Pianotech

Expand all | Collapse all

when to CA glue a pinblock

  • 1.  when to CA glue a pinblock

    Posted 20 days ago

    Hi. This question is about CA gluing old pinblocks that won't hold the pins.

    I've gotten advice from techs ranging from on one end...

    "I've never used CA glue on a pinblock. I've been able to solve every problem by driving in pins or replacing them with larger pins." ...or... "CA glue is a last resort. It will last one year and then the pinblock is done. You won't even be able to put in larger pins."

    ...to the other end...

    "This 40 year old piano has two slightly loose pins. Time for the CA glue. It will last a few years, and then we can just do it again an unlimited number of times."

    And then everything in between. The two extreme ends both sound unreasonable to me. But based on the advice I've received, I am understandably unclear about when to break out the CA glue, how long it will last, and what to tell customers. I have a 100+ year old piano coming up that will barely hold tune, and I am going to have to deal with it at some point pretty soon. Is there a definitive story on when to do the CA glue treatment and how long it will last? Thanks.



  • 2.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 20 days ago

    Hello,

    Of course, a piano that is still under warranty is not a good candidate for CA treatment. 

    For virtually any other piano, I would say yes-provided the procedure is done properly and cleanly.

    We use fresh thin CA glue, applied with a new 20 mL syringe fitted with a blunt needle. This gives us excellent control over the amount and placement of the glue while minimizing the risk of making a mess.

    With an upright, we tip the piano onto its back. After applying the CA to each small section of the pinblock, we immediately place a baby wipe over that section. It helps contain the fumes while the glue cures.

    In our experience, the treatment can remain effective for many years. Best to advise the client that there are no guarantees, as every pinblock and every piano is different. Used in the right circumstances, however, CA treatment can be a very effective way to restore tuning stability and extend the service life of an older pinblock.


    Allan Sutton, m.mus. RPT, TEC

    www.pianotechniquemontreal.com






  • 3.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 20 days ago
    Jonathan.

    I have used CA glue on a few pianos, but only on a limited basis. One was a 75 year old piano in basically good condition, except for the bass end. On another, I applied CA on a few very bad pins on a very old grand which was not worth rebuilding. From my experience, CA glue is long lasting. 





  • 4.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 20 days ago
    I need to add that, in my opinion, CA glue is good for a couple of pins, at most a section, like the bass end. But I would not use CA glue on 100 year old grand piano. That one would get a new block. 





  • 5.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 20 days ago

    One thing to keep in mind is whether the piano is an eventual candidate for pinblock replacement. Several rebuilders have mentioned spending an extravagant amount of time trying to break the CA bond between the plate and the pinblock.

    Another type of piano where one should be cautious are Asian made pianos that have dense hardwood tuning pin bushings. CA glue tend to not flow toward the pinblock or even saturate the bushing. For example, Don Manino (former tech rep for Kawai) recommends against using CA on their pianos.



    ------------------------------
    Patrick Draine RPT
    Billerica MA
    (978) 663-9690
    ------------------------------



  • 6.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 19 days ago
    CA glue should only be used as a spot treatment, not globally. 

    To echo Patrick, it will do no good to try to get CA glue past the bushing in the usual manner
    of application. If you need to treat a few (and only a few) pins, get an insulin syringe which
    has a very fine needle to draw up the thin or extra thin CA and make sure it goes to the block and not the bushing by inserting the needle against the pin and pushing it past the plate bushing. Else, you will only end up with a mess and not accomplish anything. . 

    Make certain that you remove the action so no CA drips into it from above and cover the keybed with heavy cardboard (not paper towels which mght  then get glued to it). Wait 30 minutes to ensure that no more CA will continue to drip out.

    It is not only Asian pianos, but a lot of older American (think Aeolean) pianos had plate bushings. 


    --
    Dave Conte, RPT, CCT
    Owner, Rocky Top Piano
    Knoxville, TN
    817-307-5656







  • 7.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 20 days ago

    I don't think it's extreme at all, to CA treat loose pins on a 40 yr old piano.  It works fine, and if you take care not to seal off the area with excess glue, you can repeat it many times.  Personally I might tap them in a little just because it's faster, and sometimes does last quite well.  It does nothing to stop you from re-pinning with larger pins later either, I don't know where anybody's getting that idea.

    If you're dealing with a 100 yr old piano, I would suggest saturating the block more thoroughly.  Maggie Jusiel has a good demonstration of it here: https://www.youtube.com/watch?v=C0U3t8IKUMk



    ------------------------------
    Nathan Monteleone RPT
    Fort Worth TX
    (817) 675-9494
    nbmont@gmail.com
    ------------------------------



  • 8.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 19 days ago

    Use premium fresh ca glue.  I have had good luck with Locktite Pro. You may need several applications,  then tap as needed.



    ------------------------------
    Parker Leigh RPT
    Winchester VA
    (540) 722-3865
    ------------------------------



  • 9.  RE: when to CA glue a pinblock

    Posted 19 days ago

    Something I've had a lot of success with is to remove the pin completely and shim it with 1 or 2 thin and narrow strips of veneer wood.  It is a lot more time consuming and I would only use it when there are only a few problem pins.  You have to loosen the string to the point where you can get the becket out so you can remove the coil, measure and record the pin height, remove the pin completely, shim it and then turn the pin back in until you reach the measure height, replace the coil and tighten things back up.  I've tried the CA glue treatment on tuning pins and also bridge pins and it never seems to last.



    ------------------------------
    Neil Vanderschaaf
    Round Rock TX
    ------------------------------



  • 10.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 19 days ago

    Yes the dense asian bushings are a problem but for older american pianos I have salvaged more than 6 that were deemed untunable.  I this the best option: no

    but sometimes there  is no budget for a new pinblock.  CA glue must be thin, fresh and of highest quality. I have had good results with locktite professional.



    ------------------------------
    Parker Leigh RPT
    Winchester VA
    (540) 722-3865
    ------------------------------



  • 11.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 19 days ago

    I have had some good results and not so good results with CA glue.  On very old pianos, or there's no plan to restring a piano that won't hold a tune, I'll try CA glue.  I've had experience that sometimes I put a lot of glue around the pin, but it just seems to lubricate it and it still won't hold.  Once I took out the pin (amazing how far down the glue goes) and sprayed accelerator on it.  When I drove it back in, it was all good.  Since then, I have began using accelerator after allowing the glue to penetrate.  It may take a while, but that seems to work.  Swabbing the hole after removing the pin also works, and accelerator seems to help along with that.  I've had some pianos with an obviously cracked block, and had it still work.  It's a "Hail Mary" fix, but I"ve been able to make it work in most cases.  I would add caution that if you find it worked on a few pins, you might as well do them all.  Don't.  It will make them so tight you'll worry about shearing off the pin, or make them jumpy.  If there's any possibility of restringing and replacing the block, it's time to do that.  It will make a mess if you CA first and try to remove the block later.



    ------------------------------
    Paul McCloud, RPT
    Accutone Piano Service
    www.AccutonePianoService.com
    pavadasa@gmail.com
    ------------------------------



  • 12.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 19 days ago

    My MO has simply been as little as possible to make the pin "tunable". The top ofvthe hole us the primary problem (IME), and each application (post curing) builds upon the previous one, making it cumulative. Just emptying bottle after bottle into it is asking for trouble. 

    Peter Grey Piano Doctor 



    ------------------------------
    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 13.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 18 days ago

    Hi all! Haven't been on here for a while and was reading this thread when I saw Nathan shared my video. Ha! Thanks, Nathan. I'd like to respond to a couple of writers who wouldn't recommend my method. They have their reasons. If I soak a block, it's because the piano would otherwise go to the dump and isn't a candidate for pin block replacement. It actually can work, although it can still give out eventually and you either have to re-do or pronounce it dead. If there is a chance of pin block replacement, soaking isn't recommended. 😉



    ------------------------------
    Maggie Jusiel, RPT
    Athens, WV
    (304)952-8615
    mags@timandmaggie.net
    ------------------------------



  • 14.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 18 days ago

    I have had success treating a whole pinblock, and it lasted.  But, echoing Maggie and others, if this is a piano headed for the landfill eventually,  it's worth it.  If this is a piano that is worth a new block, that's another...There's a job for everyone, and that's the customer's  choice.  The piano and therefore  the repair, is worth exactly what the customer is willing to spend.  Let them decide that. 



    ------------------------------
    Clark A Sprague, RPT

    [csprague4@gmail.com]Clark
    ------------------------------



  • 15.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 15 days ago

    In pianos with pin bushings I have, on the advice of a long previous post on this forum, drilled a hole in each bushing to let the CA in. It works. You do break some bits in the process. In another years-ago post someone suggested drilling with a piece of piano wire instead of a bit. I've tried this too and I'm not sure which is more frustrating, breaking bits or slowly drilling with that plain wire. In any case, there are options for getting the CA through tuning pin bushings. It's more work, so charge accordingly. It's still way less work than replacing the block!



    ------------------------------
    John Pope
    University of Kentucky School of Music
    Lexington, KY
    ------------------------------



  • 16.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 15 days ago
    Follow up to my previous post. If the tuning pins are loose enough to require
    remediation, the bushings likewise have a bit of space around where they
    contact the tuning pins. Insulin needles/hypos are very fine, but will draw up
    thin or extra thin viscosity CA glue and can easily slip into those gaps. 
    The added benefit is that you are certain the CA goes only into the hole and
    doesn't flood the block. Only a very tiny amount is required if it gets to the 
    intended place. But make sure to remove the action and line the keybed 
    with something that will not allow the glue to pass through. 
    They are cheap enough that you don't worry about throwing them away
    after one application, as they can not be reused.

    CA treatment should only be done as an absolute resort, It should not be 
    deemed any type of restoration. Doing this is often seen by your customer
    as fixing the piano, so a frank discussion needs to take place and don't make
    any promises. If the piano is too far gone, CA won't help and nothing else will. 
     


    --
    Dave Conte, RPT, CCT
    Owner, Rocky Top Piano
    Knoxville, TN
    817-307-5656







  • 17.  RE: when to CA glue a pinblock

    Registered Piano Technician
    Posted 14 days ago

    Dave, why should CA be an absolute last resort? I would certainly try it ahead of driving the pins which requires a lot pitch raising and tuning afterwards and in my experience, doesn't last as long. I would also try it first before installing larger pins which is a lot more expense for the customer. Of course you are right that CA only fixes one problem, tunability, and leaves you with all the other problems associated with an old piano. The question becomes, does this customer want to improve the instrument in other ways? Some do and some don't.

    I think a lot of our feeling about CA being a frowned-upon treatment is left over from the old days of "Pin Tite" which I'm told had actual negative side effects like jumping pins and maybe after using Pin Tite you could not go back and install larger pins because they too would get jumpy. I remember my original mentor refering to it as "Pin block destroyer", rather that a "Pin block restorer" as it was advertised. This is probably at the root one of the OP's quotes: " It will last one year and then the pinblock is done. You won't even be able to put in larger pins."



    ------------------------------
    John Pope
    University of Kentucky School of Music
    Lexington, KY
    ------------------------------



  • 18.  RE: when to CA glue a pinblock

    Posted 15 days ago

    I'm trying to come up with a process for treating from the bottom of the pin block for those pianos with tight bushings without tipping - my days of doing that are long past! Drilling does work, but is slow going using piano wire. The problem is getting water-thin glue to go up without dripping! I had some luck with a very thin flex tube. I've never had luck controlling a syringe with glue to allow for just a drop to wick up from the bottom. I even though of making a round depression in the end of a hammer shank to place a drop in and then press up to touch the pin from below. I don't think it will take much at the foot of the pin to make a difference.

    Ron Koval



    ------------------------------
    Ron Koval
    CHICAGO IL
    ------------------------------