John, In spite of your statement, "Neither of these appeal to me as an appropriate repair", I invite you to reconsider the common nail (pun intended). Back in the 70's, I experienced an unusually high failure rate on both hangers and hanger brackets in new Story & Clark consoles. Since things tend to run in cycles, I then began finding instances of other brands with the same problem. The following primer, developed originally out of necessity, was refined and is now my SOP. Discussion: I think it's important to assess the materials under discussion. The damper rod itself is either a very hard material (in comparison to hangers), if in fact not a hardened material. The damper hangers are considered a "soft" or "mild" steel. Herein lies the key. Whatever qualifies as a soft or mild steel may be used to fabricate a replacement hanger. For instance, while they would not be acceptable, old-style wire clothes hangers fit under this heading. Likewise, nails qualify, since they will bend x or xx times without fatiguing and breaking. Since nails are available in an assortment of sizes, they are the least expensive source, and commonly available in remote areas. I don't have the article, but apparently your PTG reprint parallels this thought. In short, I have used various materials to effect a repair, but most of them were... nails. I won't address the top-down procedure, since you seem to have that covered; I will focus only the nail issue, with some possible overlap. Procedure: - Hacksaws, files, and heavy (piano) wire shears all have a place, but a corded/cordless Moto-Tool is a nice expedient. [Off-topic, but I can now highly recommend the B&D cordless "WiZard": Two preset but appropriate speeds, less expensive to "feed" (battery cost), efficient charge to use ratio, pencil-grip area on barrel for more precision work, manual chuck, spindle lock, etc. I have one in the shop, and one in the service vehicle -- it has replaced my cordless -- and sometimes corded -- Dremel devices.] - If stub of broken hanger remains in rod, support the damper rod for driving out stub (partially opened vise jaws with synthetic, rubber or hardwood faces, to prevent marring/nicking the damper rod). In field service, I would use the jaws of my B&D "BenchMate" (bench top version of WorkMate). Likewise in the field, the punch can be... a nail, rather than putting a center pin punch at risk, or using an assortment of proper pin punches -- that I don't carry! - Choose the closest nail to fit the hole in the damper rod, realizing that (a) the hole in the damper rod is the primary criterion for sizing (b) the hanger bracket *may* need to be rebushed to accommodate. A snug fit in the damper rod is good... and enough. Slightly loose is also okay, within limits. - Remove the head, and portion containing any concentric (gripping) rings just below the head. Likewise remove the pointed nail tip. Dress any rough edges/burrs on both ends for safety purposes. VISUAL IMAGE: straight, flush-cut piece of mild steel. Tools: Cut-off wheel in Moto-Tool, then either grinding wheel in same tool or file. - Here I like to polish the nail surface to a high shine. This provides an inherently slippery surface and removes any oils, contaminants, or coatings from the nail. It is also about here that the term "nail" is only a memory. Tools: [in field, polishing wheel/rouge on Moto-Tool], otherwise shop equivalents. - Create a swedge (swage?) where the nail enters the damper rod. In absence of a machine lathe and knurling accessory, this (may) be done by rolling the nail between two files (least effective, hard to control); repeated "bites" in the pipe gripping portion (not edge face) of Vise-Grip Jrs. (Mod 5WR), or, (in case the nail prevails over human gripping strength), the Vise-Grips and a hammer diligently rapped on the back of the jaw while the nail is held captive in the jaws. The width of the 5WR's jaws is coincidentally correct for the job, so make the edge of the "stock" flush with one edge of the plier jaw . Rotate the stock through several successive bites. VISUAL IMAGE: straight, polished round stock with heavy(ish) fluting on one end, similar to that of the fluted portion of a pedal pin. Any excessive fluting will be taken care of automatically during installation. Tools: as detailed. - While the stock (no longer nail) is still straight, drive swedged portion into *supported* damper rod. As promised, excess swedging is removed automatically. - File or grind a new pointed end. The only criterion is a "relief" for ease of entry into the bushed hanger, so it doesn't need to look like either a nail or a pencil point -- just a slightly chamfered area to act as a guide. - Bend an appropriate 'L' to agree with extant hangers. No word help here on the "moment" of the bend, except that sometimes you luck out by using one set of 5WR's (padded) locked on the stock where it exits the damper rod, and another set of 5WR's (padded) or a hollow dowel/tool to accomplish the bend. This is without doubt the trickiest part of the job. There may be a formula for such bends, but I don't know it. So, since I'm already tooled up, I usually make a couple hangers at the same time -- just in case! - [Alternate method] Pre-bend stock, using a wire bending brake (if they be found anymore), or the above plier trick, or a plier and a hollow device (balance rail punching settling dowel?) If possible, hammer (to add rigidity), otherwise file (negates rigidity and strength) a slight detent at the moment of the curve, and use this as an "anvil" for driving in stock. (You'll often see these detents on existing hangers, although I think these are a byproduct of a more automated bending process. Since the detents are "out of the circuit", they do no harm.) Although slight rotational adjustments can be made, they (should be) difficult and also compromise the swedging. Observing orientation of 'L' while installing is preferred. [Using this method, I try to maintain "factory" appearance and function. I've never needed any shim stock, CA glue, or other fillers. However, if the process ever failed for whatever reason, I wouldn't hesitate to try... something.] - Use "sighting" method to assure all hangers are in same plane; adjust alignment accordingly. - Rebush hanger bracket (if necessary), lube all hangers and rod, re-install. [Finally, I was once told of a replacement for a broken hanger *bracket*. The dialogue involved the use of a TV antenna part -- I want to recall something to do with a "stand-off". The stand-off's I'm familiar with do not qualify. Likewise, any other antenna hardware doesn't seem appropriate. This is added in case I'm overlooking something, otherwise as food for thought.] [cut] A new chapter member sent this question to me. Although I have realigned bent hangers, I have never replaced a broken one. Can anyone help him? The Pianotech archives only have a discussion of bent hangers. Thanks, John Baird *********************** [cut] Jim Harvey, RPT harvey@greenwood.net
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