the hammer In 90% of cases, the replacing of the felt can be carried out whichever the model, type and date of manufacture of the piano.Our felt comes mostly from Germany and offers a large variety of density, weight and thickness.  As a general rule, the choice of felt is made depending on the make and model of the piano.  It is however possible to cater for different requests regarding hardnesses, density and shape. The re-felting process requires numerous stages. Apart from choosing the felt, the pre-shaping of the band of felt and the pressing of the hammers are important stages:The pre-shaping of the band is made in a hydraulic press that can exert up to 35 tons of pressure.  It is performed at low temperatures to conserve the natural qualities of the felt.The pressing allows the band of felt to be glued to the heads of the hammers using 12 tons of pressure. Some sets of hammers, in particular the hammers made by Erard parallel type, the square pianos and the Fortepiano, require a different process for re-felting.  To conserve an identical tension on the felt, and to conserve the underfelt and the [skin traps], the re-felting is entirely performed manually, according to the traditional procedures specifically designed for these hammers.
why re-felting the hammer
how refelting the hammerhead