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Padding technique (kindly forwarded to us by Iouri Gulbas) 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 3 mm. 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 1.5 mm. 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 (stabilisers) 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 stabilisers, as well as the right profile of retainer washers and tone holes. 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 tone hole. 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 tone hole 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 5 mm.) 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 tone hole 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 silicon sealant.