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Rib re-gluing

  • 1.  Rib re-gluing

    Registered Piano Technician
    Posted 01-20-2021 11:07
    Hello all,
    If you are re-gluing ribs from the back (upright piano) with the screw method, does it matter if the tension from the strings is there or not?  I'm working on an old upright that I will be restringing, and there is some rib separation that needs attention.  I was just wondering if it's better to do it before or after I remove the old strings.  In the past I have always removed the strings first, but I was wondering if it actually makes any difference.  
    By the way, there is good crown in the board according to the thread method.
    Thanks!

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    Laura Wright, RPT
    Ivory Keys Piano Service
    Durango CO
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  • 2.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 01-20-2021 11:30
    Laura,

    I have done it both ways, and would do as the circumstances permit. The issue is generally a cosmetic one in that it is hard to get sufficient grip of the screw threads (from the back) without penetration the surface of the SB. But from a functional standpoint I see no difference. 

    Plus, even with strings removed, the plate may still get in the way of some fasteners from the front side.  So, 6:1 - 6:the other.  Sometimes it's necessary to do a combination  of both. 

    Pwg

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


  • 3.  RE: Rib re-gluing

    Posted 01-20-2021 13:11
    Why not pull the string frame while you have it apart and install a screw from the front?

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    Regards,

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

    Original Message


  • 4.  RE: Rib re-gluing

    Posted 01-20-2021 13:14
    If you haven't already done so, I encourage you to read over some posts by Jim Ialeggio in regard to soundboard/rib joint renewal.  I have found them most helpful:

    https://my.ptg.org/communities/community-home/digestviewer/viewthread?MessageKey=38690406-2395-41a2-b9da-cace7b85bbf4&CommunityKey=6265a40b-9fd2-4152-a628-bd7c7d770cbf&tab=digestviewer#bm38690406-2395-41a2-b9da-cace7b85bbf4

    https://my.ptg.org/communities/community-home/digestviewer/viewthread?MessageKey=39d3b811-c41a-428a-a970-011c1840c360&

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    Floyd Gadd
    Regina SK
    306-502-9103
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    Original Message


  • 5.  RE: Rib re-gluing

    Posted 01-20-2021 16:25
    FYI, I no longer kerf the rib/panel joint. Instead I simply scrape the panel and rib, both sides of the rib, to get about 1/4" scraped surface, and apply a fillet of West system G-flex along the entire length of both sides of the rib. Way easier, and I think actually better than compromising whatever is left of the existing original glue joint.

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


  • 6.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 01-22-2021 19:43
    Jim,
    If I understand correctly, you scrape off the old finish from the sides of the rib and about 1/4" on the panel surface, then apply the G-flex and cove it with some sort of radiused tool.  I am unfamiliar with the consistency of the g-flex material, is it thick?  Or is it thin enough to run under the rib where it is unglued?  Do you purposely try to work some under there?  Are you using any kind of screws or clamps?
    Also, is it the g-flex 650 or 655?
    This does sound like less work than the old glue and screw method.
    Thanks!

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    Laura Wright, RPT
    Ivory Keys Piano Service
    Durango CO
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    Original Message


  • 7.  RE: Rib re-gluing

    Posted 01-22-2021 21:52
    g-flex 655, ie, the thickened one.  

    Yes scrape off the finish as you describe, apply the g-flex which does not need to be "wet out" like 105 resin...just g-flex right on the woods. Tape it out beforehand on the panel and rib so it doesn't get everywhere, tool it into a cove with a Popsicle stick or thin stick you had sanded into a radius. Then immediately remove the tape. Don't leave the tape on while it cures...clean up will be a disaster. If you tape it out and remove the tape after tooling, there will be no secondary cleanup work.

    We are reducing the radius with each iteration of this. We started with 1/4" radius, and are reducing it to 3/16 or so. Its important to do the fillet on both sides of the rib, the entire length of the rib. 655 is thickened, so it doesn't run,  but I would flip the piano so you are working flat instead of vertical, as it may run a little on the vertical.

    If the rib is unglued in parts, before gluing, using a multitool with a 90 deg blade, kerf the failed glue joint, only at the failure, to new wood. If the joint has not failed, don't bother kerfing. When and if you kerf, you have to force the glue into the kerf, it will not run by itself. No screws of clamps necessary when we do it. However, I have not done it on a board that has seriously failed and the panel is curving away from the panel. If this were the condition,. I would toss the board. I only do this on reasonably intact old boards with some some cracks and separation, but where joint separation is not so bad the panel is peeling away at the crack. The ones we have done had either no cracks, or 2-3 major long cracks and some smaller cracks. We don't bother about crown. 

    Regarding panel cracks, as opposed to rib/panel cracks,  just open them up with a saw kerf to new wood, or with a utility knife, and  fill, using west 105 resin and fast hardener, thickened with flour or one of their fillers. Tint the epoxy with Transtint dyes, to color the epoxy to match the wood. Protect the panel with tape, so cleanup along the crack is easier. If its an upright, and cosmetics are not important, skip the tinting. You could use g-flex in panel cracks, but I would probably put some tape under the joint so it doesn't make a mess on the other side of the panel. 105 and thickener is cosmetically nicer than the g-flex, so if its a grand, that's why I use 105 instead of g-flex on panel cracks.

    I don't screw or clamp. If the separations are that bad, and it would be a mess without screws or clamps, I'd toss the board.  

    The idea for this was not so much about fixing really beat boards, as it is about renewing panel stiffness in a board that has gotten tired. My theory is that the old rib to panel joints even if not obviously failed have a degraded glue substance in the joint which has not catastrophically failed yet. It has not separated visually, but if one were to separate the rib and panel, one would probably see half of the original hide glue substance had powdered away. This is why I glue along the entire length of the ribs on both sides. You are renewing the old, degraded glue joint along the entire rib, not just at crack points. Doing this, along the entire rib has created for me seriously musical old boards, including one I kept as my own piano...and is one of the nicest sounding pianos I have played....vintage Chickering, original board.

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

    Original Message


  • 8.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 01-23-2021 13:37
    Jim, thanks for your very detailed explanation!  
    Most of the separations of rib and panel on this soundboard are very minor (detected with feeler gauge), but there is one spot where the panel has pulled away enough at the crack as to be slightly offset.  I'm thinking maybe in this spot I should go ahead and use a couple screws to pull the panel even again.  "Tossing" is not an option, as this is a very limited budget project (120 year old Starck upright, been in the family).  I do think the g-flex method would work well overall.
    As for the panel cracks, has anyone ever used a product called Wood Epox (pianotek sells it) to fill cracks?  I've used this product for other wood repairs, such as a cracked bottom board on an upright, but I've never tried it on a soundboard.  It's very thick, putty-like, so there is no running or sagging.
    Thanks to all who've responded!

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    Laura Wright, RPT
    Ivory Keys Piano Service
    Durango CO
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    Original Message


  • 9.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 01-23-2021 22:10
    Laura,

    I have not used Wood Epox, however I have used Lakeone Wood Rebuilder to fill cracks (unfortunately no longer available in it's original form). 

    I am familiar with wood epox, just not in this application. It seems a bit thick to me, however if I'm not mistaken you can mix their thin stuff in with it to alter the "viscosity" (if this is not correct and someone knows please correct me)! If you open the top of the crack (as if you were you going to use a shim) it is easier to get the stuff in there.

    Pwg

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

    Original Message


  • 10.  RE: Rib re-gluing

    Posted 01-23-2021 23:05
    I have used West System epoxy thickened with Microlight Fairing Filler to fill soundboard cracks.  I use masking tape on the underside of the board so that nothing drops through.

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    Floyd Gadd
    Regina SK
    306-502-9103
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    Original Message


  • 11.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 01-31-2021 12:32
    I like the idea of flipping the piano backside up, it seems like it would facilitate working on the ribs.  Would this cause any harm to an upright with the plate still in it?  Also, I'm trying to figure out how to accomplish this maneuver!

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    Laura Wright, RPT
    Ivory Keys Piano Service
    Durango CO
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    Original Message


  • 12.  RE: Rib re-gluing

    Posted 01-31-2021 14:29
    No harm to the structure...its mainly a question of how to flip it .  Easiest is to lower it face first using a chain hoist. One really needs a hoist in a shop anyway. Short of that, a couple burly young folks who want to test out whether their weight lifting actually works in the real world.

    If there's no chain hoist, you can rent an engine hoist at most rental centers for not much money.



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

    Original Message


  • 13.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 01-31-2021 17:10
    Hahaha, I've used the "buncha guys" method before in piano moves!

    I do have a hydraulic engine hoist in my shop that I use for pulling plates.  I guess my main concern is how to rest the piano once it's lowered.  If I place it on my tilt cart, it seems that it would be laying on the plate and bridges.  My husband (who's an engineer) suggested putting blocks at the four corners of the plate for it to rest on (on the floor).   Or could it rest on the case sides?  Just having trouble visualizing this.

    Jim, THANK YOU so much for sticking with me through all my questions!

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    Laura Wright, RPT
    Ivory Keys Piano Service
    Durango CO
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    Original Message


  • 14.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 01-31-2021 17:26
    Laura

    After the plate is out of the piano, I move the piano and lower the plate on 2 saw horses. Is that what you are referring to?

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    Willem "Wim" Blees, RPT
    Mililani, HI 96789
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    Original Message


  • 15.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 01-31-2021 17:36
    Hi Wim,
    No, I'm not removing the plate in this instance.  We are talking about flipping the piano backside up (an upright piano), and then laying it down to work on the ribs from a horizontal position.

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    Laura Wright, RPT
    Ivory Keys Piano Service
    Durango CO
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    Original Message


  • 16.  RE: Rib re-gluing

    Posted 01-31-2021 18:16
    Yeah, I see your visualizing point. The toe blocks are probably substantial given its a BOU, so I think as you lower it with the hoist slowly, pads under the toe blocks as it pivots I think the toe blocks would be sufficient support at the bottom of the piano, and some blocks up at the pinblock area would do it. Only thing is to find some way to be comfortable that the toe blocks are up to pivot and the weight...my sense it that they would be fine, as long as the thing is not falling apart.

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

    Original Message


  • 17.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 02-01-2021 09:01
    Laura

    Another option which would utilize the "bunch a guys" but is a wrinkle.  I have tipped uprights on their sides on many occasions for either moving through a doorway or to glue a loose toe block and do veneer repair on the lower corner.  You could roll one more time onto the lid area which has a smaller footprint.  Do this on furniture pads and you would probably have all the loose case part off anyway.  Now the piano is resting on the smaller footprint of the top of the piano and the keybed can be padded as it is lowered to the floor.  This eliminates stress on the glue joints of the toe blocks.  Just a suggestion.

    Norman Cantrell



    Original Message


  • 18.  RE: Rib re-gluing

    Posted 02-02-2021 21:03
    Two strong plywood panels, about 2' by 3', enough to go beyond the feet and keybed.
    Clamp them to the sides of the piano using bar clamps reaching to the outer back posts.
    Now you can rock the piano forward and it will be supported by the plywood, back side up.

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


  • 19.  RE: Rib re-gluing

    Posted 02-01-2021 08:16

    Hi Laura,

    Newbie here looking from the outside in. It appears to me that if you (or your engineer husband) could "reverse engineer" a wooden upright piano tilt cart, it might be a solution.

    I can envision one that includes a felt lined  "grab" area for the lower part of the piano (where the pedals are) which stays as close to the ground as possible, and then come up to the top part of the piano where you have two stancions coming up to the top of the piano where the lid would be above the tuning pin area. The stancions would make the piano level in its face down position. 

    I would figure you would need at least a two foot separation between the parallel rails with some cross bracing to make it stable, but if properly engineered, should be able to take the weight of the piano (sans front and top cabinet, action and keys). 

    I have see where people have made wooden upright piano tilt carts, and this is where I believe the reverse engineering would be applied. 

    As a newbie, I would welcome hearing constructive criticism of the above idea. 

    Thank you,
    Respectfully,
    Keith Gramlich 



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    Keith Gramlich
    East Meadow NY
    917-757-4207
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    Original Message


  • 20.  RE: Rib re-gluing

    Posted 02-01-2021 08:41
    Why are you adverse to removing the string frame?  It would make working on this so much easier.

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

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

    Original Message


  • 21.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 02-01-2021 09:36
    Jon,

    My initial thought would be because it would require removal of the sides to get the plate out. (But I'm just guessing). 

    Pwg

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

    Original Message


  • 22.  RE: Rib re-gluing

    Posted 02-02-2021 19:49
    The key bed would need to be removed, I don't the side would be unless they are built over the frame.

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    Regards,

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

    Original Message


  • 23.  RE: Rib re-gluing

    Registered Piano Technician
    Posted 02-03-2021 18:05
    In a way pulling the string frame from a vertical is easier than a grand, since it's not enclosed as tightly around its perimeter as with the rim of grand piano.  Only at the top.  So once you've cleared the nose bolts you can angle it out by leading with the left side and not have to worry so much about dinging something.

    Getting the keybed out is not challenging once you've identified which screws dismount it.   The first time I did one of these I assumed that the arms were mounted to the sides by the the evident screws.  Come to find after I'd wrestled these out and spent some time prying and banging that the arms were screwed and glued to the side.  They weren't going anywhere. You can imagine why they do this since the grain of the arms and sides run at right angles to one another.  The keybed was slotted into the arms.  Just one screw at the back securing it to a plate flange. Sometimes it's a little more apparent how the keybed comes out but I've never seen one that was permanently glued in place.

    If you decide to pull the keybed make sure to take measurements of the tops of the posts that support the action brackets vis-a-vis the soundboard so you can it back in exactly the same position.  (This is why you some times see the outer posts replaced with pins that are fixed to the inside of the arms--they don't come out.)  There's not much wiggle room here and failure to restore it to the initial location will open a Pandora's box of regulation issues that will create much more work that you've saved by pulling the frame in the first place.

    With the weight of the frame removed, the carcass also now becomes much easier to turn over if you wish.


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    Cecil Snyder
    Torrance CA
    310-542-7108
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    Original Message