David Boyce said: "Yesterday I tried hammer filing using a small Dremel-type tool for the first time. Hitherto, I've always used home-made sanding paddles. I've been meaning to ask for a while, what others do, if anything, to improve the appearance cosmetically when the top surface of the hammers is very grubby. I found yesterday that the dremel tool was quite good for that. I am attaching two pairs of before-and-after pics. One from hand filing, and yesterday's with the little drill. The angle of the photos makes it look as if all trace of grooves was removed, but actually that's not the case. Plus, the photos seem to exaggerate small unevenesses! I have read in the past, of using dressmakers' chalk to brighten grubby hammer topsides, but that seems a laborious process and somehow slightly distasteful. Best regards," David, After looking at the pictures, I would like to make some commments. First, I would suggest that more practice at getting, (and keeping), a single "layer" of felt, WITH a good sandpaper file, is the way to go, IMO. Machines, such at the Moto Tool, are not that controlable. Let's look at the reason for doing Hammer Surfacing, (please NOT 'shaping', which is a misnomer, that creates the wrong cerebral image, IMO.<G>), is to create a continuous layer of felt that is under tension. This tension, gives us the "platform" for adequate tone production, So....good hammer surfacing techniques are of the utmost! The picture, (after), showed that: 1. you need to start lower on the hammer. In the area of the widest mass of the hammer. Actually, slightly below that is the best area to begin the "peeling" of felt. Yes, that is exactly what we are doing...peeling Layers of felt.<G> 2. you need to control the squareness to the hammer postion of the sand paper file, since there are several hammers that have poor strike points. (mishapen). That is evident in the fact that the filing did not start out "square" at the shoulders. Once the initial surfacing is done, then, strip sanding is the next step. (Yamaha method) After that, then the only thing to address is the dirty felt below the shoulders. this can easily be cleaned up with a light, fine wire wheel/brush, in a small hand drill. Make sure that you have a very good shank support method to keep from stressing the action centers! I've given Hammers Surfacing Classes at a few conventions and hopefully this will help. Hammer Surfacing takes LOTS of practice, (just like tuning<G>) Best way is to get a whole bunch of reject hammers from hammer replacement projects, from yours or another rebuilder's scrap heap.<G> Good luck. Regards, Joe Joe Garrett, R.P.T. Captain of the Tool Police Squares R I -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20110313/042996a7/attachment.htm>
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