No Subject

[David Van Zandt <dvz@eskimo.com>]

   Jeremy Montagu (jmontagu@vax.ox.ac.uk) wrote on Sun, 30 Oct 1994 :

  >I have been asked for advice by the curator of the Barcelona Museum of
  >Musical Instruments, and as I have no idea of the correct answer, I am
  >appealing to MICAT-L for help.

       The question Jeremy Montagu raised about the cleaning of a Papua
 New Guinea flute in the collections of the Barcelon Museum (from Sun,
 30 Oct 1994) expresses a concern that violin repair people run into
 constantly.  When we are asked to clean the instruments of our clients
 we must make many decisions about how to go about the process of
 separating the "dirt" from the original coating.  Additionally, we are
 often asked to "polish" the instrument.
       We must make the decision of what "dirt" actually is, or at least
 what it is that we want to remove and how much of it, as well as what we
 want to leave in order not to disturb the original coating.
       The methods that violin repair persons use to clean an instrument
 are often straightforward.  A bit of warm water to clean off the water
 soluable dirt, a bit of xylene to clean off the rosin and oils, and
 Bob's your uncle...it's ready to polish and send off to it's owner.
 But unless one is able to identify an early Klotz family instrument you
 may soften and strip the varnish with warm water before you know it.
 Or if you haven't cleaned a Carl Becker III instrument you may find out
 too late that it takes very little xylene to take color off it.  While
 these examples of excentric varnishes are in the minority they serve to
 show why it is a good idea for violin repair people to spend a portion
 of their training in the workshop of someone who has been part a
 lineage of repair shops of some quality.  I think it would be a grand
 idea to have some formal training in conservation practices as well.
       The practice of polishing violins has consisted primarily of using
 alcohol to soften and "re-form" the existing varnish to fill the micro-
 pits and scratches.  And all too often it means adding alcohol soluble
 resins to the polishing rag to "even out" the sheen of the surface.  Both
 of these practices are to the detriment of the varnish since among other
 things, texture is lost, any foreign matter left on the varnish is sealed
 beneath the polish, the polish rag can add foreign matter of it's own, and
 the process as a whole is irreversible.  Mineral or other light non-drying
 or semi-drying oils are sometimes used while polishing.  Oils tend to
 creep into the micro-fissures of the varnish, contaminating it and changing
 the transparency.  These oils are impossible to remove completly.
 Never-the-less, violin repair persons must tend to the wishes of
 musicians.  Bowed stringed instruments must be cleaned and the varnishes
 maintained.  With a good eye and a bit of training the careful cleaning of
 instrument varnishes can be accomplished with minimal damage to the
 existing coating.  Polishing is much more of a problem, if it should be
 done at all.  Without a conservator's training, it is difficult to know
 what alternatives to alcohol/resin polishing are available or what
 removable modern materials might be safe to apply to a varnish in order to
 satisfy an owner's desire to have a polished instrument.  Any thoughts on
 this subject would be welcomed.
 One particular concern that I have is in protecting worn areas of
 varninsh, specifically the upper treble shoulder of the violin family,
 where heat, abrasion and perspiration wear through the varnish down to
 bare wood.  A common method of protecting this area is to first clean the
 bare wood as best as possible with a combination of water, detergents,
 and other chemicals if needed.  Then to seal and retouch the area with an
 alcohol varnish and colors.  And lastly to cover the shoulder area with a
 clear mild adhesive backed plastic tape or sheet, such as CON-TACT brand
 self-adhesive covering.  The plastic coating has a life of about 5 years
 and the adhesive can generally be removed with stoddard solvent or xylene.
 I question the use of alcohol varnish to seal the wood before retouching
 and applying the plastic.  I question the use of CON-TACT brand covering.
 Are there water soluable sealers that can be used to act as a
 barrier before retouching which are stable, benign to the wood and can be
 removed completely with safe cleaning practices?  Are there adhesive backed
 plastic films which are stable, have an adhesive that is safe to apply over
 varnishes and be easily removable?

 David Van Zandt  <dvz@eskimo.com>     Seattle, Washington