Very thorough response, Paul, and I second Alan Eder's comments re: Mario Igrec's book.
I would offer a number of 'clarifying' comments/questions, intended mostly to confuse the listener. It would, perhaps, be helpful to devise a chart that displays the range of causation as well as the potential solutions, and under which circumstances a particular remedy might be the most appropriate, or perhaps a logical order of approaches. For example, I would think that you would not find much in the way of results from H
20/ Alcohol shrinking if you've already applied protek or some other oil. If the problem IS related to pin corrosion, the only (long-term) solution would be to re-pin.
Regarding H
20/ Alcohol, the problem with using the common product, denatured or not, is that the actual water content is unknown. You would likely get some shrink response with straight de-natured product (from the residual water content), even without mixing with water. I've been using (up) a quantity of anhydrous (virtually no water content) ethanol I got quite some time ago, locally. (Place blew up a short time later, so you can try Spectrum Chemical, on-line).
I did an action last week, (pre-1900 Steinway with extensive sluggishness but no verdgris). I made up small amounts of 3 ratios of water to alcohol: 1:1, 2:1, 3:1. Started with straight anhydrous, then went to 1:1. For those that didn't respond, 2:1, and so on. Very controlled.
Two other things.
I remove parts from frame. For anything that requires consistent, marginally reliable results, I have to have the part in-hand. Depending upon the circumstances (i.e. quik-fix).
The other thing is that I use an assortment of sizes of needle applicators that are available from Gaunt Industries,
http://www.gauntindustries.com/ For controlled application of water-thin (or thinner) viscosity, I use their Hypo 16 (27 gauge) with an OD of .016" or Hypo 20 (25 gauge).(.OD .020") Don't get too confused. The higher the gauge number, the smaller the wire size (number of requisite drawings), however, I'm not sure about the inner diameters, yet. These gauges allow you to apply a drop, literally, to each bushing, which is all that they often need.
Last: the Mannino tools are called 'broaches', and should not be confuse with tapered or fluted reamers. They're very good.
Good luck.
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David Skolnik
Hastings-on-Hudson NY
914-231-7565
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Original Message:
Sent: 07-08-2014 08:17
From: Paul McCloud
Subject: Slow Returning Hammers
Hi, Nick:
This is one of the most common problems we see in pianos. Think about how the hammer flange is constructed. There's a hole lined with felt, and a pin the size of a needle is inserted as an axle. If the felt binds on that pin, you'll have the symptoms you're describing. What has caused the felt to swell and bind on the pin is usually excessive moisture. That is the most likely scenario. There are other causes of the pin binding in the felt. For example, the Steinway company used to dip the whole part in some kind of solution that was supposed to keep the part stable and free from the effects of humidity. That solution had some acidic content which corroded the pin, and it would cause friction and a sluggish action as a result. Other pianos like Wurlitzer used silicon oil for similar reasons, and after many years, it needs to be treated again with something to free up the parts.
When a piano hasn't been used for a long time, the felt can start to stick to the pin. The most often used product we have available is Protek CPL. You will need a bottle of this and an oiling pen or other applicator to apply it to the felt in the flanges. Try it on one flange, both sides, and work the hammer back and forth to see if it will free up. If doing this doesn't make it better, you likely have some other cause like moisture. Don't continue to put Protek on the other flanges. There are some steps you can take to correct the problem.
If you can identify the cause of excessive moisture, such as the piano living in a damp area near an open window, a kitchen or shower, on an island or near a beach, it will give you a hint as to why it's not working properly. You could put the action in a box with some lamps to gently heat the action to dry it out. You'll need to arrange for the moisture to escape during the process. The trouble is, even if this works the problem will return unless you address the cause in the first place. You could install an damppchaser dehumidifier to prevent the moisture from invading the piano. That would be a long term solution.
Another way is to remove the pin and ream out the felt a little bit. I use a set of Mannino reamers available from the supply stores. These were developed by Don Mannino, who also reads this list. It's time consuming to remove all the hammers and repin all the flanges, but it works and is also a long term solution.
There is another procedure which you can use that doesn't require drying or repinning. If you mix some denatured alcohol and mix with water, say about 1/4 to 1/3 ratio water to alcohol, you can apply that to the flange felt. It will cause the felt to swell because of the water, and the alcohol will make the water thinner to penetrate the felt. The felt will temporarily swell and bind even worse than before, but after the water evaporates, the pin will be looser than before. You can also vary the ratio if needed for flanges that are more or less affected. After treating the flange felts and they're dry, put some Protek on the pins. Often, the Protek will be much more effective after this treatment. Don't go too far with the alcohol treatment, or the flanges will be too loose. Don't ask me how I know (DAMHIK. Get used to this acronym. You will see it a lot on the forums). I would hesitate to use the shrink solution on a high-end piano like a Steinway since you don't know how the flanges will react, and the pinning won't be very consistent. A hammer flange should have some friction but not too much. There is a tool to measure the friction, called a Correx gauge (sp?), or you can just hold the flange and swing the hammer back and forth. It should swing back and forth 4-6 times. If you don't get that much, or you get unlimited swings, your flange is too loose or too tight.
You can also just use a heat gun to heat up the flanges and drive out the moisture. You can use the heat guns sold in the piano supply catalogs. Don't use the heavy duty guns meant to remove paint, unless you plan to burn up your flanges.
If you don't have the book Piano Tuning and Servicing by Art Reblitz, go and purchase it. You'll find it very helpful, as well as other books offered by the Guild and in piano catalogs. Steve Brady also has some very helpful guides for servicing pianos in the home. It will be easier to use these reference books even while out on the job. Just make some excuse to run out to the car to read up on something you are having a problem with. We've all done it. Make a friend at the next Guild meeting, and call him to ask what to do when you run into problems.
Well, I hope this helps.
Paul McCloud
San Diego