Restoring/Repairing the edges of an upright bass

Discussion in 'Luthier's Corner [DB]' started by CathyB, Jun 9, 2021.

  1. CathyB


    Jun 8, 2021
    My Kay has been a lot of places and played a lot of tunes, and the laying down over the years has taken a toll on the edges. Not significant damage, just wear and some small small chips and delamination at the stress points.

    I would like to restore what I can, and would like to re-glue and strengthen the bouts where they meet the ground. I'm concerned about using something that will be too brittle (super glue was suggested) that will create a mess for the next owner. Due to it's age, I want to preserve as much of the value as an "antique" as as a kick ass instrument.

    Does anyone have recommendations or has anyone tried this? Or can you suggest who may give me advice?
  2. TFM94


    Aug 24, 2020
    Disclaimer: I'm not an expert on upright basses, but I have dealt with delamination and chips.

    I would not use superglue to fix delaminations or cracks, because it can be brittle and difficult to clean up around the glue joint. In the true antique spirit, I would use hot hide glue or fish glue (if you need longer open time). When hot, hide glue can easily penetrate smaller cracks. As a bonus, you can clean up any squeezeout with a damp cloth. I don't know how old it is exactly, but chances are that the original luthier also used some kind of hide glue.
    CathyB likes this.
  3. I second this. Take it to a violin shop to have it done right, but if you try it yourself hot hide glue is the way to go. Superglue or wood glue will create a problem for the next person who has to work on it.
    CathyB likes this.
  4. Steven Ayres

    Steven Ayres Supporting Member

    Mar 11, 2007
    Northern Arizona
    This process is recently discussed and illustrated in this thread.

    Of the myriad forms of damage that can befall a plywood bass, edge damage is among the most common and most niggly to repair, so having a luthier do it will likely get expensive.

    My rule is to use hot hide glue (HHG) wherever future repairs may be necessary and I want to be able to part the bond in a civilized way, and/or I want the seam to fail before the wood does. For edges like yours, because I don't want it to come apart again ever, I use Titebond (PVA, "wood glue"). So: HHG for the seam separations, PVA for rebuilding the laminates.

    CA ("super glue) is only very rarely useful, cold hide glue can be occasionally useful for small, no-tension details, but never Gorilla Glue, never epoxy, never white glue (Elmer's, etc).

    Be assured that a good repair will not impair the value of your instrument, where a bad repair very well could, but the instrument's age or 'antique value' don't really matter much in practical terms. If you can PM me with your serial number, I'll tell you what I can about your bass.
    Chris Fitzgerald, RSBBass and CathyB like this.
  5. eh_train

    eh_train Supporting Member Commercial User

    Jan 12, 2004
    Owner, Stand Up Guy Basses (Repair/Sell/Buy upright basses)
    What Steven says!
  6. CathyB


    Jun 8, 2021
    Thank you for your reply. It is a 1940 Kay, so it definitely predates super glue. I should look into how plywood was created during that era.
  7. Greg Clinkingbeard

    Greg Clinkingbeard Commercial User

    Apr 4, 2005
    Kansas City area
    Black Dog Bass Works
    Good call. I was dealing with this issue today on a 1959 Kay. Every Kay I’ve worked on which has had separated laminates also has had open seams. I just concentrate on a few inches of seam, getting hide glue between the veneers and then the seam. Maybe 10-15 seconds and 2-3 spool clamps. I see no reason to use Titebond in this situation.
    james condino, oldNewbie and CathyB like this.
  8. eh_train

    eh_train Supporting Member Commercial User

    Jan 12, 2004
    Owner, Stand Up Guy Basses (Repair/Sell/Buy upright basses)
    Not sure how they did it at Kay, but the King basses (Mortones and American Standards) used formaldehyde glue. I've used it for veneering but it's not run of the mill stuff (it has to be mixed, and the powdered portion is carcinogenic).

    Titebond will work. Hide glue will work. It's supposed to be a permanent join.
    CathyB likes this.
  9. Strad violins were made with hide glue and they've lasted this long. Don't stray from the formula. a good way to formulate your own hide glue is to use a small potpourri crock pot, pour in a few pouches of Knox Gelatin, as a little water, let it heat up, and add water to the consistency of other glues. YMMV.
  10. james condino

    james condino Spruce dork Supporting Member Commercial User

    Sep 30, 2007
    asheville, nc
    A half pound of dry hide glue costs approx. $7; there is no reason to substitute Knox gellatin. I understand the materials and manufacturing process, but this is not a place or need to save three $.

    H. N. White ( the parent company for King and American Standard basses) had the first patent for using resorcinol, a urea formaldehyde based glue, in laminate bass manufacturing circa 1934. It is incredibly tough and has a long open time. It is also very temperature sensitive- today we know that below 70 degrees F it will not bond properly. My belief is that is the reason for the all too common "rib cancer" failures in American Standard basses. They were assembled in the cold winter shop environment where the glue never properly set. Done properly, it is also the reason that we almost never see top failures on an American Standard, yet they are common to old Kays that were made with hot hide glue until the mid 1950s when there were factory process and managerial changes.

    The main reason I would suggest caution with anything beyond hot hide glue for edge repair is that it is pretty common to find an old Kay top where 95% of it is held with hot hide glue and comes apart easily for repairs, but the other 5% is contaminated with superglue or epoxy that seeped everywhere and causes endless luthier's tears.
  11. eh_train

    eh_train Supporting Member Commercial User

    Jan 12, 2004
    Owner, Stand Up Guy Basses (Repair/Sell/Buy upright basses)
    James, huge thanks for supplying the name for my new band.
  12. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

    May 24, 2022

Share This Page