Normally bow heads break off above the stick, and I have repaired a lot of those types of breaks. Forty years ago I would use a spline. My first method was using a straight cut and then filling the kerf with another piece of pernambuco. Then I used the method of creating the kerf with a small 1" or 1½" circular blade. That method is stronger because the spline ends up being larger and you can keep it farther away from the stick. Both of these methods should have the grain at a 45 degree angle, which is much stronger but the repair is more apparent. I run across a lot of bows that break again because the spline is only a couple of degrees off. Using that method the repair can be well hidden, but it's not that strong.
My current method is using a screwed in stainless pin. I have fixed a hundred or so of broken bows using a pin method. Only one has broken again and that was because it was dropped head first onto a concrete floor. When it broke, it did not break in the original place but the new break took more that 1/2 of the stick with it.
When a bow head breaks off and takes some of the stick with it, there isn't much left to repair, the spline or the pin method would not work. I usually pass on that type of repair.
Here is a bow where the break took some of the stick. They wanted it repaired, so I was just planning on glueing it and told them to hope for the best. After thinking about it, I came up with a new solution. Make a staple to hold the break.
I get lots of bows that are not really worth fixing and usually the customer just leaves them with me. Normally if the broken bow has a full head of hair, I glue the head back together without a pin. Then put the block and hair back in and over tighten the stick and see how long it lasts. That's a good way to test a glue joint. So, I proposed that idea to Phillip V. and told him I would test it out. I "stapled" the first test bow and cranked it up for a few weeks, and it held and all things considered it didn't look too bad. So I went ahead and fixed my customer's bow.
Here is my first test.
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Here are the steps I took to fix the customer's bow.
- The broken bow showing how much of the stick was broken
- A little pin to help reinforce the break at the stick.
- Glue the head back together.
- Drill two parallel holes into the mortise
- Craft a staple out of a small piece of copper wire.
- Have the wire go into the mortise about 4 or 5 millimeters.
- Glue the wire into the head.
- Fold the wire over so it's flat at the bottom of the mortise.
- Clean out the glue, flux and solder the two wires together.
- Scrape any excess solder out of the mortise.
- Finish up the outside of the bow.
- Pul the hair back in.
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IMG 20220506 115931 111 IMG 20220507 131349 892 IMG 20220507 131601 830
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Overall I like this method because you can fix a bow that's really unfixable.
I have another bow with a broken head, the head is very dainty, but there is enough of the stick left after the break to repair it in the normal way with a stainless steel pin. The problem is that the head is so small. So for that bow I'm going to make a double wire pin that's hidden. First step is to try it on a test bow. Here are the shots of the test bow. This uses the same idea, but I make a couple of little heads, then gule those in, fold over the other end in the mortise and solder, then scrape off the excess solder.
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