Performance Evaluation of UV Inhibiting Acrylic Resin Coated Glass with Modern and Historic Glazing Systems
artificial accelerated weathering
historic window glass
Historic Preservation and Conservation
UV radiation is the single largest contributing factor in fading of interiors including fabric, carpets and other furnishings, and accounts for approximately 40% of all fading damage. Thus, photodegradation must be arrested to maintain the integrity of historic materials and finishes. The n-butyl acrylate methyl methacrylate copolymer emulsion with hindered amine light stabilizers (HALS) and ultraviolet light absorber (UVA), GOLDEN MSA, which is tested here is marketed as an art varnish compatible with various types of paint. Brush and spray applied to modern and historic glass, the coating was weathered in a controlled lab setting on mock-up windows in a Q-Lab QUV weathering machine and in the field on skylights at Eastern State Penitentiary (ESP). The coating was unconventionally applied to the exterior surface of the glass with various glazing combinations and after 1 year at ESP and 900 hours in the QUV positive results proved the coating’s efficiency in blocking UV radiation. The UV readings, obtained by an ELSEC Environmental Monitor Type 765, at ESP decreased, due likely to environmental accumulation which scatters incident light waves, while readings slightly increased in the lab samples. Both values are a marked improvement to pre-coating values and these experiments demonstrate the versatility of the product for an array of material combinations. Quantitative data was supplemented with qualitative blue wool exposures and time-lapse photography.