ctanzio

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Everything posted by ctanzio

  1. Put aside playing technique for a moment and concentrate on the physical violin. Bridge: there is no scientific reason why a modern bridge cannot or does not emulate the playing characteristics of the so-called "baroque" bridge. A crappy bridge is crappy regardless of the style, and a good bridge is good regardless of the era it purports to represent. Getting an experienced luthier to carve a "baroque" bridge will make your violin look baroque if you want. Strings: There is a distinct difference in sound and playing characteristics between gut and most modern synthetics. But there are modern strings that emulate the timbre of gut. Again, picking gut strings over gut-like modern strings seems more of a choice for appearance than sound. Neck Geometry: You can find scholarly studies on this. To the extent that baroque necks were set to give a lower projection to the bridge (a lower bridge), that could have a noticeable affect on the sound. I believe it is mostly a power (projection) issue. Violin Body: Different violins sound different, regardless of age. Other than the bassbar, is there really such a thing as a "baroque" violin body? Bow: There is a decided difference between playing characteristics of a baroque style and modern (tourte) style bow. You can partially emulate the baroque style by gripping a modern bow closer to its balance point. TLDR: Use gut or gut-emulating strings and a baroque bow, or modern bow with baroque grip. Everything else is playing technique.
  2. Don't know. Never been sober enough enough to varnish after mixing one of these drinks.
  3. I use the denatured version to start my fire pit ever since that unfortunate incident with the gasoline. Still get that lovely "wooooosh" when the match is dropped into the pit, but none of that nasty "baaaaam" that blew off my eyebrows. I save a bit of the Everclear for sipping by the fire. A little simple syrup, a little kahlua, and a dash of triple-sec provides an adequate delivery system.
  4. Look into the upper eye of bass side f-hole. The bass bar should pass near the edge of the hole that is closer to the center of the violin. If it is passing under the hole itself or closer to the purfling edge, it is a non-standard bass bar location. A highly arched violin with an aggressive arch transition closer to the edge can have the effect of making the f-hole appear wider as you look sideways at the violin. This would enable you to see more of a bass bar that is in a typical location.
  5. In Pennsylvania, it is illegal to make potable (drinkable) alcohol by distilling unless you have a license, even for personal use. Potable alcohol by fermentation is legal without a license, but that limits alcohol content to 18% at best. A liter of 190 proof ethyl alcohol makes a lot of spirit varnish. The price of it does not seem to be an issue to me, unless you are running a production line for double basses. ;-}
  6. There are currently scanning programs that make decent work of converting sheet music to one of several "standard" digital formats. They get it mostly correct unless it is something like a score for a full orchestra. More notation programs, like MUSESCORE, are offering built-in conversion/scanning options, like PDF sheet music translation. It is trivial to open those formats in a notation program like MUSESCORE, and correct any errors. And it is equally trivial to have the notation program convert it to tablature. I apologize if I sound annoyed, but the OP asked a very specific question, and people chime in with answers that fail to address it as if the OP is some sort of musical misfit for even posing the question. It comes across as a bit snobbish and uninviting to new members. I have translated ancient lute tablature into staff and my first impression was how can anyone learn to proficiently read that old format. Yet people played lutes from that tablature for centuries, so it must be a skill that a great many people did not see as impossible to master. To this day I encounter guitarists who are clueless when it comes to staff notation, yet effortlessly play from guitar tabs. If you went on a guitar forum and asked about ways to translate tabs to staff, how would you feel if they told to to forget about it, learn to read tabs just because that was what they were most comfortable with? Even if there were easy-to-use programs that would do the translation for you? This concludes the grouchy-old-man screaming at the traffic outside his window portion of our program.
  7. The freeware program, MUSESCORE, will let you enter the sheet music in standard notation, and then with just a few mouse clicks convert it to tablature.
  8. ctanzio

    Thanks

    Nice! Thanks for the pictures.
  9. As a general observation, combined bending and shear forces in the top plate would be higher at the bridge and near the ribs, and lesser everywhere else. So the tendency is to make these areas thicker to lower the stresses and avoid possible fracture or creep failure. How thick is thick enough? That would take a sophisticated finite element stress analysis to determine. Luckily, we have a few hundred years of "common practice" to draw on so computer modelling seems less compelling. But if someone has a few grand in their bank account and are willing to part with it, I'd be happy to do the computer analysis. >grin< The roll of plate thickness in the back plate is more mysterious to me. I am inclined to think of the entire back as, ideally, a vibration node point. One wants the back plate thick enough to reflect most of the vibrational energy into the air cavity and top plate. The player might enjoy the sound coming out of the back plate, as well as the orchestra members sitting behind the performer, but it seems like an overall waste of energy for the audience.
  10. Also, what are the neck and stop lengths of the instrument and the height of the center of the bridge above the plate? I am struggling to find some correlation for violas to figure out if a bridge height is off or if the fingerboard has sunk.
  11. Love the varnish. I noticed the subtle flair to the finish of the peg ends. Attention to the little details contributes to the overall visual impression, IMO. Mind if I steal that finish to the pegs?
  12. I already gave the scientific definition of Stiffness/Flexibility. Resilience is the ability to return to the original shape after a load is removed that caused a shape change. This has nothing to do with how rapidly something returns to its original shape. Some materials exhibit behaviors at small loads that cause some of the deformation to become permanent, so it does not return to its original shape after unloading. Thin wood exhibits this behavior, especially at high humidity. Since we are talking about dynamic properties of the bow, resilience is not relevant. The bow material and geometry would have to be very resilient as a default property or else it would gradually become a straight stick after a period of time. Suppleness is the ability to deform over large distances without breaking or experiencing permanent deformation. Again, this is not relevant to dynamic properties of a bow since the default expectation is that the bow will not break or exhibit permanent deformation due to normal use. The speed at which a bow "snaps back" after being loaded is most directly related to stiffness. The stiffer the bow, the more rapidly it will snap back to a neutral shape after being unloaded. There is a damping effect on all this too, or else the bow and hairs might excessively vibrate. Again, be careful when evaluating a bow. The hair tension can dramatically alter the feel. When I hear people describe bows as strong or weak, I really have no idea what they are talking about.
  13. People are confusing terms in this thread that have a very specific scientific meaning. "Stiff" means a small change in shape for a given applied force. For a bow, this means that for a given pressure or force applied to the bow, it will bend only a little bit. "Flexible" is the inverse of "Stiff". A flexible bow will bend a lot for a given pressure or force applied to the bow. If by "Strong" you mean "Stiff", then a bow cannot be both "Strong" and "Flexible". You are either misusing the terms, or using the term "Strong" in a context other than "Stiff". Adding to the possible confusion is the response of the hairs. One can have a very stiff bow, but have hairs that are rather flexible, for example, lightly tensioning the hairs with the screw, having inferior hairs or using less than the standard number of hairs when the bow is rehaired. Playing with such a bow will give the impression of flexibility, but it is not because of the bow.
  14. Vacuum also lowers the boiling point of water, so it is possible to get wood down to almost 0% MC with a vacuum chamber at room temperature. One of the challenges with thermal aging many materials is getting a high enough temperature to get results in a reasonable amount of time, versus having the material decompose through high temperature processes that would not normally activate at room temperatures. For wood, once one approaches 140C, all sorts of nasty processes begin to kick in that would normally not activate at room temperature. And this is for wood being heated in a chamber filled with non-reactive gas, like nitrogen. This is referred to in the literature as pyrolysis testing. In the presence of oxygen, all bets are off that thermal aging at elevated temperatures will simulate natural aging at room temperature.
  15. There are two broad changes that wood undergoes as it is "aged". 1. It reaches a stable moisture content with the ambient air. Freshly cut woods tend to have a significant amount of "free water". The weight of the water can exceed the weight of the wood fibers for many species of wood. But if you cut new wood to just a little bigger than the size you want to work with, typically +15% larger in all dimensions to account for shrinkage, and let it air dry in a space with about the same temperature and relative humidity as your house, it will reach a stable moisture content in about 1 year per 1 inch of thickness. Basically, for wood rough dimensioned to sizes you would need to make a violin, there is no difference in stable moisture content between 1 year old wood and "old" wood. 2. It reaches desired physical properties. Properties that are frequently discussed on this forum, like density, elastic modulus and sound speed, will mostly stabilize after the wood reaches a stable moisture content. After that, changes in these properties tend to be relatively small over many years. This suggests that new wood, rough dimensioned for violins, and dried for a year at room conditions, will achieve the same basic physical properties as "old" wood. However, there is a research to indicate that sound damping will decrease significantly up to 100 years after it is cut. Some makers have taken to thermally aging their wood to accelerate this reduction of sound damping. Kiln drying wood is a tricky thing because there are other affects associated with exposing wood to higher than room temperatures, such as destructive oxidation of the cell walls.
  16. The structural features that make a bridge efficiently and securely transfer string energy to the violin can be achieved by a variety of bridge shapes. I have no idea if the pictured bridge is one of those shapes, but I would reject it based solely on its appearance.
  17. I enjoyed viewing the restoration photos. Spectacular repair of the top plate that was cleaved its entire length.
  18. The balance point of the top plate and its center of mass are slightly different concepts. As Bruce pointed out, it is possible to balance the plate on the point of a pencil. This is the balance point. The center of mass would have the same position in some flat plane, say, defined by the plate edges, but would be located some distance below the point of the pencil on which the plate was balanced. How far down along the pencil would be a function of the arching as well as how the plate was thinned. One can use Newton's Laws of Motion and some non-trivial mathematics to compute the location of the center of mass, but that is beyond the scope of this forum. Physically, an object that is pushed at its center of mass will travel without any rotation. If it is pushed at a point away from its center of mass, it will move as if was pushed at its center of mass, but with a rotation about the point. This is a useful concept for figuring out the interactions of many moving machine parts, movements of planets about each other and the sun, and just about anything that can be treated as basically an array of rigid bodies. Most of the movement of a violin plate, once it is attached to the body, is due to bending deformation. Rigid body motion probably contributes very little to violin response. For vibrational modes, there are concepts called modal participation factors and effective mass which basically measure how much of the plate participates in a vibrational mode. This participation is one of the reasons that design just by matching vibrational modes can be misleading, especially free plate tuning without a bass bar and sound post. One can work hard to match a vibrational mode frequency, but do so in such a way that only a small amount of the plate participates in the vibration. So the mode would contribute little to the violin tone and power.
  19. If by French Polish you mean shellac dissolved in some kind of alcohol, there are two fundamental properties you should consider before using it. 1. This stuff will stick to and seal in just about anything. As has been already mentioned, dirt and discoloration will become a "permanent" part of the finish after French Polishing, even if applied as a very thin layer. Make sure the surface is clean of dirt and rosin build up and has the color tone you want before applying shellac as a varnish or a polish. 2. Shellac is highly leveling. The means using a polish technique can rapidly smooth out texture, from microscopic roughness that is making a worn surface appear dull, to pronounced corrugation due to deliberately raised grain meant to give the wood surface a more natural finish. This leveling characteristic is why shines can be achieved that approach a mirror finish. That said, shellac that still has some wax content can be used in a very dilute form, and a barely damp polishing rag, to create a soft sheen yet uniformly smooth surface that can preserve most grain texture and not change the color of the underlying varnish. The effect is similar to a fine wax polish. It has the added advantages of being wear and water resistant, and dirt and rosin can be easily removed with a soft cloth. It is also trivial to repolish areas that are subject to high wear, like the treble side upper bout plate and ribs. Unwaxed shellac, again used sparingly, gives a highly polished sheen while preserving larger grain texture and the color of the underlying varnish. Over-polish, or use a strong shellac solution, and you can quickly turn a violin into a mirror.
  20. Something transcendent and entrancing about ancient music. I suspect accidental or deliberate consumption of ergot (St. Anthony's Fire) and Psilocybe mushrooms (Flesh of the Gods) contributed heavily to musical inspiration, like rock music I listened to in the 60's and 70's. I am happy to report that after 50 years, the spontaneous voices and visions have stopped, but I can still enjoy this music. Thanks for the post.
  21. I experimented with water-based poly-acrylics and they gave crystal clear finishes. Every detail of fine and complex grain came through. But as you noted, they are difficult to get smooth. The basic problem is the short drying time (about 2 hrs) which means a short working time and lack of ability to "level" as they dry. I could not develop any type of French Polish technique to get it flat. There were always witness lines in the final direction of the rub (or brush). Also, poly-acrylics require some light sanding to the initial surface since they stick primarily through mechanical bonding. This can be a no-no if dealing with a fine colored varnish finish that you want to polish up with the poly-acrylic. I did achieve some degree of success by putting on a few coats, then carefully and progressively sanding from 600 grit to 3000 grit, and finishing with a good quality auto-paint polish. Because poly-acrylics go on so thinly, one must be careful not to sand through the layer to the underlying wood or colored varnish. Also, it is extremely important to remove every last spec of sanding dust before applying another coat or else it dries with tiny holes that look like areas of missing varnish. Unless there is some special need for wear or chemical resistance, I found it a lot simpler to polish up an oil finish with a dilute solution of clear shellac rather than deal with all that sanding and careful cleaning. Shellac is remarkably durable and can be easily refreshed. Another option I explored that might be of interest to the OP is modern oil-based spar varnishes. They have a long work time and dry flat without any brush witness lines. They have excellent leveling characteristics, dry overnight and once thoroughly dry can be easily sanded or polished to get various degrees of gloss. Most also add UV aging protection. A down side is that they create quite a thick layer with each coat. I had some limited success with various diluting liquids, like mineral spirits. Perhaps a thickish layer is not an issue with the back of a guitar or lute? Also, they do add quite a bit of transparent amber color to the finish.
  22. Thank you for posting details of your methods. Interesting to see you leaving a section of the neck flat a bit wider so you can use studs to align the fingerboard, and then trimming the flat width to match the width of the board. I've experimented with various approaches to aligning the fingerboard but I have not settled on a method. Each has advantages and disadvantages. I got the impression you will remove the board then reattach it later. How do you realign it after the neck width has been trimmed.
  23. The laws of physics say otherwise. When the neck bends up, it applies a shear and bending load to the violin box at the neck root. The violin box must deform to develop counter shear and bending loads or else the neck will continue to bend upwards until it snaps off.