Harp tuning pins "rusted" into neck

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Harp tuning pins "rusted" into neck

Postby Charlie Schultz » Mon Nov 16, 2015 8:02 am

A friend of my wife's picked up a used harp (photos below). It seems the tuning pins are "rusted" into the wood and she is afraid to turn them lest they break. My thought was to try and gently tap them out from the back but wondering if anyone had some better ideas. Oh, and if anyone recognizes the harp, that would be of interest too.

harp1.GIF


harp2.GIF


harp3.GIF
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Re: Harp tuning pins "rusted" into neck

Postby Barry Daniels » Mon Nov 16, 2015 3:44 pm

Often, these type of pins have very fine threads cut into them. Trying to tap them out may do a bit of damage to the wood. Best way would be to turn them counterclockwise in order to unscrew them, but if they are so weak that turning them would cause breakage, then tapping may be the only option.
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Re: Harp tuning pins "rusted" into neck

Postby David King » Mon Nov 16, 2015 4:59 pm

Could you heat them up a bit to help release them from the wood/rust crust?
Piano pins are also sort of threaded tapers and they are pounded in the first time but then unscrewed to be replaced by the next size larger pin (actually two sizes larger). I don't know the exact reasons for these procedures but I'm sure the reasons are good ones as piano tech is a long successful tradition.
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Re: Harp tuning pins "rusted" into neck

Postby Jim McConkey » Mon Nov 16, 2015 8:52 pm

Check out this book. The style appears to be a South American arpa folclórica, and the one pictured in the book on pages 72 and 74 has a similar Indian head and nearly identical reinforced sound ports. Any markings or labels on or inside your wife's friend's?
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Re: Harp tuning pins "rusted" into neck

Postby Mark Swanson » Wed Nov 18, 2015 10:14 am

Yes, definitely heat them with a soldering iron before you try and move them.
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Re: Harp tuning pins "rusted" into neck

Postby David King » Wed Nov 18, 2015 1:20 pm

It certainly is a cool instrument so I hope you can get it playable again. I wouldn't hesitate to show it to a harp maker to get some solid advice. Harps are notoriously delicate, finicky instruments.
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Re: Harp tuning pins "rusted" into neck

Postby Chris Vallillo » Thu Feb 11, 2016 8:04 pm

I restored an 1880 hammer dulcimer which has similar threaded pins and was also in terrible conditions. In fact, the strings had rusted off on the instrument and closed up the string holes. I'd suggest a couple things.

Yes to the heat as already suggested. Keep it light and use a hair dryer or radiant light and gently heat not just the pin, but the surrounding wood. You might gently tap the pins to break the rust bond before trying to remove. Tap gently to the side, not down or you will drive the pins in even further making them harder to remove. I'd also consider applying a bit of lemon oil around the pins and letting them sit a day or more. These will definitely be threaded so take them out as you would a rusted screw; slowly and counter clockwise. They are very similar to piano pins and need to be treated the same way. The threading is extremely fine so it will be a slow process. The pin holes may also be very slightly tapered to create more grip as the pins draws down from the threads.

Do you have the original pin wrench? You can get these at various places including elderly instruments. I've used a socket wrench, but be sure to match the size perfectly or you can strip the pin edges. I've also used an old drum key that was a perfect fit for one instrument.

Rusted metal in wood shouldn't be too difficult to remove, but you must not damage the hole or the pins won't stay tight in the future.
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Re: Harp tuning pins "rusted" into neck

Postby Charlie Schultz » Fri Feb 12, 2016 7:22 am

No, no original wrench, but it turns out my harpsichord wrench was a pretty close fit and with that we were able to get them all free. She borrowed the wrench and was going to put on new strings- I haven't heard yet how that is going (e.g. if the pins will still hold under tension). I'm guessing they have fine threads, but with the rust it was really hard to tell. The pin diameter was smaller than any of the HD or harpsichord pins I have laying around.
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Re: Harp tuning pins "rusted" into neck

Postby David King » Fri Feb 12, 2016 7:18 pm

I wouldn't hesitate to ream out the rust and start over with new larger pins. The rust can be incredibly hard and can ruin an HSS drill or reamer so it's good to have spares around.
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Re: Harp tuning pins "rusted" into neck

Postby Chris Vallillo » Sun Feb 14, 2016 11:31 pm

I soaked mine in Naval Jelly, then wire brushed them. They worked fine to this very day.
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