Steaming has worked well for me to extend the life of worn hammers on Yamaha G1"s (etc.) Steaming will lift the grooves and expand felt when compacting happens. Therefore, the timing of the steaming is critical when steaming old hammers. NEW hammers will not have artificial hardeners (excepting Steinway) so the location of excess hardness is critical. Scratch the sides of the hammer and listen carefully to the "pitch" of the scratching. With some practice you will learn to identify the depth of the offending hardness. My suspicion on the new extremely bright hammers is that surface tightness is to blame. This might be rubbed out, even by hand, or by a light sanding, or by a blunt, round , heavy object. You need to develop a sensitivity as to how the hardness is acheived, either through density (heavy mass /size) or hardener(sounds very scratchy), surface hardness (ping in articulation at any dynamic), too much filing (small hammers,hard surface), or hard throughout (scratchy, hard surface, "thud" at impact). Hammers which are hard throughout will probably need a variety of surface treatment and deep treatment. Deep needling or complete(but even) steaming can address inside hardness, and light sanding, rubbing, or shallow needling can address the more surface hardness. New hammers which have too much hardener may have begun their life as too soft, and were then saturated. The outer layers may have remained soft, resulting in a continued problem with "too soft" hammers. At this point, if the hammers were filed to attempt clarification, the result will be hardness throughout with a tight surface, and small size. I believe the only way to save this regretable situation is to steam, (breaking the interior connections of the hardeners), file to shape and "reorganize" the surfaces rubbing with pressure or heat to achieve enough articulation. Results will improve with experience! Good luck!
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