Getting the old bushings out: I used to use steam, but I heard from collegues that it´s much easier and quicker to use ethyl alcohol (spiritus). Never tried that myself. But they say that subsequent steaming is not necessary. The felt will just dissolve from the wood. Installing the new felt: thread the felt thorugh the slot between key and key button and push it with a needle from the key balance hole upwards. I apply a thin layer of TiteBond to the felt that is sidewise of the key button and pull the felt from above. I use clamps and no cauls. Look here for these clamps in the catalog (item no. 42.05.00). http://www.pianoteile.com/kataloge/pdf/Werkzeugkatalog.pdf The reason for using clamps instead of cauls: they were not available in Germany for many years. Nowadays the are available. I ordered cauls from this catalog, item no. 42.05.22. But I have not used them yet. http://www.pianoteile.com/kataloge/pdf/Werkzeug_E2.pdf Gregor Date: Sat, 11 Jul 2009 17:37:49 -0700 From: tunerryan at gmail.com To: pianotech at ptg.org Subject: Re: [pianotech] Balance rail bushings Matthew, One thing I discovered when I started replacing keybushings back in the 90's, was that it was easy to have them come out too loose. I like a firm balance rail bushing with only a few thousands of play. If you use standard 146 cauls and leave them in to dry, your balance rail bushings will be too loose. Nobody ever told me this when I was starting out! Bill Spurlock sells a set of balance rail cauls that are not oversized like the standard ones. These will leave the bushings a little tighter. Even so, I pull the cauls out after about 15 minutes to allow the bushings to expand slightly. This seems to get them very close to where I like them. Also I prefer the balance rail bushings to have ears. Others prefer to have them cut flush with the top of the key, but I see no advantage to this. By stretching the felt over the top of the key, I believe it puts a little tension in the felt which I feel is beneficial. Additionally, the ears sit up about a millimeter or so above the surface of the keybutton - this gives slightly more support - again, another advantage from my viewpoint. If anyone knows of a functional advantage of having the cloth cut flush, I'd like to know what it is. Of course, hot hide glue is the correct glue to use. It gels on the surface of the felt, leaving it more resilient, and it is easier to replace the bushings in the future. For getting old bushings out, I find it is best to soak them first before using the steam. Formula 409 seems to work the best! I mix it with 50 percent water. I use small wedges cut from hammer scraps that are small enough to fit into the mortises. These get soaked in the solution and inserted into the keys. If you leave them overnight they may dry out, so it is best to cover them with plastic wrap. In the morning you will find that they will usually almost fall out with no steam needed. Sometimes a little steam will still facilitate removal. On Sat, Jul 11, 2009 at 3:00 PM, Matthew Todd <toddpianoworks at att.net> wrote: I will be doing a balance rail bushing job soon, and just wanted to see how replacing the balance rail differs from replacing the front rail, i.e., the key buttons. I am assuming I can take off the old ones using steam. And then, what would be the best cauls to purchase. Thank you for the advice, TODD PIANO WORKS Matthew Todd, Piano Technician (979) 248-9578 http://www.toddpianoworks.com -- Ryan Sowers, RPT Puget Sound Chapter Olympia, WA www.pianova.net _________________________________________________________________ Drag n’ drop—Get easy photo sharing with Windows Live™ Photos. http://www.microsoft.com/windows/windowslive/products/photos.aspx -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090712/28aa98d0/attachment.htm>
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