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Peg Problems

Posted by admin on September 6, 2011

This is the final part in my series on violin pegs.  In this section, I cover what can go wrong with pegs and how to fix them.

What can go wrong?

Bad Lubrication

All moving parts need lubrication: the engine of your car, squeaky hinges, even your body's joints.  Pegs are no different.  When the pegs are first fitted, peg dope, a special lubricating mixture, is applied repeatedly to completely embed the maple wood of the scroll.  This should last for  years, depending on climate and humidity.  When the pegs no longer turn smoothly, they should be re-lubricated.  To do a proper job, the pegs should be taken out one at a time and a high quality peg dope such as W.E. Hill or Hindersine applied.  In my experience, peg drops or home remedies of soap and chalk never work.  The abrasive quality of the chalk has the added drawback of potentially damaging the peg hole.

While this is not a difficult procedure, it is best done by a qualified repairman.  That way, he can also check the fit of the pegs and holes to be sure there are no other problems.  Most good repair shops will happily do this for free when they change your strings.

Bad Material

Pegs should be made out of the hardest material available.  This is usually ebony, a dense, black wood that grows in Africa.  More fanciful woods such as rosewood, boxwood, and, less commonly, almond, pernumbuco, or mountain mahaghany can also be used.  These woods all withstand compression and warping when properly seasoned, will last longer, and turn more smoothly.

Unfortunately, student instruments are often fitted with ebonized pegs.  These are maple pegs that have been chemically hardened and dyed black.  They never stand the test of time and should be avoided whenever possible.  Instruments with proper ebony pegs will always be described as "all ebony fittings".

Bad Fit

Pegs that don't fit properly are equally difficult to work with. Remember the definition of normal force from above?  (And you thought there wasn't going to be a test!)  The repulsive force of interaction between atoms at close contact.  The keyword here is contact: if no contact is made, the normal force, and by extension, friction, cannot be applied.  The absolute maximum amount of contact there can be is the thickness of the two holes in the pegbox wall that the peg passes through, each of which is between 5 and 8 mm thick (7 to 10 mm for a cello).  This isn't much to work with!  So if even a small percentage of the peg isn't fitting, it can make a huge difference.  If the peg makes contact with only one side of the hole, then the peg will likely not hold at all, or only with Herculean efforts of pushing which will ultimately damage the pegbox.

A bad fit can be remedied either by replacing the pegs with a new set or carefully modifying the existing pegs.  This is something that requires both the tools and the expertise of a trained violin repairman.  Often players will mistake bad fit for poor lubrication and "fix" the problem by applying more peg dope.

Bad Breaks

Violin-family instruments are built from wood, which can be affected by seasonal changes in temperature and humidity.  A player can do much to care for his instrument but sometimes cracks do happen.  A common problem in older instruments is peg box cracks, especially on the upper-most peg hole.  One contributing factor to cracks is the taper of the peg.  Referring to our physics lesson again, the normal force increases as the steepness of the taper increases.  According to Isaac Newton's third law of motion, for every action there is an equal and opposite reaction.  The normal force goes in both direction.  That is, the peg hole pushes against the peg, and the peg also pushes against the peg hole.  Therefore, a steeper taper means more normal force which means an increased chance of pegbox cracks.

As a preventative measure, the minimum taper required should be used.  Experience has taught us violinmakers that violins and violas need only a 1:30 taper, while cellos should be set slightly steeper at 1:25.  In the days of gut strings, a taper of 1:20 was used, but that is no longer necessary.  (Why?  Good question- it has to do with string tension, and that's a story for another day.)

If you notice a pegbox crack on your instrument, bring it to your violinmaker right away- it will only get worse.  Depending on how long and how open the crack is, a patch or spline may need to be applied.  In this repair, wood is removed from around the crack on the inside of the pegbox only.  Then a new piece of wood is fitted into place, generally with the grain running perpendicular to the grain of the scroll for added strength.  If done properly, this repair is unobtrusive and barely visible.

To further reinforce the pegbox crack, a spiral bushing may be used either by itself for smaller cracks or in correlation with a pegbox spline.  A spiral bushing is made up of a thick shaving of hardwood.  This is wrapped around the peg hole in a spiral shape and glued in place.  Once both holes are dry, a reamer is used to clean out the hole and refit the peg.  In a spiral bushing, the grain runs around the diameter of the hole and creates a stronger reinforcement than a traditional plug bushing.

Spiral-Bushing.JPG

In Conclusion

Many players, myself included before I became a violinmaker, struggle with their pegs.  You shouldn't.  Pegs should turn smoothly and stick where you put them.  Sure, pegs are affected by weather so you might notice some problems during huge humidity changes.  But on the whole, you should not need to make major adjustments every time you practice.

If you are having problems with your pegs, please bring your instrument in!  A musician has enough to worry about without stressing about tuning.