TRADE SECRETS

Makers reveal their special techniques

A simple method for adding this small detail to your bows

It’s a small detail, but it’s a cool detail. A martelé button is one where the inside of the button ring is octagonal, matching the outside of the button, as opposed to having been made with the typical round on the inside tubing. People often say the purpose was to make the ring unable to turn relative to the ebony core, but I think the real reason was that one can make the martelé button with less metal, so that the bow maker’s initial cost for silver and gold was much lower.

The method I use was taught to me by Paul Martin Siefried, who sadly passed away in November 2019. It is a very logical way to fit an octagonal ring. Paul would say that he would think about a challenge until a logical solution came to him, often in a dream. I don’t know if Paul (below) dreamt up this technique, but when I’ve shown it to other makers, some of them quite experienced, most have been impressed by the simplicity and practicality of his solution.

The basic shape the ebony will be for making the button

1 In a nutshell, the technique is to hammer a round button ring on a mandrel so that the inside becomes octagonal. I prepare an ebony dowel with two small steps on it, as shown in the diagram. The diameter of the middle step (section B) is the size of the inside distance of the octagonal ring measured from corner to corner. The diameter of the distal step (section A) is the size of the inner distance of the octagonal ring measured from flat to flat.

I will slip the octagonal ring on to the smaller step (A), and then use a knife to make the larger step (B) into an octagon over which the ring will fit snugly. A maker can then finish the rest of the button in whatever fashion they normally use.

Left Standard button ring with round inner surface Right Martelé button ring with octagonal inner surface

SIEFRIED PHOTO ESTATE OF PAUL SIEFRIED. ALL OTHER IMAGES MATT WEHLING

2 The first step is to make a ring, either by soldering flat stock or by cutting tubing to length. I use round tubing about the same inner diameter as the inner flat-to-flat distance I want the final ring to be, or perhaps a little smaller. If you’re making the ring, it can be less than 1mm in thickness, although it’s good to make a few buttons using 1mm-thick metal to get the feel for the method. The ring can be a little less wide than the finished width, as it will get wider when I hammer it out. Making the ring smaller and thinner isn’t too important if using silver, but in gold every little bit saved adds up quite quickly, from a financial standpoint.

Mandrels

3 You’ll need a specialised mandrel on which to hammer the ring octagonal. Here are examples of five mandrels. At the bottom are a set of three, beautifully manufactured by Alberti Design in Oregon, US. These have a very slight taper and therefore the interior of the rings is nearly parallel. The middle mandrel is commercially manufactured and available from many jewellery tool suppliers. It has a very large taper, which some people like. At the top is the mandrel I use, which was made by Paul Siefried for himself. I am honoured to use it: in the parlance of Goldilocks, for me the taper is ‘just right’.

How the ring looks on the mandrel

4 This is the round ring on Paul’s mandrel before I started hammering it. I have put some blue tape on the mandrel marking the final inner size of the ring I want to attain. I have heated the ring until it is not quite red, and then quenched it in alcohol to soften the metal. I am using a quite large hammer which is actually a BF (16-ounce) carpentry hammer, just because that is the largest one handy next to my bench. I just start hitting the ring quite hard, and as it becomes octagonal the inner diameter starts to enlarge.

The ring is taking shape

5 I change the orientation of the ring occasionally so that there is no ‘inside’ or ‘outside’ relative to the centre piece of ebony, and I also stop to re-quench it a few times to re-soften the metal, as the hammering will quickly harden it. But fairly soon the ring is octagonal and down to my piece of tape.

The lathe is prepared for working

The ring fitted on the ebony core

6 Once I have prepared the ring and can measure it, I make the ebony core on my lathe (6a). The diameter of section A is the same as the inner flat-to-flat measurement on my ring, and this section is about as long (laterally) as the ring is wide. The diameter of section B is the same as the inner corner-to-corner measurement of the ring, and the length is just a tiny bit (0.5 mm) longer than the ring is wide. The diameter of section C is just a little larger than the outside corner-to-corner measurement of the ring, and is a few millimetres longer than I need to construct a button. For a violin bow the overall length of the dowel at this point might be 23mm.

I file the larger end of the now-octagonal ring flat, as it will be the side that will fit against the centre ebony core of the button (6b). With the ring slid on to the thinnest part of the dowel (section A), I take a pencil and mark on the middle diameter section (B) approximately where the corners of the octagon are. I also do a small registration mark on the dowel and on the ring (just a pencil mark on the wood and black marker on the metal) so that I am always putting the ring on with the same orientation relative to the dowel, as we can’t be 100 per cent sure the ring is a perfect octagon.

Cutting the ebony

7Using a long, thin knife I cut in the direction away from the core, to start to make an approximately octagonal step in the middle section (B) of ebony. Then I cut in the opposite direction towards the core to make the step almost parallel to the axis of the button. Going slowly and carefully, changing directions regularly, I’ll get it to where the ring can just barely fit on the octagon I have cut.

The shiny parts of the ebony send a message

8 As the ebony gets small enough for the ring to fit on, I shorten the length of the smallest diameter section of the ebony (A) so that I can force the ring on to the middle section of the ebony (B) by pushing it against the side of my workbench. Then I remove the ring, and the shiny parts of the ebony tell me where I need to be removing wood to allow the ring to move further along, until it butts up against the core. Once it fits all the way to the core, I remove it one final time, shorten the ebony so that it is just shorter than the ring, glue the ring in place, and then make the rest of the button in the way that I normally would.

The ring is fitted and ready

9 The octagonal ring has now been glued on to the ebony core and is ready for the next steps of being made into a button. I realise that there are some people who like to mount the ebony core on to the screw before mounting the rings. If that’s the case for you I’m sure you can easily modify the sequence I like to work for your method.

The finished button

10 Here is what the button looks like ready to be used on a bow. Note that the ring isn’t overly thick or heavy (to use the technical term, ‘clunky’), as on bows from the early 19th century one usually sees that they made these as thin as possible to save money.