Best Practises: Davide Sora Videos

I’m working away on the Best Practises page.  While you wait for those, I have added to the Best Practises page an index of the Youtube videos by Davide Sora (website).  Davide is an award winning violin maker for aesthetics and tone.  Davide and I clearly have the same philosophy in violin making, clean, neat and traditional hand made violins.

His videos are a great guide to new makers, and an inspiration to practising makers!  Check out his youtube channel, my list of his videos and the wealth of videos and photos on his blog.

All About Glue

Check out the latest addition to the ‘Best Practises’ page:  I’ve added a section on glues.  Here are some interesting tidbits:

bloomgelometer1

  • Hide glue is made from the same process which produces food gelatine (Jello), but gelatin is not the same as hide glue.
  • Similar animal glues have been in use for about 6,000 years.
  • White and yellow “carpenter’s” glue were only invented in the early 20th century.
  • Additives of urea, salt, glycerine and vinegar to hide glue modify the glue, some with detrimental effects.
  • There is an additive that prevents liquid hide glue from gelling.

I also discuss briefly the preparation of hot hide glue, the interpretation of various glue ‘bloom strengths’, and where these are typically employed.

An interesting aside: ‘Bloom’ refers to both the expansion of the dry hide glue when it expands and also the “Bloom Strength” which is actually named for the inventor the gel strength measurement device: the gelometer, seen on the right. Invented and patented by Oscar T. Bloom.

Davide Sora’s Prize Winning Strad

Davide Sora won Bronze in the 14th Cremona violin-making competition (Concorso Triennale di liuteria) along with the special prize for “the violin with the best acoustic quality” from the Union of Polish Violin Makers,   He’s posting some pics of his winning violin  on Maestronet.  It’s a beauty.

Davide noted his violin is made on the Stradivarius ‘G’ Form.  He also tells us that the varnish of this violin is made with raw shellac, a bit of mastic and naturally oxidized linseed oil (linoxin), its essentially an alcohol solvent varnish, which is his standard varnish. “The color is given in part from the resins and in part from madder lakes fixed on alum and iron.”

As one reader pointed out the shape of the kidneys of the bridge are not the typical US/UK ‘egg’ shape.  He says “In fact I prefer more elliptical kidneys and oriented in the diagonal sense, mostly for aesthetic reasons but also because I believe that more effectively lighten the top area of the bridge under  G and E strings, helping to give a more open tone and fast response.  The pointed shape  at the waist … is not my standard practice, but it derives from the ‘fine tuning’ for this violin in particular.”

The finish is not antiqued.  The regulations for this competition forbid antiquing of wood or varnish or breaking from Tradition in ‘form, decoration, color, or woods’.  Basically, a violin in the tradition of the Cremonese makers 300 years ago.

He also reports that the top plate has  an approximate density of 0.40 and a final weight of 62 gr with bassbar and a M5 resonance at 373 Hz (F#).  The back plate has a density of 0.57, a weight of 95 gr and M5 at 371 Hz (F#).  He says “Usually I don’t match the modes, but this time they came in this way, for what it’s worth.”  The top plate has an arch height of 16,5 mm and the back pate has an arch height of 15.8 mm measured before inside hollowing.

You can hear two of Davide’s past violins here (a 2008 and a 2011).