Agraff and capo problems can be corrected at least temporarily by string manipulation with special readily made tools. I found especially on high tension scales that even clean strings can wear/indent/burnish enough of an aberration to the ideal agraff interior that a gripping effect from more than minimal contact will cause the string to resist rendering smoothly or even at all. I dealt mainly with S&S B’s from ‘04 to pre forties then two D’s and an M in the 60’s, the other pianos lacked enough musicality to warrant deep attention until four M&H’s which came with their own peculiar problems being made just prior to American closing. If the indent is much deeper such as even 25 degrees around the string than the minimal grabbing it will look like a distinct groove and this at the lessened diameter of the stretched string. A tool made of at least one string size (preferably 2 or 3 sizes of the original size, four to six inches long and allowed to curve to c. 3-5” radius and scored by rolling a new fine rattail mill file on the inner 180 degrees of the curved wire, and then with the string out of the agraff the tool placed into the agraff hole and with grippers at both ends, rag the grove until the original groove is replaced by the wider groove, The hole being elongated vertically does not widen the hole to weaken the agraff to break at the holes. I have not had any agraff break at the holes. This will make uneven in height that hole with the others in the agraff and will have to be measured and corrected before restringing that agraff unless equal treatment is given the remaining holes. Any number of tools can be made to show the relative height of the holes, Having just moved to a new home the example cannot be found to be shown in use. A prime reason for redoing parts of the piano is restoration of a collectable and also not running into the meriad chores doing new aggrafs. The capo on the other hand unhardened can be subject to the same grooving which can be negated by sliding the unison sideways with a tool made of strap steel 1/8”x1/2”-5/16” with three string grooves sawed into the end and long enough to hold and with a hammer tapping the tool close to the rib to slide the strings sideways and back. If either the agraff or capo are so soft as to create from any action a feather edge on the sounding side a burnishing action may solve the problem; Loosen the string to be able to raise the string about 4-5” out from the bearing and about 2-3” high and sweeping the the raised loop in an arc of 90-100 degrees to burnish the offending edge. The string hook for lifting the string should have a large enough radius to prevent kinking the string. The string becomes the tool to burnish the bearing. I prefer the softer capo edge for serviceability because the casehardening of the edge may bring the hardness of the two elements to equality which in engineering is tantamount to friction problems. One metal of a friction pair must be softer to be lubricious. Also I am afraid that any part of the string system being harder than the string causes the string to be subject to the distortion. On Aug 7, 2010, at 9:05 AM, Ron Nossaman wrote: > Adkins, Richard wrote: >> I saw a PDF on the web this morning from Ron Overs stating >> that he makes agraffes out of hardened steel for heavy use pianos. >> I'm not sure if he sells them, or how he sizes them, or threading >> specs. If he would/does, then I would hope he would make some for >> Steinway, as that is what many of us CAUTS are needing them for. > > He had been electroless nickel plating brass agraffes too, for the > harder bearing surface. This is something anyone can do. > Ron N > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20100807/368d9b8b/attachment.htm>
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