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Rib Stock

  • 1.  Rib Stock

    Registered Piano Technician
    Posted 24 days ago
    Soundboard builders,
    Where do you get your rib stock?

    ------------------------------
    John Pope
    University of Kentucky School of Music
    Lexington, KY
    ------------------------------


  • 2.  RE: Rib Stock

    Registered Piano Technician
    Posted 24 days ago
    You can buy rib stock from Bolduc.

    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 3.  RE: Rib Stock

    Registered Piano Technician
    Posted 24 days ago
    Bolduc ribs are sold by Pianotek and Brooks Ltd. I buy sugar pine ribs from Dale Erwin.

    ------------------------------
    Karl Roeder
    Pompano Beach FL
    ------------------------------



  • 4.  RE: Rib Stock

    Posted 24 days ago
    Irwin is kind of far away, and Bolduc uses a species of spruce that sounds a bit muddy to me( I think its too soft). I prefer Eastern White Pine, The eastern sister of sugar. I found that the best quality comes from Pennsylvania. it seems to be slightly lighter and stronger than from other locales. I usually have to call around to lumber mills to get stuff that fits my criteria. Then i order about 500lbs of it at a time and have it shipped via UPS.

    -chris
    https://www.youtube.com/watch?v=54MUvzuiquU

    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    grandpianoman@protonmail.com
    Lenoir City, TN
    865-986-7720
    ------------------------------



  • 5.  RE: Rib Stock

    Registered Piano Technician
    Posted 24 days ago

    I don't think the type of wood for the ribs affects the tone much. The panel is a different. The type  of wood will affect the rib dimensions.

    Dale Erwin has sitka (boards and ribs) and ships all over. He may have other wood as well. I've always bought stock directly from Bolduc (white spruce) but there may be there venders as well.  



    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 6.  RE: Rib Stock

    Posted 23 days ago
    Talking with the loggers is always a problem. I tried several times to get an independent to gather some sugar pine for Erwin. We have it up here. I know of a whole unit that was so straight grained and knot free a carpenter was using a 12 footer as a straight edge. Sugar pine is amazingly stable. I can see why they use it for keys. It's probably heavier than you want for soundboard ribs.
    Then Dale was driving through the area and saw a quarter of a log of the real stuff. The logger was one of the tops in the area. He does the old growth around houses. They made a connection but the supply probably isn't there because the forest service stopped selling small timber sales. As bad as the loggers were environmentally, it's not good to let it go up in flames.
    I just talked to Dale and he was in Oregon buying white pine.

    ------------------------------
    Keith Roberts
    owner
    Hathaway Pines CA
    209-770-4312
    ------------------------------



  • 7.  RE: Rib Stock

    Posted 23 days ago
      |   view attached
    I hear the Terry Farrell has a ton (or two!) of aged Sitka Spruce in his climate controlled shop and that he'd be happy to slice you off a hunk or trim individual ribs to spec.


    ------------------------------
    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 8.  RE: Rib Stock

    Member
    Posted 23 days ago
    Word is that the guy, Terry, does super work.

    Deb





  • 9.  RE: Rib Stock

    Posted 23 days ago
    Sitka Spruce is the worse choice for rib stock in my opinion. The stiffness gained is at the high cost of excessive board weight. However, with Rib Crowned boards you're kind of stuck using the heavier lumber. Compression boards, on the other hand, take advantage of woods hygroscopic properties for added stiffness without the cost of adding additional weight. Weight is a very important consideration for a vibrating membrane. Its primarily what separates an amateur from a master craftsman. Look at master luthiers for example, most of everything they do is to remove excess weight. Even to the extreme of scraping final sawdust particles through the instruments sound holes.
    So for example, the difference between Sugar Pine and Eastern White Pine, is that EWP is stronger than Sugar Pine and yet  its lighter than Sugar Pine!! An acoustic advantage. Especially for light hammer enthusiasts.

    If weight don't matter, then why not use hardwood for the ribs?

    https://www.youtube.com/watch?v=b7PUihwYMOY&t=13s

    -chris

    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    grandpianoman@protonmail.com
    Lenoir City, TN
    865-986-7720
    ------------------------------



  • 10.  RE: Rib Stock

    Registered Piano Technician
    Posted 23 days ago

    I've used sitka ribs several times, also white spruce and sugar pine,  The boards I build are hybrids, light crowning with compression (emc ~5%). Sitka is stiffer so you can  actually reduce the volume (and thereby the weight) of the ribs and have them do the same work so I don't think weight is really an issue. I've never been able to tell the difference in sound with different rib stock. With panels there seems to be a subtle difference. 

    BTW luthiers often use Adirondack spruce for bracing which is quite stiff and somewhat denser than other species common in guitar building. No problem with the guitars I have built that way. 



    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 11.  RE: Rib Stock

    Registered Piano Technician
    Posted 23 days ago

    BTW both Dale Erwin and Terry Farrell make sitka ribs and I'm pretty sure Nick Gravagne uses sitka ribs as does Del Fandrich. I'm sure there are others as well. 


    Here's a link to various species and specify gravity and weight per cubic foot.  Coastal sitka is very similar to eastern spruce or eastern pine but since sitka has a higher modulus you need less of it and the rib set might actually weigh less.  

    https://www.awc.org/pdf/codes-standards/publications/updates-errata/AWC-WSDD1986-Update1992-Errata-9803.pdf



    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 12.  RE: Rib Stock

    Registered Piano Technician
    Posted 23 days ago
    Sorry, of course I neglected to mention Terry Ferrell who supplies top quality materials to several high end builders.

    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 13.  RE: Rib Stock

    Member
    Posted 23 days ago
    Sigh...Chris...and now a word from our sponsor...

    If weight don't matter, then why not use hardwood for the ribs?

    Likewise since laws don't stop folks from breaking the law, why bother having laws at all?  Some folks need to see binary certainty in everything, and others don't. ..however, the pianos all still seem to sound like...uhh...pianos.

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



  • 14.  RE: Rib Stock

    Posted 22 days ago
    If weight don't matter, then why not use hardwood for the ribs?

    For the same reason you don't use them as concrete form stakes. I had some old side boards that were oak and I ripped them and put a point on them. They bust into pieces. They are not structural as a floor joist because of the the grain.

    Sauter? was into super light boards. Aircraft engineers from what I gather. I talked to the owner/designer at Kassman Piano in Berkeley. In discussing sound transmission through glue joints,, he said using epoxy was like pouring lead into the soundboard.
    Then we listened to two different pianist play his piano.

    The older jazz guy had problems. He was a dinner show player. The bass would erupt on him with almost a burp when he tried to add a little extra. He had a hard time controlling the volume evenness. Maybe he needed some lead in the board.

    The undergraduate kid that played a classical piece,, he hit it hard and aggressive and the piano responded beautifully,,,,

    Take your best guess with what you have.






    ------------------------------
    Keith Roberts
    owner
    Hathaway Pines CA
    209-770-4312
    ------------------------------



  • 15.  RE: Rib Stock

    Registered Piano Technician
    Posted 22 days ago
    Thank you all for your input. I will now stick my neck out and show you what I'm doing with rib stock (not making soundboards):

    I've been chiseling and planing away material from the ribs of old boards, epoxying in new wood, and pressing crown into the board while the epoxy dries.

    It seems to work. I think I'll be a bit more careful about cleaning up excess epoxy after that epoxy=lead quote.






  • 16.  RE: Rib Stock

    Member
    Posted 22 days ago

    Interesting idea John.

    Regarding the epoxy/lead quote, remember Kassman is a consummate salesman....he is selling. He is finding ways to differentiate his product. I don't trust a word he or any other dealership salesman utters. Test it out for yourself.

    I and some of the other rebuilders in this country, whose work I have played and highly respect, glue our caps to the bridge root on a rebuild with epoxy. Why...because fitting and gluing a PVA or pressed joint  glue in-situ in a mobile soundboard structure is very close to impossible to achieve with what I consider an adequate glue joint. Prove by testing the joint to destruction.

    I have been, for the last 4 years or so applying a small epoxy fillet the entire length of the ribs, both sides of the rib, as a technique to reconstitute old boards. The theory is that it's the glue glue joint that fails or becomes compromised, if not obviously separated. Reconstitute the glue joint and a musically useful amount of structure is returned to the board.  Success has been musically perceptible and has enables old boards to function musically. I don't create crown, as my take is that though crown is an indication of stiffness levels, its presence is not necessary to create adequate stiffness.. Stiffness can be had without the loaded appearance of crown.

    But, re the crown, that's my choice...it works, as I do it. Yours probably will work too, as long as the rib/panel joints are challenged and proved to your satisfaction to be in good condition, along the entire length of the rib.

    Nice idea.



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



  • 17.  RE: Rib Stock

    Posted 21 days ago
    Jim,, it wasn't Kassman that I talked to,, it was the piano maker himself. Nick G knew him. I could be wrong that it was Sauter

    ------------------------------
    Keith Roberts
    owner
    Hathaway Pines CA
    209-770-4312
    ------------------------------



  • 18.  RE: Rib Stock

    Registered Piano Technician
    Posted 22 days ago

    Are we really worried about sound transmission through glue joints, especially the glue joint between the rib and the panel or, in this case, the glue joint between the laminates of a rib??? I don't think so. That's not really how soundboards work. Many connectors aren't even glued to the soundboard at all, violins or guitars with drop in saddles for example. 

    There's no reason you couldn't use a hard wood for the ribs but it might change the voice some. The purpose of ribs is to add structural integrity to the sb and create a balance between flexibility (loudness) and stiffness (sustain), and mass plays a role too but the goal isn't necessarily minimal mass: light but not too light, stiff but not too stiff, as the saying goes.

    Spruce has fairly ideal properties for that and many instrument builders use spruce not only for the soundboard but for the ribs (or bracing) as well.  Whether you epoxy the ribs or use Titebond or hide glue I don't think matters as long as the glue joint is solid and stable.  That being said I don't see much reason to use epoxy except perhaps in this case for its gap filing properties.

    Just to add, sitka top guitars often have sitka bracing (the equivalent of the ribs) and some guitars do employ maple braces. The combination of those materials and the design (and a bunch of other stuff)  are part of what gives the instrument its voice. Many different materials (that includes glue) are being used for both panels and ribs these days with many different treatments and with somewhat different tonal results. But I don't think the glue has much to do with it.



    ------------------------------
    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
    ------------------------------



  • 19.  RE: Rib Stock

    Posted 22 days ago
    Making a board lighter doesn't create problems, it eliminates them.

    Regarding the idea that using Spruce allows you to reduce the volume, and therefore the weight, does not prove true in practice,  The rib stock volume is roughly 65% of the volume of material of the panel.

    In addition to the strength/weight advantages of EWP, Its cleaner in tone than the Englemann. I would bounce the ends on a concrete floor and many of the Englemann were thuddy, and so is Sitka a lot of times. Sitka improves as a panel under compression, but as a rib its just ok. Adirondack is very musical and desireable.

    When i said in an earlier post that i often remove 3-8 lbs of weight, its because the boards were over built.
    When i make boards light, its not like in "light as never done before", i am in the ballpark of many Baldwins and Steinways,

    The latest Steinway B board I replaced was 2 lbs lighter. The B rib scale is actually pretty good.

    Steinway Soundboard original weight
    https://www.youtube.com/watch?v=aldylhAb49Y&list=PL4km3jbQ3Am6HnzTJUi5bnK2kwkpwBeGb&index=5

    Steinway/Chernobieff Soundboard weight
    https://www.youtube.com/watch?v=yi7RkPVRAb8&list=PL4km3jbQ3Am6HnzTJUi5bnK2kwkpwBeGb&index=11

    Jonathan,
    Interesting method you came up with there. Since you are using a Home Depot Small block plane. For small sections like that, you could just go a couple aisles over and find some clear pine or fir and you'll be fine. Just dry it down first. But if you want to replicate whats there, it looks like sugar pine to me.

    -chris



    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    grandpianoman@protonmail.com
    Lenoir City, TN
    865-986-7720
    ------------------------------



  • 20.  RE: Rib Stock

    Member
    Posted 22 days ago
    Foo-foo, Chris...technically speaking.

    The choice of Sitka rib stock will increase weight (slightly), only, if your assumptions, ideological or not, force you to use 1" wide ribs everywhere as you do.  If you tailor the rib cross section substituting beam height for width, in a graduated fashion, it indeed allows you to seriously lighten up the board composite weight, by reducing beam volume while maintaining or increasing stiffness.

    I do not make my Sitka boards/ribs as stiff as I use to, having backed off the stiffness profile pretty aggressively. However, even when I was making stiff boards, they were routinely several lbs lighter than the originals, in composite weight...and all Sitka, panel and ribs.

    Also, every engineering decision has its advantages and collateral disadvantages. Take, for instance the fabled Steinway high compression boards which allow the reduction of rib mass. Combined with aggressive treble diaphraming, these boards die often within a matter of years. I am currently in contract to salvage another high compression  board, a 7 year old Steingraeber, second hand price $100+K, concert grand, high compression board, which is absolutely dead, without sustain compass wide. It is striking how dead this board is, 7 years out. This premature board death, is common in concert Steinways as well...pushed to the compressive limit at birth, strikingly responsive for a short time and then DOA (dead on arrival) after a couple of years.

    Soundboard weight, while important, is just one parameter of many, which effect what sound comes out of the piano, and for how long before it ceases. There are many instances of original Chickering boards, which were not compression boards, constructed in a manner quite different than you describe as the only possible true way to make a board, that are extant and musical 100yrs out, in New England (piano hell), no less..

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



  • 21.  RE: Rib Stock

    Posted 21 days ago
    Wouldn't a 7 year old piano with a problem be under warranty? I never said "the only true way", but i think they are the best way for warm tone with projection. Installing a compression board is a timing and procedural problem to solve. Clearly something went wrong at the Steingraeber factory. When done correctly CC boards can last approximately 75 years that i have witnessed. Frankly, the ones that I have seen that did the worst over time seem to be glue disintegration ( after all the use of hide glue can add another complexity) or some other causative problem like a flat rim,  excessive  downbearing, or an unmatching bridge contour. Steinway has another particularly specific board problem that i see.  The transition period from a "regular" board to a diaphragmatic system. The string scale remained the same, and most likely the downbearing method remained the same. All while they weaken the structural side of the bridge through incorrect thinning of the panel.
    If true, i sure would be interested in why Fazioli went from RC boards to CC boards.
    One of my current rebuilds is an upright that had a very large rib scale and was flatten out. But it was a 120 years old with all of the above forementioned problems, especially glue disintegration.
    https://www.youtube.com/watch?v=Y9lvrsZkeWY&list=PL4km3jbQ3Am5XvX-mCl836y_1H4g-p0Og

    -chris

    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    grandpianoman@protonmail.com
    Lenoir City, TN
    865-986-7720
    ------------------------------



  • 22.  RE: Rib Stock

    Registered Piano Technician
    Posted 20 days ago
    Chris,
    My cheap little plane actually came from Lexington's last remaining real hardware store. However...the rib material pictured did come from an actual Home Depot! I knew someone else to have used lumber yard wood for ribs and so I selected some close-grained 2x4s and ripped them to the right dimensions. Would anyone else like to weigh in on the efficacy of this practice? I've run out of material and was thinking maybe I should use "real rib stock" on the next project which is my own Baldwin SD-6.

    I'm also wondering about your advice to dry the Home Depot wood. That, I did not do. It seems to me that we would want the new rib material to be at about an average humidity content when the epoxy dries, or about the same humidity content as the wood it's being glued to. Am I missing anything?






  • 23.  RE: Rib Stock

    Member
    Posted 20 days ago
    I do not worry about dying the rib stock. The drying process is for preparing the panel to glue ribs on. You want the ribs at 7-8%. If home depot's stock is 12%, you may want to either wait for a change in the seasons, or put it in a hot box...but only to bring it to a vanilla 7-8%.

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



  • 24.  RE: Rib Stock

    Posted 20 days ago
    John P. wrote: "However...the rib material pictured did come from an actual Home Depot!"

    I have to admit that I don't know the MOE of Home Depot spruce 2x4s, but I can only assume it is significantly lower than Sitka Spruce. One doesn't use but a few board feet of lumber for ribbing a soundboard. Seems to me that the cost of real Sitka (or whatever) is relatively minimal and certainly worth the small extra cost - especially when you consider the amount of labor you are putting into your project.


    ------------------------------
    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 25.  RE: Rib Stock

    Registered Piano Technician
    Posted 20 days ago
    Terry, I would buy the Home Depot spruce because all the boards always have the rib radius warped in.

    ------------------------------
    William Truitt
    Bridgewater NH
    603-744-2277
    ------------------------------



  • 26.  RE: Rib Stock

    Posted 20 days ago
    John,
    For a long time that little plane was one of my go to tools!!  I only recently upgraded to a Lie Nelson "violin" plane.

    The reason i suggested drying the lumber, was as Jim alluded to, that lumberyard wood is usually high in MC%. I buy all my stuff way ahead of time so it stabilizes in the shop. In your case, i would want the wood of the soundboard and the new wood to be the same MC% at install, just to be safe.


    -chris

    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    grandpianoman@protonmail.com
    Lenoir City, TN
    865-986-7720
    ------------------------------



  • 27.  RE: Rib Stock

    Registered Piano Technician
    Posted 20 days ago
    And how does one measure moisture content?






  • 28.  RE: Rib Stock

    Member
    Posted 19 days ago
    https://www.wagnermeters.com/shop/orion-920-shallow/

    But really John, for what you are doing, I would not sweat it. It will have unmeasurable differences between different rh readings. ANd the pieces are small, so differences in rh simply will not be that big a deal, at least in this case.

    Best way to deal with it in the long term, is simply keep some stock laying around your shop in long term storage. That way, all you want to do is have stock that is equilibrated at the same same conditions as the project piano in your shop. Keep rib stock and piano at the same ambient conditions, and their RH will be similar and acceptable.

    I always check out the lumberyard for good 2x12 spruce/pine/fir, which is cut through the pith, and store it for use in jigs or whatever. Cut through the pith a long wide board like a 2x12 will yield quartersawn stock. I also stock lower quality 2x stock, and use that for shop jigs and also use it in the base structure of my aircraft aluminum regulating table, for structural weight control.

    But for your uses as you described them, personally, I would not sweat it.

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



  • 29.  RE: Rib Stock

    Registered Piano Technician
    Posted 18 days ago
    Hi Jim,
    I'm interested in your recomendation for the Wagner MC meters, that model is what you ue? We currently use two Lignomat meters, an older and a newer version, here's a link:

    https://www.amazon.com/Lignomat-Scanner-SD-Moisture-Meter/dp/B003CLQIGY/ref=sr_1_7?crid=1S3QVPL5SYPUX&dchild=1&keywords=lignomat+moisture+meter&qid=1631151081&sprefix=lignomat+%2Caps%2C188&sr=8-7

    I can set my newer Lignomat to 1/4" or 3/4" depth, and check the two against each other as wood comes out of our kiln.

    Do you have any comment on the other Wagner models such as the 910? Comparison to Lignomat or other?

    Thank,

    -Dean

    ------------------------------
    Dean Reyburn, RPT
    Reyburn Pianoworks
    Reyburn CyberTuner
    1-616-498-9854
    dean@reyburn.com
    www.reyburnpianoworks.com
    www.cybertuner.com
    www.reyburntools.com
    www.reyburnkeyrecovery.com
    Facebook: www.facebook.com/dean.reyburn
    ------------------------------



  • 30.  RE: Rib Stock

    Member
    Posted 18 days ago
    Dean,

    My recommendation was really just a link to a moisture meter, as a generic question from John.

    I have an older wagner that measures to 3/4" . Frankly, I really only care about EMC when drying sound boards, not ribs. When I use the hot box for boards, I use a lab oven and lab thermometer to test samples to oven dry. Moisture meters for soundboard work are not reliable enough to be trusted, in stock that thin, and are only accurate, to +/- 2%, which makes it problematic for panel readings. Even with the lab oven drying I use, I still triangulate other readings to try and get a better idea what the moisture content is. And even so, variability within the board is almost impossible to read. So precision is really not something I will go to the mat on when claiming what the moisture level of my boards at ribbing.

    For keyboards like you are prepping wood for, I think the tolerances are wider than for my work, so these meters might be a good option for you..but I can't speak to that from experience. Maybe the moisture meter technology is more trustworthy than it used to be, but I haven't really looked into it, as I jumped ship and oven dry.



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



  • 31.  RE: Rib Stock

    Registered Piano Technician
    Posted 20 days ago
    A 7 year old Steinway wouldn’t be under warranty, Chris. Unless it’s changed, I believe that their warranty is 5 years.

    Bob Anderson, RPT
    Tucson, AZ




  • 32.  RE: Rib Stock

    Posted 20 days ago
    Some clarification,,, I hope.
    The German guy at Kassmans was an aircraft engineer. He designed gliders and such. Weight to him was extremely important. This was when I was working in Erwin's shop so I was interested in other peoples concepts of building a board,
    Rib crown,, the German guy didn't like it. He used only very tight straight grain,, I'm not sure the specie. He said cutting the grain as in rib crowning weakens the rib and the size of the rib is bigger. He glued in a dished caul and probably compression crowned to some extent.

    Being the engineer type I question sound transmission. The bridge in the piano when it becomes unglued doesn't work well. Sure other instruments use no glue probably for the reason of sound transmission but glue seems to be necessary in a piano,
    I view the glue joint as a threshold/ barrier. A hurdle perhaps. The speed that sound travels is different with different mediums. At a glue joint you probably have a reflection as well as absorption.
    My thoughts on the different glues. Please add more,,,
    Glue that has a heat plasticity would seem to have a deadening effect on sound.
    Viscosity and penetration into the wood has effect on the thickness of the glue joint.
    Hardness is a factor.


    ------------------------------
    Keith Roberts
    owner
    Hathaway Pines CA
    209-770-4312
    ------------------------------



  • 33.  RE: Rib Stock

    Posted 18 days ago
    Oven drying is not accurate at all because the behavior of a small piece is different than a large piece such as a panel. That is why i abandoned the "Gravagne" widget. I also have to deal with daily changes of humidity levels, and i finally came up with an accurate way, which is to measure water weight in the actual piece and use a secondary board for a control. I check and alter daily the RH% and adjust the heat accordingly. When the weight of the board equalizes you are good to go.

    I was thinking of Johns method in general and i have come to the conclusion that it doesn't work. The modern piano soundboard is more or less in a  compression state, and johns method puts the soundboard in tension mode. Which is counterproductive for longevity. The new glue joint for a foot long addition just would not contain the added strength that would be desirable. I would think that drying the whole board would be a prerequisite for any chance of this working and filling cracks with new wood in the panel as an "evil" necessity?  Some kind of accurate means of measuring the results as time progressed would also be necessary to determine success. Otherwise a new board is still the best way to go.

    -chris

    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    grandpianoman@protonmail.com
    Lenoir City, TN
    865-986-7720
    ------------------------------



  • 34.  RE: Rib Stock

    Member
    Posted 18 days ago
    could you clarify your procedure for reading emc?  Its not clear to me what you are doing. How can you have a control, when the control, even out of the hot box, is constantly changing, depending on the ambient conditions. Could you describe your process in detail?

    This all speaks volumes at to why compression boards like Steinway's are so inconsistent. Knowing exactly what the moisture content of a board is, is not possible with the precision compression crowning requires. That begs a whole different subject, which I have been R&D'ing for several years, which is developing ways to "adjust" the board stiffness profile, selectively, after ribbing and after glue in to the rim. But, it still remains an incredibly mobile target.

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



  • 35.  RE: Rib Stock

    Posted 17 days ago
    Jim I. wrote: "How can you have a control, when the control, even out of the hot box, is constantly changing, depending on the ambient conditions."

    IMHO, that is why controlling soundboard building environmental conditions - even when you can do that real well - still leads to inconsistencies in soundboard performance and longevity. Every piece of spruce is going to have different grain (annular ring) densities AND different ratios of winter wood (very dense) to spring/summer wood (much less dense). Many folks think that low grain density equals low wood density and tight grain means higher density. That may often be true, but I've seen lots of Sitka that had very high grain density that was still very low density wood because the winter wood to summer wood was very low.


    ------------------------------
    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
    ------------------------------



  • 36.  RE: Rib Stock

    Member
    Posted 17 days ago
    It all argues for protocols that allow one to adjust the "as-built" board system.  The fact that we don't prioritize after-the-fact adjustability of the board system, is somewhat mind boggling, if you ask me. We have after-the-fact impedance adjustments in hammer voicing, but they only get one so far, when the problem is not exclusively the hammer's problem.

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 37.  RE: Rib Stock

    Registered Piano Technician
    Posted 17 days ago

    I think different outcomes with compression crowned boards has more to do with differences in the particular piece of wood than the ability to control EMC which really isn't that difficult. It's easy to control a hot box environment and time required to stabilize the wood at a particular EMC depending on the panel thickness is a known quantity. Whether Steinway was consistent or not doesn't mean it's not possible to be consistent especially for the one-at-a-time small shop. Working time once out of the box depends on the ambient conditions, of course, and many people don't rib boards in high humidity conditions for that reason. But to suggest that it's just a crapshoot or not controllable I don't think is correct. 

    Impedance levels can be controlled to some degree with changes in bearing made easier by adjustable perimeter bolts and adjustable nose bolts. You won't salvage a board that doesn't crown for some reason with changes in bearing but small tweaks can be made and are done routinely by some of the top manufacturers. 

    Ron Nossaman made me a very clever EMC gauge some years ago which I still use that is a very reliable indicator of changing EMC. There's discussion of it in the archives I'm sure but it consists of a smallish piece of spruce connected to a dial gauge that shows any change in expansion or contraction in or out of the hot box. It simply follows the panel around when you are working on it. Using pneumatic presses it takes very little time to glue up half the ribs before the dial shows any change and then the panel goes back in the box until it's ready again for the remaining ribs. Of course if you are ribbing boards in Arizona where the ambient humidity often correlates to the target EMC it's not a problem. If you're ribbing boards in Florida it's a bit trickier. 



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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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  • 38.  RE: Rib Stock