Violin Forum/Message Board

Michael Darnton · Posted: Tue Feb 12, 2013 3:46 pm Post subject:

I suspect it's there, but you're used to it when it falls in the normal range. I only find it irritating when the dip is too deep for my little plane to get into. Otherwise, it's not a trouble, and I don't see it.
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hillyer43 · Junior Member Joined: 27 Jan 2013 Posts: 11

Mr. Darnton......I just fitted a bar in a yard-sale fiddle that I'm repairing and I followed your suggestion to get the best fit I could visually first and only going to light chalking towards the end of the process. It really helped to do that, so thanks again for the advice. I got the bar very close to a final fit in about 2.5 hours, which is a record for me!

One (of very many) things I don't know....what is the effect on a violin's tone, volume and playability of a conventionally sized and placed bar that doesn't fit too well?

Michael Darnton · Posted: Wed Feb 13, 2013 8:27 am Post subject:

There's really probably no tonal effect. The problem is that the misfit will telegraph to the outside surface and be visible.
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actonern · Super Member Joined: 15 Aug 2007 Posts: 444

Michael, from your description of how you fit a bar it appears that you don't spring the bar... any opinions either way on that issue?

Best regards,

E

Michael Darnton · Posted: Wed Feb 13, 2013 9:10 am Post subject:

I was taught to spring it, and used to. Now I consider the violin and the player, and spring it or not, depending. Weaker top + stronger player = more spring.
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pmccombs · Member Joined: 15 Jan 2013 Posts: 87 Location: Utah

Michael Darnton · Posted: Wed Feb 13, 2013 5:41 pm Post subject:

Springing is making a bar that fits the top somewhat like a rocking chair, with the ends lifted so that it rocks from end to end. When the bar, and the ends, are glued down, the center is stressed to be pressing upwards against the downward pressure of the bridge foot. If it's not done properly, the ends will also be pulling the top down, and that will be seen as depressions and warpage of the top in the neighborhood of the ends of the bar. There are ways to do it so that this doesn't happen.

The amount of spring is never more than about 2mm at the ends, usually less.

There's some dispute regarding whether this does anything, whether the effect remains after the top is glued on, whether the stress built in is lost over time as the pieces warp permanently to their new positions, whether any of this matters, etc. People who spring the bar are usually more philosophical about it, where the non-springing group often tends to sound more like a religious cult preaching against the devil. :-) There's a school of thought that a violin (which in use is under about 75 pounds of tension from end to end, and 27 pounds downward at the bridge) should be made completely without stresses built into it.

The earliest mention of the practice was in an Italian book on making violins Cremona style that was published in 1786 by Antonio Bagatella, if I am remembering correctly. . .

I'm mostly agnostic about it. There appear to be some times where spring would be useful, others where it wouldn't. Proving anything in any way that would be regarded as legitimately scientific is nearly impossible, which leaves lots of space for cult interpretations and practices to develop. :-)

I've only seen one Bagatella violin, which was quite wonderful and could have passed for a Peter Guarneri of Mantua, so one might gather that the man wasn't an idiot on the topic of Cremonese practice.
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kjb · Super Member Joined: 06 Feb 2013 Posts: 385

I believe the chalk that they use for art, white , I can't remember the company I bought it from. though.

Michael Darnton · Posted: Thu Feb 14, 2013 12:08 am Post subject:

This is the stuff I use, white:
http://www.eternityarts.com/gospel-chalk-art/chalk-drawing-supplies/basic-drawing-chalk/

It's not incredibly visible, but it doens't have anything in it to damage the glue joint.
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hillyer43 · Junior Member Joined: 27 Jan 2013 Posts: 11

pmmcombs....I have had the same problem as you in that I find it difficult to see the chalk on the bar, but the trick seems to be to try all sorts of viewpoints when looking at the bar....I hold it sort of in the shadow of the bench and twist it around and suddenly, with a certain angle of illumination, the chalk becomes very visible. It's then easy to pencil around the chalky high spots and remove those as carefully as possible before refitting and testing. It still takes me a long time though....having fitted only a dozen or so bassbars and mandolin tonebars, I'm still a beginner.....

kjb · Super Member Joined: 06 Feb 2013 Posts: 385

I have not tried this but i wonder if a light with more ultra violet ( not enough to hurt your eyes) would show up the chalk better, white usually does.

Michael Darnton · Posted: Thu Feb 14, 2013 9:12 am Post subject:

I put a flex-arm desk lamp right next to my head. The chalk shows up better lit that way. Even better is to hold the bar so I'm looking down into the dark space under my bench--the bare wood reflects the darkness, the chalk reflects the light.
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