How to Restring a Violin Bow. Some refer to it as restringing the violin bow and others call it rehairing. The proper terminology would be rehairing since the bow string is made of horsehair. The follicles of the hair grip the rosin and score the surface of the strings. Whichever term you use, rehairing or restringing the violin bow, it takes patience and some understanding to do it properly.
Preparing the Area and Hair
Attempt to restring a violin bow that isn't valuable if you're just learning. If you make an error or cause damage, you won't have much of a loss.
Purchase horse hair. While light colored hair is preferred, totally white hair may be bleached, causing the hair to be brittle. Instead, look for cream to golden.
Cut the old hair off the bow 1 inch from the frog. Remove the ring by placing a small piece of leather on it and grabbing it with pliers and jiggling it off.
Insert a knife between frog tongue and the wedge. Gently remove the wedge from the tongue using needle nose pliers. Discard the ring wedge and purchase a new one. Take off the slide by pushing it with the thumb and tapping with a hammer. Pry out the wedge, making certain you don't touch the slide channel.
Clean the old glue off the frog tongue and the cavity. Pry out the tip wedge without breaking the top lining. Clean and buff the ring,back frog lining, and end button.
Wrap the light end of the hair with a strong rubber band, leaving the rope on and pushing it close to the rubber band. Cut a 7-inch length after you have removed one of the ropes. Super glue the top end together.
Measure the amount of hair you'll need with the feeler gauge. Make sure that the hair is flush with the gauge as possible and cut close to the tie.
Hold the hair in the left hand with the thumb at a right angle. Put the wire next to the thumb, leaving 3/4 inch out. Wind about 6 inches of wire. Use less for a smaller cavity. Leave 3/4 inch out at the end. Clip the wire and twist together with the first end using a pliers.
Cutting the Hair to Length
Place the frog so that the front faces the tip of the stick. Put both into the clamp, making certain that the frog cavity is directly over the clamp bolt. Tighten the bolt snugly.
Measure the length of the cavity and subtract 1 1/2mm. Cut the hair that length. Put a drop of super glue on it and, holding the tied end upside down, spray it with an accelerator. Fit the hair in the cavity by placing the tie on the right side and pushing the hair down with a push tool. Make certain the tie is perfectly flat.
Add powdered rosin on top of the tie. Place the new frog wedge on the cavity. Stab the wedge by hitting the middle with the blunt side of a knife and positioning it into place. Remove the knife and push down with a push tool.
Hold the slide with the index finger and thumb and push it into place while pulling and twisting the hair.
Use the bottom of an opened paper clip to string the hair through the ring. Put a drop of glue between the hair and the frog tongue and insert the ring wedge. Even the hair and tap the wedge into place by putting leather on top and using a tack hammer.
Cut the wedge in two places, no deeper than 1 mm from the hair, using a razor saw. Bend the wedge back and forth until it breaks at the cuts.
Put the frog on the bow stick and insert the end screw. Place the stick into a clam that is held onto a desktop with C-clamps making certain the frog does not touch. Put the bow in the clamp and extend the hair 1 inch past the tip and make a cut with the scissors.
Attaching the Hair
Take the frog off the stick. Submerge the hair in water. Don't get the ring wedge wet. Lift it straight out, pressing the water out of the hair as you remove and wiping once with a paper towel. Reattach the frog to the stick and the stick back into the clamp. Comb the hair.
Determine the exact length of the hair and adjust the length for the season. If it's summer subtract 1mm length. Wet the hair again and comb.
Wrap the end with wire as you did in Step 7 of Section 1. Crimp the wire flat and twist the end tight. Cut the wire and bend over the top of the tie. Crimp tight. Measure the cavity and subtract 1 mm. Cut the hair that length using the wire end toward the middle as the starting point. Put a drop of glue on and spray with accelerator.
Insert the hair by placing the wire tie on the right part of the tip cavity and pushing down with the rounded part of a screw driver. Make certain is flat on the bottom. Pack some rosin in.
Tap in a wedge and make certain that it is secure. Remove the stick from the clamp and let the hair and frog hang down to make certain it isn't twisted. Put the frog on the stick. Comb the hair from frog to the middle and from the tip to the middle. Do this three times. Remove broken hairs one at a time.
Let the hair dry. Heat the hair over a gas burner or alcohol lamp to shrink loose hairs. Apply powdered rosin.