Dual action truss rod rattle

Discussion in 'Luthier's Corner' started by sd396, Feb 1, 2019.

  1. sd396

    sd396 Junior Member

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    So I have been building my first 2 LPs over the last year and I'm at the point where my necks are almost complete and ready to glue in. The only thing left to do there is install the frets. My concern before moving forward is if I should do something now about the truss rod rattle. I used the dual action rods from Allparts and used silicone on the ends (where the nut blocks are) when I installed them but nothing in the middle. When the rods are loose they rattle a lot and when I put tension on them in either direction they can still rattle if I knock on the fret board. Is this normal with dual action truss rods? Will this be OK when under string tension?
    I did a google search and searched here for a fix but most of the reply's are about the traditional single action LP rods so I'm still not sure how I should deal with this. Being that the frets are not installed yet I thought that drilling through one of the fret slots to inject something might work to quiet the rods but I'm not sure what I should use or if it will actually work.
    If anybody has any experience with these rods and this problem can you give me some advice on what I should do or if I'm worrying about nothing. Pulling the fret boards off (again) is not really an option I want to go through.
     
  2. B. Howard

    B. Howard Premium Member

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    A slight rattle in " neutral" is quite normal, once strings are on the neck will always have tension against the rod.

    It should however not rattle with tension even if the neck is struck quite sharply. This will likely cause unwanted buzzes and overtones... Fixing this issue with a 2 way rod is more involved as there are two rods to stabilize that must be able to move independent of eachother. Fitting these rods to their slots is critical when installing. Any excess room will cause the issue you have. This can also happen to a nicely fit rod if the necks are mot completely dry and stable. The wood dries, the slot gets bigger and the rod rattles...

    Being unfretted, at this point I would pull the FB and address the issue directly.
     
    Freddy G likes this.
  3. lowatter

    lowatter Senior Member

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    Is this the truss rod?
    https://www.allparts.com/products/lt-1422-short-double-action-truss-rod
    I'm no expert but if you do pull the fret board and there was some shrinkage, (and I'm just throwing this out there) I was thinking that you may be able to wrap the assembly with Teflon tape and reinstall it. I did this on a build before because I felt the slot was slightly too wide. I hope this helps. Sorry that you ran into this issue and great looking builds BTW.
     
    Last edited: Feb 2, 2019
  4. sd396

    sd396 Junior Member

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    Yes, that is the truss rods I used. I have already had the fret boards off once due to bad clamping and barely managed to save them. before I installed the rods I did try wrapping them with Teflon tape but I did not like how it impeded movement so I took it off. My mistake. It sounds to me that it is the upper flat bar that makes most of the noise against the fret board.
    Here is where the build is at so far.
    20190112_173209.jpg
     
    lowatter likes this.
  5. sd396

    sd396 Junior Member

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    Being one who hates following threads that are unresolved I thought I would post an update.
    I know that pulling the fret board would have been the proper fix but having done that once already (twice actually) I felt that the fret boards wouldn't survive coming off again and would use that as my last resort.
    What I thought I would try is to drill into the truss rod channel through a couple of the fret slots and using a hypodermic needle inject flowable silicone used for windshield repairs. I did not expect it to get past the top flat bar of the truss rod but it did and worked quite well to quiet all rattles. I made sure to keep the truss rod free by rotating it back and forth while the silicone set up. It now works perfectly and makes zero noise.
    Maybe this will help someone in the future.
     
    lowatter, 61LPSG, Tonyd145 and 2 others like this.
  6. fretman_2

    fretman_2 Senior Member

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    Awesome...good to know!

     
  7. 61LPSG

    61LPSG Senior Member

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    I love a happy ending. Thanks for the resolve. Nice looking builds.
     

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