How to know...when to clean bow hair?

February 12, 2020, 1:50 PM · Most high-level professional simply have their bows rehaired on a regular schedule. One might be able to spend around an hour cleaning the hair, and get the hair to last longer that way, but at what cost and risk, if they can earn around $100 an hour from teaching?

Edited: February 12, 2020, 2:00 PM · What David said. I'd just get the bow rehaired. 15-month-old hair on a bow that is used as much as you report is hair that should have been replaced at least three months ago.

February 12, 2020, 2:04 PM · Oh my, hadn't considered that but it makes sense. It will be my backup bow, I find the feel and balance of my JonPaul Corona much better, but I want this bow to sound good as well. Rehairs doesn't cost my anything with the service agreement I have on my violin and that bow...

February 12, 2020, 3:03 PM · If rehairs don't cost anything extra, I'd get my bow rehaired twice a year!

Edited: February 12, 2020, 4:45 PM · Rosin twice a week? Brushing with a toothbrush?...
What the heck?

As someone who practises upwards of three and a half hours every day, seven days a week, I have to apply rosin to my bow every hour. When my hair starts giving me less grip (usually after 3-5 months), I just change it myself. I don't imagine you would get very much extra time from cleaning it, but maybe you could squeeze out another two weeks from bad hair with this method.
But then... why go through the trouble?

February 12, 2020, 5:46 PM · Cotton - I only play one hour a day, and probably not near in the same way that you do :-) I was taught to be be conservative with rosin. About the time that Mary Ellen estimates my bow needed a rehair I read someone here post in another thread that brushing it with a toothbrush from time to time assured the hairs stayed separated. It actually really helped the sound, for an hour or so, but then the problem returned. Certainly an indication that I needed to have the rehair I am sure.

As I am playing more, and more aggressively than I once did, I will be revisiting my rosin practices with the new bow, and after rehairing my original bow.

February 12, 2020, 6:27 PM · I wrote an article a while back explaining some things to look out for to determine if you need a rehair. It can be found here:

https://adbowsllc.com/2018/04/11/how-often-to-rehair-a-bow/

From the symptoms you mentioned, I'm fairly certain you need a rehair, but you may still find the info helpful.

February 12, 2020, 9:02 PM · I use rosin very sparingly, maybe every other day or so.

Edited: February 12, 2020, 11:31 PM · Victor wrote, "Bow hair under a microscope looks like barb wire. When we play these barbs are removed and that is why we get a slippery effect on old bow hair."

Is that actually true? Are there electron micrographs of worn out bow hair vs. the same hair when it was new? I will try to research this a little. Until then, here's an interesting read: http://www.scavm.com/norman.htm

I endorse Andy Victor's alcohol "prep pad" cleaning method without reservation. One thing about it is that it's super cheap and easy, and it WILL extend the life of your bow hair. What's not to like about that?

Invariably in these threads folks will say how little rosin they use. Most of the folks who say they use very little rosin are pros or highly skilled amateurs -- people who worked on tone generation with expert guidance over a period of many years. Not students and returners and intermediate amateurs. One time at my violin lesson I told my teacher that I was trying to use less rosin. He gave me a look like "you've GOT to be kidding" and said, without hesitation, "Paul, rosin your bow."

I can't imagine how the amount of rosin you use would effect the lifetime of your bow hair.

Edited: February 13, 2020, 12:41 PM · I won't wait so long for a rehair next time...and will be using more rosin.

Paul, I took a brief look at your link and am looking forward to spending more time with it later, thanks!

February 13, 2020, 2:41 PM · Search in the page for the word "wear" and read around that part.

Edited: February 13, 2020, 3:30 PM · Hair under magnification doesn't look like barbed wire, nor does it have scales. A rather simple question one might ask oneself is, assuming the hair has some mythical roughness, why, after a re-hair, doesn't the hair grip the strings at all until it's rosined? What are those supposed scales doing then? They're not doing anything because they're not actually there.

And I already know that I'm an outlier in holding to my opinion that if the hair is intact, not excessively worn or stretched, and not contaminated by a bad habit of handling it with your oily hands (I've seen many players who do this as an unconscious habit, completely unaware that they do it, and who will deny that they do it when asked.), or being subjected to cigarette smoke filled environments (Remember those?), then it probably doesn't need to be replaced. I once took several bows that hadn't been re-haired for many years in for a re-hair because I believed the opinions of others about the value of doing it, and when I got the bows back I couldn't tell any difference, before and after. What's more, its mechanically hard on a bow to be disassembled incessantly, so my opinion is don't do it unless it's really needed, and it rarely is.

February 13, 2020, 3:01 PM · +1 Mark

February 13, 2020, 3:28 PM · It's almost like a meditation to practice regularly and be aware of the variations of a practice session day-to-day. Was I feeling tired? Does my bow need a rehair? Maybe my strings are bad? Is the humidity different? And so on...

It's tempting to fixate on your equipment - Why do you think some people have 10 different types of rosin? The fact is that violin is difficult; the more you practice, the better your ear gets, and therefore you start hearing issues in your playing that you didn't detect before; and the way you hear yourself can be kind of inconsistent day-to-day or even week-to-week. Sometimes you have a bit of a slump, and if you just kind of practice through it, it goes away, and you don't worry about it and take it in stride.

It's not a big hit to rehair your bow (cleaning the hair?), but I probably rosin about as much as you do, practice a few hours a day, and my bow doesn't strictly need a rehair every year or 1.5 years that I do it. Don't fixate on your equipment - A lot of that is magical thinking. Keep practicing.

Edited: February 13, 2020, 8:11 PM · Actually the question, and title, was "clean", my reaction to comments and thinking about everything caused me to change my focus. Hopefully that was at least as clear as mud...

February 13, 2020, 9:39 PM · I use rosin sparingly. But I’m using Baker’s so I have to be fairly judicious as there’s a waiting list to purchase more.

I’ve run into hair issues during the summer, say a humid day in late June. It’s a good idea to get a re-hair periodically as it gives an opportunity for the bow specialist to look over the stick and frog in general.

I make it point to never touch the bow hair as oils from the hands could contaminate the bow hair (I make it a point to wash my hands before playing regardless). Also, I don’t use very much tension when tightening the hair. I don’t know if that helps prolong the use of the hair but I suppose it doesn’t hurt.

February 14, 2020, 6:30 AM · "I’m using Baker’s so I have to be fairly judicious as there’s a waiting list to purchase more."

Why don't you just get back on the waiting list the moment your new cake comes in the mail?

You can have a bow specialist give your bow a checkup without having it rehaired. It's less expensive.

February 14, 2020, 7:16 AM · The rosin adhesion to the hair is more like a chemical bond. Over time that quality of that bond breaks down, with or without use. Hair does have tiny scales under magnification, I've seen it for myself. You can successfully clean your hair when it gets dirty which will prolong the function by removing dirty rosin and oils. Unfortunately, the process of cleaning tends to effect the evenness of tension across the band of hair. This is why it is advised for most professional musicians to just rehair the bow rather than clean it. They are good enough to tell the difference and need their tool running in tip top condition. Taking a bow apart repeatedly for rehair is not an issue to the bow, it is specifically designed to be successfully taken apart and put back together. In the hands of a qualified technician, there is no risk to getting your bow rehaired. The key word here is qualified. Here are some photos of things that were only caused by someone working on a bow: https://adbowsllc.com/2018/04/01/the-importance-of-finding-a-quality-bow-technician/
When a bow is brought in for rehair, all parts get cleaned, lubricated, and/or protected, actually extending the function, life, and condition of the bow.
As Paul mentioned, a bow specialist will be happy to look over your bow without having to rehair it, a wellness check up never hurts.

Edited: February 14, 2020, 9:03 AM · As with any violin topic, I read a lot of myth in this thread regarding how hair and rosin work together, however there is one thing to be aware of that has not been mentioned in favor of regular rehairs and that is that as a bow loses hair its behavior changes.

Usually hair loss is on the "playing" side--away from the player--and this will cause the bow to curve when tightened, changing the way it works.

The other thing that happens with hair loss is that the perception of the strength of the bow changes. As hair is lost, each hair bears more of the tension and the player's perception is that the bow becomes stiffer. This is a good reason not to feel cheated when you don't get a big wad of hair in a rehair, too---too much hair and a bow becomes flaccid and weak. Every bow/player combination has an ideal amount of hair, and a good rehairer will consider this. Ten perecent hair loss can change playing qualities--in a bow, that's only about 15 hairs!

February 14, 2020, 9:45 AM · According to this article:

https://www.wqxr.org/story/what-does-rosin-actually-do-violin-bows/

a hair does have scales but they too small to be able to "pluck" the string; the plucking is done by rosin particles. However, the scales are important for keeping these rosin particles seated along the hair. So, it is not inconceivable that when hair wears out, scales are damaged, and rosin particles do not remain fixed to the hair (which is what a violinist notices with worn hair: the rosin doesn't stick to it anymore).

February 14, 2020, 10:04 AM · "Hair under magnification doesn't look like barbed wire, nor does it have scales."
_______________

The hair does have scales, but these are insufficient to produce sound without rosin.

February 14, 2020, 10:15 AM · Look at the magnification of the images. The pictures you're looking at are probably electron micrographs. The surface structures that you're seeing therein are exceedingly small. The conventional slip-stick physical mechanism for how the bow "grabs" the string does not depend on features at this scale. The area of contact with the string is enormous by comparison. The notion that the string somehow gets underneath these "scales" and cleaves them off really isn't reasonable. These surface features are likely a consequence of the molecular chemistry of the hair and the manner in which it grows from the hair follicle. Jean is still correct that it's "not inconceivable" that such structures could be damaged while bowing, but I've never seen any corroborating evidence of that. I've also heard that the reason horsehair seems to work so well is because of its excellent functional relationship with rosin -- it just seems to hold the right amount of rosin very well. I don't know whether the sub-microscopic scale features are responsible for that, or whether it's due to features closer to the molecular scale (maybe another factor of 100 or so compared to the features you're seeing in those images).

Edited: February 14, 2020, 4:23 PM · I would like to recommend the 1997 book "The Violin Explained" by the late Sir James Beament,FRS for these and so many other questions that come up here. I was lucky to purchase a hard copy when the book was first published (its retail price has since risen like the DOW). It is a non-technical book by a scientist/musician (also husband of a violin maker) that provides a wonderful introduction to almost everything you would want to know about string instruments and their accessories.

In the first days of the 21st century I started making measurements of my bows and come to the same conclusions MICHAEL DARNTON has stated above. Actually, it all started after my CODA Classic violin bow had its first rehair. I noticed it was much more sparsely haired than it had been coming from the factory a few years earlier. When I questioned the technician about this he replied that this was how it should be. It turns out he was correct, the bow played better than ever before.

I proceeded to make stiffness measurements and calculations on 29 bows to which I had access (15-violin, 6-viola and 8-cello). Before I was through I had also measured the Young's modulus of several individual bow hairs and come to a conclusion as to how much strain of the hairs seem to provide the best bow performance -- and from that a correlation between the number of hairs that corresponded to the stiffness (or flexibility) of any given bow stick. The Young's modulus value I arrived at from my measurements agreed within 3% with the value published by Anders Askenfelt (I later found), a scientist who had been studying such things for decades. I then took the semi-risky step of reducing the number of hairs in most of those 29 bows (only all the ones I owned) to agree with the equation for optimum hair tension at which I had arrived. Indeed it seemed to work!
(EUREKA - and all that!)

I was prepared to measure a great many more bows (after my son had built me a portable rig for the bow stiffness measurements) and I had Jay Ifshin's approval to make measurements on bows in his shop, when the morning of 9/11/2001 happened and I decided to spend the rest of my life trying to make music instead of measurements.

The EXCEL spreadsheet containing my measured data and calculations was available on line for the next decade or more (until I closed my website and gave my URL to the victortechnology calculator people).

Edited: February 15, 2020, 2:58 PM · Lo and behold, my CodaBow Protegee was replaced with a new Prodigy. Apparently the agreement reached between the store and CodaBow requires bows from that special run for that bow to be returned to CodaBow for rehairs and other work. My store just replaced it with a standard Prodigy and my old one will be refurbished for someone else. Very interesting. The special Protegee just differs in looks and name, it's the same bow.

I still prefer my trial JonPaul Corona, it has a rather different balance point. It won't be a "trial" bow for much longer...