>>B72 is probably more permeable than the paint, so vapor permeability 
is not likely an issue.<<

Except that if you are adding the B72 to the coatings on the wall the 
total permeability will be decreased, whether or not this is a critical 
issue would have to be determined.

I like Rudy's notion of simply adding weather protection, which could be 
a simple "shed roof" that projects from the wall one foot or more, just 
above the sign, protecting the sign from some of the rain water and 
sunlight. While this might be good for preservation of sign, it might 
not be good for visual interpretation and appreciation of the sign.

Also, rather than preserving the sign itself, preserving the tradition 
trades that created the sign could be considered. Implement a project to 
document the sign, determine how it was made, what it was made of, who 
made it and why it was made, etc. Then teach some painters how to make 
signs like this. When this sign is too worn out to be useful the 
painters can create a new one, in its place, or on another brick wall. I 
imagine Coke still has a pretty good budget for advertising. Maybe there 
will be a revival of traditional hand-painted wall advertising.


Take care, work safe and keep in touch.

John
by hammer and hand great works do stand
by pen and thought best words are wrought

John Leeke, American Preservationeer
26 Higgins St.
Portland, ME  04103
207 773-2306
[log in to unmask]
www.HistoricHomeWorks.com

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