Pianotech

Back to discussions
Expand all | Collapse all

Loss of sustain with application of CA to treble bridge pins

  • 1.  Loss of sustain with application of CA to treble bridge pins

    Posted 02-03-2017 18:10
    I've just revisited a piano I treated with thin CA back in December.  I think I was pretty conservative in terms of my application.  The false beating is gone, but so is much of the sustain.  This is not the first time I've run into this.  Recent discussion suggested that there wasn't much to worry about in this direction. 

    Am I the only one experiencing this problem?

    ------------------------------
    Floyd Gadd
    Regina SK
    306-721-9699
    ------------------------------


  • 2.  RE: Loss of sustain with application of CA to treble bridge pins

    Posted 02-03-2017 18:20

    Did you pluck the strings to isolate if it's the strings vs the hammers?




    Original Message


  • 3.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-03-2017 19:11
    Floyd,
    Yes, your observation is correct. CA can cause loss of sustain when applied while the string is on the bridge. To keep this to a minimum apply only one small drip behind the bridge pin (not on the speaking length side) and away from the string. This can be impossible if the spout on your application bottle is too big. When I want to completely eliminate the loss of sustain, I let down the tension of the string just enough to pull the string away from the bridge pin then apply the CA. This must be done carefully by releasing both ends of the strings (the adjacent tuning pin) equally to avoid re-tensioning the strings with the established bend at a different point on the bridge which will possibly cause a worse false beat than what you've tried to eliminate. Of course this is impractical within the context of a tuning job, so applying the CA in very small amounts is a skill you will want to establish. 
    To correct your present situation reduce the tension of the string just enough to break the glue bond between the string, bridge pin, and bridge cap and hope you don't introduce more false beats in the process.
    Roger  



    Original Message


  • 4.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-03-2017 21:42
    I have done the CA bridge pin treatment to four pianos. In every case I have experienced a noticeable improvement in both tone and sustain. What I lose is noise and unwanted harmonica/partials, and it took me a while to differentiate between this loss of noise and improvement in tone. Initially I thought I had lost brightness, which can make you think that you have lost sustain, when, in fact, I had actually gained clarity. Give it a second listen. 

    ------------------------------
    Geoff Sykes, RPT
    Los Angeles CA
    ------------------------------

    Original Message


  • 5.  RE: Loss of sustain with application of CA to treble bridge pins

    Posted 02-03-2017 22:29
    Closely inspect the area immediately in front of the pin with a magnifying glass. In this area, a bead of CA can form between the wire and the slope of the notch. I use dental picks to clear the area and scrape the wire for migrating CA. I apply the glue in a controlled, measured amount with an old-style drafting pen. Even when applying in small amounts, a bead can form.

    ------------------------------
    Regards,

    Jon Page
    ------------------------------

    Original Message


  • 6.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-04-2017 06:42


    I apply the glue in a controlled, measured amount with an old-style drafting pen.
    Jon - You've mentioned 'old-style' pen a number of times.  What distinguishes this from a 'modern' drafting pen? It's obviously re-fillable.  How frequently do you have to change tips? Do you have to refill before each application or do you routinely carry CA in the device?  
    I've been using the Gaunt LDPE with the two thinnest needles, but the tip caps have no effective gaskets, so they can leak, if so disposed.  
    Thanks
    - 

    ------------------------------
    David Skolnik
    Hastings-on-Hudson NY
    914-231-7565
    ------------------------------

    Original Message


  • 7.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-04-2017 09:16
    I don't know if this will have any bearing on the matter (forgive the pun) but when I did this to a Steinway upright I had in the shop (which had a really bad false beat problem), initially it appeared to kill the treble and I thought: "Uh-oh, I'm in big trouble now". It's a good thing this piano is more decorative than used. 

    Well, by the time I came to tune it in the home about 4 months later, it sounded great!  Most false beats gone or minimized in the section where I applied it, tone was nice and sustain good too.

    Years ago someone showed (in the PTJ) how to modify a standard plastic syringe to "surgically" apply metered drops of CA in this manner. It's a bit of a chore but it does work well.

    Pwg


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

    Original Message


  • 8.  RE: Loss of sustain with application of CA to treble bridge pins

    Posted 02-04-2017 09:41
    I don't use hypo-oilers for this, for both the gasket reason David stated and also because the flexible bottle doesn't let you control the dispense...it always gets all over the place when you turn the bottle upside down.

    I do use a 22ga luer lock blunt syringe needles with a 10cc syringe.  I had trouble getting fischer scientific to sell me these because of drug abuse protection regulations, but then I recently went on amazon and got them without any vetting.

    22 ga luer lock blunt dispensing needle

    I'd insert a link for the 10cc syringe, but the link manager can't seem to deal with more than one link.

    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------

    Original Message


  • 9.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-04-2017 10:20
    I believe anything less than 18ga requires a prescription. I have had good luck with 18 and the 22 Jim mentions for all types of liquids for our field.

    ------------------------------
    -Phil Bondi
    ------------------------------

    Original Message


  • 10.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-04-2017 10:21
    Here's the link for the syringes I use:

    https://smile.amazon.com/Easy-Glide-Luer-Syringe-Piece/dp/B008Z16QSG/ref=sr_1_1_a_it?ie=UTF8&qid=1486221607&sr=8-1&keywords=10cc+syringe

    ------------------------------
    -Phil Bondi
    ------------------------------

    Original Message


  • 11.  RE: Loss of sustain with application of CA to treble bridge pins

    Posted 02-04-2017 11:58
    The pen is dipped into the CA (in a small lid or disposable med cup) for each pin. Photo is here:
    Pianotech
    Ptg remove preview
    Pianotech
    Hidden page that shows all messages in a thread
    View this on Ptg >


    It has a quick-release for easier cleaning. A problem I've had with syringes is with the plunger grabbing and when a little force is applied, too much glue squirts out in a puddle. The pen delivers a small controlled amount. There are no disposable items.




    ------------------------------
    Regards,

    Jon Page
    ------------------------------

    Original Message


  • 12.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-04-2017 12:59
    Found drafting pen I'm ebay for about $15. I get syringes at feed and grain stores, veterinary section.

    ------------------------------
    Larry Messerly, RPT
    Bringing Harmony to Homes
    www.lacrossepianotuning.com
    ljmesserly@gmail.com
    928-899-7292
    ------------------------------

    Original Message


  • 13.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-04-2017 13:55
    The secret to using the syringe is that you thread the plunger shaft, then use a corresponding wing nut to stop the plunger. That way even if it does get stuck it won't go any further than what the wing nut will allow. Whoever thought of it was brilliant. You can dispense one or two drops at a time. If I can't find the info I'll post a pic of what I made with the instructions.

    Otherwise, if someone could figure out how to meter one of those little bubble thing dispensers that would be the best!  Use it and throw it away.

    Pwg


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

    Original Message


  • 14.  RE: Loss of sustain with application of CA to treble bridge pins

    Posted 02-04-2017 16:46
    Peter,
    I'm the one who thought of threading the wing nut on the syringe plunger.
    But I like Jon's ruling pen better. Easy to clean, and it lasts forever!
    Ed

    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
    ------------------------------

    Original Message


  • 15.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-04-2017 17:05
    Floyd,

    You're right about loss of sustain if you apply too much CA. Some bridges soak up thin CA immediately. Continue to do so until it can't hold any more... within reason. At the point of saturation, additional CA will pool. That pooling is what causes loss of sustain. Look closely with light and a magnifying glass and you can see it dampening the string. When CA dries it becomes brittle, like plexiglass. Maybe playing the piano causes it to shatter, which eliminates the dampening effect?

    Remove pooled CA immediately using a paper towel. Touch the CA, and the paper towel will soak it up. If you still have loss of sustain, you will have to remove the dried CA anyway you can: Scrape with dental tools like Jon suggested, loosen the string and physically remove it from the bridge pin, etc.

    With practice, my hope is to develop a better sense of when to stop repeat applications that lead to pooling. I also want to better assess how well a bridge will soak up CA before I begin. For example, If the wood is shiny (e.g. from lacquer), will it pool sooner?

    Good discussion,
    JP

    ------------------------------
    John Parham, RPT
    Hickory, NC
    828-244-2487
    john440@me.com
    ------------------------------

    Original Message


  • 16.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-04-2017 17:49
    Ed,

    Ah yes, now I remember. I still think it was pretty ingenious. Just a little challenging to make.

    Pwg

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

    Original Message


  • 17.  RE: Loss of sustain with application of CA to treble bridge pins

    Member
    Posted 02-05-2017 09:07

     I have been using epoxy syringes from West Marine that work well but you need to learn how to control the flow. The key is when drawing the glue into the syringe not to get air trapped and also to use two hands with one near the tip and the other at the top using small thumb pushes. To insure a bubble free fill pour the ca into a baby food jar or other jar you can put a cover on. You will be able to place the syringe down into the ca and keep air out as you pull up on the plunger.

    Bridge cracks and small cracks in action parts are hard to repair with this method however I found some very good clear flexible tips at the hobby shop that twist on the CA bottle tip and just finished a number of bridge cap crack repairs with no pooling or mess.
    For real precision you can get a special CA glue applicator that allows you to deliver glue by drops since It has a needle eye like loop at the end of it.

    A few years ago I purchased a commercial glue dispenser that allows you to preload glue into cartridges and always be prepared. It is also possible to load clp and other lubricants and has dozens of tips. It was more of a shop tool at the time however I am planning to use it more in the field since I have been doing more and more pinblocks in the field.

    If you come to St Louis and July I will talk about these methods as well as the need to work safe with CA. I have some good stories to tell -some funny and some not so much. 

    ------------------------------
    James Kelly
    Pawleys Island SC
    843-325-4357
    ------------------------------

    Original Message


  • 18.  RE: Loss of sustain with application of CA to treble bridge pins

    Registered Piano Technician
    Posted 02-27-2017 23:19
    James:  what more can you tell me about the 'twist-on" extensions you found at the hobby store?  I'd like to try those...

    ------------------------------
    Ron Bergeron, RPT
    Austin, Texas
    ------------------------------

    Original Message