integral bass bar

[JacksonMaberry]

A bar fits or it doesn't - spring or no. Davide is right, fitting a sprung bar well is more challenging. That is not a value judgement. 

A new bar is not a defensible method of correcting deformation.

A bar is almost never too short or too long, if it is made thoughtfully and intentionally by the maker to achieve a desired effect. Much idiocy is done in the name of standardizing everything in the trade, eg "all bars must be x mm long, y mm wide, etc".

It is impossible to tell if a bar was fit with or without spring unless you have removed it. 

You cannot generalize about the tonal or performance differences between an unsprung or sprung bar. You can somewhat on a bar that actually fits vs one that does not - remember this is a binary condition, either it fits flawlessly or it does not fit. 

[kyproset]

12 minutes ago, JacksonMaberry said:

A bar fits or it doesn't - spring or no. Davide is right, fitting a sprung bar well is more challenging. That is not a value judgement. 

A new bar is not a defensible method of correcting deformation.

A bar is almost never too short or too long, if it is made thoughtfully and intentionally by the maker to achieve a desired effect. Much idiocy is done in the name of standardizing everything in the trade, eg "all bars must be x mm long, y mm wide, etc".

It is impossible to tell if a bar was fit with or without spring unless you have removed it. 

You cannot generalize about the tonal or performance differences between an unsprung or sprung bar. You can somewhat on a bar that actually fits vs one that does not - remember this is a binary condition, either it fits flawlessly or it does not fit. 

In my case, the fixing of the 1mm deformation of the top is collateral benefit of the sprung bar. I know both bars (unsprung and the one with spring, were both expertly fitted by reputable luthiers and they didn't come cheap). As a professional player, I can only assess the difference in the tone and response of the instrument before and after. 

[JacksonMaberry]

4 minutes ago, kyproset said:

In my case, the fixing of the 1mm deformation of the top is collateral benefit of the sprung bar. I know both bars (unsprung and the one with spring, were both expertly fitted by reputable luthiers and they didn't come cheap). As a professional player, I can only assess the difference in the tone and response of the instrument before and after. 

Of course, which is fair - you have experience with a single instrument that you know very well before and after. But to generalize based on this anecdote would be an error.

[David Burgess]

9 hours ago, kyproset said:

In my case, the fixing of the 1mm deformation of the top is collateral benefit of the sprung bar.

With a bit of time, what this will often do is simply transfer the deformation to a less visually conspicuous place.

[kyproset]

5 hours ago, David Burgess said:

With a bit of time, what this will often do is simply transfer the deformation to a less visually conspicuous place.

Isn't some (or all) of the BB spring (depending how much spring), expended in raising the plate to it's original arching?

[Jeffrey Holmes]

1 hour ago, kyproset said:

Isn't some (or all) of the BB spring (depending how much spring), expended in raising the plate to it's original arching?

Improperly executed (too much or in the wrong place), or performed on a top without enough support in the upper and lower bouts, a sprung bar may pull down the arching toward the ends... and the "original" deformation may return in some form despite the effort. During a restoration of an old instrument when a cast is required, I'll often fit the bar with the top in the cast (after any corrections that are required have been made; no spring).

[Davide Sora]

1 hour ago, Jeffrey Holmes said:

Improperly executed (too much or in the wrong place), or performed on a top without enough support in the upper and lower bouts, a sprung bar may pull down the arching toward the ends... and the "original" deformation may return in some form despite the effort. During a restoration of an old instrument when a cast is required, I'll often fit the bar with the top in the cast (after any corrections that are required have been made; no spring).

I agree. I want to clarify that when I speak of bass bars with spring I am referring only to new violins adequately conceived and with an adequate construction method that takes it into account. Antique violins are too delicate and need to be treated appropriately by people who know what they are doing.

Basically I am referring only to my violins, I am not a restorer and I would never recommend a bassbar with spring for precious antique violins.

[JacksonMaberry]

8 minutes ago, Davide Sora said:

I agree. I want to clarify that when I speak of bass bars with spring I am referring only to new violins adequately conceived and with an adequate construction method that takes it into account. Antique violins are too delicate and need to be treated appropriately by people who know what they are doing.

Basically I am referring only to my violins, I am not a restorer and I would never recommend a bassbar with spring for precious antique violins.

Agree. 

Jeff, I love the cast idea. I've pondered making some kind of quick cast, maybe even with instamorph, for just the area beneath the bar, for fitting bars on my new axes. Been thinking a lot in general about new, light but rigid bar clamping setups.

[jacobsaunders]

29 minutes ago, JacksonMaberry said:

Agree. 

Jeff, I love the cast idea. I've pondered making some kind of quick cast, maybe even with instamorph, for just the area beneath the bar, for fitting bars on my new axes. Been thinking a lot in general about new, light but rigid bar clamping setups.

Just think, you could save all that p+++ing around if you just did an "integeral" bar

[Don Noon]

34 minutes ago, JacksonMaberry said:

Been thinking a lot in general about new, light but rigid bar clamping setups.

This might give you some ideas.  My bar gluing setup... support screws can be adjusted for whatever arching and/or "spring" you want.  Scary dangerous weighted sticks can give you some idea of how much clamping force is applied.

Except for this photo, I always finish-shape the bars first.  Otherwise it doesn't work for springing.

[JacksonMaberry]

23 minutes ago, Don Noon said:

This might give you some ideas.  My bar gluing setup... support screws can be adjusted for whatever arching and/or "spring" you want.  Scary dangerous weighted sticks can give you some idea of how much clamping force is applied.

Except for this photo, I always finish-shape the bars first.  Otherwise it doesn't work for springing.

Haha, great stuff. Thanks! Actually rather similar to what I was seeing in my head!

[JacksonMaberry]

32 minutes ago, jacobsaunders said:

Just think, you could save all that p+++ing around if you just did an "integeral" bar

Indeed!

[Jeffrey Holmes]

I've put this photo up in the distant past... In the cast, I've been very happy with these acceptably lightweight Herdim clamps, so I never looked further... I guess you get used to what you've used.  

 

[JacksonMaberry]

16 minutes ago, Jeffrey Holmes said:

I've put this photo up in the distant past... In the cast, I've been very happy with these acceptably lightweight Herdim clamps, so I never looked further... I guess you get used to what you've used.  

 

Works great since they're light and have a flat, rather than arched surface to engage at the bottom of the cast. Mine are identical in form, by made of cast iron. Too heavy!

[Jeffrey Holmes]

17 minutes ago, JacksonMaberry said:

Works great since they're light and have a flat, rather than arched surface to engage at the bottom of the cast. Mine are identical in form, by made of cast iron. Too heavy!

Yes... Great clamps, but I don't think Herdim makes them any longer... at least I haven't been able to find them... They make similar forged steel clamps (I have some... useful but I don't love them) and a light clamp with a lace body, but these aluminum ones must have fallen out of their catalog.

[jacobsaunders]

One can always “go to town” restoring violins, although considered soberly, one might ask oneself if the exercise was worth it at the end of the day. I have used this method, when re-fitting an original bar back in over repair cleats, where bass bar cracks were to be repaired, but the customer insisted on retention of the original bass bar. For a straight forward bass bar replacement, it does rather leave me thinking of the old joke about “how many violin makers does it take to replace a light bulb?”

[Mark Norfleet]

I cannot think of a situation where I wouldn't use a cast to fit and glue a bass bar if I already had one for the instrument.  I find fitting the bar to be significantly faster and the chance of induced distortion is dramatically reduced when using a cast.  I also use them when fitting, and clamping/gluing cleats.

[JacksonMaberry]

11 minutes ago, Mark Norfleet said:

I cannot think of a situation where I wouldn't use a cast to fit and glue a bass bar if I already had one for the instrument.  I find fitting the bar to be significantly faster and the chance of induced distortion is dramatically reduced when using a cast.  I also use them when fitting, and clamping/gluing cleats.

Makes a great deal of sense to me, Mark. One doesn't often make a full cast in the course of new making, unless you do prophylactic post patches I suppose. But perhaps I should.

[Jeffrey Holmes]

3 minutes ago, JacksonMaberry said:

Makes a great deal of sense to me, Mark. One doesn't often make a full cast in the course of new making, unless you do prophylactic post patches I suppose. But perhaps I should.

Using rigid insulation board, I find full casts very easy and relatively quick to make... and in terms of restoration they almost always seem to come in handy even if the "reason" to make one wasn't evident at  the get-go. I believe Jean Jacques Fasnacht makes a top cast as a matter of standard procedure.

[JacksonMaberry]

2 minutes ago, Jeffrey Holmes said:

Using rigid insulation board, I find full casts very easy and relatively quick to make... and in terms of restoration they almost always seem to come in handy even if the "reason" to make one wasn't evident at  the get-go. I believe Jean Jacques Fasnacht makes a top cast as a matter of standard procedure.

Extremely interesting, thanks for sharing this. I've got the hydrocal and the insulation, so why not?

[Jeffrey Holmes]

28 minutes ago, JacksonMaberry said:

Extremely interesting, thanks for sharing this. I've got the hydrocal and the insulation, so why not?

For what it's worth, I switched over to Tecstone (buff) a number of years ago when we used it at Oberlin. Stronger, seems like less shrinkage and easier to work with for me than Hydrocal (which I used for years before).

[JacksonMaberry]

12 minutes ago, Jeffrey Holmes said:

For what it's worth, I switched over to Tecstone (buff) a number of years ago when we used it at Oberlin. Stronger, seems like less shrinkage and easier to work with for me than Hydrocal (which I used for years before).

I appreciate the tip!

[Mark Norfleet]

2 hours ago, Jeffrey Holmes said:

Using rigid insulation board, I find full casts very easy and relatively quick to make...

I have varnished two part stacked plywood dams that I've been using for decades.  They aren't fool proof, but they save me a LOT of time over what I used to do.

[FiddleDoug]

Ever take a piece of wood and dampen it, and then put a little bend on it? Some of that bend will stay. It has always been my opinion (no hard data as proof) that when you do a sprung bar, and then put hot (and wet) glue on it, and clamp it in place, it will loose a lot, if not all of the spring, and conform to the top. I don’t spring bars.

[JacksonMaberry]

17 minutes ago, FiddleDoug said:

Ever take a piece of wood and dampen it, and then put a little bend on it? Some of that bend will stay. It has always been my opinion (no hard data as proof) that when you do a sprung bar, and then put hot (and wet) glue on it, and clamp it in place, it will loose a lot, if not all of the spring, and conform to the top. I don’t spring bars.

You know, I had the same thought at one point. I soaked out a sprung bar I had just put in, and checked it when it and the plate had dried. 

Spring was still there.