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. ----- Original Message ----- From: "The Leshers" <lesher@jdweb.com> To: <ilvey@sbcglobal.net>; "Pianotech" <pianotech@ptg.org> Sent: Thursday, January 05, 2006 11:58 AM Subject: Re: adhesive for ivories >I find that PVC-E or any glue that you can get off your hands with water >causes the ivory to curl like a blue-hair perm. The exception is when the >underside of the keytop still has most of its original glue wafer still >attached. The wafer serves as a barrier, in which case PVC-E does okay. > > I guess if you have enough clamps and enough time, curling may not be a > problem with any glue. > > For quick field repairs, I find that my fingers are usually the clamping > devices. I often don't have the time to mash that sucker until PVC-E > sets. About the time I think I've got it, I release my fingers, take a > look from the key end and the darned keytop is smiling back at me. I use > CA. > > If you're in a shop situation, concerned with color consistency as well as > the glue joint, with the time to prepare both glue surfaces to fresh wood > and ivory, I think the wafers might be the best way to go. > > Cliff Lesher > Winfield, PA > > ----- Original Message ----- > From: "David Ilvedson" <ilvey@sbcglobal.net> > > Subject: RE: adhesive for ivories > > >> >> PVC-E glue is the glue of choice for most of us. CA doesn't last... >> >> David Ilvedson, RPT >> Pacifica, California >> >> >> >> ----- Original message ---------------------------------------- >> From: reggaepass@aol.com >> > Subject: adhesive for ivories >> >> >>>I haven't replaced any ivory for many years. Is there a more up-to-date >>>way to glue an individual ivory to the keystick than using the adhesive >>>impregnated cloth that you soak in water first, then clamp in place >>>with heat? >> >>> Thanks! >> >>> Alan Eder > > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives >
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