Best way to repair split / cracked brace inside ABG?

Discussion in 'Hardware, Setup & Repair [BG]' started by Robodie, Mar 12, 2017.

  1. Robodie


    Jun 17, 2015
    Hello all! I've run into an issue I've not had to tackle before, and would really appreciate some advice!

    The instrument in question is a Michael Kelly Dragonfly-4 acoustic electric fretless. While doing routine maintenance tonight, I saw something funky through the sound hole.

    It's an x-brace patterned ABG, and the top brace has not only come unglued from the bottom one on the lip (it's an odd style, for me anyway).

    What's even worse, it now has a substantial split / crack running through the length of it. Ack! It's hard for me to see for sure, but the split looks to be at least 4" or so.

    I'll try to get a pic posted this morn, if I can figure out a safe way!

    Obviously John Coffee (the Dragonfly) will need to be repaired ASAP...glued, clamped, etc.

    I freely admit that I'm nervous, as this will be my first attempt at a serious brace repair. But what's really getting me is that the split runs semi-diagonally. Hope that makes sense -- basically, if it gets much worse, it may completely break off.

    Any words of wisdom?

    I know a picture is pretty much required on this one, so I'm off now to try my hand at getting one without damaging anything else!
    Thanks in advance for even reading this...and my apologies for being so long-winded!
  2. Robodie


    Jun 17, 2015
    These are horrible, but all I can get right now. Had to resort to the old tiny mirror maneuver, which is much harder when holding a giant cellphone!

    Bass Brace 1.jpg Bass Brace 2.jpg Bass Brace 3.jpg Bass Brace 4.jpg
  3. Turnaround

    Turnaround Commercial User

    May 6, 2004
    Toronto Canada
    Independent Instrument Technician
    Oh, you're going to have fun with this! Do not restring the instrument until you get this fixed.

    You will need to get some quality glue (Titebond or the like - NOT Gorilla glue) into that split, the use a brace jack to clamp it shut. Getting the glue in there won't be easy you will need to be using a mirror, so you will be seeing everything backwards. Be sure the surface of the split is completely covered with glue. Then when using the brace jack you will need some support cauls on the outside of the instrument for the jack to push against - don't rely on the top and bottom plates alone to provide the necessary support.

    Or get a luthier to make the repair.
    Robodie and Zooberwerx like this.
  4. Robodie


    Jun 17, 2015
    (This is REALLY long...)

    Thank you! That's pretty much sums up in one paragraph what takes hitting multiple websites to get half of your process.
    I do not have any brace jacks, I'm afraid, but will be heading out shortly to see what I can find...Grizzly is closed today, so worst case I can go tomorrow.
    Is this basically what I'm looking for?

    No worries about Titebond: I'm a gal who has a tool chest specifically for glues, epoxy, and other fixatives. People may laugh, but when they need glue, THAT'S who gets sent home with the Gorilla Glue. (insert evil laugh here)

    So, I've had success with using Titebond through a syringe, and a decently small gauge needle. I was thinking that would help make sure I get the glue directly into the crack, if I'm careful...what do you think?

    One last question, I'm sorry. The lip-type piece that's closest to the sound hole: I'm thinking it should be easy to glue and clamp based on where it is -- but should I hit it at the same time, or wait for that crack to cure?

    I'll have fun once the initial nerves pass and I get started. I definitely prefer to do this myself, which is good, because one of our dogs is getting ready to have major surgery (patella and cruciate ligaments), so a Luthier is out.

    But hey, at least I can at least afford the jacks.
    Thank you again so much for your help! It's truly appreciated.
  5. Tim Skaggs

    Tim Skaggs

    Sep 28, 2002
    It appears you *might* also be able to get to this with a deep throated "C" clamp aka "U" clamp. It's hard to tell the distance from the sound hole to the brace separation / split in the pictures. If you can get at it with a clamp, it eliminates the need for support cauls on the top that you definitely need if using jacks. You would only have to protect the outside of the top &/or the bridge from the clamp tensioning screw disc. Turnaround may be able to describe / confirm this better. My acoustic repair experience is mostly on the upright, which is a little better suited to withstand bull-in-the-China-shop style lutherie.....
    Robodie likes this.
  6. Turnaround

    Turnaround Commercial User

    May 6, 2004
    Toronto Canada
    Independent Instrument Technician
    You can use the StewMac jacks, or do the equivalent yourself. Find a thin, flexible bit of wood - like a popsicle stick (though that may not provide enough force). Cut a bit of a V-notch in one end so that the V fits over the brace. Cut the stick to length - a bit longer that the distance from the opposite plate (back in your case) and the brace, and wedge it in place between back and brace. Be sure to apply pressure to the top and back of the instrument from the outside as I mentioned before.

    If a flexible stick doesn't apply enough pressure to close the split, you can use a stouter piece that doesn't bend. It's just a bit harder to get the length cut just right to put enough pressure while not too long to prevent it from wedging in place.

    I would treat the two breaks separately. Do the long split first. If you get yourself a flexible palette knife from an art supply store, use that to work the glue into the split. A small blob of glue on the blade carefully inserted into the split and swiped along it's length. Repeat as needed until you are sure that the entire split is coated. Wedge in the jack and cleanup the squeeze out. You may need more than one jack.
    202dy and Robodie like this.
  7. Robodie


    Jun 17, 2015
    Off to the store now, see what they have (or another place) so being quick.

    Though not too quick to tell you that you guys ROCK!
  8. 202dy

    202dy Supporting Member

    Sep 26, 2006
    A few notes on suggestions above:

    The Stew-Mac jack is a turnbuckle with rods rather than loops. If you are handy and in a hurry you can fabricate this with hardware store parts, some hardwood, and a bit of cork or leather padding.

    The flexible stick is a go-bar.

    Turnarounds method is spot on. If you do not like using mirrors, but can feel your way through it you can work some Titebond in with a pallet knife. Closing your eyes sometimes helps. This is especially helpful when setting a jack.

    C and U clamps may be employed. If you use a heavy clamp you may have to brace the top level with a go-bar from back to top. Alternatively you can prop the clamp with the stick.

    Order of repair as suggested by Turnaround: Long crack first. Then the little guy. One at a time.