<html> <body> Keena, You've gotten an extremely thorough post from Horace (which I'm definitely going to save, Horace!) :-) but if this isn't already too late and if you're very limited on time, here might be a solution from a post I'd saved from Charles Ball at UT/Austin. (Although I think I'd stick with the "liquid" solution Horace mentions or use a VERY thin solution of the other!) ======================================================================== Take a small piece of music wire, perhaps 17 or 18 gauge, and dip it in your favorite keytop solution.  Then quickly lay it across a string groove in one of the hammers you want to "brighten".  Repeat this process for each string groove.  Two or three applications may be necessary.  This will give just a bit more edge, without any big voicing consequences, since the hardener does not penetrate beyond the surface of the felt, and without any change to the UC voicing. When the piano is returned to its permanent home, you can lightly file away the residue, or just give the hammers a light brush or two with a suede brush and you are back in business. This works like a charm with the hard compressed hammers one finds in Asian and European instruments, because the basic foundation of firm felt is already there, and it is only the surface that needs a boost.  It is also great for lazy technicians like me, who do not want to have to do extensive voicing after juicing! Good luck, Charles ==================================================== Hope this helps. Avery University of Houston <blockquote type=cite class=cite cite>I have a Hamburg Steinway D to tune for a concert and the Artist would like to have the bass hammers brighter but not louder. Any thoughts are appreciated. Keena Keel,RPT</blockquote></body> </html>