That is pure speculation, but if I had my old shop and "silly
scope" I could test it. That would be fun, one of the burdens of old age
and a reduced space is the lack of tools.
OK, I've blessed/cursed you all with my ramblings. I'm very curious as
to your reactions. In the harp world there is a continuing argument over
the "solid" soundboard and the laminate - but it is a bit silly as the
"solid" isn't solid. A harp requires that the "long grain" of the wood
be across the soundboard, else the tension of the strings would
immediately split it (the total tension on a medium sized Celtic harp is
over a thousand pounds). To make a solid soundboard in one piece would
require a tree of four feet diameter, so they take the solid pieces and
put a backing on them - which is a laminate anyway. Which comes back to
the split in the lute soundboard, and the "new wood" by gluing with
sawdust. Doesn't seem to have affected the sound of "solid" soundboard
harps.
One wants to maintain the integrity of the vibrations within the wood,
and from one part of the body to another. Small variations won't be
heard, it is the overall resonance that is important. I think it is
important to understand where that resonance comes from in the various
instruments - and they are not all the same. The final object it to put
a sound in the air (neglecting amplification and pickups as that is
another matter, and one I'm adamant on - music is changed as soon as it
passes through any device, even if it is perfectly recorded it still
depends on the ability of the speakers, and subtlety is lost). There is
but one device that properly interprets the mixed vibrations that we
call musical sound, and I'm in awe of it. The human ear can hear a mix
of vibrations and separate them, and the auditory portion of the human
brain can re-assemble them into the individual sounds. Think of it, you
couldn't do that with the best of computers and Fourier analysis. You
could break out the individual sine waves of the mixture, but you'd
never know which came from the oboe or the flute. It is the re-assembly
that is magnificent.
Best, Jon
On 6/15/2012 4:47 AM, sterling price wrote:
Richard--thanks very much---this is just the sort of info I was looking
for.
Taking a lute apart sort of scares me--the fear is I will just ruin
it. This lute has other issues--it came from England to very dry Utah
18 years ago and the soundboard developed a split at the seam soon
after it got here. Now the split goes almost the whole top but it has
not hurt playability. Perhaps I should just make a new soundboard....
I will keep you all posted on what I do.
--Sterling
From: Richard Lees<rel...@sbcglobal.net>
To: sterling price<spiffys84...@yahoo.com>;
"lute-buil...@cs.dartmouth.edu"<lute-buil...@cs.dartmouth.edu>
Sent: Friday, June 15, 2012 12:03 AM
Subject: [LUTE-BUILDER] Re: Archlute Bridge
Hello Sterling!!
Its been a long time posting for me, I have been pretty busy with
work...
I offer what I have done in the past.
Many of the EXCELLENT builders who post here will no doubt have
wonderful input to give you , no doubt..
For my part, having replaced a number of bridges in restoration work
as well as gluing on bridges in new construction, I would say
It is much better to remove the top. MUCH BETTER in fact
Your description is good by the way, and certainly justifies replacing
the bridge.
Also since the current bridge is not to be kept, you do have a great
advantage here.
However there are issues .
Removing a well glued on bridge is no easy task. Heat and moisture are
required and the application of these forces can easily damage a top
beyond repair...
After you remove the top from the bowl , you must focus the heat and
moisture very carefully, and take extreme caution not to be impatient
and lift up the bridge with any force as this could create tear outs in
the top underneath. This situation is a nightmare to deal with , but
CAN be addressed if the damage is shallow.
Given that you are going to make a new bridge, I suggest that you
begin by removing whatever top detail has been placed on the top of the
old bridge ( if any) and then to CAREFULLY plane down the old bridge
with a block plane to where the remaining bridge is perhaps 1.5 mills
thick or less if you can ...
Now you can place hot water on a rag cut to fit EXACTLY on top of the
remaining bridge with a LITTLE overlap and then cover the cloth with
tin foil or saran wrap to prevent the water from evaporating. Please
leave this in place for a while .
As thin as the remainder of the bridge now is, the water and heat
should penetrate fairly well into the top and glue joint underneath,
and begin to loosen the bond.
Now under one of the ears see if you can't slip a single edged razor
blade between the bottom of the bridge and the top... You must not
force this .... if there is any resistance you should stop immediately!
You will need to apply more heat and moisture using hot water and a
SMALL iron directly on the top of the remainder of the bridge on the
area where you wish to start, and try again... I stress that it is
important to be careful to control how much heat and moisture is
absorbed in the top and most importantly to keep this in area as close
to the perimeter of the bridge as possible..
If you have removed the top, of course you can apply moisture and heat
from UNDERNEATH the top just below bridge, and be very effective as the
top itself is more porous than the ebony.
Carefully move the razor blade along the joint until the bridge
remainder lifts up completely along its length....
At this point I recommend damping the top at least around the area
where there has been heat with cold water and prefer myself , to damp
the entire top - top and bottom to equalize the tensions so as to to
help avoid selective shrinking of the top and the ensuing warps that
will incur as a result. If you do damp the entire top , AVOID the ROSE
TOP AND BOTTOM !!!!!!!!!!!!!!!!
Just after the top has been damped, I then place the top (topside down
) in a go bar box ( you must use some cellotape on the go bar box
bottom where the bridge area is going to be , so that the remaining
glue in the bridge area of the top doesn't bond it to the box) and
then using cellotaped bars of your manufacture (say 1/2 x 1 x 12
inches or so) go bar clamp these bars down across where the bridge was
located to ensure that the top is flat in this critical area. Also
brace the existing lateral braces of the top by placing go bars in the
center of each of these lateral braces and at each end , and put go
bars on the J bar as well as the treble bars.... I recommend leaving it
like this for several days until the top has stabilized, is flat, and
all moisture you have put into the top is gone.
Now comes an interesting thing......
The new bridge should actually be glued on with the top with the same
humidity as when all the braces were glued down in the first place.
This is to prevent stresses from being introduced into the top which
will will deaden the sound.
Since we have most likely no record of what this humidity figure was ,
we now have a bit of a mystery !~!!!
In one lute I worked on and which needed a complete bridge re gluing -
the bridge was lifting up under the ears and also under the first
course but was otherwise perfect, my client wanted to reuse the
original bridge.
This instrument by the way was made by a well known and well respected
American luthier.
As such, I faced this problem of not knowing the relative humidity
used during the gluing of the braces
I discovered that keeping the top in a go bar box at 44 percent
humidity to start with, the top developed a bow with the center of the
top depressed relative to the edges, and this within less than 20
minutes from removing the go bars, and this in a room with a relative
humidity of around 55 percent! This indicates to me that the top was in
fact braced at a higher humidity.
I slowly raised the humidity in the box 5 percent at a time, with a
good deal of time used to stabilize the top at each setting and this
over the next week or two.
I discovered that only around 55 to 60 percent humidity in the go bar
box, did the top hold its flatness fairly well after removal ......
WEIRD!!!!!
I later learned from one of our best lute players here on the west
coast that this particular builder (who he knew) built his instruments
in a dampish basement and didn't use a humidity controlled go bar box
to brace his tops.......
Well anyway (and having no choice) I glued the bridge back at 55% .
The instrument sounded great thereafter, our builder did do an
admirable job.
This hopefully will give you some idea at least of my process in this
kind of repair...
best
Richard Lees
On 6/14/2012 9:27 PM, sterling price wrote:
> Hi-I'm not sure if this list is still active so here goes---I have
a
> small archlute with a bridge that is made of ebony and I would
like to
> replace it with something more appropriate. Also because the
string
> spacing and action is all wrong. My question is--what is involved
in
> removing a bridge and replacing it without removing the
soundboard? I
> just need some advice on how to proceed, or if I should leave it
alone.
>
> --Sterling
>
> --
>
>
> To get on or off this list see list information at
> [1]http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
>
--
References
1. http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
