Bow tip replacement – part one

A detailed method to remove an old tip and fit a new one, before shaping

Makers reveal their special techniques

Luthier and bow maker based in Portland, OR, US

The tip on a bow has several jobs: to protect the pernambuco head from damage, to reinforce the mortise in the head and to look stylistically cohesive. I recommend replacing tips that are no longer performing their functional duties, especially tips that have cracks or are missing any pieces around the mortise. In this two-part article, I’ll describe my step-by-step process of replacing a tip. This first part describes my process for removing an old tip and fitting and gluing a new one.

Making a mortise template

1 My standard tip material is Elforyn, which is flexible, easy to carve and looks nice. If there have been any repairs in the head, then I’ll use Tip Shield or Tip Armor for reinforcement. These two products are incredibly durable but take longer to shape. I avoid using mammoth ivory for ethical reasons as well as travel/sales limitations.

I study pictures of bows by the original maker, if possible, or by makers from the same region and time period. I note the thickness of the ebony and ivory on the headplate and beak, the curve and ridge in the beak area, and the mortise shape that I want to copy. If I don’t have much information about the bow, I use the thicknesses in the table below as a starting point. The ebony liner, ivory flat and ivory beak thicknesses get consecutively thicker by 150 per cent.

To be kind to my future self, I make a mortise template by covering the old headplate surface in graphite and putting clear tape over it, removing it, and saving it for later. This will help me to carve the mortise in the new tip more quickly and accurately.

ALL PHOTOS JENELLE STEELE

2 I first cut off the ivory beak by using a chisel to cut down between the ivory and ebony, with support behind the headface (2a). I then carefully insert a knife between the ebony liner and the ivory at the back of the head, cutting towards the beak and up and away from the head to remove the ivory headface (2b). The tip will usually pop off in chunks, so I press it against the bench for stability. Removing the ivory nose first helps prevent damage to the pernambuco when removing the rest of the plate.

Then I carefully cut most of the ebony liner off with the knife (2c). To remove the remaining ebony and glue, I use a flat hand file. Whenever I am filing something, I mark it generously with graphite first to help me understand where I am removing material. I also frequently check my file to make sure I’m filing glue and ebony (white or black dust) and not hitting the pernambuco (orange dust). Checking that the headface is flat from side to side is especially important.

I rub soap or wax on the sides and back of the head, and anywhere I don’t want the glue to adhere. I then thoroughly clean the headplate surface with alcohol and use a knife to cross-hatch the headplate surface (2d).

Removing the old tip 2a

2c

2b

2d

The ebony liner 3a

3b

3c

3d

3 I apply Scotch tape on one side of the ebony veneer that is at the finished thickness measurement. I cut it long enough to cover the headplate and leave 5mm for the beak plus a little extra. I cut off the little ebony beak piece and save it for later. I clean the non-taped side of ebony with alcohol and then hold it against the pernambuco headplate surface as if gluing it. This is an opportunity to make sure that there are no gaps between the ebony and the pernambuco headface, that the ebony overhangs the pernambuco on all edges, and that the grain of the ebony runs parallel to the sides of the head.

I use a piece of plastic as a barrier between my hands and the taped side of the ebony liner. If the tip is relatively flat, I apply a layer of thick super glue on the non-taped side of the ebony and quickly hand-clamp the ebony in position against the headface for a few minutes (3a). But if the tip is very curved, I hold the liner and head of the bow in place and have a friend help glue it with thin super glue, which will wick between the pernambuco and the ebony liner. In either case, I hold it firmly for a few minutes and have a friend sprinkle baking soda over the top, which helps the glue cure. I then leave it for at least an hour.

Using a chisel, I shape the sides of the face ebony to be slightly narrower near the beak. While supporting the headplate surface against a hard cutting surface, I use a sharp chisel to make small cuts directly down through the ebony at the end of the beak (3b). I keep working my way closer to the beak, removing any old ebony and cutting the new ebony to be flush with the pernambuco beak.

Ideally, I want the beak surface to be perpendicular to the stick when viewed from above (3c), although I will always match the original angles and never remove pernambuco to achieve this. The ebony should match the angle of the pernambuco beak when viewed from the side (3d), and from all angles, the beak surface should be flat.

I cut the piece of ebony for the beak into a small square, clean the non-taped side with alcohol, and cross-hatch it with a knife. Using thick super glue, I glue it by pressing firmly in the middle of the beak (3e), making sure that the grain of the ebony is running parallel to the sides of the beak and that the ebony is overhanging every surface. I let it cure for at least an hour.

I keep the backing tape on the ebony pieces for now, and file down the underside of the ebony beak until it is flush with the tape layer on the headplate surface (3f). Then I remove the tape from both pieces of ebony and level it again (3g). I make sure the curve of the headplate surface flows and doesn’t dive off at the beak. I again check for side-to-side flatness.

For aesthetic reasons, I want the angle of the ebony nose-liner to the face plate to be 90 degrees or less (3h). If the pernambuco beak angle is greater than this, I will glue on a slightly thicker piece of ebony than the headface ebony and file the angle to be 90 degrees or less.

3e

3g

3f

3h

Preparing and gluing the ivory 4a

4c

4b

4d

4 I draw the outline of the ebony-lined tip on the inside of the ivory-tip material and cut it out a little proud of the outline with a jeweller’s saw. Then I check if the angle of the ivory beak matches that of the ebony liner. To check it accurately, I hold the ivory headface surface against the ebony headface close to the beak. I slide the ivory down, as shown by the arrow in 4a, until the ivory beak touches the ebony. If the angle doesn’t match exactly, I’ll score a line at the base of the inside of the ivory beak with a chisel. This helps to avoid removing any material from the ivory flat as I then proceed to cut a slight angle on the inside of the ivory beak with a chisel.

I’ll keep alternating scoring and cutting until the angles match (4b). Next, I clean the ivory tip and ebony surface with alcohol and cross-hatch the ebony headface and beak with a knife. I put a small dot of thick super glue on the ebony beak and immediately hold the ivory tip plate on the outside corner of the beak and apply a little pressure (4c). I’ll hand-clamp it for a few minutes and set it aside to cure for a few more. Then I put a piece of Scotch tape on the outside of the ivory tip. I’ll use a plastic bag as a barrier for my hands and hand-clamp the ivory flat against the ebony.

I ask a friend to apply thin super glue along the sides of the tip.

I quickly flex the tip, then clamp it solidly. My friend dusts the glue with baking soda while I hold everything in place. After several minutes of holding, I set it aside to cure for at least an hour (4d).

Don’t worry, it’s supposed to look like that! But have no fear, I’ll show you my process for shaping it into a beautiful tip in part two.