Over there David Stanwood has a good deal of knowledge specific to your question. Andre here in Europe also has built up a good deal of direct knowledge. I believe Stanwood often does a class about hammer felt, how its made, what grading is about etc. One thing I believe is part of how the grading of the felt is determined is the fineness of the individual felt fibres themselves. Higher grade hammer felt is finer stuff. More processing in this regard means seeling out thicker stands and as such will not affect the degree of lanolin left in the felt. The elasticity in the individual fibres for any raw material will be unchanged as well. What will be changed is the number of fibres in any given finished felt block. At least thats my understanding at present. Stanwood may volunteer more on the subject. In the end tho... I have the sensation that it is easily as much the pressing process that molds the felt into the hammer that is important as much as the ground floor quality of the felt itself. I cant lay any specific scientific data on the table, but Renner Wurzen II hammers are much nicer to work with and produce much nicer results then their Wurzen I hammers do. I also understand that Yamaha chooses Wurzen II for their most expensive line and uses I for the rest at present, tho I still have not been able to confirm directly from Yamaha that this is so. Talk to Stanwood about felt. RicB Can anyone comment about different grades of felt generally, Wurzen felt specifically. Does a higher grade mean more processing necessarily? If so, does it also mean less lanolin left in the felt, less elasticity for in the fibers or anything else that might be considered a detriment? It seems to me that higher grade may not necessarily produce a more resilient hammer (felt), or better tone. Any comments? David Love davidlovepianos at comcast.net www.davidlovepianos.com
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