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Thread: Seam separation repair on Loar era F-4

  1. #1
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    Default Seam separation repair on Loar era F-4

    Thought I would share a useful little shop built tool I used to repair a seam separation in a Loar era F-4 I had in the shop a few months ago. I got the idea for this from my old friend, Larry Cohea, who is a long time luthier in the San Francisco bay area and considered one of the "go to" repair guys for vintage instruments in that region. I cut a couple of ell shaped pieces out of some scrap curly maple, glued some leather onto the bottom surfaces, drilled small holes through the bottoms which lined up with the string hole in an old guitar tuner shaft from the tuner that was attached to the side. The way it works is by inserting a very small guitar (or better yet a mandolin) string through the crack and bringing it out through the sound hole. A cleat with a predrilled hole is slid onto the string followed by stringing a ball end off of a guitar string, then tying a knot in the wire to hold it all together. A bit of Titebond is then placed on the inside surface of the cleat and the whole shebang is pulled up snug on the inside surface of the repair. The string is then cut off a couple of inches above the top surface and inserted into the little clamping device string winder just far enough to get it to wind easily and wound up to where you have a good clamp. The repair on this instrument required two cleats so I used both clamping tools simultaneously. I removed the tools the next day and wicked HHG into the seam for some added insurance. Later I did a little cosmetic touchup and blended it all in with a few wipes of Truoil.Click image for larger version. 

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  2. #2
    Registered User sunburst's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    Those are from the Don Teeter repair book from so many years ago. It helps to have a little support under the end of the string post.
    Click image for larger version. 

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    Default Re: Seam separation repair on Loar era F-4

    Thanks John. Mine seemed to work fine as they are but it would be pretty easy to add some support to the sides and as I continue to use them I'll watch and see if I need to do that.

  4. #4
    Registered User Mark Marino's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    I'm a degreed engineer with a Masters, yet I'm currently doing that motion showing my head exploding in awe.... great idea and I'm always amazed at the ingenuity out there
    "If you hit a wrong note, then make it right by what you play afterwards." - Joe Pass

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    Default Re: Seam separation repair on Loar era F-4

    How do you draw the seam back together from side to side?
    Don

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    Default Re: Seam separation repair on Loar era F-4

    Don, the pressure from top to bottom clamping draws both sides of the seam and the separated wood grain into alignment and seemingly back together as they were before they came apart and stabilizes the seam to keep it from separating further. There wasn't much of a gap in this one and the wicked in hide glue is thought to have further stabilized it.

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    Registered User David Houchens's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    Usually humidifying inside the instrument will close slightly open seams. Don't want to over do it though.

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    Registered User pfox14's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    I use the exact same cleat clamps as shown above. They work great.
    Visit www.fox-guitars.com - cool Gibson & Epiphone history and more. Vintage replacement mandolin pickguards

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    Formerly F5JOURNL Darryl Wolfe's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    Yep....I did this in 1974 on a 1966 Martin top. An old (at the time) luthier in the Knoxville area tol;d a friend who told me about the tip
    Darryl G. Wolfe, The F5 Journal
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    Registered User woodenfingers's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    It seems to me that you now have a steel string sticking out of the glued crack. What do you do with that?

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    Default Re: Seam separation repair on Loar era F-4

    Clip it off and pull it out through the sound hole. It removes easily. The hole it leaves is pretty tiny and there are various ways to cosmetically conceal it depending on preference. A wax crayon of the right color is one way.

  12. #12
    Registered User David Houchens's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    A .009 banjo string leaves a very little hole to deal with. John showed me this trick a few years back and it has come in very handy. I used a banjo tuner at the time. I have a several now using guitar tuners,with different shaped bases for various applications.
    Did you tune to 440?

  13. #13

    Default Re: Seam separation repair on Loar era F-4

    Don't even need to use nice tuners.

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    Registered User j. condino's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    Nice. I lived just a little bit down the road from Don around 1986 when I was stationed Tinker AFB in Oklahoma City. Don was a wealth of information back when there was almost nothing available, and he was very generous with his time to a young kid with a pile of broken old guitars. He sold me my first vintage National guitar- a style 3 tricone from 1929, I think it was serial number 930- for $75!!! They were just old guitars back then....
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    Default Re: Seam separation repair on Loar era F-4

    Quote Originally Posted by Dobe View Post
    Don't even need to use nice tuners.
    You mean the Waverly's I bought for this are too much!
    THE WORLD IS A BETTER PLACE JUST FOR YOUR SMILE!

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    Default Re: Seam separation repair on Loar era F-4

    I made some years ago from old clear plastic Seymour Duncan pickup boxes. I turned the box upside and mounted the tuner on one of the sides. Anyway, they worked pretty well and being clear I could see what was going on better than if the crack was hidden by the tuner base. If I can figure out where I "stored" them, I'll post a picture.....

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    Registered User fscotte's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    So there’s a tiny hole left and you just fill it in?

  19. #18

    Default Re: Seam separation repair on Loar era F-4

    Quote Originally Posted by fscotte View Post
    So there’s a tiny hole left and you just fill it in?
    The hole on a 9 string is smaller than a pore on a mahogany back or side, so it really can't be seen.....

    If you fill it, it would probably draw more attention to the repair, IMHO....FWIW

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    Registered User amowry's Avatar
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    Default Re: Seam separation repair on Loar era F-4

    Tuners are great for all sorts of clamping-- I've used them for building rosettes:Click image for larger version. 

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