Twisted bow head


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Hi all,

Long story short, my luthier guy inspected the bow while rehairing it, and discovered that the bow tip seems to be twisted, and end up not able to have a straight stick when being tighten up, even with balanced hair tension.

When the stick isn't under tension, the stick looks fine, with a slight hint that the head rotated anti clockwise if looking from the adjuster.

I've heard many times recambering bow sticks, but have not heard any similar stories like mine. It is a really nice bow and I love it a lot especially the sound it draw out of my violin. How should this problem be approached?

PS: When I got the bow, it seems to be fitted with oversized plug, maybe that was intended to counter the twisted head? I don't recall the bow had this problem prior to the first rehair since I own the bow, and was rehaired "normally" since after.

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It sounds like the rehair is uneven - generally if the bow is good without tension it should be good under tension.

Hmm I actually checked the hair tension and it seems to be pretty even, though I might be wrong - I slowly tighten the bow hair and check if all of them tighten up at the same time. I've had other unevenly rehaired bow that one side of the hair will get tighten up quicker than the other side. Other than that the hair ribbon seems to be consistent to my eyes.

I can see the slight hint of the twisted head. Just some information about the bow, the plug on the head is oversized that it protrude like 0.5mm or so. Everything seems to be working just fine. Ever since the first rehair the stick was never straight again. During the 2nd rehair the luthier sort of did a little counter by working around with the hair tension where 1 side has a little less tension so the stick become straight but with the expense of tilted frog/hair ribbon.

If there's a bit of a twist in the stick this can generally be taken out by an expert - bows are only the shape they are because they're bent into shape ....

It is possible to correct a twisted bow with heat just as it is possible to correct crooked or incorrectly cambered ones.

If this need to be done the same way as recambering, I'll have to choose my luthier very carefully then...

Thanks for the inputs!

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Yes, a twisted bow can often be untwisted. The technique for doing such is similar to the straightening/recambering process, but instead of simply placing pressure on the hot stick to change the shape, untwisting the stick involves a "gripping & twisting" approach. This is often riskier, as it is easy to really bend the stick out of shape and camber if you are not careful. Also, resist the urge to get leverage in twisting the stick by placing pressure on the side of the head.

That said, before I untwist a stick, I always check to make sure that the frog fits the stick properly, and that there is no side-to-side wobble in the frog that causes the mis-alignment in the stick under pressure. For the bows that cross my bench that come in twisted, the twist in at least one-third of them is caused by something funky with the frog as the stick is tightened. Sometimes, simply tightening the eyelet one-half turn will take any wobble out of the stick, and take care of the twist. Othertimes, one or both of the screwholes is out of round (or crooked), and needs to be bushed. Another possibility is that the eyelet hole in the frog is drilled at an angle, causing the frog to fit poorly on the stick.

My only comment about your original rehair with the oversize plug sticking out--that sounds like sloppy work to me, and not any attempt to correct anything in the bow.

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Yes, a twisted bow can often be untwisted. The technique for doing such is similar to the straightening/recambering process, but instead of simply placing pressure on the hot stick to change the shape, untwisting the stick involves a "gripping & twisting" approach. This is often riskier, as it is easy to really bend the stick out of shape and camber if you are not careful. Also, resist the urge to get leverage in twisting the stick by placing pressure on the side of the head.

That said, before I untwist a stick, I always check to make sure that the frog fits the stick properly, and that there is no side-to-side wobble in the frog that causes the mis-alignment in the stick under pressure. For the bows that cross my bench that come in twisted, the twist in at least one-third of them is caused by something funky with the frog as the stick is tightened. Sometimes, simply tightening the eyelet one-half turn will take any wobble out of the stick, and take care of the twist. Othertimes, one or both of the screwholes is out of round (or crooked), and needs to be bushed. Another possibility is that the eyelet hole in the frog is drilled at an angle, causing the frog to fit poorly on the stick.

My only comment about your original rehair with the oversize plug sticking out--that sounds like sloppy work to me, and not any attempt to correct anything in the bow.

Often the twist is very severe ,i once had a 19th century French bow that had a head at almost 45 degrees to where it should be. It would also lose camber . I had to untwist it and recamber approx every 6 months but eventually gave up. It was a nice bow to play as well.It was probably a fault in the wood or not seasoned enough when made.

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You're welcome Casey. I'm glad the advice helped.

Is there some trick or device for applying torque to the stick without pressing on the side of the head?

Yes, Brad, I do sometimes use a little leather strap that I wrap around the stick to grip it. It also helps to hold the hot stick without burning my fingers. The leather strap is about 1" wide by about 6" long and is rough on one side. I use the rough side to grip the stick, which usually works quite well (especially if the varnish is hot and a bit sticky). As the pictures below show, I wrap the leather over the stick, and hold it tight to the stick with my fingers, and with the ends of the leather in my palm. In this manner, I can grip the stick in my left hand and twist the stick further back where I'm holding it in my right hand. By holding the stick firmly where it has been heated, but twisting the stick where it is not heated, this technique will take a twist out of the stick, while minimizing the tendency to remove camber or warp it.

post-25151-0-55586500-1327261601_thumb.jpg post-25151-0-85205200-1327261602_thumb.jpg post-25151-0-02043800-1327261604_thumb.jpg

Cambering, straightening, and removing a twist on a bow stick can be quite risky. Practice first on bows of nominal value. I highly recommend anybody that has not been trained in this technique take their bow to a professionally trained bow restorer.

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