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Main Action rail - sand paper

  • 1.  Main Action rail - sand paper

    Posted 10-24-2018 13:46
    This 1920's Baldwin G has the horrible old black plastic/rubber on the main action rail (under the flanges). It is, of course, causing issues as I remove and re-pin flanges while testing flange friction.

    I've decided I need to pull all the flange screws, scrape the old material off, and re-align and re-travel them all.

    This Baldwin has a metal rail. Is sandpaper the best current material to use a top the main action rail? 
    Super 77 adhesive? 
    Any recommendations on what grit paper?
    Also favorite material for traveling hammers?

    Any thoughts greatly appreciated.

    m9FtssPwRzyleQrtJ5hK_Screen Shot 2018-10-24 at 10.42.25 AM.png

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    Daniel Petrzelka
    Mount Vernon WA
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  • 2.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-24-2018 14:31
    Rubber cement works very well as an adhesive. Use 220 grit wet/dry sand paper.

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    Willem "Wim" Blees, RPT
    Mililani, HI 96789
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  • 3.  RE: Main Action rail - sand paper

    Posted 10-24-2018 20:59
    I buy a roll of 320 grit, pressure sensitive adhesive from Klingspor. 6" rolls with strips cut to the length of the rail. There is no need to punch holes because you install two strips, one on either side of the screw line. Heavy J weight paper.

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    Regards,

    Jon Page
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  • 4.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-24-2018 22:08
    I do much as Jon does on the flat rails. Two strips on either side of the screw holes. I do use 3M 77 spray glue on the metal Baldwins. I prefer the grip of 220 grit.

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    Edward McMorrow
    Edmonds WA
    425-299-3431
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  • 5.  RE: Main Action rail - sand paper

    Posted 10-25-2018 00:26
    Thanks all.
    Two strips sounds very straightforward - I had been scheming on measuring punching the holes out prior to gluing, but that will save considerable time.

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    Daniel Petrzelka
    Mount Vernon WA
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  • 6.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-25-2018 00:55
    Two thin strips is a good idea. But you also glue on a solid strip and use an awl to punch holes where the screws will be. It's not that difficult. Done it many times.

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    Willem "Wim" Blees, RPT
    Mililani, HI 96789
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  • 7.  RE: Main Action rail - sand paper

    Posted 10-25-2018 13:38
    Leaving a gap at the screw line is OK. Some Baldwins have machine screws and punching with an awl will not work. For S&S rails, I use fine emory cloth (bought in rolls from Klingspor) and double sided tape (3M for window treatment) and punch the holes with an awl.

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    Regards,

    Jon Page
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  • 8.  RE: Main Action rail - sand paper

    Posted 10-25-2018 14:26
    Yes,  this Baldwin G with metal rail does have machine screws for the flanges-10-24 thread I believe, with a tapered point for alignment. I would be concerned about abrasive entering the treads if I were to punch with an awl and then tread the machine screws.

    Two parallel strips seems like a safer bet for this one.

    I have cloth backed emory rolls, 1" wide, but it seems pretty thick for this application. Any concern about the effect on the geometry? I'm inclined to use the thinner 220 sheet abrasive cut into to strips.

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    Daniel Petrzelka
    Mount Vernon WA
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  • 9.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-25-2018 14:39
    The thickness of the rail cloth will have minimal effect on regulation. 

    I agree if there are machine screws, punching the holes should not be done.

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    Willem "Wim" Blees, RPT
    Mililani, HI 96789
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  • 10.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-25-2018 15:17
    I was first taught about substituting sand paper for cloth on Steinways by someone who used 80 grit. I have done that, but have more recently used 120 to 220. After learning of Jon and Ed's practices, though, I think I will try a finer grit next time.

    Alan

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    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
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  • 11.  RE: Main Action rail - sand paper

    Posted 10-25-2018 20:11
    For wooden action rails, I use a heavy "J" weight paper which has pressure sensitive adhesive from 6" rolls. Two strips cut to width needed for the length of the rail.

    For S&S, I use fine emory cloth in 1" rolls and rip[ in half lengthwise to fit the rail's width. For the tenor section, I bend the center brass support to get the double-sided tape and cloth laid down in one piece.

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    Regards,

    Jon Page
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  • 12.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-27-2018 18:49
    Any speculation on why Steinway used/uses cloth/felt on the hammer rail anyway?  Why not on the whippen rail?  Why not just straight to the rail?

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 13.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-27-2018 19:13
    Mr. Grey.

    I was told by the engineering department that the purpose of the cloth on the hammershank rail is to dampen noise. Specifically  the noise caused by the vibrations transmitted from the hammer striking the string back to the hammershank flange. Any gaps between the flange and the rail could cause unwanted sound when the vibrations caused the flange to flex. Given the Steinway flange mounting system, there will usually be a lot of such gaps caused by the use of traveling paper. The repetition experiences no such violent collision due to the escapement mechanisms. Thus no cloth on the repetition rail.

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    Karl Roeder
    Pompano Beach FL
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  • 14.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-28-2018 01:21
    I have heard this claim about cloth under hammer flanges "damping" noise and it simple does not pass the smell and double blind test. There is a screw whose head must firmly contact the flange and this can transmit all the vibration available right into the action frame and keyframe right past the cloth. 

    Do a test sometime. Remove the cloth from a few notes, (and be sure to line the hammer up the same as it was), and play the notes. I can't hear any difference! Maybe some can, I don't know but I can only go by what my own ears tell me.

    I despise the self-adhesive pressed felt hammer rail strips Steinway uses. They compress over time so every time one travels and or spaces the flange the cloth has to settle and this changes the travel and spacing again. I want it STABLE!

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    Edward McMorrow
    Edmonds WA
    425-299-3431
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  • 15.  RE: Main Action rail - sand paper

    Posted 10-28-2018 07:55
    I'm with Ed as far as the screw telegraphing the impact into the rail. There was a period of time when there was no felt on the rail.

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    Regards,

    Jon Page
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  • 16.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-28-2018 08:44
    My gut is in agreement.  I never thought that the old stringing cloth could possibly do much of anything as far as damping. 

    The only rational thing I can think of would be if the flanges started to get a little loose on the rail (which of course they do). Then there might be some sense in the cloth. Sandpaper could evidently serve the same function with greater stability.

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 17.  RE: Main Action rail - sand paper

    Posted 10-28-2018 10:25
    Based on my still limited understanding of the fine physics of the action, we'd want the more efficient connection between the flange and the rail to limit any, even if only very slight, movement or loss of energy at that point.

    On the most extreme end, with a soft felt/cloth under the flange we could get twisting (axial rotation of the shank), rocking (fore and aft) or simply variation in impact based on force-harder hammer blow would lead to more movement of the flange on a soft support. 

    On the other hand, nothing under the flange could make aligning and maintaining hammer alignment a little more challenging as there would be little friction between wood/wood or wood and metal-we'd have to over tighten the flange screws, exacerbating wear from seasonal humidity changes. 

    Maybe the difference is negligible in practice?

    I appreciate the recommendation for sandpaper and have some nice Norton wet/dry 220 that is black. Thinking it should work nicely. I'll post some photos for other to reference once I get into it.

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    Daniel Petrzelka
    Mount Vernon WA
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  • 18.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-28-2018 12:44

    Hi all.  I rebuilt many actions of Steinway M's when at UNL. For fun (?) I replaced one with no under flange stuff at all.  I found no difference before I left.   Maybe the new tech has discovered it, but it made no undesireable sounds. Maybe the flanges drifted a bit to need realignment, which is understandable under heavy use, but I didn't see it or hear anything. That is over 7 years ago, and maybe things have changed. I cleaned the rail and even Flitzed it and had no probs 3 years before I left.  Maybe Adam has insight on this as he's discovering the fun stuffs at UNL. I think the under flange stuff is to keep the flanges true longer as hammer to strings.

     

    I found that hammers and shanks need to be replaced every 5-7 years on practice grands depending on use in practice rooms from my previous post to CAUT. We have many that have hammers over 10 years old. I get a new project tomorrow for an L where the hammers are shot. Replaced 11 years ago. I may or may not put stuff under the flanges. I haven't decided. Would be a good test. I'll be here awhile until I retire.

     

    Adam, have you found it yet? Don't remember which one. Pretty sure it was a practice grand. Your input is key!

     

     

    Best,

    Paul

     






  • 19.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-28-2018 14:03
    Indeed. Engineering notions merit empirical testing.


  • 20.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-28-2018 10:48
    I heard that it also facilitates spacing the hammers, having a softer
    surface there is a margin for turning the flanges slightly.




  • 21.  RE: Main Action rail - sand paper

    Registered Piano Technician
    Posted 10-28-2018 15:04
    It is the screw head that will "lock" the flange into the proper orientation if you restrain from final full screw tightness until the hammers are all spaced and traveled properly. That way the screw indents into the flange. I have found on actions I have prepared this way that when I remove the flanges, they go right back into proper position when I carefully re-install them. 

    I use travel paper that stays with the flange and on Steinways I "cross" paper the corners to rotate flanges that need that.

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    Edward McMorrow
    Edmonds WA
    425-299-3431
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  • 22.  RE: Main Action rail - sand paper

    Posted 10-29-2018 07:36
    I also install washers which clamps flange better and avoids twisting.

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    Regards,

    Jon Page
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