Coated specimens of fast-grown and slow-grown Norway spruce (Picea abies (L.) Karst) and of Scots pine heartwood (Pinus Sylvestris L.) were subjected to liquid water exposure based on the European standard EN 927-5. The exposure time was prolonged and both amount of absorbed water and moisture content gain was studied after different time intervals up to 18 weeks. Waterborne top coat without primer led to more water absorption than waterborne top coat with solvent-borne primer, and solvent-borne top coat with no primer led to the smallest amount of absorbed water. The performances of the coatings relative to each other were similar within each wood type. On average the coated Scots pine heartwood had lower uptake of liquid water and lower moisture content gain than any of the Norway spruce types. Studying moisture content gain as well as amount of absorbed water was of value in understanding the differences between wood types.
Keywords: Liquid water absorption, coated wood, wood properties, Norway spruce, Scots pine, heartwood
Authors
Sivertsen M.
Mycoteam AS, Norway
Flæte P.O.
Norwegian Institute of Wood Technology, Oslo, Norway
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