I heard similar anecdotes from the work at the US Capital but I thought the
mortar deep in the wall was still wet. It stands to reason, at least for me,
that carbonation would only be so deep cause you need air.



Please Note My New Direct Telephone and Fax Numbers

Eric Hammarberg
Associate Director of Preservation
Associate
LZA Technology
641 Avenue of the Americas
New York, NY 10011-2014
Telephone: 917.661.8176
Mobile: 917.439.3537
Fax: 917.661.8177
email:  [log in to unmask]




-----Original Message-----
From: Michael Edison [mailto:[log in to unmask]]
Sent: Thursday, January 31, 2002 6:14 PM
To: [log in to unmask]
Subject: Moosh is Good


"Evidently you didn't have the pleasure of our company sometime back when
one
of our esteemed unfortunate colleagues was working on a 1880's building with
sharp-edged molded-brick laid in butter joints, and had to figure out how to
repoint it after the mortar had turned to moosh and only remained in place
because the joints were so narrow."

It may be somewhat out of the mainstream, but I tend to think the moosh
phenomenon is actually one of the beneficial properties of lime. Dry it out
and it un-mooshes.

I asked a related question at the conference which had to do with the lime
cycle and the rate of conversion from hydrated lime to calcium carbonate as
a result of curing and carbonation. I kind of think that's why the joints
turn to moosh - incomplete conversion. The experts disagreed with each
other. I thought the English cement chemist had it right, claiming that
samples taken from 300 year old English castles showed very little
carbonation once you got past a thin surface layer of carbonated material.

Michael P. Edison
President
Edison Coatings, Inc.
3 Northwest Drive
Plainville, CT 06062
[log in to unmask]
Phone: (800) 697-8055 or (860) 747-2220
Fax: (800) 697-8044 or (860) 747-2280
Internet: www.edisoncoatings.com

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