On Thu, Mar 4, 2010 at 2:33 PM, Paul McCloud <pmc033 at earthlink.net> wrote: > Unless you remove the pin from the flange, no matter what type of heat you > use (soldering iron or zapper) the pin is conducting heat to the birds-eye. > Now if you remove the pin and disassemble the flange, reinsert a pin and > heat it, then it's a whole different ball game. Ironing down the fibers is > going to be a good thing if not overdone and scorching the cloth. There has > to be some temperature limiting system. Sizing the felt with a shrink > solution, with a pin inserted, works well to compact the felt in the > bushing. It seems to me, though, that doing that makes it likely that a big > increase in humidity is going to re-swell the bushing again. Back to square > one. > I'd like to hear from some old-timers about this process of > shrinking/sizing the bushings, and the longevity of it. It seems that on > pianos made overseas (China especially) that bushings seem more prone to > seizing because of the climate change. > Paul McCloud > San Diego > > -----Original Message----- > From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On > Behalf Of Poppy Miles > Sent: Thursday, March 04, 2010 10:05 AM > To: David Ilvedson; pianotech at ptg.org > Subject: Re: [pianotech] Center Pin Zapper > > Although I'm still entertaining the idea of making a zapper ( I saw one > that seemed to work without burning the birdseye or the bushing cloth). This > zapper is pretty elaborate, and manages to deliver a very small charge > through the pin, and has a beeper that goes off when you locate the sides of > the pin with sharpened tongs made of spring steel ( the charge is deadened > with a block of wood where you grab it.)The main thing that has discouraged > me from making a copy of the one I had used, is I don't like the idea of > heating up the birdseye. I've heard they can be worse than a waste of time. > I would have to make, and study the effects of this tool on a scrap part > beforefeeling confident it would be safe and reliable. A few of you said > they are not. Without a sort of experiment where the humidity is > controlledor measured alongside a reamed part, I can't be sure. Reaming > workswell, but all pinning changes with humidity. Also, after reaming > thebushing cloth is fuzzed up, so the action center needs to be worked in > order to smooth it. You also have to be very careful to ream evenly, and > there is a chance of pushing out a bushing. Sometimes, after repinning the > part becomes looser, because the part wasn't worked enough.I've seen > alcohol/ water treated bushings regain a little of their tightness, but I'm > not sure if that was due to a change inthe humidity or not. It's also easier > to get a small change with reaming, than with a solution. You also have to > wait for it to dry. I've saw a demonstration at convention where the > lecturer used the old trick of heating up the centerpin with a lighterto > loosen it. I tried this and wished I hadn't, ( the bushing looked a little > charred). I'm sure there are people who this technique works well for, but I > will pass. I do actually reason forgiving youall this well known info: all > methods seem to have drawbacks. So why not try a new one? My key > bushing iron works well, so maybe using heat instead of electricity, > reaming, or solutions could work. Maybe there's not enough pressure on the > bushing with a zapper, and the problem of heating the birdseye could be > eliminated ( by separating the parts.) If anyone feels like designing a > heated centerpin caul type tool ( modified soldering iron attachment), > avariation on the lighter method where the amt of heat would be controlled > more carefully,I think it might work. That said, I will continue using my > reamers, after all, I am patient as is anyone who has read this incredibly > long post. > > > > > > >_________________________________________________________________ > >http://redirect.gimas.net/?n=M1003xHotmail2 > >Alles in einem Postfach Ich will Hotmail! > > > > > > I guess I qualify as an "old-timer" after 40+ years? The question is apparantly more detailed than I originally thought, some are expecting miracles, ie clearing of vertigris, while others are only trying to speed up a sluggish moving hammer or jack on a non S&S piano. Verdigris is an ongoing problem and the zapper will not cure it. It MIGHT be benificial but IMHO I doubt it. I have used the zapper with limited results, due primarily to the necessarily short time one uses it. It cannot "iron" the felt because the action joint remains static while it is used, so all it really does is dry, through the process of heat, the action center. If measures aren't taken to counteract the humidity that caused the humidity related sluggishness in the first place, it will return, soon! Even if measures are taken it will probably return. I have used alcohol & water with much better results. Some of you may recall or may have come across the Wurlitzer actions from the early through mid '70's, when they were making their own actions, very tightly center pinned. I still find some today, if they aren't played regularly the hammer/flanges become very slow & sluggish. On some of the worst ones the whippen flanges will also hang up and even the jacks will return slowly. I bring the action into the shop, wet down w/Q-tips every action center with a 50/50 mix of isopropyl alcohol & water & let it sit, depending on the severity of the sticking anywhere from overnight to a few days. I then use a hair dryer, heat guns get too hot and will cause glue joints to let go plus they don't have the blower force of the hair dryer, to dry what hasn't dried naturally. I rarely have a problem with them after that. On the opposite of that 4 years ago I ran across a Samick about 7-8 years old that had "sticky keys". Upon examination I saw the jacks weren't returning just in the tenor section, I stretched the jack springs but it only helped a few, I asked if the had any rubbing alcohol and a few Q-tips, I was 30 miles from home, I "treated the jack flanges, tuned the rest of the piano with my ETD, then borrowed their blow dryer and dried them and no more "hanging jacks". I tune that piano every year and the sluggish jacks haven't returned. (snip)the bushing cloth is fuzzed up, so the action center needs to be worked in order to smooth it. You also have to be very careful to ream evenly, and there is a chance of pushing out a bushing.(snip) Poppy, after you ream a bushing you should burnish(Center pin Burnisher Schaff Pg.49 No. 155) it then it wouldn't be "all fuzzed up", that's what burnishing tools are for. As for reaming evenly, The Mannino reaming tools(Schaff Pg.50 No. 220) removes the guesswork from that. As for pushing out a bushing, it happens. I have a pin zapper, on a shelf in my shop, it's rather dusty as unused things in piano shops tend to be. Mike -- It is the mark of an educated mind to be able to entertain a thought without accepting it. Aristotle (384 BC - 322 BC) Michael Magness Magness Piano Service 608-786-4404 www.IFixPianos.com email mike at ifixpianos.com -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100305/0eae9328/attachment.htm>
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