By Scott
M. Haskins, Mural Conservator
Forethought about protecting murals from
graffiti is an essential part of the planning for art in a public place.
First of all, you need to understand the “why”
before you can discuss the types of protective varnish to use form
anti-graffiti protection.
These insights are offered to you by the professionals
hired by the City of Los Angeles to consult on protecting and preserving art,
paintings and murals, Fine Art Conservation
Laboratories.
Murals are part of a community’s heritage, part
of the architecture, part of a community’s vibe and culture. They are not just a decoration. In the
professional mural conservation field, when asked how long should art last, we
think in terms of “generations.”
Professionals mural conservators (restorers) are
bound by Ethics and Standards of Practice. These standards would theoretically
imply:
1. We
do no harm to the original artwork... the materials we use should not cause
harm to the original mural as they age or if they have to be removed
2. This
means, also, that anything we do to the mural should be reversible or safely removable
in the future... even distant future.
Here’s the
problem to be solved: Murals painted in acrylic paint remain very
soluble-dissolvable (Keim and oil to a lesser degree but still...) forever. So,
cleaning with anything except water is a problem. Of course, none of the stuff
sprayed, spilled or deposited on murals is cleanable-removable in water. Solvents
and citrus based strippers used to remove graffiti also attack-remove the
original paint.
In other words, ANYTHING that is used to varnish
the mural, will become part of the mural because it cannot be removed safely
(for the artwork). So, let that idea
percolate for a moment... if the varnish yellows, that will be the look of
the mural in the future and there will be no way possible to remove the yellow.
If the varnish cracks and peels (obviously unevenly) then you can’t remove it
to redo it later.
This photo shows a hazy brown varnish layer over
the artwork.
Despite this warning or inevitable negative
situation, some entities have chosen a chemically unstable hard resin “permanent”
protective varnish over a chemically stable sacrificial
layering of removable or “thinnable” varnish. I think their choice is based on
ignorance based on the opinions of non-conservation-preservation services
within their bureaucratic channels, not because there has been a logical choice
specifically for the benefit of artwork/murals.
The two
schools of thought
for the
choice of protective layer or varnish are:
1. The City
of Los Angeles has adopted a policy, with the excuse of future minimal
maintenance, to use a “permanent” hard coating. The name is “GCP
1000”
Polyurethane
Topcoat. Here is the link for application instructions. I suppose that because
this is a commercial product, that this appeals to bureaucrats. I’ve also been
told that some graffiti can be removed from this protective layer with a
commercial cleaner called Goo Gone (another long term preservation problem).
The Office
of Cultural Affairs chose this material at the recommendation of their graffiti
abatement contractor. The photo below shows a brown varnish under the graffiti.
This was a permanent hard coating applied over a sacrificial varnish, that was
not yellowed or brown.
2. A
“sacrificial” varnish layer is one that is applied so thickly that when tagged,
the graffiti can be removed along with a layer of varnish without having to
remove all the varnish. This means that the cleaning-removal solutions don’t
come into contact with the original paint. After the graffiti removal, the
surface needs to be re-protected or in other words, the sacrificial varnish
layers need to be reapplied.
The resin
used for the sacrificial layers is not a commercially available product, but
can be purchased from conservation suppliers. The resin used is Rohm and Haas’
Paraloid B72. We usually spray apply 4 heavy coats of 15% solids (in xylene solvent). Then we follow up with 4-5
coats of 30% applied with rollers as thickly as can be possible applied without
creating drips. On the mural in the video below, the artist originally thought
to apply the thicker sacrificial layer only up on the wall about 8’. But
yielded to reason when I showed him the nefarious techniques some vandals use
to spray way up high on walls. So, we applied all the layers over the entire
mural.
This photo
shows the before and after of removing a decade of graffiti off of a thick protective
sacrificial varnish.
Here is a
quick video of applying the sacrificial varnish layer to a new mural at street
level in Northridge (Los Angeles), CA and a short testimonial for our
collaboration.
If you found this article interesting, please
leave a constructive comment and give this webpage a “thumbs up.” Thanks!
Contact
info for participants on this project
Scott M.
Haskins, Virginia Panizzon, Oriana Montemurro Art
Conservators 805 564 3438 faclartdoc@gmail.com
Don Larson, Northridge Beautification Foundation 818 401 5522 don@northridgebeautification.foundation
805 564 3438 faclartdoc@gmail.com
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