Cleaning epoxy off soundboard joint --- was glues

[MICHAEL MORVAN]

Dale,
    If the epoxy was applied over the hide glue, you may be in luck. The original hide glue will have saturated the pores in the area you need to glue the board and have prevented the epoxy from taking a good permanent hold. I would remove as much of the old board as possible and quickly scrape it down to the epoxy, then go around the rim with an iron (the hotter the better) and a wet face cloth, this will soften the epoxy, and if the epoxy was applied over the hide glue it should come off pretty easy. Epoxy will not stick to hide glue well, they are not compatible glues. Heat should activate and release both glues. A sharp off-set chisel will clean the glue surface well. Fortunately the surface you glue the soundboard to is a hardwood, this will make removal and scraping easier.

Michael A. Morvan
Blackstone Valley Piano
Dedicated To Advancing The Art Of Keyboard Restoration
76 Sutton Street
Uxbridge, Ma. 01569
(508) 278-9762
Keymaestro at verizon.net
www.pianoandorgankeys.com                                                                                              

  ----- Original Message ----- 
  From: Erwinspiano at aol.com 
  To: pianotech at ptg.org 
  Sent: Wednesday, January 24, 2007 8:51 PM
  Subject: Cleaning epoxy off soundboard joint --- was glues


    Great Post Mike
    Hey Mr glue.  So tell me....I'm redoing a belly job that failed. A compression crowner gone amuck. It's Not my board, but  some body else & the board was glued into the rim with Epoxy.  Ughhh!
     I'd ideally like to get down to the bare wood.  as the epoxy is laid down on top of the old hide glue & all. My question is how to get it off in ten minutes without gnashing of teeth.  Yes I've tried scraping...takes forever.  tried soaking a section in acetone for a short while.  Tried carbide grinders.  I'm looking for the easy answer..Stuffs like steel.  I suppose I could just leave the epoxy which is flat a smooth & glue the new board back in with epoxy but I don't like this idea because of what I'm currently dealing with.  My admonition to other bellyheads is, that epoxy isn't necessary to keep a sound board ....which is wood to stay glued to a rim....also wood......JMO
    suggestions?
    Dale
    List,
        Some helpful information on glues:

    White glue (Elmer's, consumer grade glue,  etc..,)  and yellow glue (Titebond, industrial grade wood glue,  etc..) are both PVA'S,  (Polyvinyl Acetate) and both are "Aliphatic Resins". PVC-E glue is also in the PVA family with a few different compounds added to make it remain semi-flexible when dry. Aliphatic Resin is a general chemistry term that implies "at the molecular level, these products (glues, etc..) arrange themselves in chains". When yellow glue came out, manufacturers needed a fancy slogan to differentiate yellow glue from white glue so they called it Aliphatic resin, but in reality, not economy, they both are Aliphatic Resin. A lot of the Yellow Glues are stronger than the White Glues, but they are both PVA'S and are both Aliphatic Resins. PVA'S are further broken down into subgroups based on their strength, application, water resistance etc.. The PVA'S are a huge family of glues that most of us use and think they are something distinctly different because of what they are called or what someone recommends they be used for. Choose your glues carefully, any supplier/manufacturer can supply you with a specifications sheet or MSDS, this will give you the properties of the glue and most importantly will tell you what the MANUFACTURER created the glue for, not simply what a supply house markets it as. Of all the glue books I have read, "The Glue Book" by William Tandy Young makes all this easy to understand. Remember, spare the next technician the pain of fixing an improper glue job, because the next technician might be you. I think Reblitz said something like that first.

    Michael A. Morvan
    Blackstone Valley Piano
    Dedicated To Advancing The Art Of Keyboard Restoration
    76 Sutton Street
    Uxbridge, Ma. 01569
    (508) 278-9762
    Keymaestro at verizon.net
    www.pianoandorgankeys.com 
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