Ibach piano built between 1925 and 1930, length 165.
Despite its age, the piano has been used very little; however, the hammers were too marked and therefore have been shaved. Obviously, the distance of the escapement point from the hammer strings has changed. The shaving did not remove more than 2 millimeters. Is it sufficient to adjust the jack button or must all the mechanical ratios be reviewed?
The key dip is currently 10 millimeters.
Is it worth regenerating the hammer felts with a brushing?
A curiosity: there is no trace of graphite on either the tangent or the tip of the jack. The surface feels very smooth to the touch; is it worth applying it or not?
Let's start with the escapement lever. Some manufacturers do not use graphite, but a glossy varnish. In that case, it is not advisable to apply graphite. If the rollers should make noise, "cracking," when lowering a group of keys slowly, then one can rub them with soft graphite sticks for drawing ( ? perhaps 6 B?).
When the hammer rail has been shaved, the regulation must be varied. After restoring the correct hammer-string distance, we will then adjust the escapement point and check the hammer drop and the distance of its repetition from the string. The 10 mm should not need to be changed. We will have a little less power due to the reduced mass of the hammer, which must be retuned.
The most important thing, however, is the striking point. Shaved hammers will strike the strings at a different point than the original relative to the capstan. Therefore, it will be necessary to restore it by raising the action (upright piano) or pushing the action-keyboard slightly further in (in the case of a grand piano).
It is evident that, in any case, a shaved hammer rail, due to the change in regulation, changes the "geometry" of the action. In particular, the verticality of the escapement lever relative to the wooden core of the roller is altered. This will slightly compromise the attack of the Forte and Fortissimo.
