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Thread: strut fallen inside my Epiphone MM-50E

  1. #1

    Default strut fallen inside my Epiphone MM-50E

    Hi, thanks for letting me join the forum.

    I have just received a 5 year old Epiphone MM-50E and the seller advised that there was a piece of wood rattling around inside it.

    The wood turns out to be a strut. I think it was attached to the underside of the top surface. It is difficult to tell as the view through the f holes is limited.

    The strut is too long to pull out through the holes. I'm guessing it is around 6" long

    2 questions..

    1 - The strut has been 'rattling around' for a few years, according to the previous owner, so do I need to get it repaired and glued back where it came from or can I leave it?

    2 - if YES then is this possible without taking the mandolin to bits, ie: taking the back off

    thanks for your help

    Click image for larger version. 

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  2. #2
    Kelley Mandolins Skip Kelley's Avatar
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    Default Re: strut fallen inside my Epiphone MM-50E

    It sounds like a tone bar has come loose. I have glued them back in without removing the back but let me tell you, It ainít easy!

  3. #3

    Default Re: strut fallen inside my Epiphone MM-50E

    Thanks Skip

    I'm more familiar with guitar construction and have not heard the term 'tone bar' before.

    Is the bar required to give the correct tone? ie: will my mandolin sound bad without it in place?

  4. #4
    Registered User Drew Streip's Avatar
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    Default Re: strut fallen inside my Epiphone MM-50E

    In the mandolin world, "tone bar" and "bracing" are synonymous and are just fancier words for "strut."

    Most arch-top mandolins have two tone bars, either roughly parallel to the grain and each other, or in an X-shape.

    The absence of one of them would certainly affect the sound to some degree. But it's also a structural component of the top, making sure the soundboard doesn't sag or split due to the string tension pressing down on the bridge.

    One of the most crude repairs I've seen involved cutting a 4" square out of the back, and covering it with a square of pickguard material screwed in at all four corners. So yes, it's "possible" but not ideal!

    You may want to get a mirror and see which side it came off of (treble or bass). This is an interesting repair method that could be of use, but you'd have to find a luthier willing to try it: https://www.youtube.com/watch?v=DwDaPZIH8GE

  5. #5
    Moderator MikeEdgerton's Avatar
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    Default Re: strut fallen inside my Epiphone MM-50E

    The other question is how long has it been that way? If it's been years and the strings have been tight it "might" not fail. Then again, it might. There are some mandolins that were built without tonebars but I'm assuming they were carved or pressed with that in mind. You might want to take a look at these images.
    "Bargain instruments are no bargains if you can't play them". These are the words of J. Garber.

  6. #6
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    Default Re: strut fallen inside my Epiphone MM-50E

    First, if you can I would return the mandolin. This is not minor damage. The cost of having professionally repaired could exceed the value of the mandolin. As others have mentioned this is a structural part of the instrument. The normal method if repair would involve removing the back and re-gluing. There are methods for working without removing the back but they are difficult.

  7. #7
    Adrian Minarovic
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    Default Re: strut fallen inside my Epiphone MM-50E

    Quote Originally Posted by Nevin View Post
    First, if you can I would return the mandolin. This is not minor damage. The cost of having professionally repaired could exceed the value of the mandolin. As others have mentioned this is a structural part of the instrument. The normal method if repair would involve removing the back and re-gluing. There are methods for working without removing the back but they are difficult.
    Regluing of loose end of tonebar is possible but I don't think any (reliable) way how to reglue bar completely fallen off the top through f holes.
    Adrian

  8. #8
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    Default Re: strut fallen inside my Epiphone MM-50E

    I agree with Adrian. Once the thing is completely off, there's no way to accurately realign it to where it once was. There's glue residue on both the brace and the top. It would all have to be removed to reglue safely. And on that instrument, the cost of doing it right would cost more than the mandolin is probably worth.

  9. #9
    Teacher, luthier
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    Default Re: strut fallen inside my Epiphone MM-50E

    There is one other possibility here. The mandolin may have both its tone bars intact, and the piece of wood rattling around in there may somehow have been left inside during assembly.

    Sounds far-fetched?? Well, recently someone brought an Epi electric hollowbody in here for some minor work, and there was a loose piece of wood floating around in it. It was not a brace. I mentioned it to my young friend who works in the Epi division, and he says that he has seen the same kind of thing several times.

    To the OP-- see if you can feel a strut through both f-holes, near the bridge. If there is a strut on both sides, you might just have a stray piece of wood that was accidentally left inside at the factory. If so, it can carefully be broken up and removed.

  10. #10

    Default Re: strut fallen inside my Epiphone MM-50E

    A family friend bought a then-new 1968 Mercury. Upon peering into the cowl vent, directly in front of the windshield, you could see a styrofoam cup half-full of coffee sitting there. Obviously, put there by a worker on the assembly line during assembly, then forgotten about until the car was welded together and too late. Our friend chose to leave it there and laugh it off as a pretty good conversation piece.....

    If the action is fine and the top is not sinking, I wouldn't worry about it. It would cost a fortune to fix the "right" way, by removing the back. As others have said, if it bothers you, you can remove it in pieces through the sound holes using a jeweler's keyhole saw or possibly breaking it with needle nose vice grips or similar. A challenge, but not impossible. I'd tape the edges of the f-holes with blue tape first.

    FWIW, I've had guitars with loose braces floating around inside, that I removed intending to reglue at a later date, but never got around to it. Some, 20-30 years later with no ill effects.....

  11. #11

    Default Re: strut fallen inside my Epiphone MM-50E

    thanks for all your very helpful replies and apologies for the late reply. I teach music full time and this time of year it all becomes a bit too full on. I got my phone into the mandolin for a look around and got the following pics. There is only one tone bar left in place and you can see light marks from where the fallen bar was attached at one time.

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  12. #12
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    Default Re: strut fallen inside my Epiphone MM-50E

    Difficult repair. The cost of the repair could approach or exceed the value of mandolin.

    Decoding the specs on the Epi website, it appears to have a machine carved solid top and a laminated back, pressed into an arch over a mold. The lowest level Eastman and Kentucky F models at least have solid backs.

    The mandolin might or might not hold together without fixing it.
    The mandolin might or might not sound better if it was fixed.

    An opinion: If you can't return it, play it until the top sinks. The money it would have cost to repair it could instead be better spent on replacing the instrument when the time comes. If you like the electronics on the Epi, they could be salvaged and installed on the instrument that replaces it.
    Last edited by rcc56; Dec-05-2018 at 8:23pm.

  13. #13

    Default Re: strut fallen inside my Epiphone MM-50E

    Thanks rcc56

    one thing that worries me is the tone bar appears to have fallen off due to poor quality glue or maybe even due to not enough glue.
    The other tone bar may keep the instrument together but it probably has the same glue issues and therefore may not be solidy in place. I'm thinking that I should somehow get the fallen tone bar glued back in position. If I end up with no tone bars then I will definitely have a major issue.

    I agree the cost could be prohibitive and so I will explore the low cost options.
    I know a repairer who loves this kind of work and I think I will take it to him and maybe suggest the repair method suggested by Drew Streip https://youtu.be/DwDaPZIH8GE

  14. #14
    Registered User Drew Streip's Avatar
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    Default Re: strut fallen inside my Epiphone MM-50E

    Quote Originally Posted by hollowbody View Post
    Thanks rcc56

    one thing that worries me is the tone bar appears to have fallen off due to poor quality glue or maybe even due to not enough glue.
    The other tone bar may keep the instrument together but it probably has the same glue issues and therefore may not be solidy in place. I'm thinking that I should somehow get the fallen tone bar glued back in position. If I end up with no tone bars then I will definitely have a major issue.

    I agree the cost could be prohibitive and so I will explore the low cost options.
    I know a repairer who loves this kind of work and I think I will take it to him and maybe suggest the repair method suggested by Drew Streip https://youtu.be/DwDaPZIH8GE
    Bear in mind that everybody else who has replied to this thread is a very competent builder or repair person. Iím just a tinkerer who absorbs a lot of information. And there are varying opinions about some of Mr. Rosaís techniques. That said, if itís your only option and this isnít an heirloom instrument, my motto tends toward ďdonít let perfect be the enemy of good.Ē

    Good luck, and update us on your progress.

  15. #15
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    Default Re: strut fallen inside my Epiphone MM-50E

    I have re-glued loose braces through the sound hole in flat top guitars many times, and have even completely replaced a few damaged braces without taking the instrument apart. I've also re-glued tone bars that were partly loose in f-hole mandolins a few times, though my method was different than Mr. Rosa's.

    But I don't know if I could come up with a way to re-glue a completely fallen brace in an f-hole mandolin without taking the back off. And it is quite difficult to remove the back on a modern factory made instrument. The glues that are used are generally not friendly to disassembly. The chances of cosmetic damage to the instrument are high.

    When you can't get your hand inside an instrument, everything changes, and the simple becomes difficult or even impossible.

    I suppose you could drill the brace like Mr. Rosa did, locate and glue one end, let it cure, and then go after the other end. Accurate placement and alignment would be difficult. If it was at all possible to remove the brace through the f-hole prior to executing the repair, it would be better-- then you could remove any old glue from the brace, thereby insuring that the new glue joint would hold.

    No matter how you look at it or go about it, this is a tough job. It's kind of like doing surgery through a crevice with your eyes closed. My hat will be off to anyone who can do this job easily, quickly, and accurately.

    For what it's worth, here's another couple of ideas you can pass on to your repairman. I have dry clamped alignment blocks in instruments a couple of times. Rare earth magnets also might be of use here. However he goes about it, he's going to have to be inventive.

    I wish you and your repair person the best of luck.

  16. #16
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    Default Re: strut fallen inside my Epiphone MM-50E

    If you decide to take the back off I would use Randy Woods technique of using a no kerf saw and sawing off where the binding meets the side. I think it was Randy, but I have done this with a guitar and it is fairly quick. I wasn't going to put the back on the same guitar so can't tell you about regluing, but this should help if you decide to remove the back.
    THE WORLD IS A BETTER PLACE JUST FOR YOUR SMILE!

  17. #17

    Default Re: strut fallen inside my Epiphone MM-50E

    I still think the cost of the repair has to fit the value of the instrument -- unless you are able to do the work yourself. Common sense would say, we don't spend $500 to fix a $400 instrument. And, it goes without saying that, sure, on a $5000 instrument we can afford to spend the money to remove the back and correct the problem. On a less expensive instrument, I say play it until it implodes -- which may be 30 years from now or may NEVER happen. Another technique frowned upon by this forum and I only mention it because I heard it first from none other than David Grisman, himself..........so I feel that lends at least a certain amount of legitimacy to a "last ditch" repair -- David told me that early in his career one of his mandolins had a sinking top and he was able to jam a stovebolt, nut, and some glue through the f-hole to jack up the top.....of course, I gave him a funny look, and he said, it worked and made it sound BETTER!

    So, I think there are a couple ways to approach it. Over-spending is not one of the ways I would approach this instrument, but it still might be salvaged, one way or another. In another neck repair thread, it was mentioned selling the instrument, as is, to a repairman or student repairman to learn from, and putting the proceeds toward another instrument.

    I see silly advice all the time on this forum and others, where somebody says "just" take the back off or "just" order a new neck and put it on, etc. -- these are major repairs that are certainly not for the beginner and if you had to pay someone $65 an hour to do this kind of work, you would be upside down on most instruments very quickly. And again, I repeat, on a vintage instrument or boutique instrument it is certainly worth the cost of doing the repair correctly, just to be clear.

    Good luck. I know "learn to live with it" is not what you want to hear......

  18. #18
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    Default Re: strut fallen inside my Epiphone MM-50E

    I don't recommend taking an Epiphone apart. Too much work, too expensive for an instrument of less than professional grade.

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