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We provide professional instrument restoration services and bow rehair services. Please contact us for a quote or visit our retail shop for a free consultation.

 

 


 

Bow Rehair Services Offered by JX Young.

J.X.Young provides professional bow rehair service using the best quality bow hair available.  We face many challenges daily during rehairing; most of these are results from previous bad rehairing probably perform by a not so qualified person.  Very often we come across hair held together with super glue and stuck into the mortise or part of the frog glued together.  This makes our work more difficult and it is a real challenge to reverse a bad rehair. In order to educate our customers about the kind of work we can do, a simplified bow rehair procedure is provided below. Do contact us for some professional advice if you are unsure what you should do with your bow.


- To begin, let’s look at the diagram below to learn the technical names of the different part of a bow.

- To start the rehair, we snip off the old hair before removing the tip wedge.  We inspect the stick and frog for possible cracks and damage inflicted; and clean off old glue if any.

- We then remove and disassemble the frog and again check for damage.  This can be full of surprises.  We have even come across wedges made from plastic and bow hair held together by a screw inside the frog!

- Remove the ferrule and the pearl slide; inspect all parts to ensure that they are not damaged and can be put back together. Again, we often come across poorly done rehair in which the ferrule or slide had been super-glued to the frog!  Sometimes, we have no choice but to break the pearl slide in order to access the inside as the previous person doing the rehair may use superglue to cover up a badly done job.  This is such a waste because some of these slides can be very beautiful or precious.

- Like violin making, bow making and rehairing is an art.  We select the amount of bow hair to be used based on a combination of experience, customer’s requirement and the type of hair that we are using.  Usually we uses around 5 to 6 grams for a violin bow.  Although we buy the best bow hair, we sometimes come across a few bad strain of hair which has to be picked and discarded.  This can be time consuming but necessary in order to maintain the high standard of rehair.

- We secure the hair with strong cotton strings once the amount of hair to be used has been decided.  A little super glue or rosin can be use in this case to hold the tip of the hank together.  However, this cannot be overdone to avoid the hank sticking onto the bow’s mortise.  Different bow maker have slightly different practise but the key is not to do any irreversible damage to the bow.

- Once the hair is in the mortise, the various step that follows (cutting the wedge for the mortise etc) need to be done with great care and precision.

- The combing of the hair, estimation of hair length etc can greatly affect playability and experience is needed to judge the length of hair needed.  Very often bows brought in from cooler climax become too loose in the tropics and we need to tighten the hair.

- Place the hair in cold water to ease combing.  We remove the frog from the stick and coil the hair into the jar of water and hook the frog over the edge of the jar (allow 1" between the frog and the water so the moisture won't wick-up into the frog ferrule wedge).

- Replace the frog back onto the stick and secure to the jig.

- Adjust the frog's position (relative to the stick) so that after the screw comes into contact with the eyelet, make 3 or 4 complete turns to allow for the adjustment of the new hair after it shrinks overnight from drying. Be sure that the frog is pushed completely forward in its mortise while secure in the rehairing jig.

- Comb the wet hair into an even ribbon by squeezing firmly between your thumb and fore finger; excess water will be removed during this step. Make every effort to get the hairs running exactly straight-and-even prior to clamping the ribbon in place with your securing clamp. Try to avoid breaking hairs off during this process. You can use your fingers to squeeze the hairs into a flat ribbon --- pulling too hard at this point will result in making the hairs too short (after drying) and generally uneven in tension, so don't overdo the pulling.

- Tie off the hair beyond the edge of the mortise. The tie-off point is exactly one length of the mortise, beyond the edge of the mortise.

- Unclamp the hair and trim off the excess (again, 1 to 1 1/2 mm beyond the wrapping. Hold the hair firmly at this point so that it doesn't shift in the tie-off.

- To install the hair, be very careful to keep the ribbon of hair flat and correctly referenced with respect to the tip mortise (as you remove the frog and place it off to the side in preparation to press the hair into the tip mortise).

- Press in the tip wedge. When fully pressed in, the top surface of the wedge should be level with the adjacent edges of the bow tip, and the hair should be drawn over the wedge such that it completely covers the wedge. There should be no evidence of a bulge. If too much wood remains after pressing fully in the mortise, you may trim the excess by paring it away with your violin knife (don't cut any of the hairs!). I will place a dull single edge razor blade between the violin knife and the hair to avoid losing hairs.

- Proceed by placing the frog back on the stick, such that the hairs run in an exact even ribbon from tip to frog. You may establish the ribbon's alignment by running a medium comb through the hair.

- Loosen-up the hair (back off the screw) and allow it to dry thoroughly over night. Prior to drying, the hair should not be tight, as it will shorten considerably as it drys. If you do not allow sufficiently for this shrinkage, it will probably result in a popped-loose hank, or worse yet, a snapped-off tip!
So what is a perfect re-hair?  Do bear in mind some of the points below when inspecting a bow; weather it’s a stick that has been rehaired or a new bow you are considering buying.

A. The hair should be very secure at the tip and at the frog.

B. All hairs are even and run a straight line from frog to tip.  The ribbon should cover the tip wedge fully.  The ribbon should be evenly distributed beneath the frog ferrule with none of the hairs slipping around the sides of the ferrule wedge.

C. When you loosen the hair fully, the hair should just begin to show evidence of a loose bundle. It should not be so loose that it falls limply around the stick, nor should it be so tight that you cannot fully remove the tension on the bow. A delicate balance must be met here.

D. As you slowly tighten the hair, it should "rise" slowly off the stick to form an even flat ribbon. If the sides of the ribbon come up to tension before it’s' centre becomes taught, then your hair is uneven. If the centre becomes taught before either side, then again, your hair is not drawing evenly. If either of these conditions or variations are allowed to persist, then the bow stick will likely begin to warp over time. There should be equal tension on all the hairs across the ribbon of hair. This can be determined by bringing the bow up to tension and drawing you thumb across the ribbon, checking for an even resistance across the hair.

E. The ferrule wedge must fill the entire space between the hair and the ferrule; it should be secured tightly, and reinforced with aliphatic resin (carpenter's glue). You may check for this by first bringing the bow up to tension, then grasping the hair in front of the ferrule and try to physically move it back-and-forth in the ferrule. Movement generally suggests that the ferrule wedge is too loose, or has slipped.

F. There should be no evidence of a "bulge" at the pearl slide, indicating that the hair has dislodged from its' wedge inside the frog.

G. Make sure that the screw-to-eyelet alignment is in adjustment. If this adjustment is out of alignment, the frog will not adjust smoothly, back and forth when tightening and loosening. You may improve a sluggish frog somewhat by applying some cork grease (or other paste lubricant) to the threads of the screw and the frog liner.  When adjusted correctly, there should be an absence of side-to-side wobble of the frog on a superior bow. This is a mute issue on the inexpensive plastic bows; however, even these less expensive bows may be adjusted to be fairly secure.