Graffiti on brick wall

Michelle C. Messinger <mcmes [at] parks__ca__gov> writes

>We have several exterior brick walls, dating back to the ca. 1860
>that have been spray painted with graffiti very recently. What would
>be the best ways to remove the spray paint (graffiti) successfully
>without compromising the surface of the bricks?
>
>How about the use of a paint and epoxy remover, followed by the use
>of a pressure washer at ca. 1500-200 psi with a fan tip?

Paint remover is fine. I would suggest one of the new products based
on hydrogen peroxide. There is one called "Removal" sold by
Pittsburgh Paints, and another sold by Cathedral Stone Products
(their "CSP" line). Both are based on the technology developed by
Napier Environmental Technologies Inc.(www.napierenvironmental.com)
There are different flavors, and I do not have enough experience
with the two product lines to make a specific recommendation. 1500
psi seems a little high for brick of that vintage. I'd see what you
can accomplish with much lower pressures (100-500 psi). Be aware
that, due to the fine pigment particle size, some colors of spray
paint can be very difficult to remove (black and red, for example).
Also, don't delay the removal too long, as spray paint becomes more
tenacious with time.

Lorraine Schnabel
Architectural Conservator
1:1:6 Technologies Incorporated
610-565-3340


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                  Conservation DistList Instance 17:62
                  Distributed: Friday, March 26, 2004
                       Message Id: cdl-17-62-006
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