(modified 9_20_2020)
Page V-103

Cremona 'Secrets'.....

 Web Host: David Langsather {Violin Maker, Researcher.... Salem, Oregon, USA
www.violinresearch.com}

...What I really mean is: what is some of the trade craft of the most productive violin makers the world have ever known, that is Not currently known about / or applied in modern Violin Making?
...Most agree that Stradivari and Joseph Guarneri del Gesu had certain making practices that were not passed on. These factors resulted in (some of) their violins' have sound characteristics that are in demand by the best violinists of today.
Joseph Guarneri del Gesu (1698-1744)
Stradivari
...There are three items I believe meet these conditions and they have been carefully tested by us... They are:

# 1 : Hematite Burnishing...

# 2 : Dutch Rush final sanding of wood surfaces...

# 3 : Fuller's Earth Varnish Ground...
...As the result of two years of Violin Timber {that is what makes for a superior and pleasing violin sound or voice.} research focus One of the apparently important features to meet this goal is to produce an instrument that increases the loudness of the lower overtones and decreases the upper overtones.
   Our ears are much more sensitive to higher pitch sounds so that for us to enjoy a fuller musical experience; we need to hear music played on an instrument that has this attribute.
   Each of the above three items do just this.
  We analyzed the sounds produced by exceptional instruments of these two foremost violin makers with modern sound analyzer software and excellent audio recordings; selecting passages where only the violin was playing a single note. As you will see later on in this discussion.
...First let us look at Hematite Burnishing technique and see how this was done 'back in the day.'
..Kahlil Gibran, a professional guilder, and instrument maker, states that a piece of Hematite was found in Stradivai's work shop possessions. He believes this explains the burnished striations characteristic of 18th century violins. I have discovered that there is a desired acoustical characteristic produced in reducing the strength of upper overtones.
..Low angle light reveals the surface striation left in the wood surface; even this maple surface. I suspect that only the outside surfaces were Hematitie burnished.
..My research suggests an increased positive acoustical effect with also burnishing the inside of the plates as well. Whether this is overdoing the effect is still under investigation.... David Langsather
..The technique is to press down on the wood grain, carefully supporting on back side, and stroke in one direction, and then moving over one grain and returning. When completely done, repeat for second time. Research has show that twice gives the optimal effect.
..Secondly, Dutch Rush sanding of finished surfaces, inside and out (excepting glue joint surfaces) gives a similarly improved acoustical result of lowering the upper overtones. Twice is also found the optimal number of applications:
violin108001.jpg
..Fuller's Earth Powder added...
..Stirred in well...
..Tinting dye added to ground mixture...
..Second tinting dye color added...
..Mixed in well...
..After first coat of ground applied...
..After second ground coat applied...
..After final two clear coats varnish...