CAUT

  • 1.  Steinway Hamburg Bushings

    Registered Piano Technician
    Posted 12-21-2020 09:37

    Hi, all. 

    I recently needed to replace the balance rail bushings on a nine year old Hamburg D. This is a

    piano in an auditorium that gets heavy use. Hammers/shanks/flanges and key end felts were part

    of the replacement.

    The original bushing cloth was white. Peter at S&S Parts Dept. said this is not available outside

    the factory. So I put in the red cloth from Pianotek with hot hide glue.

    While I was regulating the action with new h/s/f, the bushing started coming out. Upon examining

    them, I found that the glue had bonded to the cloth, but not the inside of the mortises. I will have

    to re-bush the set again, but the question is why they came loose to begin with. What is Kluge using

    as an adhesive? They came out with steam normally so it is obvious it was a water soluble glue. 

    Anybody have any idea what was used and how to get the residue out of the mortises? 

    Thanks!

    Dave



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    Dave Conte
    Owner
    North Richland Hills TX
    817-581-7321
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  • 2.  RE: Steinway Hamburg Bushings

    Registered Piano Technician
    Posted 12-21-2020 11:58

    Dave,

     

    Could it be that a silicone based lube has been used on the bushings?  That could keep the glue from adhering maybe.  If VS Profelt was used on these bushings in the past, that could possibly be an issue. But it seems that steaming out the bushings would clean up the wood enough to keep the silicone from being that pervasive to prevent adhesion.  I'm just thinking through it here . . . . .

     

    It's likely that Steinway / Kluge uses a heat activated glue, similar to hot melt glue.  It is applied to the bare cloth in a thin film, then the bushings are just hot-ironed in place.  I know they have used that style of bushing cloth insertion in their NY made action center bushings.   I don't know why that would keep the hide glue from penetrating and bonding to the wood.  You probably would have noticed this when removing the original cloth, though, as the back side feels rubbery and smooth after you remove them.

     

    Was it a really cold day when the bushings were installed, so that the hide glue was gelling before you put the bushings into the mortices?  I don't know which technique you use, but I have had poor joints in the past using the Spurlock technique, where I applied the hide glue to the cloth in a long strip and was too slow inserting the cloth into the keys.  So in some keys the glue didn't bond well.

     

    Don Mannino

    Using Mail for Windows 10

     




    Original Message


  • 3.  RE: Steinway Hamburg Bushings

    Posted 12-21-2020 13:08

    I've done a few Kluge bushed rails. I found that I needed to glue-size the mortice first.



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    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
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    Original Message


  • 4.  RE: Steinway Hamburg Bushings

    Member
    Posted 12-22-2020 14:21
    try scraping the wood with an exacto knife to get any film left from previous glues. if you use a good headlamp you should be able to see into the mortise . i had problems with using too much pvce glue that would squeeze out , get like rubber and hang up the key. I now use fish glue. I use the mortise sizing and final cauls i got from Spurlock when i do key work but i tend to send the key jobs out to Walker Key Service that has always done great work

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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    843-325-4357
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    Original Message


  • 5.  RE: Steinway Hamburg Bushings

    Registered Piano Technician
    Posted 12-22-2020 14:54
    Hi, Jon.

    Again, there seems to be some issue with the glue bonding to
    the wood on this keyset, so glue sizing would still present the
    same problem. But I did in fact size the mortises with Spurlock
    cauls and they fit perfectly tight. These are Kluge keys. 

    --
    Dave Conte, RPT, CCT
    Dave Conte Piano Works
    817-581-7321





    Original Message


  • 6.  RE: Steinway Hamburg Bushings

    Registered Piano Technician
    Posted 12-22-2020 14:58
    I had this problem with a Hamburg last year.  One of the things I noticed was that they applied the glue to the keys instead of the bushings which is typically what you find.  In the picture you may be able to see what I'm talking about.  After installing the bushings I size them with Profelt.  I quickly noticed if I didn't reinsert the caul, the bushing would begin to come loose.  I've never had that happen before.  After sizing they seemed to be fine.  This was a set for another technician and I told him if there where any problems bring them back and I would redo them.  I haven't heard back.


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    Bill McKaig, RPT
    Tampa, Fl
    813-831-4179
    mckaigpianoservice.com
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    Original Message


  • 7.  RE: Steinway Hamburg Bushings

    Registered Piano Technician
    Posted 12-22-2020 15:09
    Thanks, Bill. I only did the balance rail, since the prior tech did not have the .129 cauls for the front rail. Did you bush the balance rail and if so, did you notice any difference from the front rail?

    Thanks!

    Dave

    --
    Dave Conte, RPT, CCT
    Dave Conte Piano Works
    817-581-7321





    Original Message


  • 8.  RE: Steinway Hamburg Bushings

    Registered Piano Technician
    Posted 12-22-2020 17:27
    The balance rail was the same as the front rail.




    Original Message


  • 9.  RE: Steinway Hamburg Bushings

    Registered Piano Technician
    Posted 03-15-2021 14:25
    I recently discovered a can of "Action Treating Solution" buried at the back of a cabinet in the shop.
    The label say Dimethyl Silicone. My guess is that this was what was used to treat the keybushings in an
    effort to reduce friction. Overkill anyway since the bushings on this 7 year old SS D were over-eased so 
    much that they needed replacement. 

    Anyone think this might have made it difficult for the hide glue to stick? Maybe the only reason the Titebond
    liquid hide glue held is because I cleaned the mortises with Acetone. 



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    Dave Conte
    Owner
    Knoxville TN
    817-307-5656
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    Original Message


  • 10.  RE: Steinway Hamburg Bushings

    Posted 03-17-2021 13:00
    Dave-I think you've found the answer to your question about having difficulty getting new bushings to stay glued.  I meant to chime in sooner!

    Over 25 years ago, my husband and I were working on a customer's Baldwin L from 1972.  We, too, had trouble making the new key bushings stick.  Then I remembered a sticker, from the factory, on the plate.  Although unfortunately I didn't record what it said, we were pretty sure from the wording that it meant the bushings had been treated with a solution, at the factory, to help reduce friction in the key bushings.  That bit of information allowed us to try various treatments to the bare wood.  We went forward with the assumption that silicone contamination had reared its ugly head.

    We eventually were successful, after trying a few solvents and a little bit of fine sanding.  We may have also tried some glue sizing, although I don't remember exactly what solved the problem.

    Good luck to you!

    Margie



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