Results 1 to 7 of 7

Thread: Repair of top strut

  1. #1
    Join Date
    Jun 2014
    Location
    Umeň, Sweden
    Posts
    255

    Default Repair of top strut

    Hello, there is a "strut", the one just below the sound hole, in my solid mahogny ukulele that is loose. I want to reglue it. Do you have any suggestions how to make that?
    I┤d rather not take neither the top nor the bottom off or either drill a hole in the top.

    Regards Henning


    CAM00907.jpg
    If you please you can pry it through the mirror shown on the photo.
    Last edited by Henning; 04-14-2017 at 08:35 AM.

  2. #2

    Default

    This is a pretty easy repair, but we need to ask, why is it loose? What has failed?
    It is entirely possible that the brace was lacking glue in that area, and has come loose. But it is also possible that there was a bad batch of glue used, or the brace is warping badly, which means you might want to reconsider gluing it back in place, as it could warp the top. Also, it could have come loose because of some other failure.
    Reach in and hold the brace in place. What happens? Does it take a lot of pressure, or just a tiny bit? Does it warp the top to hold it in place? Does it pop off the rest of the way and fall into the instrument?
    And, most importantly, is anything else loose?
    We don't know what kind of glue was used here, which also complicates things a bit, but not badly.
    I would do the following -
    Glue some 120 (or so) grit to an old gift card or other thin, stiff backer. Cut this into a section that you can work with, and use it to do just a little sanding in the gap. This will clean up some of the old glue.
    Get some blue tape, and place it on either side of the brace, to keep glue from spreading everywhere. I would also cut out a sheet of paper that will fit inside of the uke and cover the back of the uke from glue drips.
    Work some glue into the joint, and then clamp it shut. I would put a flat piece of wood or acrylic on the face of the uke to protect the top, and use a small c-clamp without much pressure (very little, it doesn't take much) to hold it in place. Let dry for 24 hours.
    As far as glue goes, you would be pretty safe to glue it with regular Titebond wood glue.

  3. #3
    Join Date
    Jun 2014
    Location
    Umeň, Sweden
    Posts
    255

    Default

    Thank you, that is a nice answer. I feel inclined to tell it is the second time I try to glue it. The first time I used hideglue. I don┤t have any titebond but just plain white wood glue. I thought as the uke is from about the 1950s it might actually have been built with all hideglue.
    I suppose the ukulele was exposed to dryness because the top is concave. Either that or the pressure from the strings has caused this concaveness.

    I think it takes a rather lot of pressure to push the brace up to the top. (Maybe 3 - 4 N just very roughly estimated) when that┤s done it flattens the top.

    Best regards

  4. #4

    Default

    Ideally a brace is held in place by a small block on the side. When you glue it back in place, add a small block of wood on the side of the uke to keep it in place. (And then watch as the other end of the brace pops off a week later.)

    You are probably right about it originally being hide glue. White glue will probably work, just make sure that you clean out the old glue.

    Good luck!

  5. #5
    Join Date
    Jun 2014
    Location
    Umeň, Sweden
    Posts
    255

    Default

    Do you have any ideas how to properly apply the glue, either hide or white glue, please?
    Best regards
    Last edited by Henning; 04-16-2017 at 10:49 PM.

  6. #6
    Join Date
    Jan 2015
    Posts
    111

    Default

    One thought from me is that if this repair may hold for a while and then need to be redone from time to time, you should stick with hide glue. You can glue hide glue to itself repeatedly with no loss of strength. White glue (and Titebond) has to be completely removed, as it doesn't stick to itself.

    Nelson

  7. #7

    Default

    Quote Originally Posted by Henning View Post
    Do you have any ideas how to properly apply the glue, either hide or white glue, please?
    Best regards
    If you use hide glue again, you need to act FAST, as it cools it stops losing it's adhesiveness. (Unless you are using some kind of cold hide glue, which you can get a LOT of opinions on when you ask. I don't have an opinion on it, as I've never used it.)

    No matter what kind of glue you use, you mask off everything that you don't want glue on, and then mush the glue in with your fingers, working the brace up and down to further spread it. Then you clamp it down. After clamping, you can use a paper towel to wipe off the excess, and then pull the masking tape off before it gets glued in place. After you pull the masking tape, you can use a warm damp cloth to remove even more squeezeout.

    Here's the trick - rehearse! Without any actual glue, try going through the whole sequence. Do this a few times until you have worked out what is going to go wrong. Clamping is usually the hard part.

    Mark

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •