MIMF

Over the centuries the thickness of violin ribs has standardized to roughly 1.2mm. I've always assumed that this is because such thickness was determined to have both the strength needed and the least effect on compromising sound viabration.

But why? What detrimental effect do ribs that are a little thinner/thicker have overall? And what limits on thin/thick are acceptable? I've seen some violin ribs (not many it's true) that were maybe .9mm and some viola ribs that were nearly 2mm, and both of these instruments sounded fine to me.

Any opinions?

I think you'll find a lot of it has to do with the bendability of highly figured maple. For the small radii you're after, particularly in the c-bout, is not easily bendable in thicker stock.... very tough approaching .080", although a viola is a bigger instrument. I typically have to thin to .065ish for my guitar horn/cutaway, & it's nowhere near a c-bout in tightness.

Maple bends nicely at 2 and even 3mm, so that;s not the issue.

What we(luthiers) strive for all the time is a minimal. We seek to reach the minimal thickness that any given piece needs in order to be strong and stable enough to hold up, yet thin/light enough to be resonant, and/or not to add unnecessary weight.

In other words, you can definitely make your ribs 3mm thick, and the violin will sound just fine, but it will be heavier than necessary. Same as you can make your ribs 0.5mm, but then your violin will be too delicate and prone to problems.

Some of it has to do with ease of bending, alot of highly flamed european maple suddenly becomes alot easier to bend once you get below 1.5mm thickness, in some of the Guarneri del gesu violins the rib thickness goes under 0.5mm in the tightest curves of the c-bouts where the ribs are glued to the cornerblocks, here you can go quite thin without making the violin to weak, and it probably made the bending alot easier.

Ribs thicker than 1.5mm are more difficult to bend, and are not realy needed because the ribs of a violin are narrow and supported by very tall linings in proportion to the heigth of the ribs, so the rib structure of a violin is quite strong in proportion to the rib thickness.
Ribs thinner than 1mm would most likely be to weak and prone to cracks.

I am not sure how thicker ribs would change the sound, but the classical violin is a very standarised instrument, and while thicker ribs would probably work it would move the sound farther away from what classical violinists expect.

E H Roth violins from the 1920s are known for thick ribs. They are also known for how much better they sound when the ribs are thinned to a more standard thickness.The ribs actually radiate a lot of sound.

On trade violins, I wouldn't think that they'd make all that much difference, but on better instruments, "everything affects everything".

Thanks for all the responses guys. Sounds like a little experimenting is in order (though I'm sure it's been done a thousand times).

Michael, your info about the Roth's addresses my original question about the effect of rib thickness on sound. Were the Roth ribs thinned down with the violin intact? And if so, do you know the method used?

Øyvind Taraldsen wrote:Some of it has to do with ease of bending, alot of highly flamed european maple suddenly becomes alot easier to bend once you get below 1.5mm thickness, in some of the Guarneri del gesu violins the rib thickness goes under 0.5mm in the tightest curves of the c-bouts where the ribs are glued to the cornerblocks, here you can go quite thin without making the violin to weak, and it probably made the bending alot easier.

Ribs thicker than 1.5mm are more difficult to bend, and are not realy needed because the ribs of a violin are narrow and supported by very tall linings in proportion to the heigth of the ribs, so the rib structure of a violin is quite strong in proportion to the rib thickness.
Ribs thinner than 1mm would most likely be to weak and prone to cracks.

I am not sure how thicker ribs would change the sound, but the classical violin is a very standarised instrument, and while thicker ribs would probably work it would move the sound farther away from what classical violinists expect.

With great respect, I would need to see that verified. Ribs less than half a millimeter in a violin would never be intentional......but a mistake. Consider that 0.5 mm is just 500 microns or the thickness of 5 human hairs.

Barry Guest wrote: With great respect, I would need to see that verified. Ribs less than half a millimeter in a violin would never be intentional......but a mistake. Consider that 0.5 mm is just 500 microns or the thickness of 5 human hairs.

The source of this information is Roger Hargrave's pdf book on his site http://www.roger-hargrave.de/PDF/Book/C ... ld_PRN.pdf

"As a rule, Del Gesù thicknessed his ribs fairly
evenly to about 1 mm. Exceptionally, as in the case of
Paganini’s “Cannon”, they average 1.5 mm. Occasion -
ally, as with the “Soil” of 1733, in the immediate corner
block gluing area they are reduced to as little as
0.3 mm. Thinning the rib ends in this way was only
viable because the block itself provided a stable backing.
This may have been done to make the curves of
the centre bouts easier to bend."

Again, this extremely thin thickness is only done where the ribs are glued to and supported by the cornerblocks.

I suspect that the ribs began at normal thickness and were bent at normal thickness, but became that thin -after- they were bent and glued to the blocks, by aggressive scraping, likely because of slight scorching of the rib during the bend. Been there. Done that.

These guys were masters of the craft, and bending even the most highly figured maple at 1.5mm is very, very easy, thereby it's very unlikely they would have resorted, and only at random times, to extremely thin ribs to assist the bend. F-5 style mandolins have ribs of about 2.25mm(.090") in thickness, and the bends are very similar in radius; the first time I bent violin ribs(at 1.5mm/.060") I laughed and smiled through the entire process, it was such a joy.



What this shows us is that we need to separate the working thickness from the final thickness when discussing such a subject.

I have to agree with Mario...I believe that 1.they certainly had the skill to bend the ribs and 2. this was done after gluing. Probably and effort to blend the curve for any number of reasons.
I have thinned ribs to .9mm with great results but as they get thinner you have to be very careful how much water you use or they will wrinkle vertically. Also they need to be strong enough to hold up to being clamped as you glue the plates.

I cannot say for sure whether the ribs where thinned before they where bent or bent at full thickness and then later scraped thinner, as this would only be speculation and i have no proof for either of them.
Roger Hargrave suggests that del gesu might not have had the best method, or tools for the rib bending process, as he found numerous cracks in the tighter curves on some del gesu violins, but again, this is pretty much speculation, and i do not state this as a fact.
I am not suggesting that del gesu was not a master violinmaker, he certainly was, but even the great masters where not flawless.


These thicknesses are also unique to a few del gesu violins as far as i am aware, no ribs as thin as this is found in Stradivari, or other makers violins from the same period as far as i know.
I am not suggesting that ribs this thin are nessecary, or beneficial, i am just saying that it is possible to go this thin in the cornerblock areas without any obvious ill effects, and therby trying to answer part of Doug's original question on what the limits of rib thickness are in some cases.

.....and is nobody game enough to suggest that vigorous scraping to get a curve right after assembly could be a mistake, or that in attempting to remove scorch marks in overzealous attention could result in an "oops" moment.

Somewhere I read that " Del Gesu" was a hack, compared to Stradivari and others when it came to construction of the instruments, but that he managed to make them sound great in spite of that.

Yeah Clay, I'm a hack, so why can't I get a mill for a violin? But seriously, from my reading you are correct.

Sorry I didn't get back to this for some time. Thanks for the responses guys. I wasn't thinking about a drastic thickness change. I usually go to 1.2mm as I always thought that was standard. I have some rib stock that comes in right at 1mm that I thought might be a tad to thin, but it sounds like it will be fine to use. Thanks again.

I was taught from the beginning to make ribs 1mm thick, so yours sound fine to me; unless you still have to smooth them a lot, in which case they will be thin by the time you have them ready to use.

Chet Bishop wrote:I was taught from the beginning to make ribs 1mm thick, so yours sound fine to me; unless you still have to smooth them a lot, in which case they will be thin by the time you have them ready to use.

Me, too. I make mine initially 1.1mm. No problem, as I cold bend the entire rib structure, as Craig taught.

Johnson-Courtnall states 1.2mm. Strobel says 1.0mm

Hi Guys,

I'm resurrecting this thread in case anyone is still subscribed to it. I'm new here and a hobbyist guitar maker who is researching before starting a violin build (will be my first). The last entry mentioned "cold bending" the ribs. Can anyone explain this process to me? Even as thin as 1 mm, I would expect highly figured wood to break if bending the corner areas of the ribs. Also would expect spring back. So I assume there's more to it. Off topic but I wonder if anyone can recommend a particular set of Strad 4/4 plans, plans for the inside mold, and where to buy them. I'm surprised how challenging it's been to find resources for violin family lutherie versus guitar making. Thanks for the help! Beth

Here's a thread on the subject in the Library. (Charlie --- the link to the original post by CT doesn't work).

http://www.mimf.com/library/Cold_bendin ... -2011.html

Basically, cold bending is gradually bending the wet wood, cold, around a form, then letting it dry. Once dry, it will come off the form and retain it's shape.

What I do is to swish the wood around in distilled water for about a minute, then sandwich it between two stainless steel straps. Clamp the middle, then slowly --- every maybe 5 or ten minutes, walk the clamp around, sometime spraying with water to keep it wet. Let dry for several days or a week. Remove from form. Drying could be quicker if put in the sun, or slightly heated.

Wow, thanks for that, John!