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Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

  • 1.  Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-10-2018 06:36
    Is there any contra-indications to the use of Cyano Acrylate glue on old grand piano wrest-pin planks? The reason for the question is that the Broadwood Grand piano in question is of significant historical importance.
    Michael Gamble


  • 2.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-10-2018 17:24

    I think it depends on the situation.
    Many of those old Broadwoods have actual machine threads on the tuning pins, which thread through the plate into the block below.  With this kind of an arrangement, I would be extremely careful with CA (meaning I would not do it). You do not want the pins to become glued into the plate.  Remember: first, do no harm.

    Some old pianos can not be kept limping along anymore with band-aid solutions- they need wholesale work to be rendered into a playing condition.  If the funds are not available at this time, they may have to remain
    non-tune-able, non-playable artifacts until the day that the owners decide to make the plunge.



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    Jurgen Goering
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  • 3.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-10-2018 21:39
    I love band aid fixes because it generally means happy customers.  In fact, I often hear how i was able to fix something that the other guy couldn't.
    Regarding the Broadwood. I consider Broadwoods to be one of the most complicated pianos to rebuild properly. Very challenging. I love them for that.
    You could take the pin out, and coat the wood part of the pinblock with west epoxy. You won't be able to drill out the hole and put in a wood plug from the top because of the steel part of the pinblock. However, If you have an angled drill you may be able to drill from underneath and put in a plug.
    On the last broadwood i rebuilt, the customer wanted everything as original as possible. The tuning pins were "rust welded" in place. I ended up drilling all the broken pins out, had a welder repair the holes, tap new threads. Then I had custom made tuning pins made as per original specs. To have the custom tuning pins made cost $2,200. Yes, that was two thousand + dollars. But that was what the CUSTOMER WANTED.
    Attached are some pics.










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    45 2020

    chernobieffpiano.com
    865-986-7720
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  • 4.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-10-2018 22:37
    I love what CA can do for loose tuning pins, but an historic old Broadwood is definitely NOT a candidate!

    By the way, Chris, those replica tuning pins are gorgeous.

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    Susan Kline
    Philomath, Oregon
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  • 5.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-11-2018 16:47
    "I love what CA can do for loose tuning pins, but an historic old Broadwood is definitely NOT a candidate!"

    Why? Sure, new pin block is best way to go - absolutely. But as we all know, if the funds are not available, CA can be an effective band-aid approach. If the piano in question has the threaded plate like in the picture that Chris posted, the only way that I'd use CA would be to remove the pin, coat the inside of the tuning pin hole in the block with CA, and then replace the pin. No muss, no fuss, and hopefully, with fingers crossed, a tunable string.

    "By the way, Chris, those replica tuning pins are gorgeous."

    If you mean the kinda shiny one next to the ruler - I'm guessing that is an original that was cleaned up.

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 6.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-12-2018 00:46
    Terry, you don't seem to have read Chris's post. These pins are threaded into steel. The shiny pin was a replica tuning pin, one of a set made at great expense.

    CA can be used for loose tuning pins in a wood pinblock. It would be totally disastrous for threaded tuning pins in metal, especially since they are very old, and many are already rusted in place.

    Let's see if I can paste in Chris's post:

    ----------------
    I love band aid fixes because it generally means happy customers.  In fact, I often hear how i was able to fix something that the other guy couldn't.
    Regarding the Broadwood. I consider Broadwoods to be one of the most complicated pianos to rebuild properly. Very challenging. I love them for that.
    You could take the pin out, and coat the wood part of the pinblock with west epoxy. You won't be able to drill out the hole and put in a wood plug from the top because of the steel part of the pinblock. However, If you have an angled drill you may be able to drill from underneath and put in a plug.
    On the last broadwood i rebuilt, the customer wanted everything as original as possible. The tuning pins were "rust welded" in place. I ended up drilling all the broken pins out, had a welder repair the holes, tap new threads. Then I had custom made tuning pins made as per original specs. To have the custom tuning pins made cost $2,200. Yes, that was two thousand + dollars. But that was what the CUSTOMER WANTED.
    Attached are some pics.










    ------------------------------
    Susan Kline
    Philomath, Oregon
    ------------------------------



  • 7.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-12-2018 06:16
    Hi Susan. I did indeed read Chris' post and my response incorporated that the pins are threaded through the iron plate. But where I may be off base is that I presumed there to be a wooden pin block under the plate/threads. Perhaps not. I'm not familiar with this old Broadwood setup. Is there a wooden pin block in addition to the threaded plate?

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 8.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-12-2018 06:18
    Oh wait - hold the phone. Based on Michael and Jurgens early posts, it sound like indeed this piano does have a wooden pin block under the threaded plate. So I'll stand by my post suggesting an option might be to remove the tuning pin, swab out the hole in the wood and re-install the pin.  :-)

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 9.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-12-2018 12:01
    Test

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 10.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-12-2018 10:08
    You can get copies of original pins from Italy in several sizes and it won't cost $2,200.





  • 11.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-15-2018 23:32
    In regard to using CA glue as a bandaid approach. I treated the pin block of an Steinway M 5 years ago; it was near impossible to tune and the owners were not yet ready to invest in a rebuild. 5 years and the piano is still quite tunable and holds well, the pins feel just as they did after I first did the treatment. If someone else tuned the piano I doubt they would sense that the block had been juiced.
    While the piano should still be restrung, as long as it can be tuned, it is just fine from my customer's viewpoint. My point is that a CA treatment should be considered more than just a bandaid.

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    Steven Rosenthal
    Honolulu HI

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  • 12.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-15-2018 23:59
    Of course CA glue in a failing wood pinblock can often work wonders! But the Broadwood in question apparently may have threaded tuning pins into metal. Plus Michael said it was historically significant.


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    Susan Kline
    Philomath, Oregon
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  • 13.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-16-2018 10:26
    This is really a nomenclature comment, Steven. I was promoting the treatment of loose tuning pins to another technician and he asked me how long it would last. He said he had cut open pinblocks that had been "doped" and the "dope" had only penetrated something like 1/8". I don't think it is accurate to characterize CA glue as "dope" or "juice". CA glue IS glue, after all, and it glues wood cells together as well as filling voids. Pinblock restorers (and any other name they are called be) are, I think, mixtures of water, alcohol and rosin. They swell the wood and create some kind of added friction. I think it may be useful to make the distinction. Does that seem correct?

    Bob Anderson
    Tucson, AZ




  • 14.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-16-2018 11:00
    Traditional pin dope contained glycerin, which attracted moisture from the air to swell the pinblock and increase torque. It also rusted the pins.
    CA glue hardens and becomes plexiglas, almost instantly. After that it is completely inert.
    My impression is that it does not penetrate deeply into the wood, but that it fills gaps and forms a collar around the pin.

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 15.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-16-2018 11:48
    Personally, I don't actually like referring to CA as "glue". Yes, it says "glue" on the bottle, and is sold as a "glue", but in my mind I prefer to think of it as a liquid that turns to a solid...very quickly (and somewhat controllably).  Yes, I know that all "glues" do this, but the speed and other aspects of the transformation seem to set it apart from others (perhaps in my mind only).

    This allows me to expand my realm of uses for the stuff. (Remember that when it was first 'discovered' they didn't have a clue as to what to do with it so they shelved it).

    Similarly, I do not think of, or refer to, EPOXY as "glue" (even though technically it is, or can be), because it's specific properties put it into a category somewhat different from what is typically called "glue". Those properties allow me to expand its usage beyond the realm of simply "glue".

    Okay, so what's you're point, Grey?

    In this particular type of instance, I would have no problem using CA in the wood portion of the pinblock, provided of course that the metal area can SAFELY be bypassed. The fact that the wood in the PB would be similarly threaded, this would actually be a very good platform for the CA to accumulate and reduce its diameter. Whether it soaked into the wood or not is somewhat irrelevant. The goal is to make the hole smaller so as to hold the TP reliably.

    I would remove the pin, use either a Pro-tip or a pipette to go into the hole and saturate the wood underneath the plate. (Obviously protect the keybed from drips if the holes are drilled through). Chances are I would do it at least twice, testing the tightness in between. Each layer will build on the previous one by about .001"-.002" (effectively .002"-.004" on circumference).

    I would consider this to be a conservative and viable repair option...not a band aid. The stuff is very durable.

    My .02 only.

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 16.  RE: Re-enforcement of 19th.Century Wrest-pin Plank with CA Glue

    Posted 07-17-2018 07:27
    Peter wrote:
    "I would remove the pin, use either a Pro-tip or a pipette to go into the hole and saturate the wood underneath the plate. (Obviously protect the keybed from drips if the holes are drilled through). Chances are I would do it at least twice, testing the tightness in between. Each layer will build on the previous one by about .001"-.002" (effectively .002"-.004" on circumference).

    I would consider this to be a conservative and viable repair option...not a band aid. The stuff is very durable."

    This is basically what I suggested doing earlier. A couple months ago I did this exact treatment to a few tuning pins on a Yamaha C3 that I see every two weeks. Several bass tuning pins would just barely hold pitch while I was there, but would be flat two weeks later. I pulled the pins out, swabbed out the holes with thin CA - and then, following my philosophy of "is some is good, more is better!" (I know, not always a good philosophy to follow), I actually coated the tuning pins with CA. Then I turned pins back in and strung it up. I tuned the bass on that piano yesterday - I wish I had brought my torque wrench - the pins had to be a bit more than 150 inch-pound torque range - really tighter than one would like. Next time I try something like this I think I'll skip coating the pin - swabbing the hole will be more than adequate I should think.

    In this particular case with the Broadwood with a threaded plate AND a wood block underneath it (that's what I understand the construction to be), I should think removing the pin and swabbing out the hole with CA would be an excellent band-aid approach.

    ------------------------------
    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------