adhesive for ivories

[Alan Barnard]

Having said all that, what are you recommending? Only wafers, even for
incidental repairs?

I, like many others apparently, have had good success with the PVC-E.

On another note (A B-flat, perhaps), when I have had thin, very white
ivories to replace, I have not been above spray painting the wood white
before applying glue and ivory. Anybody else do that?

Alan Barnard
Salem, Missouri


> [Original Message]
> From: MICHAEL MORVAN <keymaestro@verizon.net>
> To: Pianotech <pianotech@ptg.org>
> Date: 01/05/2006 2:29:54 PM
> Subject: Re: adhesive for ivories
>
> Water based glues/adhesives will curl natural products, in this case
ivory. 
> To counter this effect slightly wet the top off the ivory with water and 
> you'll find less warping takes place. If the underside of the ivory still 
> has the wafer attached, then you are not gluing ivory to wood, you are 
> gluing glue to glue, with another glue (what remains on the ivory and the 
> key). Compatibility of glues is a factor. Ivory is translucent, so what
one 
> does with glue will show through (repairs etc..). The linen wafer is what 
> makes ivory appear white. Titanium dioxide helps only a little at best. 
> Titanium dioxide mixed with glue remains in suspension, it does not
dissolve 
> in the glue, so when it is clamped nearly all the glue (and whitening) is 
> squeezed out leaving a tan ivory appearance not the desired "white" 
> appearance. Pvc-e glue is not a wood glue. Wood, bone and ivory are
natural 
> materials and should be bonded with a glue made to glue "natural
materials" 
> together.  Pvc-e glue has very poor strength, creep and rigidity
resistance. 
> Pvc-e glue works well for plastic to wood in the case of plastic keytops. 
> Plastic is not a natural material and is not affected by environmental 
> changes that much, when wood moves with environmental changes you need a 
> glue that remains gummy and offers very little resistance. If the top
can't 
> move with the key it will break. Ivory and bone are natural materials and 
> move together, plus the joint between the head and tail acts as a
built-in 
> expansion joint. When applying one-piece ivory tops you must use a glue
with 
> less creep and rigidity resistance or it will crack between the head and 
> tail.
>