What are the steps to follow to unmount the hair from a bow and install a new set ?
What kind of tools and products do you need beside a new set of bow hair ?
How do you measure/adjust the length before mounting ?
Essentially, the hair is held in place at both ends of the bow by wooden wedges. To change the hair, you need to gently remove the old wedges and cut new ones, then push the hair back into place under the new wedge. No glue is used at all. The length of the hair doesn't need to be super accurate because the bow is obviously adjusted with the tightening screw. As long as the hair is fairly loose when the bow is untightened.
However, this is quite a skillful piece of work - I really wouldn't attempt it yourself with a bow of any value.
I can recommend Matthew Coltman: http://www.matthewcoltman.com - who is very experienced and does a postal rehair service.
Hope that helps. Steven
First off, I would seriously consider having it done by a professional. Violin bow rehairing can cost about $50 with cello and bass bows costing a bit more. Given that it is quite a skilfull operation, that might be a consideration worth your while because there is always a risk of damaging your bow.
I would suggest, however, that if the $50 rehairing fee seems a bit much, you could clean the bow hairs with alcohol just to get out the rosin - if you use a wipe you can avoid getting alcohol on the bow, and if you want to you could also get a fine-toothed comb (or toothbrush) and gently comb out the horse-hairs - and that'll also get out rosin clumps.
Also, consider washing the bow hair - this can help the unusable bit at the base of the bow that gets dark and dirty:
To wash the hair, you first need to release the frog from the stick by completely loosening the screw. Please make sure that the hair at the frog and the tip are not pulled in a different direction than usual during their normal use, and the loosened hair should not be twisted either. Have a small container of rubbing alcohol ready, and wash out the old rosin with careful massaging motions. You must be extremely careful to ensure that the alcohol does not come in contact with the stick, where it can leave lingering marks. The second phase is to remove other kinds of soil, especially fats, with a bit of soap or shampoo and water. Last but not least, the violin bow hairs are carefully dried with a towel, the frog is put back into place and secured in place with the screw. To speed up the drying process and make sure the hair is in the proper position, we recommend gently combing the hair with a fine-toothed comb or an old toothbrush. After things have dried properly, the hair can be re-rosined.
Lastly, if you have loose or broken bow hairs, it is not necessary to pull them out - simply take a pair of scissors and cut them as short as you can.
Overall - if the bow isn't too worn down, try these techniques to avoid rehairing. If you must rehair, consider going to a professional.
First: here are the materials you'll need:
- Horse hair
- Needle-nose pliers
- Sharp Scissors
- Thin wire
- Wire cutters
- Hair clips or hair slides
- Well, here’s a bow and a very handy fixture for securely holding the bow while it’s being worked on. It’s made to gently clamp the bow at the tip and frog end (the ebony grip is called the frog) and accommodate various length bows.
After inspecting the bow, I remove the frog from the stick and fold back the hair at the tip end in order to remove the small wooden plug that secures the hair to the bow tip. The plug should not be glued in. It’s unique compound wedged shape allows it to lock in place due to the pulling action of the hair. Sometimes, however, it takes a bit of digging to remove the plug. If it stays intact then I may reuse it.
The plug is quite small - see the attached imgur album for a photo.
Once the plug is removed the bundled hairs are pulled out of the mortise. Now it is time to remove the old hairs from the frog.
The metal ferrule is a tight fit and needs to be pulled off carefully. I use a piece of rubber and a small vise.
The small triangle of wood is called the spreader — it serves to do just that — spread the hairs into an even band. A drop of glue holds it in place and as a result they often get ruined during removal. I always replace these anyhow to ensure a proper fit with the new bundle of hair.
Next the abalone slide is removed. It has angled edges that fit into the channel creating a dovetailed way. These also can be recalcitrant due to tight fits and rosin buildups!
Fold back the hairs and the frog-end plug can be seen and then removed.
The frog is carefully cleaned, metal parts polished, and the channels for the slide are lubricated with graphite (pencil). After selecting and measuring a new hank of hair I tie the end off tightly with very strong thread. I use three clove hitches — a self binding knot – finished off with a reef knot.
The end is then dipped in powdered rosin.
Then the rosin is melted into the hair, using an alcohol lamp, while the heat also serves to swell the hair ends, locking them firmly in place. All of these efforts are taken to prevent hairs from pulling out while the bow is in use.
You can start attaching the hair at either end, but I prefer to begin at the tip. Insert the hair so the knot is settled at the bottom of the mortise and then takes a bend to come up the back wall.
Then insert the plug to capture the hair bundle. I reused the old one which was made of hard maple and still seemed serviceable despite the small chip in the corner. I always give firm pressure on the hank of hair at this point, simulating use, to be sure that the plug is working properly and will hold the hair in place.
After a bit of preliminary combing to straighten and spread the hairs evenly, I use a rubber band to pull the hairs down tightly at the tip.
Next, I wet the hairs, comb and tension them and tie off the frog end. Now is the time to thread the ferrule onto the hank. Slide it up out of the way. Then the plug is inserted to capture the hank in the frog.
The frog is installed on the stick. The abalone slide is slipped into place and the ferrule is put back on — it goes on easily without the pressure of the spreader clamping it. Here is some mahogany that has been shaped for a spreader. I insert it as is and mark and score it a little oversize for length.
Finally, a dot of glue goes on the tip that will be against the ebony of the frog. the spreader is inserted into the ferrule, separated at the score mark and the hairs carefully fanned out and evenly distributed. Then the spreader is pushed all the way home.
It’s a good job if the bow hairs all tighten up evenly when the bow is tensioned and all the hairs are properly aligned.
If that doesn't work well enough for you, consider the steps on this site.
As posted in this article:
Here's what you'll need:
- Horse hair (like this $7 pack on Amazon)
- needle-nose pliers
- super glue
- gauge (like this one)
- thin wire
- wire cutters
- hair clips or slides
Here's how to do it:
- Remove the old hair by cutting it with your scissors. Leave a few inches at each end.
- Using your needle-nose pliers, grip the very end of the few inches of remaining hair on the plug side of the bow. Roll the pliers into the hair, so that it wraps around them.
- Keep rolling the hair onto the pliers while simultaneously pulling it from the plug. Some plugs release the hair much more easily than others. Either way, be careful not to damage the plug.
- To remove the hair from the heel of the bow, loosen the screw at the back of the frog wedge first by twisting it to the left. This will loosen the ferrule. Note: You’ll probably need to spend some time rocking the ferrule back and forth before it loosens. Be patient. You don’t want to cause any damage to the wood.
- When it is released, remove the small wooden wedge at the bottom and then use the same method with the pliers as you did on the plug side.
- Use the gauge to measure how much horse hair you will need. It should be approximately the same width as the ferrule that you removed earlier. Gather the hair that you cut off and clip it together using simple clips or hair slides, so that it stays together and doesn’t get tangled while you are working with it.
- Use the wire to tie the hair closely together at each end. Use the glue to get the hair to stick together at the part where it is slightly protruding from where you tied it together with the wire. This will ensure that it fits neatly, without any hairs sticking out. Give the glue time to set.
- Once the glue has set, insert the hair at the top of the plug (with the wooden wedge removed) using a thin stick or screwdriver to poke it in and get it in the correct position.
- When you have the correct positioning, put the wooden wedge back in place, to ensure the hair stays where it should. You want the plug to be flush with the tip of the bow.
- Before attaching the hair to the heel or frog side of the bow, remove the clips and use a small comb to comb out any tangles that may have appeared. You want the hair to form a thin ribbon shape (not bulky like rope).
- Once you’ve got it nice and combed, put the clips back to prevent any future entanglement. Tie the loose side of the hair off with wire and fuse the hairs together with glue, just like you did before with the other end.
- Slip the hair through the ferrule. Remove the bow from the frog to give you a little bit of extra room to work with. Place the hair into the small hole in the frog from the top down. Use the screw driver or stick to get it in the correct position, before putting the wooden wedge back in place. Slide the [abalone] back, keeping the hairs away from the rail.
- When you have finished reattaching the last wedge, you can use apply light heat quickly along the hair, to get the strands to fuse together a bit for finer playing. Then use some rosin to prime the bow. Crush it and gently pat and rub it all along the hair.
Also, there is this 2-part video tutorial posted in the article: