General Tips
One of the most important maintenance steps is to contact a competent luthier. Generally,
a call to the local symphony’s business office will result in some acceptable shops to call.
Beware of those who use white glue, carpenter glue or super glue. Beware of those who suggest
re-varnishing.
Seams
Gluing seams is the most frequently needed repair. Instruments in the violin family are put
together with relatively weak hide glue. Hide glue has high shear strength and low tensile
strength – the opposite of white glues. Tops are glued on with half strength glue for a good
reason. Wood expands with high humidity and contracts with low humidity. If the tops and backs
were solidly glued, the wood, especially the top, would crack because it would not be able to
loosen during humidity changes. Cracks can depreciate the value of the instrument somewhat,
especially those over or under the sound post or along the length of the bass bar. So, letting
the seams open is much better than causing cracks in the instrument. A symptom of open seams is
buzzing. Sometimes, the open seam is visible. Have the open seams glued together by a professional.
This is a very low cost repair. Time to glue a seam may take around three hours.
Sound Post
The sound post may need changing from time to time. The body of the instrument is constantly changing
due to seasonal changes and other environmental conditions. Usually, the sound post becomes too short
and a new one needs to be made. Adverse environmental conditions can cause the need for a shorter post
or an adjustment. Please do not adjust the post yourself! Adjusting the sound post too frequently can
cause a concavity in the top, and the setter can damage the f-holes. Never use scissors as an adjustment
tool! They will wreck the sound post and the f-holes.
Bridges
When set at the proper 90-degree angle (tilt), the bridge must not be bent. The feet must show good contact
with the top on all edges (no gaps). The strings must not be buried into the bridge grooves. If any of these
conditions exist, the bridge needs to be replaced by a professional. Bridges do come in various quality levels.
The better the wood, the higher the price of the blank. All bridges must be custom fitted and shaped (tuned)
for your particular instrument. Improperly fitted bridges not only damage the top, but also cause an inability
to produce optimum sound.
Fingerboards
When a fingerboard comes loose, wrap the tailpiece with something soft to prevent scratches, then loosen the
strings. If not loosened, the neck will bend due to string pull. If the strings are tight for 24 hours, the
neck will have a permanent bend, resulting in a more costly repair. Fingerboards, over a period of years, become
rutted in their high traffic areas. Sometimes, the board changes shape. Both problems result in buzzes and poor
intonation. At this juncture, the board needs re-contouring for proper smoothness and swoop. This is done by
planing the board and sanding. Re-contouring should be done every 4 to 10 years, or when badly worn. Eventually,
the board will need replacement, as it may get too thin. Boards are replaced every 40 to 50 years. When the board
is replaced, the nut will be adjusted to the proper height and with the correct grooves.
Saddles
Saddles, under the tailpiece at the end block, do come unglued, causing difficulty in maintaining tune. It is a
simple job to re-glue or replace a saddle. The saddle needs to be shortened every 5 to 10 years. The top shrinks
and the saddle doesn't, making it too tight. If not shortened often enough, cracks will develop up the top from the
saddle ends. Incidentally, a high saddle tends to sweeten the sound. A low saddle tends to make the sound more
brilliant.
Pegs
Balky ill-fitting pegs are impossible to deal with by the player. New pegs, when installed, should be used several
times a day to make them and their holes maintain roundness. Unused pegs shrink into oval shapes, as do the holes
they are installed in, resulting in the familiar "ratcheting" feel, like cogs slipping and not holding at some spots.
Pegs do wear out and change fit over time, refusing to stay put. Normally, pegs tighten in the summer and loosen in winter.
Frequent use prevents this problem. However, when the small end of the peg sticks out 3 mm or so from the peg box wall,
it is time to re-peg. Eventually, the peg hole becomes enlarged by many fittings of new pegs. The holes must then be
filled with new wood (bushed), and new pegs must be fit. If the holes are left large, the peg box is in danger of splitting
out, especially at the A peg on violins and the D peg on violas and cellos. New pegs will soon need lubrication, such as
"Hills Peg Dope," to make them work right. If they slip, a small amount of a dope, like "Hiderpaste," will make them hold.
Your friendly luthier will normally do this at no charge... especially if he's the one who put the pegs in!
Serious Repairs
Serious cracks, crunches and broken necks require expert attention. See your favorite luthier for advice. When the strings
are too high off the fingerboard to fit a bridge, there may be several causes. The first suspect is that the heel of the
neck has pulled out of the mortise. This requires a neck reset. Next, the heel button could be broken away from the back,
at the purling, pulling the neck out of the mortise. This is a very expensive repair that requires the instrument to be
opened, a button patch to be placed inside and the instrument to be re-blocked, closed and reset the neck. Lastly, the
fingerboard could have warped, sagging drastically. Only a new fingerboard will solve this problem. When the strings
are too close to the fingerboard and a new bridge can't solve the problem, there are several causes. First, the
fingerboard may have been partially unglued in the center of the neck, bending the neck due to string pressure.
This pushes the fingerboard end very high, bends it or does both. The cure is straightening the neck, and probably
replacing the fingerboard. The most common cause of the strings touching the fingerboard is body drift. Think of the
top, back and blocks of the instruments, when viewed from the side, as a rectangle. The body can drift to a trapezoid
shape, the top and back parallel, but the end block top and heel block top leaning toward the neck assembly. This
raises the fingerboard end drastically. Bridges are not made high enough to raise the strings off the board. The
cause is an unglued end and heel blocks. String pressure tries to draw the end toward the heel, pushing the fingerboard
up. In good instruments, they are taken apart, given new blocks, and the necks are reset.
