CAUT

  • 1.  Backrail cloth: glue both edges?

    Registered Piano Technician
    Posted 04-30-2025 16:01

    Greetings,

    Going through the action on a 1933 Mason & Hamlin model "A". The original backrail cloth had both edges (front and back) glued down to the backrail of the keyframe. While I do not always replace backrail cloth when regulating, this is the first one I have noticed that did not have just a single edge glued down.

    The question is: what are the pros and cons of gluing both edges? Any recommendations as to whether or not it is advisable to do the same with the new b/r cloth?

    Thanks,

    Alan



    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------


  • 2.  RE: Backrail cloth: glue both edges?

    Registered Piano Technician
    Posted 04-30-2025 16:21
    Hi Alan,
    Presumably there is a thin strip of felt (or cloth) under the middle of the thicker one that is glued on both sides. My take is that this creates a slightly more stable system with respect to regulation (key height) - or that this was the reasoning behind it. 

    I'm not sure I buy that argument, but I have always duplicated what I found. A little more troublesome, as you need to hold the second side down with some force while the hot hide glue sets, making sure the cloth is stretched evenly and neatly. Otherwise, you defeat the purpose.

    Regards,
    Fred Sturm
    http://fredsturm.net
    www.artoftuning.com
    "One's real life is so often the life that one does not lead" (Oscar Wilde)






  • 3.  RE: Backrail cloth: glue both edges?

    Registered Piano Technician
    Posted 04-30-2025 18:08

    Hi Fred,

    Thanks, as always, for your input. Much appreciated!

    Yes, there is a felt strip that runs the length of each piece of back rail cloth, creating a slight rise in the middle of the width of the cloth.

    i was going to use Quick & Thick glue for this but noted that you use hide glue. Is that for reversibility when the cloth is again removed (at which time I will be pushing up daisies, most likely!). But even if I am dead and gone, I will still care…

    Alan



    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------



  • 4.  RE: Backrail cloth: glue both edges?

    Registered Piano Technician
    Posted 04-30-2025 18:58
    Hide glue is faster, doesn't soak into the cloth (if thick enough). I hadn't heard of Thick and Quick. It is probably fine. I like hide glue because I always have it, it keeps forever, and it is both fast and easily reversible. Bottles of glue tend not to get used up, and to have shelf lives.

    Call me an old timer, I guess I am one. Stuck in my ways :-)

    Regards,
    Fred Sturm
    fssturm@comcast.net
    Youtube Spotify Deezer Apple Amazon 
    http://fredsturm.net
    www.artoftuning.com
    "All of humanity's problems stem from man's inability to sit quietly in a room alone. " Blaise Pascal
















  • 5.  RE: Backrail cloth: glue both edges?

    Posted 04-30-2025 19:10
    Agree on the hot hide glue for this.  Take some time to nicely clean up the frame before gluing new stuff down.  I cut strips of wood just the right length for each section to clamp them down after gluing.  

    Dennis Johnson, R.P.T.
    Facebook.com/johnsonpianoservice
    (612) 599-6437  (cell)





  • 6.  RE: Backrail cloth: glue both edges?

    Registered Piano Technician
    Posted 05-01-2025 09:38

    Hi Dennis,

    Thanks for your input on this.

    I am in complete agreement with you about thorough prep of the wooden backrail before carefully gluing on the cloth. As my late, great mentor, Keith Hardesty, always insisted, "The glue we use likes to adhere to bare wood, not to glue residue or vestiges of cloth."

    Also share your practice of using sticks cut to length for each section to provide for more even clamping pressure. May not be totally necessary, but it couldn't hoit! (I use the sticks from sets of Renner shank & flanges, but any properly sized scraps will do.)

    Alan



    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------



  • 7.  RE: Backrail cloth: glue both edges?

    Registered Piano Technician
    Posted 05-13-2025 17:07
    I know that this is old.  But it keeps coming up over And over.  Hide glue is best for back rail cloth, any felt etc.  As far as cleaning the wood; it is too difficult to remove pvc and pvce wood glue from the wood and you can't successfully go back to hide glue after you use the other glues. It  is a must for key bushings if you ever this have to rebush another time.  It doesn't need to be completely removed from surfaces to apply the next time water and heat reactivates it.  There is also a fish glue that is stronger that luthiers use with the same properties.  If you need instructions on how to use this glue you can find them on line.  Hide glue or leave it alone. 
    So sorry for the rant!
    Sent from Gmail Mobile





  • 8.  RE: Backrail cloth: glue both edges?

    Registered Piano Technician
    Posted 05-13-2025 19:10

    Hi Jessica,

    Last thing first: What rant? I didn't read no stinking' rant… ;-)

    My apologies for broaching a subject that has previously been covered. I do read the vast majority of the post on these lists, and usually remember what subjects have already been covered. Apparently, I lapsed this time.

    Very much appreciate your input and advocacy for high glue. Point taken.

    Best,

    Alan



    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------



  • 9.  RE: Backrail cloth: glue both edges?

    Registered Piano Technician
    Posted 05-13-2025 22:08
    Alan,  I don't think this topic and use of fasteners can be covered enough.  

    Here is a question for you? Your Mason Hamlin has a curve for the wippen cloth are there som piano that are flat that need that strip of extra cloth?  I have been have some of my older steinway grands starting to chip at the wippen cloth.  I think it is from previous use of chemicals.  If I use powdered soap stone/talc there it goes away.  

    When the key end felt is glued do we glue the entire surface? I don't I wasn't taught ti do it that way and most older pianos are free at the end of the key.  Over time there is less noise glued like this. 

    Most key frame back cloth is only glued down at the front for about 5/8".  But some pianos have an under strip and glued front and back edges.  If we knew what was original, especially in the thickness you should stick with what they di originally.

    I am sure that you know most of this. Hide glue can be reheated but loses some of its strength each time.  Urea can be added to it to slow the drying but it causes the glue to be weaker than without it (think of the old school house glue dabber. 

    I guess the last thing is to think about what glue was used in the first place, because hide glue won't stick well over some types of glue.  But hide glue usually can be removed completely by scraping and sanding.  

    My first glue pot was an electric coffee percolator with a baby food jar hung from the top using brass wire.  It seems a big deal now to find the bigger electric jacketed glue pot.  

    There is a book written by Stephen A Shepherd all about using hide glue for more information.



    Sent from Gmail Mobile







  • 10.  RE: Backrail cloth: glue both edges?

    Posted 04-30-2025 19:02
    Hi-  
     I have always understood that the purpose of gluing backfelt on the front side only is to reduce noise.  This has been routine practice on Steinway but the M&H pianos I restored also got this improvement.  It is a little more time consuming to insure the felt is fit nicely and clamped properly after gluing, but worth the effort in my opinion.  I also glue the thin under felt on one edge only.  If the piano is getting a complete action job that is part of the process, but otherwise I would probably work with what is there if it's not too old.  

    Best,
    Dennis. 

    Dennis Johnson, R.P.T.
    Facebook.com/johnsonpianoservice
    (612) 599-6437  (cell)