The leather pad on the baroque flute key usually bears against a flat area around the tonehole in the foot joint. To seal properly the pad must lie perfectly flat against the flat area when the key is closed. It is very unlikely that the square flap of the key onto which the pad is bonded will lie perfectly against the flat to the accuracy needed. Even a gap the thickness of a piece of paper causes a noticeable leak. Misalignment can be due to any number of reasons and slight misalignment can be caused by the leather not being exactly the same thickness as that used originally, a slight twist in the key shank caused by a drop, or the wood of the keyway slot shifting slightly with moisture. .

However, the leather pad is bonded to the key using an adhesive which will fill up the gaps and corrects for slight misalignments. Two adhesives were commonly used to bond pads onto keys, shellac and sealing wax. They both share the property of becoming a thick gooey liquid when initially melted, rather than paraffin wax or beeswax which go from a solid straight to a runny liquid. This means that the wax or shellac can be melted while the key and pad are assembled on the flute and the pressure of the key will settle the pad perfectly into position.

The leather used to make the pad should be soft and thin. This is because the thin leather usually has the finest grain and being thin will conform to any slight irregularities in the surface of the flat sealing area. It is often possible to buy offcuts of the leather used for glove making. Craft shops sometimes sell assorted bags of scraps, each scrap being large enough to make twenty or thirty pads! Many of these will be bright colours, but usually there are a number of brown and black pieces. Brightly coloured scraps can be dyed black if necessary.

The adhesive is usually shellac or wax, both of which can be removed gently heating the back of the square portion of the key over a candle and then stroking the square portion pad side down across a piece of kitchen towel. Once the key has cooled put the square portion of the key down onto your piece of leather and either mark out the size with a pen, or use the square portion as a guide and cut around it with a scalpel. If you do use a scalpel to cut around the key then be careful not to catch the key with the edge of the scalpel, as the silver is so soft the scalpel will shave a small amount away!

If the previous owner or repairer used a solvent adhesive (like UHU or Bostik) then you will have to chip the adhesive away, being careful not to score or bend the key. If you can find a solvent for the adhesive then this may soften it enough to allow more straightforward removal. For this reason it is not a good idea to use a solvent adhesive to bond the leather pad into place.

To check for misalignment remove the key and remove all traces of the old pad and adhesive. Assemble the key back onto the flute and slip the new pad under the key to space the key slightly away from the flat around the hole and allow the key to close trapping the pad in position. Check the gaps between the corners of the key and the flat. If the key shows signs of serious misalignment with the flat (i.e. greater than 1mm difference between the gaps at the corners) then the key needs to be re-set. This is best done by a woodwind repairer, flute maker, or at a pinch a jeweller. If you are going to try to straighten a bent key then wrap something around the key before gripping it in pliers or whatever. Silver is an extremely soft metal that bruises easily, and it will take you a lot longer to remove plier marks from a key than it will straightening it! If you are ch

Shellac

1. Remove key, remove old pad, and trim a new pad to fit.

2. Trim a flake of shellac to approximately the shape of your new pad.

3. Assemble the key onto the flute.

4. Open the key and slip the pad into position on the flat (shiny side down of course).

5. Slip the flake of shellac onto the pad and align.

6. Close the key sandwiching the flake and pad underneath.

7. Heat the square portion of the key gently using a candle or a match until the shellac melts and starts to seep out.

8. Allow the key to cool and carefully trim off the excess shellac that has squeezed out. It should snap off when cold.

Sealing wax

1. Remove key, remove old pad, and trim a new pad to fit.

2. Heat square portion of key gently over a candle testing temperature continually by pressing a stick of sealing wax against the underside.

3. When the wax melts smear a coating over the underside trying to keep the thickness of the wax as even as possible.

4. Assemble the key onto the flute

5. Open the key and slip the pad into position.

6. Close the key trapping the pad underneath.

7. Heat the square portion of the key gently using a candle or a match until the wax melts and starts to seep out.

8. Allow the key to cool and carefully trim off the excess wax that has squeezed out. It should snap off when cold.

Don't try to drip sealing wax onto the underside of a cold key. The metal surface chills the wax instantly and it won't stick. Be careful when heating the key when it is assembled onto the flute. It is easy to overheat the wood which can lead to it cracking. Make sure the heat only acts on the back of the square portion of the key. I use a soldering iron to heat the key, but I keep an iron specially for this purpose. Any residues of solder on the iron could stain the silver on the back of the key, so use a new iron or a new bit if you want to do this.

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