NCPTT tested limewashed handmade and modern brick samples using artificial weathering,
adhesion, and abrasion testing according to ASTM standard methods. We photographed samples
before and after each test and monitored them for color change with a Minolta colorimeter. To
perform artificial weathering, we placed the samples in a QUV weatherometer and subjected them to
four hours of UV light exposure and four hours of condensation in the dark continuously alternating
for 800 hours. This accelerated weathering gives us an idea of how the limewash may age over
time. For the adhesion test, we cut an "X" through the limewash to the sample, and then placed
pressure sensitive tape over the cut. Upon removal of the tape, we assessed how much limewash
was removed. This test evaluates how firmly the limewash bonds to the samples. In the abrasion
test, we placed samples in a holder and poured measured amounts of falling sand on to the surface to
determine how much sand is needed to remove a 4 mm (.1575 inch) diameter circular area of
limewash. The abrasion test allows us to rank how a limewash will stand up to abrasion from windand
rain-borne particles and from people touching the buildings. With the help of Quality Finish, we
also performed a solids test to determine how much limewash is being applied to the samples.