It occurs to me that perhaps a contributing reason for the RTV lobby
seemingly being so anti-hide glue, may be its rapid gelling time.
I'm sure it catches the best of us out at times.
It is possible to modify animal glues to reduce their grab and gelling
times, with little effect on performance. In the book, "Violin
Restoration - A Manual for Violin Makers," by Hans Weisshaar and
Margaret Shipman, (C) 1988 by Weisshaar-Shipman, George DeBoth of the
Peter Cooper Glue Company writes:
"Urea (not Thiourea, a known irritant) slows down the jelling time
without adverse chemical effects on the structure of animal glues.
The joint strength produced by this glue solution is indistinguishable
from the joint strength produced by an unmodified glue solutions.
Jell time can normally be extended enough by adding up to 10% urea,
measured by weight of the dry glue. Commercial liquid animal glues
contain as much as 30% urea and remain fluid at room temperature."
A friend, who is a maker of baroque keyboard instruments, will use this
urea-modified animal glue for some glueing sequences where more control
is needed, veneering especially.
I can make available a PDF copy of Mr. DeBoth's chapter on animal glue,
with due acknowledgement, if anyone is interested.
Tim Crake
Auckland, New Zealand
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