Architectural Paint Investigation – Ultraviolet Examination
Cross-section examination (with Ultra-violet Fluorescence)
The examination of paint samples mounted in cross-section at high magnification under incident (normal) light and ultra-violet illumination can be very informative.
Every paint layer is evidence of a decision to alter an interior – and an indication of the taste, aspirations and wealth of the occupants.
Add text herePost WWII alkyd-resin and vinyl-emulsion paints can readily be distinguished from lead-based paints under ultra-violet illumination. Layers of applied varnishes appear as distinctive white layers when viewed under ultra-violet light.
This paint sample taken from a 19th century lamp-post reveals the two early varnish layers and the more recent post WWII schemes.
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Zinc white was a pigment commonly used by housepainters from the mid 19th century, but fell out use in the early 20th century. When viewed under ultra-violet light zinc white exhibits a bright sparkly appearance.
This means that it is a useful marker material for the dating of paint. The distinctive white particles in the second decorative of the cross-section below are particles zinc oxide.
Text to go hereThis paint layer was in applied in 1853 when the Duke of Wellington’s Dining Room at Apsely House was redecorated for the first time after the death of the Duke in 1852.
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leo.