Rogerio, I have a "stand" that was designed by Del Fandrich. This stand supports one hammer shank at a time, in a high position above the rest of the hammers, at rest. I use a sandpaper file with 60 grit emery. Make several "swipes" across the tail, at the arc area. And, while you are at it make a pass along each leading edge of the hammer tail, to "soften" that edge. This whole procedure, for a whole set of hammers, should take around 1/2 hour. It will assure good checking without damage to the backcatch leather. It is standard procedure on all new and used hammer sets, before doing the regulation. Oh, it will create some sawdust that gets into the action, so be sure to blow out the action afterwards. Best Regards, Joe Garrett, RPT, (Oregon) Been There, Didn't Like It, So I'm Here To Stay! [G}
This PTG archive page provided courtesy of Moy Piano Service, LLC