rubber buttons-CA & Aliphatic Resin Combo

Billbrpt@AOL.COM Billbrpt@AOL.COM
Sun, 10 Oct 1999 21:01:49 EDT


In a message dated 10/10/99 5:19:52 PM Pacific Daylight Time, 
skline@proaxis.com (Susan Kline) writes:

<< As someone else who 
 tried the glue combination on rubber buttons wrote me, "It stuck like 
 a hot damn."
 
 If you use too much glue, it will squeeze out of the hole when you put in 
the 
 button, and you must clean it up very carefully. It will smear a finish 
quite 
 nicely, and is hard to remove. 
 
 Susan 
  >>

Dear Susan and List,

I have been too busy lately to participate on Pianotech now with recent 
business in Chicago and New York but I had time to see what was being talked 
about today.  Specifically, I wanted to confirm that Susan's discovery in 
which Aliphatic resin glue (sometimes called "yellow glue" or Carpenter's 
Wood Glue, a popular brand name is "Titebond") and CA adhesives can work 
marvelously well in combination with each other.  Using the combination can 
be the best choice in certain circumstances.  

I congratulate Susan on this discovery and think it is a good example of the 
type of practical repairs that she is known for describing in detail.  It is 
also a good example of how two substances which any common sense might have 
said were incompatible can actually work together very well.

Gluing back on an ivory which has come loose is a commonly needed repair but 
a simple, clampless method that will really hold and not discolor the ivory 
has been difficult to find.  I had read about this idea and decided to try it 
recently.

I used yellow glue which I normally carry with me but using white glue would 
tend to discolor the translucent ivory even less.  I spread the yellow glue 
on the wood of the key as thinly and evenly as possible and leaving only a 
scant amount at the edge.  I spread the heavier viscosity, "slow" setting CA 
glue sparingly but evenly on the ivory, avoiding the edges.

I put the back edge in place lined it up then pressed it down very firmly 
with my two thumbs and held it for about a half minute.  I sensed that it was 
curing but I did not disturb it    I did try it later and it seemed really 
thoroughly stuck.  I only hope to find this repair holding up years later.

When I have used CA glue alone, it takes too long to set up.  It would need a 
light clamp.  When I have used CA glue with the usual accelerator, it would 
seem to work well but the bond always proved to be very weak.  The ivory 
would always pop off again, sometimes the very next day.  If I would test 
one, I could usually pry it right off.

Susan's suggestions about rubber button gluing make very good sense too.  CA 
glue alone on buttons doesn't set up fast enough.  Using the accelerator is 
difficult (not to mention dangerous and toxic) and it seems that in certain 
cases, it causes the glue to just "fry up" into something that doesn't have 
much holding power. 

In this case, the water based white or yellow glue serves as an accelerator 
but a slower one.  I tend to think that the joint is still not fully cured 
until the moisture from the white or yellow glue has been fully absorbed, 
just as is the case when using it the standard way.  But the holding power is 
evident in a nice, comfortable working time rather than a few fleeting 
seconds.

There are other difficult circumstances where this has worked well too.  
Replacing the defective Corfam or other synthetic hammer butt and catcher 
coverings.  I would readily recommend it for quick and sure repairs that 
involve gluing felt to any surface, hammer butt felt replacement for example. 
 Put a dab of slow CA glue on the wood, spread some white or yellow glue on 
the felt, press and hold a few seconds and move on.

I can also see glue combinations working in gap-filling bonds.  Any knowledge 
or experience with this anyone?

Bill Bremmer RPT
Madison, Wisconsin


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