violin bow rehair

[chanot]

I'm an amateur maker and decided to learn the above as well. bought Wake's book.. ran into problem.. he says do tip first then wet hair, comb out and then make a mark 1/4 inch beyond the hairing mortice on the frog then cut wet hair to that length and insert in frog. apparently the frog to be fully back ie: in tightened position during that time...set aside to dry and to prepare to relax screw as the hair shortens as it dries...everytime I do this the hair ends up too short pulling the stick up like a baroque bow.. I can't understand the need for wetting the hair? could one not just attach hair at each end in turn in a dry state with frog forward and the hair just touching the stick ie: like the position we would leave bow with hair relaxed ? does the wetting of hair and then drying change the length that it was when I received it.Does it have some beneficial effect. I've got the technical aspects working out but the wetting and length problem persists..Any advice would be appreciated

[Craig Tucker]

Hair the tip, fold the hair as it comes out of the mortice flat against the tip surface with the side of the comb and secure the hair tight to the tip with a rubber band.

Then comb the length of the hair out, and make the frog mortice knot exactly the depth of the mortice behind the trailing edge of the mortice hole, so that it will wrap around the wedge, pass down the depth of the mortice, and the knot will sit exactly under the wedge when it's in. (all this with the frog in the full FOREWARD position.)

Put on the slide, slip on the ferrul, put a medium pull on the hair with the screw and fit the spread wedge.

Loosen up the hair and wash it with hot water and a wet wash cloth. Pat it dry so that it is merely wet, not dripping and then the pinch the hair with your thumb and first finger starting at both extreme ends of the ribbon then bring your hands together so that all the very loose hairs gather together into a two or three inch length and lightly flame that area so that the worst offenders are shortened somewhat by the heat. repeat the procedure along the entire length of the hair ribbon shifting the area you flame until all of the longest hairs are shortened throughout their entire length and all of the hairs are generally the same length.

Then, lightly tighten the hair and flame the entire length of ribbon the longer hairs will shorten and the tight ones will relax slightly. Then put it out in the sun to dry throughly...

You can get a really close rehair just by being careful with the knots and wedges... Then again, you can take the worst possible rehair and make it look perfect with good flaming technique. So, if you combine a careful rehair with good flaming you should wind up with a professional job.

Practice makes perfect and rehairs require quite a bit of practice.

Shortly, I hope to have the entire procedure on DVD...

[sweetmusic]

what craig says

[Brad Dorsey]

I can sympathise with what you're going through, because I tried to teach myself rehairing from Wake's book over 25 years ago. It was endlessly frustrating, and I now believe that it is impossible to learn rehairing from that, or probably any other, book. I like the rehairing instructions given in Strobel's book better than Wake's, but I don't know if I would have been any more successful trying to teach myself from Strobel. I finally learned by receiving instruction from two superb bow makers who were also excellent teachers.

Speaking to your questions: If your hair always comes out too short using the 1/4 inch measurement, you could try to figure out how much too short it is, add that amount to your 1/4 inch, and do everything else the same. I now put the hair in the bow, head first, dry. Then I tighten the hair, wet it, and let it dry. I was told that the purpose of wetting the hair and letting it dry under tension is to pre-stretch the hair and even out the tension between the hairs. I loosen the hair as it's drying, if necessary, so it doesn't pull too hard on the stick.

[Regis]

Chanot,

You can count on CT's process (except everyone doesn't have the sunny/dry weather that he has). Remember if you leave hair too long, you can always tie another knot and cut shorter. You don't want to do that but, may be necessary in the beginning. Also, that flaming to shorten the hair takes awhile to get used to. Don't expect success immediately and you definately will burn some hairs.

Best of luck and enjoy.

Regis

[muddycreek]

I've been rehairing bows for years and it can be one of the most frustrating jobs ever or one of the most satisfying. Practice is the key.

CT, that is a wonderful idea for a cd. I think it would be very much needed because there is not much material out there on rehairing.

[chanot]

Brad, thank you for your kind advice. I'm glad I'm not the only person who found Wake's instructions on length a bit difficult. Can I trouble you to clarify these points? Thats a good idea to give myself a bit more than the 1/4 inch. Am I right though that you actually do the measurement dry? I was so discouraged I sold his book . Now just purchased an old bow I'd like to repair and rehair and want to try again. Unfortunately now can't remember if the measurement as you do it dry is with the frog in loosened or tightened position or midway? You then note that you wet the hair after it is installed in tip and frog. I believe you then put some tension on hair and let it dry and loosen in increments as the hair shrinks as it dries. Would this mean the initial dry measurement is done with the frog in the fully tightened position?However then I couldn't put further tension to start the drying process? I'll review the advice the others kindly provided as well but your ideas based on your early experience with Wake's work should be a great help.

[chanot]

Dear CT.. Hope you don't suffer from carpal tunnel syndrome. I'm a physician...Thanks for your detailed instructions. I remember hearing about the need for the flaming and that it has to be done carefully.I like the idea of doing the good insertions of dry hair in tip and mortice as you wisely explained with the frog in the loosened position. The tips on using your fingers to gather up the folds of the longer hairs for flaming is an excellent idea . Does the wetting plus a bit of tension have somewhat of a averaging effect on shrinkage or is it to facilitate the flaming or both. Your very professional and detailed instructions are most appreciated.I've got to repace the bone tip as well -I have some replacements.. bent bone with fibre lining.. do you use a dry or wet heat if more convexity is required or will the bone bend any more ? it has a slight convexity now.. maybe enough as I don't have the bow in hand yet to look at? Thanks Again

[Michael Darnton]

Wetting helps pull the hairs together and straight in a neat ribbon without them coming loose until you've got a knot on them.

I was sooooo happy when I started work at Bein and Fushi and discovered that they had a separate bow department and I'd never have to rehair another bow!!!!! But now with Craig's method, and having watched my shop-mate do it, I think it would be a lot easier if I ever had to do it again.

[chanot]

Regis Thanks for your support. Frustrating is the word ..I bought enough hair 250 gms but used up several batches each bow before I got an average result. Sold hair and jig and Wake's book.., Like a golfer throwing his clubs in the water hazard.. now I've got to make my own jig but have a little hair remaining Thanks

[Brad Dorsey]

I found Wake's instructions on everything difficult.

I tie the knot and cut the hair to length with the hair dry and the frog in fully-loosened position. The 1/4 inch doesn't sound like enough to me. As Regis said, if you tie off and cut the hair too long, you can always shorten it a bit; if you cut it too short, it's impossible to lengthen it. So until you get the length thing figured out, err on the side of safety by leaving it too long. Another length trick I use is to tie the frog knot in two sections: I take a few turns around the hair with the thread, knot it, take a few more turms, and knot it again. This way, if the hair turns out too short, I have a little extra in the frog that I can let out by undoing the second knot. It's like being able to lenthen a skirt by letting out some of the hem.

I don't use the type of holding fixture that Wake shows in his book. Instead, I have a head holder and a frog holder - separate fixtures that are simple and very safe because neither one acts as a clamp. There are lots more little tricks and details that come from practice after watching someone who knows what he/she is doing. Craig's forthcoming CD will probably be very helpful. For a while, Wake was selling a rehair video that was so bad the only person I know who bought it sent it back for a refund.

[Jimbow]

Not to be a contrarian here, but I was trained to install at the the frog end first and feel it is much simpler and less prone to problems.

I will attempt to summarize the main steps.

First, install the hair into the frog and temporarily mount it on the stick. Comb the hair a few times until it is flat and even.

I allow length of about 4.5mm beyond the mortice for the inside beginning of the tie at the tip. ( hair dry / violin bow)

Measure and pencil mark the ivory. Then, with frog in full loose position and hair combed smooth and flat, mark across the hair. After tepid wetting the hair for 60 seconds up to within 4 inches of the tip tie, wipe the hair of excess moisture and then recomb and tie with 5 or 6 turns of waxed double strength buttonhole thread. Tie should be a bit on the frog side of your pencil mark. After completing the tie, slide the tie out to your mark -never backwards direction as that could cause some loose hairs. Notice that the hair has lengthened from the moisture so the pencil marks on the hair and the ivory no longer align. Use the hair pencil mark now.

Also, if the mortice plug is significantly thicker or thinner than average, adjust the 4.5 mm accordingly. Takes a bit of experience to judge this.

Cut hair and apply medium C/A to hair end and flatten with pliers. Do it again. With the Frog removed,install the hair and plug into the tip mortice.

After installing the tip plug , reinstall the frog and tighten about 2mm from full loose position. I put a toothpick through the hair (50/50 ea.side) and on the backside of the stick and allow overnight drying. Seldom have I had to use heat for stray long hairs,but have occasionally used a match flame or alcohol lamp as Craig recommends.

I've used this technique for a few hundred bows and feel it works best for me.

Max Moller and Strobel describe it in some detail.A comment of Moller that may be of consolation to violinmakers is: "The layman, as a rule, has not the faintest idea how troublesome a job it is. The violin-makers nearly all dislike it."

John Bolander states "...A bowmaker has a different attitude toward rehairing than a repairman...Seldom hear a repairman say he likes to rehair bows...a bowmaker is working on his pride and joy and... does not like to see his bows nicked and spoiled with careless worksmanship and this is not in the least understood by repairmen who complain that work for repairing is underpaid especially with the extremely high price of hair and so the unlucky bow has to suffer...prospective bowmakers have to realize that their bow will have to be continuously rehaired and you can only hope it will be done properly"

Kun & Regh describe the Tip first method of rehairing as do most articles.

Max Moller, in his last paragraph of his May June 1959 article states, "The method I describe here," (Frog First) "is not generally used. As a rule , one begins by fastening the hairs to the head and then to the frog. According to my experience, however, this method is more complicated and less accurate."

He also states, " ..The number of bows which have been broken or damaged by repairers exceeds by far the number of bows lost through normal use.

Accuracy of carving mortice plugs is extremely important. Frank Passa article in Journal of VSA Vol.VII No.3 includes some excellent drawings of plugs and spreader wedges that are very helpful. Article also explains other problems and corrections in rehairing. (He does Tip First, claiming he can make more final adjusting corrections at the frog if necessary)

Two things I am working to perfect are 'Compensating for length in the hair path' (Kun & Regh) and 'getting the orderly arragement of hair at the ferrule without crossovers' (Bohlander ). Both are important and I am continuing to improve but I am "not there yet"

Excuse me for rambling but I hope something may be of use to you here. Different people prefer different methods. There is no right or wrong--they both work!

Just my opinions and limited experience FWIW !

Jimbow

[chanot]

Brad Thanks for the clarification a great help

[chanot]

Hi Jimbow. Thank you for your detailed description . Amazing experience doing over 100 bows. It was gratifying to read some of the quotes you provided with no one apparently particularly enjoying the job.Your advice with length was very helpful.For an amateur like myself the fabrication of the wedges is a tricky job but I am improving.

I discovered a technique to cure the problem with wear on the insides of the bow slot allowing lateral movement of the frog. Although Wake says to cut a new plug to fill the slot and redo it to the correct dimensions.which I am sure is the best ,I found the following techniqe speedy and effective. I cut two thin slivers of metal the length of slot from an auto feeler gauge.. stainless steel with spring ... height no higher than the slot..you can choose the thickness of feeler gauge that just narrows the slot to reduce the freeplay but is not too tight... tnen putting one on each side they slip in with a compression fit and don't need adhesive .. snugged up against the little threaded eye through which the main tightening screw passes.The frog moves perfectly lengthwise of bow and no longer wiggles from side to side.. the metal being sping like and if proper thickness doesn't bind by bowing out into the slot .

[fiddlecollector]

The same can be done preferably with pernambucco veneer!

[cellocelloareyouthere]

Hair the tip, fold the hair as it comes out of the mortice flat against the tip surface with the side of the comb and secure the hair tight to the tip with a rubber band.

Then comb the length of the hair out, and make the frog mortice knot exactly the depth of the mortice behind the trailing edge of the mortice hole, so that it will wrap around the wedge, pass down the depth of the mortice, and the knot will sit exactly under the wedge when it's in. (all this with the frog in the full FOREWARD position.)

Put on the slide, slip on the ferrul, put a medium pull on the hair with the screw and fit the spread wedge.

Loosen up the hair and wash it with hot water and a wet wash cloth. Pat it dry so that it is merely wet, not dripping and then the pinch the hair with your thumb and first finger starting at both extreme ends of the ribbon then bring your hands together so that all the very loose hairs gather together into a two or three inch length and lightly flame that area so that the worst offenders are shortened somewhat by the heat. repeat the procedure along the entire length of the hair ribbon shifting the area you flame until all of the longest hairs are shortened throughout their entire length and all of the hairs are generally the same length.

Then, lightly tighten the hair and flame the entire length of ribbon the longer hairs will shorten and the tight ones will relax slightly. Then put it out in the sun to dry throughly...

You can get a really close rehair just by being careful with the knots and wedges... Then again, you can take the worst possible rehair and make it look perfect with good flaming technique. So, if you combine a careful rehair with good flaming you should wind up with a professional job.

Practice makes perfect and rehairs require quite a bit of practice.

Shortly, I hope to have the entire procedure on DVD...

 

As you know i'm about to try and take my own horse hair. To straighten them all up, do you suggest i use a flame? I was just going to use a pair of scissors.... but was interested by your "flame" comments!