Plastic solution on a Schimmel hammer is, in my opinion, a mistake. That is a tensioned hammer that should not require hardeners to make it brighter (unless it has already been excessively needled in the crown). A light filing or even ironing the felt should sharpen the attack. If the hammer has not received deep shoulder needling, that can sometimes released tension toward the crown of the hammer and result in a brighter tone. You need someone with voicing experience. Shortcuts make for long delays, as they say. David Love
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