The one thing that will for a fact happen as you continue to enjoy the sounds of your cello is bowhair breaking and stretching, subsequently needing a good and inevitable bow rehair; which amazingly, even you can personally do given a good DIY cello bow rehair guide.
This is because, hair will naturally wear out and further, because of its brittle nature. Wouldn’t it be nice if the hair just grew back? But hey, to hear the sounds, you have to keep rehairng when inevitable.
The brittleness makes it break and wear out; as a result, the grip on the string is lost. A rehair job may not only be replacing the hair, but could also include cleaning and/or polishing of bow, as well as some other minor fixing to the bow if any.
The frequency of a bow rehair is mostly influenced but not limited to the following factors; it could be any of them singularly or all of them together:
- The frequency of play,
- Environmental factors, say humid conditions,
- And obviously, the bow hair quality.
These factors working together or even singularly will eventually result to indicative signs such as below that it’s time for a bow rehair ;
- Broken hair mainly at the middle of the bow,
- Uneven tension on the stick whose correction is by the risky stick requiring a straightening,
- Signs of dirt and gloss accumulation on the hairs,
- When it starts to need more rosin than usual to feel as good,
- When the hair has overly stretched or has uneven stretching such that no tightening can improve it,
- Also, In case of a rehair job which doesn’t eventually result to the results expected, you may consider a repeat rehairing to correct that.
This could also apply when, after using it and suddenly sense it’s not performing as expected. Then it may be time for a bow rehair. However, this is rather subjective and not necessarily objectively inspired.
It is therefore important to be on the lookout on all or any of the possible triggers and resultant signs to ensure a timely rehairing. In anycase, a rehaired bow will definitely have a longer life as well as optimum level of playability.
The hair that is highly preferred and proven, with regards to giving your bow that reliable hank and grab of hair due to its range of thickness and strength varieties is the horsehair.
You want just the right grip and attack playing your cello? Then get the blend of black and white hair.
The grab is softened by the blending, reducing the coarseness of the black hair. The blended hair is also known as “Salt and Pepper”. It is popular with bass players.
Effects of humidity to bow hair,
Humid and warm air causes the hair to stretch and thus not sufficiently tight, while cold and dry air will make it shrink.
Luckily, in another article here, it’s explained that hygrometers are available to help you determine humidity. Some cello cases however, come with an inbuilt one but you still can buy one here. Portable and fits well in the cello case.
It’s noteworthy that it’s practically very difficult to have hair that will remain unchanged in both humid and dry air even after a bow’s rehairing.
The effect of hair length variation with climatic changes, particularly the shrinking is evidenced by the flexing of the stick.
The stick mostly losses it’s camber because the curve is flattened by the bowhair tightness.
However, unlike the somewhat tough and stiff sticks mostly made of carbon fiber which are tensions variation resistant, this phenomenon is especially so for the soft bows.
How to do a bow rehair
First, let it be abundantly clear that, due to the very delicate nature of bows, a DIY cell bow rehair is without a doubt a daunting and risky exercise which can easily end up with unnecessary cost implications.
For that reason, a professional luthier is always the best bet for guarantees in quality work and safety of your piece. However, it’s obviously at a cost which is not comparable with what it would cost you to replace a broken piece.
However, do you know you still can do it by yourself? This is only recommended though, if you have good enough experience with the functioning and understanding of the cello bow and the process.
Easy to follow DIY Cello bow rehairing guide
The following steps would be a helpful guide for a DIY cello bow rehair when and if you opt to do it yourself and not engage the services of a Luthier.
It’s presumed that you are well aware of the inherent risks. However, it’s still doable.
You will obviously start by buying the horse hair, available on Amazon.com. Out of experience and recommendation, get the lightest hair possible. Further, ensure it’s not tangled, else it’s unusable.
#01. Old hair removal:
Being the start of a delicate DIY cello bow rehair exercise, you may at this point need to first inspect the general condition of the stick for any signs of damage and their extent if any.
- Using scissors, snip the hair on both ends of the hair length. Caution however, please ensure to leave a few inches on both ends,
- Using pliers (needle nose preferably), pull on the few inches hairs left after cutting from the plug, by rolling the hair on the pliers,
- Do the same with the hair on the heel after loosening/removing the ferrule ring by twisting to the left, the screw at the frog wedge,
- You can now remove the tip block, the block and the slide; then clean the stick, the winding, the button and metal of the frog only if deemed necessary.
While doing the cleaning, hair ends and their holding wooden edges MUST not get into contact with water.
You may consider other commercial cleaners, although they come with some down sides with them.
One of the non-appealing challenges with them is that, the cleaner’s solvent softens rosin that rehardens around the hair leaving a sticky and glassy mess.
#02. Preparing and setting the new horse hair
This is a delicate exercise that must be done carefully lest all the risky efforts come to naught.
- Start by getting just the right horse hair amount. This you can measure with a measuring gauge. However, you must ensure its width is relatively the same size as the ferrule.
- With a very strong thread (preferably cotton blend) or a strong but very thin wire, tie the hair at the end as tight as possible. The hair ends past the knot can be glued together or carefully burnt off.
#03. Replacing the hair
This stage could make or break the delicate effort so far in this whole DIY cello bow rehair “adventure”. However, it’s still possible; just keep focus and be overly keen and careful and the results will show.
- With the wedge still unreplaced, right at the top of the plug, insert the hair in the mortise hole slowly but perfectly to the right position.
You may do with a little push to get it through though. While, in the mortise, ensure it’s flat and snug.
- With the tip of the bow being flush with the plug, replace the wedge to hold hair in the right position.
- From the grip, note by measuring, how far the frog is to be placed and make the tip block. Replace the slide and the ferrule ring.
- Now, make the hair thin and ribbon like as is ideal. This you do by combing it with an even pressure ensuring that the comb has a smooth run through the hair. This removes hair tangles if any and makes the hair less bulky.
- After getting the measurement (note above), get the correct corresponding hair length to match. And like the first knot, with a strong thread or wire, tie the hair, just a little past the tip block. Again, cut the hair after the knot.
- For some good working space if needed, detach the bow from the frog and then, through the ferrule, slip in the hair.
Further, in the frog’s small hole, place the hair from up downward while ensuring to get the hair in the correct position. You can then replace the frog. At this point, you may do bow screw lubrication.
- Finish by sliding back the abalone ensuring to flip the hairs further from the rail and close with the wedge reattachment.
- To immaculately prime you bow, you can apply powdered rosin ready for use.
With that, you have successfully accomplished seemingly tricky DIY cello bow rehair exercise. The success of it must be very gratifying.
As the bow hair ages or gets affected by other negative factors to it’s playability, your bow will inevitably lose the good grip and sound as well as good articulation options that come with a newly rehaired bow.
Subsequently, there are limited options and as such, you may need to consider a DIY cello bow rehair as one of the rehairing options.
The main hair strand has little tiny hairs that, while the bow glides on the cellos strings, they grab to produce the sound. They however slowly but gradually break with the playing.
In summary, a life span of about 6months or slightly a few months above that would be ideal for a cello bow rehair. If too frequently needed, then, DIY cello bow rehair may not be recommended as it could be indicative that you are not doing a good job yourself. At a professional Luthier’s shop then should be next stop.
By the way, a good luthier would string two halves of the hair going in opposite direction. Mostly done by those that really know their craft, and would do with a bit of art too.