How does CA cure?

[John M. Formsma]

Robert,

I posted a hyperlink to the list not too many days ago.  I would find it
again, but it's late, and my eyes are a little droopy.  :-)  You can search
from Altavista and find it fairly quickly.  (Search for "cyanoacrylate.")

What I recall is that CA has a stabilizer molecule which, while in the
container, prevents the adhesive from doing its thing.  With moisture
present, the stabilizer molecule (I think) combines with the moisture,
allowing the glue to work.

If the accelerator makes the CA turn white, then you've used too much, which
results in a weaker bond.  If sprayed on, it only takes a little bit of
accelerator in the general vicinity of the glue.

John Formsma
Blue Mountain, MS

-----Original Message-----
From: owner-pianotech@ptg.org [mailto:owner-pianotech@ptg.org]On Behalf
Of Robert Scott
Sent: Friday, November 12, 1999 9:21 AM
To: pianotech@ptg.org
Subject: How does CA cure?



The recent discussion on CA and tuning pins makes me wonder if I
understand how CA actually "cures".  What component of air makes CA
cure upon exposure?  (I think someone indicated it was the moisture in
the air that does it.)  And is there any difference in ultimate
strength between CA that has cured naturally and CA that has been
accelerated with a kicker?  For tuning pin applications, it would seem
that if you could wait a day or so, CA would definitely be done curing
even without a kicker.

-Robert Scott
 Ann Arbor, Michigan