Please contact me by email flutes@hoffmanweb.info or phone +447793047007.
I shall be developing this page in my free time (haha!)

Meanwhile, here is an article on padding flutes I wrote for the Pan magazine about ten years ago. There have been developments since then, notably improved pad design by Jim Schmidt and Straubinger.

On becomming a padder

I can’t imagine you could write immense amounts about padding - or could you??

This was my invitation from the editor of Pan magazine. Well, I like a challenge, after all this is how I started in this work. When I got my first flute at the age of 13, I knew that the first thing I had to do was to take it to bits and find out how it was made. This was nothing new for me, I would do this with most objects which came into my life, assured by the fact that my omniscient dad was always at hand should I get into trouble.

In the course of my studies, first in a music school in Poland, then at the Purcell School in London I gradually progressed to helping out trusting friends with emergency repairs. I shall not attempt to describe the most unorthodox methods I used during that time. I like to think that I have not caused any damage, and the instruments usually worked better afterwards.

Coming to RNCM at last put me in touch with people who knew about flutes. Trevor Wye, as well as being very knowledgeable on the subject, kept a large cupboard full of tools at our flute studio. He also invited Ian McLauchlan to conduct repair classes for the students.

My turning point, and the only formal training I received, was a two day course given by American flute maker and player, Eldred Spell. He introduced me to the finer details of what he called Boston padding, a process I shall describe later. I made several tools at that time which I still use today. The course also gave me the confidence to accept money for my work.

Twelve years later, I am still trying to figure out where padding fits into my life. I have always thought of myself first as a flute player, teacher and more recently a father. Repairing flutes isn’t even in my timetable. Every year, though, my work has been getting better, the quality of the instruments I work on has improved, and finally I am finding myself only taking on the work I really enjoy, which is mainly old French instruments. By the time this edition of Pan goes to print I shall be living in a bigger house where I will not have to do my padding on a kitchen table.

Development of the pad

The design of the pads has changed much over the centuries. The first pads, as used on baroque flutes, were made of a square of thin leather stuck to the key flap. The leather was porous and the tonehole had no rim. This combined with the shaky nature of a key moving inside a wooden saddle and a sluggish flat spring makes the seal somewhat less than effective. The problem was multiplied by the number of keys the flute had.

During the frenzy of the early nineteenth century flute development, the flute padding had to keep up with the increased number and size of the toneholes. The holes were profiled, the leather pads changed shape, even pewter plugs were used to close the holes.

When Boehm designed his cylindrical flute with the large toneholes he knew that the old pads would not suffice. In his book, ‘The Flute and Flute Playing’, Boehm described in detail the construction of the pad, for which he used a felt ring backed with card and wrapped with two layers of fine membrane. This design is still used on most flutes today.

The main problem with Boehm type pads is that they are made from organic materials which are not stable in a moist environment. This brings with it the necessity for adjustments, and more work for the padder. There have been several attempts at improvements. One route has been to find a synthetic material which could be used without the skin. So far, foam pads have suffered from stickiness and a spongy feel. Research into space-age materials is not something most flute makers can afford.

A successful alternative has been developed by an American flute maker David Straubinger, incorporating a synthetic (delrin) base, thin foam and traditional goldbeater skin covering. These pads feel stiffer than the felt ones, require a very accurate mechanism and are more expensive. The pads themselves are stable, and can work very well when installed with care.

Padding technique

This is by no means a guide on how to fix your flute. If you’re not sure where to start get ‘The Complete Guide to the Flute…’, by James Phelan, or the ‘Landell Flute Tune-Up Manual’, the latter being available free on the internet.

The method I use is based on that described by Boehm. The principle is very simple. The pad sits in its key cup at a level where the visible surface of the pad is just outside the cup. The level is regulated by adding paper rings (shims) between the pad and the cup. Additional crescent shaped sections of shims are added as required to ensure that, when the key is reassembled, the pad closes evenly on the rim of the tone hole.

Now for a few refinements. First of all, make sure that the key moves freely around its axis, and not in any other direction. If there is a pin securing the key to the rod, check that it is not loose. The key cup should also be central over the tone hole.

There is often a choice of pads you can use. Felt pads 3mm thick fit many modern flutes. The thickness of the felt allows for the pad to be squashed under the pressure of the fingers. This means that even an uneven pad can be made to seal the tone hole by pressing harder with the finger. However, the extra pressure creates undue wear on the flute. It also affects playing technique, and can even lead to injury. This type of pad can be badly affected by moisture as there is so much felt to swell up.

Thin felt pads of 1.5mm thickness are a little more stable, especially under changeable climatic conditions or irregular practice routines. They are somewhat less forgiving than thicker ones, as they cannot be compressed as much. Flutes designed for these pads often have plastic or metal inserts (stabilizers) in the key cups, giving a flat surface at the right level for the thinner pad. The level can be built up with paper, but some form of waterproofing is helpful. Some felt pads with a thick card backing do not respond well to this method of padding.

Delrin backed pads, such as those made by Straubinger or Brannen, are best at resisting moisture. However, as they do not adapt to the precise shape of the key, water can get to the shims underneath the pad and spoil the adjustment. Straubinger recommends using shims waterproofed with wax. He also makes many sizes of pads to minimise this problem. These pads require stabilizers, as well as the right profile of retainer washers and toneholes.

Having chosen the type of pad, keep in mind that no two pads will be the same. In fact, for one reason or another, most pads I buy end up in the waste bin. It is important to find the right pad for each key. If you leave gaps around the sides, water will find its way behind the pad and destroy your work. If the pad is squashed in, the card backing will wrinkle and make the adjustments unreliable. It may also be difficult to get the outside surface of the pad flat.

The skin itself is rarely even. Choose one which looks smooth, has no fraying, and no bumps anywhere near the point of contact with the tonehole. Only experience will tell you what sort of pad can survive the padding process and give a few years of reliable use. When you find a good match, make a mark on the pad near the key arm, so that you can get it back in the same way round.

Partial shim adjustments will deform the card backing. Bending the pad gently will soften the card and speed up the settling process. When you bend it, wrap the pad in clean cigarette paper so it doesn’t pick up oil from your fingers. If at any point the pad becomes contaminated with oil, start again.

Initial adjustments can be done by eye. Put enough paper under the pad, so that it contacts the front and the back of the tonehole at the same time. When it looks about right you will need to use feelers to check for small leaks. A thin strip of cigarette paper is easy to use. You can use a wider strip to start with (about 5mm) and reduce the width for more accuracy. I have been using cassette tape with some success. It has a less abrasive surface and it is half the thickness of cigarette paper, which gives more accuracy, but it is less manageable.

When you find a leak, note it’s position. I write it down as the hours on a clock. I use portions of shims of .002″ and .001″ thickness for the adjustments. For delrin pads it is best to use only the thinnest shims. You can glue the shim sections onto the pad, or onto either side of the top complete shim, but mark it’s position first. Press the pad firmly into the cup every time, using a cigarette paper to protect it. I would also mark the position of the retaining washers, as even the best ones aren’t quite flat. Using very light finger pressure, keep locating and filling leaks until the feeler drags evenly all the way round.

Next, a spot of ironing. This is the hardest part to learn, as the temperature of the ‘iron’ is hard to control. First wet the skin of the pad thoroughly, and then using a hot piece of sheet metal iron the visible surface. If the iron is not hot enough it will drag on the skin and not dry it sufficiently. If you get it too hot the skin will either singe or start sticking to your iron leaving it frayed. If this happens it’s time to take a short break, perhaps a scream, and start again from the beginning. No doubt, one day some frustrated repairer will come up with a suitable temperature controlled gadget.

After ironing the pad it will probably need more adjustment, as its shape is likely to change. If all the adjustments take too long, or if you use too much finger pressure the pad surface is likely to fray. When I come back to padding after a break, I often spend too long on the first pad and end up having to replace it.

When all seems well, heat up the key and close it onto the tonehole for a few minutes using a light clamp. To protect the pad from moisture it also helps to seal the edges and the retaining screw using lacquer or a silicone sealant.

The final touch

You may think that by using such a thorough technique and with sufficient time and care every flute would turn out perfectly. I have known most of this information for years, yet the best of my early efforts do not compare with the worst mistakes I make now. I am also well aware that my search for perfection is very far from over. I have seen some brilliant padding over the years. My wife’s Lot, padded by Ian McLauchlan, worked perfectly until the pads crumbled of old age. I hold onto this image and attempt to get closer to it with every flute I pad.

Looking through this article, it strikes me how how dull and repetitive padding must appear to most people. There must be something which keeps me and my fellow padders going. Part of it must be the search for self improvement. Most of you flute players will probably identify with a certain perfectionist streak. The deep satisfaction of knowing that you have excelled yourself has a lasting appeal.

Perhaps the most satisfying part of my work is my collaboration with the player. I really enjoy working with a particularly fussy client who makes me stretch my ability to a new level of precision. I am always very pleased when hearing someone make a great sound on one of ‘my’ flutes.

Another inspiration for me is the love for the instrument. This is why I am so happy working on the old French flutes. They are full of challenges, but the anticipation built up over the twenty hours of work is always rewarded with a most unusual and often stunning result. For me, having these flutes to play for a couple of days justifies working into the early hours. This is also the time when I do the last crucial 5% of the work.

On self help

A group of middle school pupils sit around a large table. They get their flutes out, I put a box of screwdrivers on the table and we all get to work. A couple of hours later, everyone has had their flutes in bits, put them back together with minimal help, learnt a lot about the construction of the instrument, and had some fun in the process.

I have conducted several repair classes in Chetham’s School, Manchester, and I have yet to see any damage caused to the instruments. This is the sort of work, including padding, which everyone can do. Even if you choose not to do all the work yourself, armed with rudimentary knowledge of your instrument you can diagnose problems and know what to expect or demand from your repairer.

Martin Hoffman, 1997